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7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Official reprint from UpToDate www.uptodate.com 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved. Atrial fibrillation: Atrioventricular node ablation : Bradley P Knight, MD, FACC : N A Mark Estes, III, MD : Nisha Parikh, MD, MPH All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Jun 2023. This topic last updated: Jan 09, 2023. INTRODUCTION In patients with atrial fibrillation (AF), the ventricular rate is determined in large part by the conduction properties of the atrioventricular (AV) node. In the typical patient with untreated AF, the ventricular rate can reach 150 beats per minute or higher. There are three important reasons to prevent a rapid ventricular response in patients with AF: Avoidance of hemodynamic instability. (See "Hemodynamic consequences of atrial fibrillation and cardioversion to sinus rhythm".) Avoidance of bothersome symptoms. (See "Atrial fibrillation: Overview and management of new-onset atrial fibrillation", section on 'History and physical examination'.) Avoidance of a tachycardia-mediated cardiomyopathy. (See "Arrhythmia-induced cardiomyopathy".) A rapid ventricular response can be prevented either by restoring sinus rhythm (ie, rhythm control) or by using therapies that reduce the ventricular response (ie, rate control) to AF. When rate control is chosen, it can usually be accomplished with pharmacologic therapy. However, some AF patients will respond poorly to or be intolerant of rate control medications. Options for such patients include reconsideration of a rhythm control strategy or nonpharmacologic methods to control the ventricular rate. (See "Atrial fibrillation: Overview and management of new-onset atrial fibrillation" and "Management of atrial fibrillation: Rhythm control versus rate control".) https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 1/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate The use of AV node ablation to achieve rate control in AF will be reviewed here. Pharmacologic therapies for rate control in AF are discussed separately. (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy".) GENERAL PRINCIPLES Choosing the appropriate rate control therapy for a patient with AF is guided by an understanding of the determinants of the ventricular rate and an assessment of the adequacy of rate control. The discussions of rate control and the determinants of ventricular rate in patients with AF are found elsewhere. (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy".) There are several strategies for assessing the adequacy of rate control efforts. With any strategy, rate control should be assessed both at rest and with exertion. Rate control goals are discussed separately. (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy", section on 'Evaluation and goal ventricular rate'.) INDICATIONS AV node ablation is an option for rate control in AF patients who have failed medical therapy for rhythm control, have failed or are not candidates for catheter ablation for rhythm control, and have failed aggressive attempts at pharmacological rate control. Many of these patients are labeled as having permanent AF, which is the term used to identify individuals with persistent AF where a joint decision by the patient and clinician has been made to no longer pursue a rhythm control strategy. Patients who are candidates for AV node ablation should be highly symptomatic, hemodynamically intolerant of AF, or have cardiomyopathy that is thought to be at least some part tachycardia induced. In general, the procedure is most commonly performed in elderly patients, many of whom have a preexisting pacemaker or implantable cardioverter-defibrillator (ICD) ( table 1). Other patients include those who are not candidates for rhythm control with catheter ablation or drug therapy, those with refractory AF with tachycardia-induced cardiomyopathy, or those with a preexisting pacemaker. Careful thought needs to be given to other treatment options, including curative attempts with catheter ablation before proceeding to AV node ablation in patients in whom medical therapy has failed to control the ventricular rate. The specific clinical scenario will dictate the appropriateness of AV node ablation vis-a-vis other treatment options. In younger patients, all https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 2/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate treatment options should be considered/exhausted before proceeding to AV node ablation. AV node ablation may be more appropriate in older patients, particularly those with preexisting pacing devices, and in those in whom curative attempts at AF ablation are unlikely to be successful (eg, very longstanding/permanent AF, marked left atrial dilatation, etc). Prior to performing AV node ablation, the patient needs to be informed about the invasive nature of the procedure, the requirement for lifelong permanent pacemaker therapy, and the long-term risk of a pacing-induced cardiomyopathy when RV apical pacing is used. PROCEDURE AV node ablation usually produces complete AV block and often leaves the patient with a slow junctional or idioventricular escape rhythm. Consequently, patients require implantation of a permanent pacing device to adequately control the ventricular rate ( waveform 1A-B). If a preexisting pacemaker or ICD is not already in place, a permanent pacemaker or ICD is implanted prior to AV node ablation. This is usually carried out immediately prior to the AV node ablation, but in some cases the device may be implanted in advance of the ablation procedure. Traditional leaded devices are implanted in the subclavicular region; a leadless pacemaker may be implanted directly in the right ventricle. (See 'Device selection' below and "Permanent cardiac pacing: Overview of devices and indications", section on 'General considerations'.) If a functional pacemaker or ICD is in place and no system revision is planned, the femoral vein is generally used for access for ablation of the AV node. An ablation catheter is advanced to the AV junction where a bundle of His potential can be recorded. Radiofrequency ablation of the AV node/bundle of His is performed. Ablation lesions should be delivered at a site proximal in the AV conduction system where a large atrial electrogram is also recorded to increase the likelihood of a junctional escape rhythm after creation of AV bock to avoid pacemaker dependency. With a successful lesion, there is usually an accelerated junctional rhythm and then heart block. If initial ablation is ineffective, or if conduction recurs, a larger lesion can be created with either a larger tip or saline-irrigated catheter.(See "Overview of catheter ablation of cardiac arrhythmias".) On rare occasions, AV node ablation cannot be accomplished via the right heart. In these cases, establishing femoral arterial access allows passage of an ablation catheter retrograde across the AV node. A bundle of His potential can be recorded just below the aortic valve, in the septal aspect of the left ventricular (LV) outflow tract. Alternatively, ablation by way of the left heart can be accomplished using a patent foramen ovale or transseptal puncture. If left heart access is necessary, systemic anticoagulation with intravenous heparin is generally administered while the left heart is instrumented. https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 3/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate If a leadless pacemaker is placed, the same femoral venous sheath can then be used to advance the ablation catheter (see "Permanent cardiac pacing: Overview of devices and indications", section on 'Leadless systems'). Care must be taken to make sure that newly placed leads or a leadless pacemaker are not dislodged by the ablation catheter. In rare cases, when right heart ablation of the AV node is ineffective and a new leaded pacing system has just been placed, it may be reasonable to defer the left heart AV node ablation for days/weeks to obviate the need for intravenous heparin with the attendant risks of bleeding. Device selection Following AV node ablation (see 'Procedure' above), most patients are pacemaker dependent. Therefore a device with pacemaker capability must be in place prior to the ablation procedure. The choice of which type of pacing device is implanted depends on the patient's clinical profile. Single-chamber ventricular pacemaker In patients with persistent AF, a single-chamber (right) ventricular pacemaker is often adequate. After AV node ablation, the patient's ventricular rate will not naturally respond to increased demand; therefore, a device with rate-adaptive capabilities is used (ie, VVIR pacing). All contemporary pacemakers have rate-adaptive capabilities. (See "Modes of cardiac pacing: Nomenclature and selection", section on 'Rate responsiveness'.) Leadless RV pacing (see "Permanent cardiac pacing: Overview of devices and indications", section on 'Leadless systems') has also been used in association with AV node ablation [1]. Dual-chamber pacemaker In patients with paroxysmal AF, dual-chamber pacemakers are preferred to single-chamber devices because they maintain AV synchrony during periods of sinus rhythm (eg, DDDR pacing). (See "Modes of cardiac pacing: Nomenclature and selection", section on 'Physiologic pacing'.) In order to prevent rapid ventricular pacing during episodes of AF, patients with dual-chamber pacemakers following AV node ablation should have devices with automatic mode-switching capabilities. All contemporary pacemakers have this ability. (See "Modes of cardiac pacing: Nomenclature and selection", section on 'Mode switching'.) In patients with paroxysmal AF, two randomized trials demonstrated that dual-chamber pacemakers with mode-switching capabilities improve symptoms and quality of life compared with single- or dual-chamber pacemakers without mode-switching capabilities [2,3]. Many patients who undergo AV node ablation with pacemaker implantation for paroxysmal AF eventually progress to persistent AF [4]. Although dual-chamber pacing has not been shown to prevent this progression [5], we favor dual-chamber pacing in patients with paroxysmal AF https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 4/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate because of the clinical benefits of physiologic pacing. (See "The role of pacemakers in the prevention of atrial fibrillation".) A leadless RV pacemaker capable of sensing atrial mechanical systole and providing AV synchrony has been approved by the U S Food and Drug administration. At this point, leadless RV pacing is not able to pace the atrium, so it would not be an optimal choice in a patient with sinus node dysfunction and paroxysmal AF who is to undergo AV node ablation. (See "Permanent cardiac pacing: Overview of devices and indications", section on 'Leadless systems'.) Cardiac resynchronization therapy The majority of well-selected patients improve hemodynamically following AV junction ablation and standard right ventricle (RV) pacing. However, RV pacing causes the RV to contract before the LV (interventricular dyssynchrony), which may impair LV systolic function, reduce functional status, and increase mortality. In patients with significant dyssynchrony due to intrinsic conduction disease or pacing, cardiac resynchronization therapy (CRT) can improve ventricular synchrony. Use of CRT in patients with AF with or without AV node ablation is presented separately. (See "Cardiac resynchronization therapy in atrial fibrillation", section on 'Atrioventricular node ablation'.) There is a trend toward using CRT in many patients who undergo AV node ablation. If the implant and ablation are to be done concurrently, we use CRT with an atrial lead if the AF is paroxysmal and no atrial lead if persistent/permanent. In addition to providing CRT, two ventricular leads mitigate the unlikely but potentially disastrous effects of RV lead dislodgment and loss of RV capture. If transient pacing inhibition due to RV lead malfunction is noted, the sensing vector can sometimes be reprogrammed to an LV vector, which may mitigate the need for urgent lead revision. If, however, in the unlikely event that RV lead dislodgement or fracture results in continuous oversensing and inhibition of pacing, the additional LV pacing lead will not prevent asystole. If the patient has a preexisting non-CRT device and is undergoing AV node ablation, we will usually see how the patient responds to unopposed RV pacing, particularly if LV function is preserved. If LV function is significantly depressed and/or systolic heart failure has already been an issue, we may upgrade the patient to a CRT pacing or defibrillator system (as appropriate) at the time of AV node ablation. The main "downsides" to concurrent device upgrade are the associated procedural risks, most notably the risk of infection in a patient who will be pacemaker dependent. Adding a device upgrade procedure to an AV ablation increases procedure time considerably, so in patients who are very tenuous hemodynamically due to rapid ventricular rates and/or rate controlling, it may be reasonable to initially perform AV node ablation alone, and then upgrade the device if the patient does not improve. The relative efficacy of CRT with AV node ablation for rate control and pulmonary vein isolation for rhythm control in patients with HF is discussed separately. (See "The management of atrial https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 5/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate fibrillation in patients with heart failure", section on 'Atrioventricular node ablation with pacing' and "The management of atrial fibrillation in patients with heart failure", section on 'Catheter ablation'.) Implantable cardioverter-defibrillators All of the aforementioned pacing modalities (eg, single chamber, dual chamber, and CRT) and functions (eg, rate adaptive pacing and mode switching) are available on contemporary ICDs. Thus, patients with an ICD who require an AV node ablation procedure can sometimes be managed without changing the device. As most of these patients have significant LV dysfunction and systolic heart failure (given the indications for prophylactic ICD implantation), consideration should be given to upgrading to a CRT-D system with an atrial lead, if appropriate, at the time of AV node ablation. (See "Implantable cardioverter-defibrillators: Overview of indications, components, and functions".) Physiological pacing CRT (or biventricular pacing) is a strategy to avoid the dyssynchrony associated with standard RV apical pacing in patients who become pacemaker dependent after AV node ablation (see 'Cardiac resynchronization therapy' above). A potential alternative to CRT is the positioning of a pacing lead near the His bundle ( image 1) or deep in the ventricular septum near the area of the left bundle branch. A pacing lead near the His bundle will activate the native conduction system, resulting in less dyssynchrony and a more normal QRS complex. It is technically difficult to place a conventional pacing lead in a position that results in capture of the His bundle at a reasonable pacing output because the His bundle is insulated from the endocardium. Newer, small caliber, screw-in pacing leads that are delivered using a guiding sheath rather than a stylet may improve the ability to accomplish permanent His bundle capture [6]. The value of this approach was evaluated in a prospective single-center trial of 52 patients with heart failure and refractory AF who underwent attempted AV node ablation and permanent His bundle pacing; backup RV or LV leads were placed as well [7]. During His bundle pacing, the average QRS duration was 105 msec, compared with 107 msec at baseline. The mean New York Heart Association functional class improved from baseline 2.9 in patients with heart failure with reduced ejection fraction to 1.4 with His bundle pacing, and from baseline 2.7 in patients with heart failure with preserved ejection fraction to 1.4. LV end-diastolic dimension, LV ejection fraction (LVEF), and mitral regurgitation all improved with His bundle pacing compared with baseline. https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 6/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Successful His bundle pacing is technically difficult to accomplish. In addition, lead dislodgement may be more likely compared with conventional pacing sites. Pacing thresholds may also be higher with His bundle pacing, leading to shorter generator longevity. Lead dislodgement would have serious complications in this setting due to complete heart block after ablation of the AV node. Another alternative to CRT is left bundle branch area pacing. Pacing the left bundle branch has been shown to avoid some of the limitations of His-bundle pacing such as high pacing thresholds and atrial oversensing, and has been used in patients undergoing AV node ablation. This is accomplished by placing an active fixation, sheath-delivered, pacing lead deep into the RV septum to capture the left bundle branch, giving rise to a relatively narrow QRS complex to minimize pacing-induced ventricular dyssynchrony. An image shows the position of the tip of a left bundle branch pacing lead in the RV septum during administration of contrast through the delivery sheath at the time of implant. (See "Permanent cardiac pacing: Overview of devices and indications".) Further studies in larger populations are necessary to clarify both the clinical benefits and safety of these physiological pacing approaches in patients undergoing AV node ablation. In addition, given the risks of lead dislodgement, the safety and efficacy of His bundle pacing should be compared against biventricular pacing. At this point, a backup RV lead is generally placed when His bundle pacing is employed, particularly in pacemaker-dependent patients. Ventricular rate regularization Ventricular rate regularization (or ventricular rate stabilization) is a pacemaker mode that can attenuate the rate and irregularity of the ventricular response during AF [8]. The ventricle is paced at a variable rate at or near the mean native rate. This causes concealed retrograde conduction into the AV node, which makes it refractory to subsequent anterograde impulses from the atria. This tends to reduce the number of short RR intervals, which may improve symptoms by making the ventricular rate more regular during AF and sometimes slower. A potential advantage of this approach is that no catheter ablation of the AV junction is performed. However, this technique may be less effective at controlling AF during physical activity than at rest. EFFICACY AV node ablation is highly effective, as demonstrated by the following reports: AV node ablation was acutely successful in 97.4 percent of 646 patients, although 3.5 percent had recurrence of AV conduction during follow-up [9]. https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 7/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate In a report from the prospective Ablate and Pace trial, the procedure was successful in all but 1 of 156 patients who underwent radiofrequency ablation of the AV node [10]. Persistent complete heart block was present in 96 percent; 33 percent of patients had no escape rhythm, while 35 percent had an escape rhythm with an escape rate <40 beats per minute. OUTCOMES Symptoms and quality of life are significantly improved in patients with poorly controlled AF who undergo AV node ablation and permanent pacemaker implantation [11-15]. In a series of 107 such patients, ablative treatment was associated with significant reductions in [11]: Physician visits (5 versus 10 prior to ablation) Hospital admissions (0.17 versus 2.8 prior to ablation) Episodes of heart failure (8 versus 18 prior to ablation) Antiarrhythmic drug trials Further support for the benefits of this approach come from a meta-analysis of 21 studies, involving 1181 patients [12]. This report noted significant improvement in all 19 outcome measures evaluated, including quality of life, ventricular function, exercise duration, and health care use [12]. While such benefits are often due to improved LV systolic function, improvement in some patients occurs independent of changes in LVEF and probably results from the slower and more regular heart rate [13,14]. To date, there is no convincing evidence of a mortality benefit with AV node ablation [12,15,16]: AV node ablation has also been compared with other nonpharmacologic therapies. In the 2008 PABA-CHF study, in which 81 patients were randomly assigned to AV node ablation with cardiac resynchronization therapy pacing or pulmonary vein isolation, the composite primary endpoint (Minnesota Living with Heart Failure score, 6MW distance, EF) favored the pulmonary vein isolation group [17]. COMPLICATIONS AV node ablation incurs risks similar to other catheter ablation procedures that require right heart access, though typically only a single venous sheath is required. If a pacemaker or ICD is implanted immediately prior to AV node ablation, the risks of device implantation are also https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 8/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate incurred. If simple RV pacing is used, there will be a risk of developing LV dysfunction and/or heart failure. (See "Cardiac implantable electronic devices: Periprocedural complications".) Specific to patients who undergo AV node ablation and pacing is a very rare but catastrophic risk of ventricular fibrillation (VF) and sudden cardiac death (SCD). In a review of 334 patients who underwent AV node ablation, nine (2.7 percent) experienced SCD [18]. Four events occurred within four days of the procedure, an additional three events occurred within three months, and two occurred late and were thought to be unrelated to the procedure. Possible causes of post-ablation VF include [18-20]: Underlying heart disease Activation of the sympathetic nervous system Prolongation in action potential duration Repolarization abnormalities induced by bradycardia Increased dispersion of ventricular refractoriness The potential for reducing the frequency of early VF with post-ablation pacing at a higher rate was evaluated in a report of 235 patients [21]. The incidence of VF was 6 percent in the first 100 patients in whom the post-ablation chronic pacing rate was 70 beats per minute. In the next 135 patients, however, a pacing rate of 90 beats per minute was used for the first three months after the ablation, and there were no episodes of VF. Pacing at a rate of 90 beats per minute decreases sympathetic activity, which may contribute to the reduction in VF or SCD [19]. Other procedural risks are those related to catheter ablation and pacemaker/ICD implant/upgrade procedures. (See "Overview of catheter ablation of cardiac arrhythmias", section on 'Complications'.) NEED FOR ANTICOAGULATION While AV node ablation results in adequate heart rate control, it does not stop the atria from fibrillating. Thus, the risk of thromboembolic events is not affected [22]. As a result, there is a need for long-term anticoagulation similar to that in patients with chronic AF whose heart rate control is achieved pharmacologically. (See "Atrial fibrillation in adults: Use of oral anticoagulants".) RECOMMENDATIONS OF OTHERS https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 9/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Our recommendations for patients with AF in whom a rate control strategy has been chosen are in general agreement with those made in major societal guidelines [23-25]. SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Atrial fibrillation" and "Society guideline links: Arrhythmias in adults".) SUMMARY AND RECOMMENDATIONS Background Atrioventricular (AV) node ablation is an option for rate control in atrial fibrillation (AF) patients who have failed medical therapy for rhythm control, have failed or are not candidates for catheter ablation for rhythm control, and have failed aggressive attempts at pharmacological rate control. Indications For AF patients with a rapid ventricular response who do not respond to or are intolerant of aggressive attempts at pharmacologic therapy to slow the ventricular rate, and in whom nonpharmacologic approaches, including curative attempts at AF ablation, are not successful or appropriate, we recommend AV node ablation in association with implantation of a permanent pacing device to improve symptoms and quality of life (Grade 1B). (See 'Indications' above.) Pacing procedure For AF patients who undergo AV node ablation, a pacing device is needed to prevent symptomatic bradycardia. A single-chamber ventricular pacemaker with rate-adaptive capability may be appropriate for patients with persistent AF, and a dual- chamber pacemaker with both mode switching and rate-adaptive capabilities may be appropriate for patients with paroxysmal AF. The roles of cardiac resynchronization therapy, physiological pacing, and implantable cardioverter-defibrillator depend on left ventricular function, heart failure symptoms, and history. (See 'Device selection' above.) No need for anticoagulation AV node ablation has no impact on thromboembolic risk and most individuals require long-term oral anticoagulation. (See 'Need for anticoagulation' above.) ACKNOWLEDGMENT https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 10/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate The UpToDate editorial staff acknowledges Leonard Ganz, MD, FHRS, FACC, who contributed to an earlier version of this topic review. Use of UpToDate is subject to the Terms of Use. REFERENCES 1. Yarlagadda B, Turagam MK, Dar T, et al. Safety and feasibility of leadless pacemaker in patients undergoing atrioventricular node ablation for atrial fibrillation. Heart Rhythm 2018; 15:994. 2. Marshall HJ, Harris ZI, Griffith MJ, et al. Prospective randomized study of ablation and pacing versus medical therapy for paroxysmal atrial fibrillation: effects of pacing mode and mode- switch algorithm. Circulation 1999; 99:1587. 3. Kamalvand K, Tan K, Kotsakis A, et al. Is mode switching beneficial? A randomized study in patients with paroxysmal atrial tachyarrhythmias. J Am Coll Cardiol 1997; 30:496. 4. Gribbin GM, Bourke JP, McComb JM. Predictors of atrial rhythm after atrioventricular node ablation for the treatment of paroxysmal atrial arrhythmias. Heart 1998; 79:548. 5. Gillis AM, Connolly SJ, Lacombe P, et al. Randomized crossover comparison of DDDR versus VDD pacing after atrioventricular junction ablation for prevention of atrial fibrillation. The atrial pacing peri-ablation for paroxysmal atrial fibrillation (PA (3)) study investigators. Circulation 2000; 102:736. 6. Dandamudi G, Vijayaraman P. How to perform permanent His bundle pacing in routine clinical practice. Heart Rhythm 2016; 13:1362. 7. Huang W, Su L, Wu S, et al. Benefits of Permanent His Bundle Pacing Combined With Atrioventricular Node Ablation in Atrial Fibrillation Patients With Heart Failure With Both Preserved and Reduced Left Ventricular Ejection Fraction. J Am Heart Assoc 2017; 6. 8. Wood MA. Trials of pacing to control ventricular rate during atrial fibrillation. J Interv Card Electrophysiol 2004; 10 Suppl 1:63. 9. Scheinman MM, Huang S. The 1998 NASPE prospective catheter ablation registry. Pacing Clin Electrophysiol 2000; 23:1020. 10. Curtis AB, Kutalek SP, Prior M, Newhouse TT. Prevalence and characteristics of escape rhythms after radiofrequency ablation of the atrioventricular junction: results from the registry for AV junction ablation and pacing in atrial fibrillation. Ablate and Pace Trial Investigators. Am Heart J 2000; 139:122. https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 11/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate 11. Fitzpatrick AP, Kourouyan HD, Siu A, et al. Quality of life and outcomes after radiofrequency His-bundle catheter ablation and permanent pacemaker implantation: impact of treatment in paroxysmal and established atrial fibrillation. Am Heart J 1996; 131:499. 12. Wood MA, Brown-Mahoney C, Kay GN, Ellenbogen KA. Clinical outcomes after ablation and pacing therapy for atrial fibrillation : a meta-analysis. Circulation 2000; 101:1138. 13. Brown CS, Mills RM Jr, Conti JB, Curtis AB. Clinical improvement after atrioventricular nodal ablation for atrial fibrillation does not correlate with improved ejection fraction. Am J Cardiol 1997; 80:1090. 14. Weerasooriya R, Davis M, Powell A, et al. The Australian Intervention Randomized Control of Rate in Atrial Fibrillation Trial (AIRCRAFT). J Am Coll Cardiol 2003; 41:1697. 15. Ozcan C, Jahangir A, Friedman PA, et al. Long-term survival after ablation of the atrioventricular node and implantation of a permanent pacemaker in patients with atrial fibrillation. N Engl J Med 2001; 344:1043. 16. Garcia B, Clementy N, Benhenda N, et al. Mortality After Atrioventricular Nodal Radiofrequency Catheter Ablation With Permanent Ventricular Pacing in Atrial Fibrillation: Outcomes From a Controlled Nonrandomized Study. Circ Arrhythm Electrophysiol 2016; 9. 17. Khan MN, Ja s P, Cummings J, et al. Pulmonary-vein isolation for atrial fibrillation in patients with heart failure. N Engl J Med 2008; 359:1778. 18. Ozcan C, Jahangir A, Friedman PA, et al. Sudden death after radiofrequency ablation of the atrioventricular node in patients with atrial fibrillation. J Am Coll Cardiol 2002; 40:105. 19. Hamdan MH, Page RL, Sheehan CJ, et al. Increased sympathetic activity after atrioventricular junction ablation in patients with chronic atrial fibrillation. J Am Coll Cardiol 2000; 36:151. 20. Evans GT Jr, Scheinman MM, Bardy G, et al. Predictors of in-hospital mortality after DC catheter ablation of atrioventricular junction. Results of a prospective, international, multicenter study. Circulation 1991; 84:1924. 21. Geelen P, Brugada J, Andries E, Brugada P. Ventricular fibrillation and sudden death after radiofrequency catheter ablation of the atrioventricular junction. Pacing Clin Electrophysiol 1997; 20:343. 22. Gasparini M, Mantica M, Brignole M, et al. Thromboembolism after atrioventricular node ablation and pacing: long term follow up. Heart 1999; 82:494. 23. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 12/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Heart Association Task Force on practice guidelines and the Heart Rhythm Society. Circulation 2014; 130:e199. 24. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021; 42:373. 25. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society in Collaboration With the Society of Thoracic Surgeons. Circulation 2019; 140:e125. Topic 1012 Version 28.0 https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 13/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate GRAPHICS Clinical factors favoring atrioventricular node ablation in patients with refractory atrial fibrillation Favors atrial fibrillation ablation Favors atrioventricular node ablation/pacing Clinical characteristics Age Younger Older, particularly very elderly Atrial fibrillation pattern Paroxysmal Persistent, particularly very longstanding ("permanent") Left atrial size Normal/near normal Markedly dilated Comorbidities Minimal Extensive Overall health Robust Frail Miscellaneous High infection risk Previous failed atrial fibrillation ablation Courtesy of Leonard Ganz, MD. Graphic 129004 Version 1.0 https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 14/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Intracardiac and surface ECG recordings during electrophysiologic study in a person with atrial fibrillation Three surface ECG leads (I, aVF, V1) and intracardiac recordings from the atrioventricular unction region (HBE1-2, HBE3-4), and the right ventricular apex (RVA3-4) in a patient with atrial fibrillation. The patient has extremely symptomatic, medically refractory atrial fibrillation with rapid ventricular rates and recurrent heart failure. The mapping catheter (HBE) has been maneuvered from the area of maximal His bundle activity to a more proximal position, where a larger atrial (A) and smaller His electrogram (H) are recorded. ECG: electrocardiograph; V: ventricular electrogram. Graphic 74286 Version 5.0 https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 15/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Intracardiac and surface ECG recordings during electrophysiologic study and radiofrequency catheter ablation of the AV junction in atrial fibrillation Three surface ECG leads (I, aVF, V1) and intracardiac recordings from the region of the atrioventricular junction (HBE1-2, HBE3-4), and the right ventricular apex (RVA3- 4) in a patient with atrial fibrillation. Application of radiofrequency (RF) energy from the tip of the mapping catheter (HBE1-2) causes complete AV nodal block; pacing (P) is initiated from the right ventricular apex. A permanent VVIR pacemaker was implanted, and the patient has noted a marked improvement in symptoms. ECG: electrocardiograph; AV: atrioventricular. Graphic 67363 Version 5.0 https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 16/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Para Hisian pacing lead Patient #6. Right anterior oblique (RAO) and left anterior oblique (LAO) fluoroscopic projections showing leads position during the "ablate and pace" procedure and Hisian pacing; 1 = quadripolar Hisian mapping catheter; 2 = screw-in bipolar lead positioned in close proximity to the His-bundle; 3 = bipolar passive fixation positioned in right ventricular apex. Reproduced with permission from: Occhetta E, Bortnik M, Magnani A, et al. Prevention of ventricular desynchronization by permanent para-Hisian pacing after atrioventricular node ablation in chronic atrial brillation: a crossover, blinded, randomized study versus apical right ventricular pacing. J Am Coll Cardiol 2006; 47:1938. Copyright 2006 American College of Cardiology Foundation. Graphic 56944 Version 3.0 https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 17/18 7/5/23, 7:59 AM Atrial fibrillation: Atrioventricular node ablation - UpToDate Contributor Disclosures Bradley P Knight, MD, FACC Grant/Research/Clinical Trial Support: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; MDT [Electrophysiology]; Philips [Electrophysiology]. Consultant/Advisory Boards: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; CVRx [Heart failure]; MDT [Electrophysiology]; Philips [Electrophysiology]; Sanofi [Arrhythmias]. Speaker's Bureau: Abbott [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Transeptal catheterization]; BSCI [Electrophysiology]; MDT [Electrophysiology]. All of the relevant financial relationships listed have been mitigated. N A Mark Estes, III, MD Consultant/Advisory Boards: Boston Scientific [Arrhythmias]; Medtronic [Arrhythmias]. All of the relevant financial relationships listed have been mitigated. Nisha Parikh, MD, MPH No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/atrial-fibrillation-atrioventricular-node-ablation/print 18/18

7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Official reprint from UpToDate www.uptodate.com 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved. Atrial fibrillation: Catheter ablation : Rod Passman, MD, MSCE : Bradley P Knight, MD, FACC, N A Mark Estes, III, MD : Nisha Parikh, MD, MPH All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Jun 2023. This topic last updated: May 27, 2022. INTRODUCTION The three principal goals of therapy in patients with atrial fibrillation (AF) are the alleviation of symptoms, the prevention of tachycardia-mediated cardiomyopathy, and the reduction in the risk of stroke. The first two goals can be achieved with either a rate or rhythm control strategy (see "Management of atrial fibrillation: Rhythm control versus rate control"). For patients in whom a rhythm control strategy is chosen, catheter ablation (CA) and antiarrhythmic drug therapy are the two principle therapeutic strategies to reduce the frequency or eliminate episodes of AF. (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy".) This topic will discuss the use of CA in patients with AF and provide the clinician with much of the information needed to discuss the procedure with the patient. The discussion of surgery to prevent recurrent AF is found elsewhere. (See "Atrial fibrillation: Surgical ablation".) Stroke prevention is usually achieved with anticoagulation. This topic is discussed in detail separately. (See "Atrial fibrillation in adults: Use of oral anticoagulants".) WHAT TO TELL YOUR PATIENT When discussing CA to reduce symptoms in an AF patient, the following information should be provided: https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 1/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate CA is a reasonable treatment option for AF patients when medications are unable to adequately control symptoms or are not tolerated. All patients who undergo CA must take oral anticoagulation for at least two to three months after the procedure. Anticoagulation should be continued long term in many patients with risk factors for stroke even if AF is not present after the ablation. This is because patients may continue to have some AF episodes that may be asymptomatic; in addition, the reduction in AF burden seen post-ablation has not yet been shown to reduce stroke risk. It is a common misconception that patients who undergo successful ablation can stop oral anticoagulation. About 70 to 75 percent of patients are symptom free at one year [1]. A lower percentage is likely for persistent AF (about 60 percent). About 50 percent of patients have detectable AF at one year (this includes symptomatic and asymptomatic patients) [2,3]. The success rate for ablation in patients with long-standing persistent AF (over one year) is poor. The risk of a major complication is about 4 percent, with vascular access complications being the most common. Other important, less common complications include stroke, cardiac perforation, or damage that includes injury to the pulmonary veins, esophagus, or phrenic nerve. The risk of dying within 30 days after an AF ablation procedure is about 1 in 1000 patients. The risk of a major complication is significantly higher at low-volume ablation centers. [4]. TECHNICAL CONSIDERATIONS Technical considerations for CA are presented separately. (See "Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists", section on 'Ablation techniques and targets'.) COMPARISON WITH ANTIARRHYTHMIC THERAPY For patients with symptomatic paroxysmal AF in a rhythm- rather than a rate-control strategy, either a trial of an antiarrhythmic drug or CA is a reasonable approach. We are more inclined to https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 2/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate perform CA in patients for whom the odds of success are high and if they prefer to avoid the use of long-term antiarrhythmic drug therapy. Studies comparing these strategies are discussed separately. (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy", section on 'Patients without prior antiarrhythmic drug treatment'.) EFFICACY CA leads to significant symptom improvement in most patients. Over 70 to 75 percent are symptom free at one year. Some symptoms may be due to atrial or ventricular premature complexes rather than AF. The absence of symptomatic AF recurrence is the primary efficacy outcome in most studies. However, with continuous invasive monitoring, approximately 50 percent of patients have had one or more documented episodes lasting 30 seconds or longer at one year. This becomes part of the rationale to continue long-term oral anticoagulation in many patients. (See "Catheter ablation to prevent recurrent atrial fibrillation: Anticoagulation", section on 'Our approach to anticoagulation'.) How is recurrence defined and measured? Recurrence of AF after CA is categorized as early or late. Each have distinct mechanisms and management implications [5]. From a clinical perspective, recurrences after the initial two-to-three-month post-ablation healing phase are more clinically relevant. Early recurrences of AF are defined as those that occur within the first two to three months after CA. This period is often referred to as the "blanking period," and recurrences during this time are not included in studies examining the long-term success of AF ablation. Early recurrences occur as often as 40 percent of the time with radiofrequency ablation (RFA) [6] and about 17 percent of the time for those treated with second-generation cryoballoon [7]. It is postulated to be related to several potential mechanisms including sterile pericarditis, recovered pulmonary vein (PV) conduction, or proarrhythmic effects of the ablation procedure [8]. Some studies suggest that early recurrence appears to be a predictor of late recurrence, especially when the episodes occur late in the blanking period. However, most clinicians will treat early recurrences with antiarrhythmic drug therapy before consideration of repeat ablation in these patients. Episodes of AF occurring after three months are considered to be recurrent AF and are referred to as "late recurrent AF." The possible mechanisms for late recurrent AF following CA are discussed separately. (See "Mechanisms of atrial fibrillation", section on 'Specific clinical situations'.) https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 3/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate The frequency of late recurrent AF varies significantly across studies in part due to factors such as the method and intensity of surveillance, whether other atrial arrhythmias such as atrial flutter are counted, whether patients remained on antiarrhythmic drug therapy, and patient characteristics (eg, paroxysmal or persistent AF). In some studies, success has been defined as the absence of recurrent AF or other atrial arrhythmias with or without antiarrhythmic drug therapy; a more rigorous definition requires the absence of AF >30 seconds in patients not taking antiarrhythmic drugs. The following studies illustrate the rates of late recurrence [9]: The DISCERN AF study evaluated episodes of symptomatic and asymptomatic AF (as well as atrial flutter and atrial tachycardia) before and after the procedure in 50 patients (80 percent with paroxysmal AF), using an implantable cardiac monitor capable of recording all AF episodes [10]. The total atrial arrhythmia burden was significantly reduced by 86 percent from a mean of two hours per day per patient before to 0.3 hours per day after. The ratio of asymptomatic to symptomatic episodes increased significantly after ablation from 1.1 to 3.7. After 18 months and a mean of 1.4 ablations, 58 percent of patients were symptom free. A 2013 meta-analysis of 19 observational studies (n = 6167) with outcomes at 3 years found that freedom from atrial arrhythmia at long-term follow-up (mean 24 months) after a single procedure was about 53 percent [11]. With multiple procedures, the long-term success rate was nearly 80 percent. However, there are several limitations of this analysis, including significant heterogeneity among the studies, disparities in post-ablation AF surveillance, and the inclusion of patients ablated with early-generation technologies no longer in current use. In the MANTRA and RAAFT-2 randomized trials, which allowed for antiarrhythmic drug use after CA, freedom from AF at two years was 85 and 72 percent, respectively [12,13]. (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy", section on 'Patients without prior antiarrhythmic drug treatment'.) In a meta-analysis of seven studies of first-generation cryoballoon ablation, one-year freedom from AF was 73 percent, but the analysis evaluated studies that allowed inclusion of patients taking antiarrhythmic drug therapy in the CA group [14]. Two real-world population studies found significantly lower rates of freedom from AF when only patients not taking antiarrhythmic drug therapy were counted (40 and 41 percent at one year) [3,15]. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 4/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate The 2019 CIRCA-DOSE study randomly assigned 346 patients with drug-refractory, paroxysmal AF to contact-force-guided RFA or two differing duration protocols for cryoballoon ablation [1] (see 'Technical considerations' above). All patients received an implantable loop recorder, and they also received noninvasive surveillance. Follow-up was for 12 months. The primary endpoint of one-year freedom from atrial tachyarrhythmia (symptomatic or asymptomatic) as detected by continuous rhythm monitoring was about 53 percent in the three groups. One-year freedom from symptomatic atrial tachyarrhythmia, defined by continuous monitoring, ranged between 73 and 79 percent (p = 0.87). AF burden was reduced by about 99 percent in the three groups (p = 0.36). Predictors of recurrence Recurrence is more likely in patients with underlying cardiovascular disease such as hypertension, complicated heart disease (including valvular heart disease), older age, persistent as opposed to paroxysmal AF, procedure performed at a low-volume center, untreated obstructive sleep apnea, obesity, increasing plasma B-type natriuretic peptide level, or left atrial (LA) dilation [8,16-22]. LA dilation We rarely perform CA in patients with long-standing persistent AF and severe LA dilation (>5.5 cm). LA dilation should be assessed by volume determination rather than linear measurements if possible [23]. One study has shown that an LA volume 130 cc, assessed by computed tomography, predicts a recurrence rate of >90 percent at one year [24]. Other LA remodeling parameters Greater atrial wall thickness, lipid composition, and epicardial fat volume on cardiac computed tomography also predict AF recurrence in observational studies, but low measurement reproducibility may limit their clinical use [25]. Among 732 patients undergoing CA, 270 had AF recurrence after seven months. Patients with AF recurrence had higher LA wall thickness (anterior wall 1.9 versus 1.7 mm), 3 epicardial adipose volume (145 versus 129 mm ) and lower LA wall attenuation reflective of higher lipid composition (-69.1 versus -67.5 Hounsfield Units). Comparison of radiofrequency and cryothermal ablation The commonly used approved energy sources for CA are RF and cryothermal ablation. The efficacy and safety associated with these two energy sources have been found to be similar in multiple studies [1,14,26-30]. The three major randomized trials comparing the two energy sources are as follows: In the FIRE AND ICE trial, 762 patients with symptomatic, drug-refractory, paroxysmal AF were randomly assigned to cryoballoon ablation or RFA [31]. The primary efficacy endpoint https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 5/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate was the first documented clinical failure (eg, recurrence of AF, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) following a 90-day blanking period after the index ablation. Arrhythmia surveillance was noninvasive. The mean duration of follow-up was 1.5 years. The primary efficacy endpoint was similar in both groups (34.6 versus 35.9 percent, respectively; hazard ratio 0.96, 95% CI 0.76-1.22). In the FreezeAF trial, 315 patients with paroxysmal AF were randomly assigned to RFA or cryoballoon ablation [26]. The primary endpoint of freedom from atrial arrhythmia with absence of persistent complications was similar in the two groups at 12 months (70.7 versus 73.6 percent). Arrhythmia surveillance was noninvasive. In the 2019 CIRCA-DOSE study, which is discussed above, the two energy sources led to similar efficacy outcomes. (See 'How is recurrence defined and measured?' above.) Complications of cryoballoon ablation may differ somewhat from standard RFA. Pericardial effusions, tamponade, and atrioesophageal fistula have been reported less frequently in cryoballoon ablation. Non-AF atrial tachyarrhythmias have also been less frequently reported in long-term follow-up of cryoballoon ablation. However, phrenic nerve paralysis has been reported in up to 6.3 percent of 1349 procedures, significantly higher than seen with standard RFA. Resolution occurs acutely in most patients and in >90 percent within one year [14]. The use of larger balloons that prevent distal ablation and the assessment of diaphragmatic compound motor action potentials have lowered the rate of this complication. Recordings of diaphragmatic electromyograms during cryoballoon ablation for AF accurately predict phrenic nerve injury [32]. Patients with persistent atrial fibrillation The majority of patients in the studies of CA presented above had paroxysmal AF. The efficacy of CA in patients with persistent AF is lower than in patients with paroxysmal AF [33]. Our threshold for recommending CA is higher for patients with persistent AF given the lower success rates. Also, we avoid the use of CA as first- line therapy in patients with persistent AF. We believe CA is a reasonable choice for individuals with symptomatic persistent AF who either fail or cannot tolerate antiarrhythmic drug therapy or, in certain circumstances (ie, tachycardia- mediated cardiomyopathy), where there may be a benefit to maintaining sinus rhythm even in the absence of symptoms. To improve outcomes, standard pulmonary vein isolation (PVI) with or without additional ablative lesions can be performed. However, the utility of these additional lesion sets has not been consistently demonstrated, and we recommend standard PVI without the creation of additional lesions for the first ablation attempt in the majority of patients. We consider https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 6/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate additional lesions in patients with long-standing persistent AF or a markedly enlarged LA (see "Atrial fibrillation: Overview and management of new-onset atrial fibrillation", section on 'Classification and terminology'). In patients with persistent AF, one small randomized trial (VENUS) found that the addition of vein-of-Marshall ethanol (see "Mechanisms of atrial fibrillation", section on 'Role of premature atrial complex and other arrhythmia triggers') infusion to catheter ablation, compared with catheter ablation alone, increased the likelihood of remaining free of AF at 6 and 12 months [34]. Further study of this procedure is needed. A 2014 systematic review and meta-analysis identified 46 randomized trials and observational studies of 3819 patients who underwent CA for persistent AF [35]. Compared with medical therapy, CA reduced the risk of recurrent AF (odds ratio 0.32, 95% CI 0.20-0.53). Various ablation strategies were employed in the studies, and the most efficacious combined isolation of the PVs with limited linear ablation (eg, roof ablation, mitral isthmus ablation) within the LA. The success rate after two procedures was about 60 percent in all groups. (See 'Comparison with antiarrhythmic therapy' above.) The STAR AF II trial was published subsequently to the meta-analysis [2]. In this trial, 589 patients with persistent AF were randomly assigned in a 1:4:4 ratio to ablation with PVI alone, PVI plus ablation of electrograms showing complex fractionated activity, or PVI plus additional linear ablation across the LA roof and mitral valve isthmus. There was no significant difference in the rates of the primary endpoint of freedom from any documented recurrence of AF lasting longer than 30 seconds after a single ablation procedure at 18 months (59 versus 49 versus 46 percent, respectively). Although serious adverse events appeared to be lower in the PVI-alone group, there were too few events for this endpoint to achieve statistical significance. Patients with concomitant atrial flutter Atrial fibrillation and flutter often coexist in part due to their common risk factors. In many atrial flutter patients, AF is thought to be the inciting arrhythmia, and as much as 55 percent of patients who undergo ablation for typical atrial flutter are also found to have AF on long-term follow-up [36]. Some studies have shown that PV triggers play an important role in the development of flutter [37]. While ablation of the tricuspid annulus-inferior vena cava (TA-IVC) isthmus is a highly successful treatment option for atrial flutter, the ablation approach to the patient with concomitant AF and atrial flutter requires a more extensive approach and has been evaluated: In a study of 108 patients with both AF and typical atrial flutter, patients were randomly assigned to either a dual-ablative procedure (PVI and TA-IVC isthmus ablation, 49 patients) or PVI alone (59 patients) [38]. After ablation, the following observations were made: https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 7/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate During the first eight weeks post-procedure, none of the dual-procedure patients and 32 patients treated with PVI alone developed atrial flutter and required cardioversion and/or antiarrhythmic drugs. After eight weeks, all antiarrhythmic drugs were discontinued. Only three patients treated with PVI alone had further recurrences of atrial flutter, which was successfully treated with TA-IVC ablation. Seven of the dual-procedure patients and six of those treated with PVI alone developed recurrent AF. Of these 13 patients (12 percent of the total group), 10 underwent successful repeat PVI, and three remained in sinus rhythm on antiarrhythmic drugs. These findings suggest that AF initiated by PV triggers may be the precursor rather than the consequence of atrial flutter. This conclusion is consistent with the observation that atrial flutter often starts after a transitional rhythm of variable duration, usually AF [39,40]. (See "Electrocardiographic and electrophysiologic features of atrial flutter".) Attempts to control all atrial arrhythmias in patients with atrial flutter by performing PVI alone or at the time of an atrial flutter ablation have been studied: In the Triple A trial, 60 patients with atrial flutter but no documented AF were randomized to receive antiarrhythmic drugs alone, ablation of the cavotricuspid isthmus (CTI), or PVI. The primary endpoint, defined as any recurrent atrial tachyarrhythmia, occurred in 82.4 percent of the drug-treated group, 60.9 percent in the CTI group, and 10 percent in the PVI group during a mean follow-up time of 1.42 years [37]. In the PReVENT AF study [41], 50 patients with atrial flutter and no documented AF were randomized to CTI ablation alone or with concomitant PVI. More patients in the isthmus- ablation-only group experienced new-onset AF during follow-up (52 versus 12 percent), and the one-year burden also favored the combined ablation group compared with the isthmus-ablation-only group (8.3 versus 4 percent). These findings suggest that PVI either alone or in conjunction with atrial flutter ablation may have a beneficial effect on long-term suppression of all atrial arrhythmias. However, we do not recommend performing this procedure in lieu of or at the time of TA-IVC ablation in patients whose only documented arrhythmia is atrial flutter given the potential risks associated with additional ablation. (See "Atrial flutter: Maintenance of sinus rhythm".) Patients with structural heart disease The presence of structural heart disease may influence both the safety and efficacy of ablation procedures. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 8/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Heart failure CA appears to be safe and effective for the prevention of AF recurrence in patients with heart failure or impaired left ventricular function. The experience with ablation in this setting is discussed elsewhere. (See "The management of atrial fibrillation in patients with heart failure", section on 'Rhythm control'.) Cardiac resynchronization therapy CA as an alternative to cardiac resynchronization therapy with atrioventricular node ablation in patients with heart failure is discussed separately. (See "The management of atrial fibrillation in patients with heart failure", section on 'Preference for rhythm over rate control'.) Mitral valve prosthesis A potential concern with CA in patients with a mitral valve prosthesis is injury to the valve. Furthermore, entrapment of the ablation catheter in a mechanical mitral valve, necessitating open-heart surgery, has been reported in patients undergoing left-sided ablation procedures. This issue was addressed in a report of 26 patients with mitral valve prostheses who were compared with a matched group of 52 patients without a mitral valve prosthesis [42]. The rate of maintenance of sinus rhythm was the same in the two groups, but the patients with a mitral valve prosthesis had longer fluoroscopy times with greater radiation exposure and a higher rate of post-ablation atrial tachycardia (23 versus 2 percent). Rheumatic heart disease The role of CA for chronic AF in patients with rheumatic heart disease is not well defined. One study performed electrophysiologic mapping in 17 patients with mitral stenosis who had chronic AF and were converted to sinus rhythm after balloon valvulotomy [43]. An organized atrial arrhythmia, which degenerated into AF, was induced in all patients; the focus was most often near the coronary sinus ostium. RFA was successful in 13 patients and, after a mean follow-up of 32 weeks, 10 were still in sinus rhythm. Cardiac surgery Either the Maze procedure or off-pump CA using an epicardial approach should be considered in patients with AF and an indication for open-heart surgery. These approaches are not generally recommended for patients without an indication for cardiac surgery, except in special circumstances, because of the mortality and morbidity associated with surgery. (See "Atrial fibrillation: Surgical ablation", section on 'Maze procedure'.) Patients with hypertension Renal sympathetic nerve denervation has been proposed as an adjunctive treatment to CA in hypertensive AF patients. We do not feel the available evidence supports its use in this setting. The rationale for the adding renal nerve denervation to CA is that hypertension is a major risk factor for the development of AF and that many hypertensive AF patients have increased https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 9/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate sympathetic tone. Renal nerve denervation has been evaluated as a treatment for hypertension, but its efficacy has not yet been established. (See "Treatment of resistant hypertension".) The issue of whether renal nerve denervation, when added to CA, can further lower the rate of AF recurrence was evaluated in the ERADICATE-AF trial [44]. In this study, 302 hypertensive (paroxysmal) AF patients were randomly assigned to CA or CA plus renal nerve denervation. The primary endpoint of freedom from AF, atrial flutter, or tachycardia at 12 months occurred in 56.5 and 72.1 percent of the two groups, respectively (hazard ratio 0.57, 95% CI 0.38-0.85). There was no significant difference in the rate of procedural complications between the two groups. Although the use of renal denervation as adjunctive therapy to CA improved the primary outcome, the lack of a sham-control group, that is CA plus sham renal denervation, is a major limitation of this study. COMPLICATIONS The types and rates of complications that occur in patients undergoing CA vary from series to series ( table 1 and table 2). The overall rate of major complications is about 4 percent, with vascular access complications being the most frequent [45]. There may be an increased rate of adverse effects with more extensive circumferential ablation [46-50]. (See "Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists", section on 'Ablation techniques and targets'.) Two large studies published in 2013 came to somewhat differing conclusions as to whether the complication rate was falling with time: An analysis of 93,801 CA procedures performed in community hospitals in the United States between 2000 and 2010 did not identify a trend toward lower mortality [51]. The majority (81 percent) of procedures were performed in low-volume hospitals by low-volume operators. The overall frequency of complications was 6.29 percent, and there was a small but nonsignificant rise with time. In a meta-analysis of 192 published studies, including 83,236 patients, there was a significant decrease in the acute complication rate from 2007 to 2012 compared with 2000 to 2006 (2.6 versus 4 percent; p = 0.003) [52]. In these studies, cardiac complications accounted for at least 50 percent of all complications. Most [51,53], but not all [54], studies have suggested that advanced age and female sex are risk factors for complications. In addition, annual operator (<25 procedures) and hospital volume (<50 procedures) have been associated with adverse outcomes [51]. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 10/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Complications reported in series of patients undergoing CA to prevent recurrent AF will be reviewed here. Other complications that might occur with any electrophysiology study, such as radiation exposure and valve, vascular, or myocardial injury, are discussed separately. (See "Overview of catheter ablation of cardiac arrhythmias", section on 'Complications'.) Mortality Early case series found a death rate of about 1 to 1.5 in every 1000 patients [55,56]. More recent studies suggest a mortality closer to 5 per 1000. In the two large series (2000 to 2010 and 2007 to 2012) discussed directly above, the in-hospital mortality rates varied between 4.6 and 0.6 per 1000 patients [51,52]. The leading causes of death were cardiac tamponade (n = 8, 25 percent), stroke (n = 5, 16 percent), and atrioesophageal fistula (n = 5, 16 percent). Other causes included pneumonia, pulmonary vein (PV) perforation, and sepsis [55]. Cardiac tamponade Cardiac tamponade resulting from perforation is the most frequent serious complication of CA for AF, occurring in slightly more than 1 percent of procedures using radiofrequency (RF) [53,55,57], and it is the leading cause of death [55]. Tamponade results from either catheter perforation of an atrial or ventricular free wall, especially with overheating during energy delivery, or less frequently with transseptal puncture. Some cases of tamponade may be delayed in onset. In one study of delayed tamponade, the median duration was 10 days, with a range of several hours up to 30 days [55]. Pericardial effusion associated with PV isolation (PVI) was significantly less common in patients who underwent cryoballoon ablation (0.8 versus 2.1 percent) in one meta-analysis [30]. The treatment of tamponade caused by CA is similar to that in other settings. (See "Cardiac tamponade", section on 'Treatment'.) Catheter entrapment Entrapment of the circular mapping (LASSO) catheter in the mitral valve apparatus is a rare complication that can require cardiac surgery to resolve. The estimated incidence of this complication ranges between 0.01 and 0.9 percent, and specific sites of transeptal puncture or catheter manipulation may predispose to this adverse event [58-60]. Pulmonary vein stenosis PV stenosis is a potential complication of ablation near or within the PVs. The lesion is characterized by fibrosis and scarring of the PV; specific pathologic changes include intimal thickening, thrombus formation, endocardial contraction, and proliferation of elastic laminae [61]. The diagnosis may be delayed or missed entirely, as symptomatic patients may come to attention months after their initial ablation. In one series, symptoms developed 4 3 months after the most recent ablation, and the average delay between the onset of symptoms and diagnosis was 4.4 5.4 months. Symptoms of PV stenosis include dyspnea with exertion (or less often at rest), cough, chest pain, hemoptysis, and recurrent lung infections [62,63]. The mean onset of symptoms is two to five months after the https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 11/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate procedure [62-64]. The intensity of symptoms may be directly related to the degree of obstruction and inversely related to the duration of time to develop the stenosis [65]. Incorrect diagnoses including pneumonia, bronchitis, or suspected malignancy are often considered and result in unnecessary testing, treatment, and delayed intervention. Delays in diagnosis and treatment may allow for progression of stenosis and irreversible intraparenchymal lung damage. The reported rate of PV stenosis depends not only on the factors described above, but also on the definition of stenosis severity and the intensity of screening. Early reports cited rates as high as 38 percent, but more studies cite rates for severe stenosis as low as 1 to 3 percent [53,58,63,66]. A minority of diagnosed patients appear to develop symptoms [67,68]. The incidence of severe PV stenosis is between 0.32 and 3.4 percent, but the risk may be lower with cryoballoon compared with radiofrequency energy [69]. The rate of PV stenosis requiring intervention may be as low as 0.1 to 0.3 percent [57]. Diagnostic evaluation for PV stenosis should be performed in patients who develop respiratory symptoms after RF ablation (RFA). The joint Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society expert consensus statement of catheter and surgical ablation of AF suggests computed tomography or magnetic resonance imaging (MRI) as the preferred tests in suspected cases [65]. A ventilation/perfusion lung scan can also be used to diagnose PV stenosis. Stent placement is a more effective therapy for PV stenosis compared with balloon angioplasty [69]. It is associated with a significant and almost immediate improvement in symptoms and pulmonary blood flow [62-64]. In series of patients who underwent balloon angioplasty with or without stenting, in-segment or in-stent stenosis requiring repeat intervention developed in approximately 50 percent of patients [63,64]. The roles of either elective stenting or surgery are not well defined [65]. However, the incidence of PV stenosis has significantly decreased due to improvement in ablative techniques, especially with moving the ablation lesions toward the atrial side of the PV-atrial junction. Periprocedural embolic events Patients undergoing CA to prevent recurrent AF are at risk for embolic events before, during, and after the procedure. The incidence of clinical stroke or transient ischemic attack is between 0 and 2 percent [9]. The role of anticoagulant therapy in this setting is discussed in detail separately. (See "Catheter ablation to prevent recurrent atrial fibrillation: Anticoagulation".) MRI-detected brain lesions and cognitive impairment Stroke and transient ischemic attack are not the only neurologic sequelae of CA. Multiple MRI studies performed within 24 hours https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 12/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate after RFA have demonstrated new cerebral lesions in 7 to 44 percent of asymptomatic patients [70-72]. However, in a study of 60 AF patients at relatively low risk for stroke who underwent CA, only one patient developed new asymptomatic lesions on MRI soon after the procedure [73]. These lesions were presumed secondary to microemboli [74]. Studies of the impact of these lesions on neurocognitive function have come to differing conclusions as to the significance of these lesions, as illustrated by the following studies: The prevalence of cognitive impairment after RFA was evaluated in a study of 150 patients: 60 undergoing ablation for paroxysmal AF, 30 for persistent AF, 30 for supraventricular tachycardia, and 30 matched AF patients awaiting RFA (the control group) [75]. All RFA patients received periprocedural enoxaparin, and most patients with AF had a CHADS 2 score of 0 or 1 ( table 3). All patients underwent eight neuropsychological tests at baseline and at 2 and 90 days after RFA. The prevalence of neurocognitive dysfunction at day 90 was 13, 20, 3, and 0 percent, respectively. In a study of 37 patients with paroxysmal AF who underwent 41 ablation procedures, MRI performed within 48 hours showed new brain lesions in 41 percent of patients and 44 percent of procedures [72]. Follow-up MRI at six months found glial scar in about 12 percent of those with lesions. However, there was no decline of neurocognitive function on testing. Vascular complications Vascular complications are among the most common adverse events related to AF ablation, likely due to the number and size of intravascular sheaths and the need for anticoagulation both during and immediately following the procedure. These complications include hematoma at the sites of catheter insertion, pseudoaneurysm, arteriovenous fistula, or retroperitoneal bleeding. Pseudoaneurysm and arteriovenous fistulae rates of 0.53 and 0.43 percent, respectively, have been reported [57,58]. This risk can be significantly reduced by the use of vascular ultrasound, which was demonstrated, in one study of 689 patients, to reduce the risk of vascular access complications from 5.3 to 1.1 percent [76]. Conservative management alone is usually sufficient for large hematomas and retroperitoneal bleeding, though anticoagulation may need to be held, and transfusion may be necessary in those patients where the risks of such interventions are warranted. Echo-guided manual compression and percutaneous intervention are usually effective treatments of femoral pseudoaneurysms or arteriovenous fistula, but direct surgical intervention is sometimes required [77]. Atrial esophageal fistula This is a potentially life-threatening medical emergency for which the exact mechanism is unknown. The overall incidence is 0.3 to 0.54 percent, and mortality is between 50 and 83 percent [78]. Early recognition can be missed due to the low awareness of https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 13/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate this rare complication. It is important for patients to be educated as to warning signs and to contact their AF ablation center should any suggestive symptoms develop. Clinical manifestations usually present one to four weeks post-ablation (range of 2 to 60 days), and the most common symptoms are fever, chest pain, and recurrent neurologic events from septic emboli. Chest computed tomography is the preferred diagnostic modality. Endoscopy with air insufflation should not be performed. Arrhythmic complications New reentrant circuits created by the ablation lesions can lead to atypical left atrial (LA) flutter. These circuits tend to develop around regions of LA scar and often involve the perimitral region. Due to anatomic variability and technical challenges, successful ablation is more difficult than that for typical right atrial flutter involving the isthmus of the inferior vena cava and tricuspid annulus. A significant percentage of LA flutter following PVI may also involve the musculature of the coronary sinus or the roof of the left atrium [79]. (See "Electrocardiographic and electrophysiologic features of atrial flutter".) Typical atrial flutter may also occur after LA ablation due to alterations in activation patterns of the LA and may have an unusual electrocardiographic morphology. LA flutter appears to be more common following circumferential (as opposed to segmental) PVI [49,79-82]. In a randomized comparison of circumferential and segmental PVI, LA flutter developed in 9 of the 50 patients undergoing circumferential PVI, and in 1 of the 50 patients in the segmental PVI group [49]. In addition, many of the recurrent LA arrhythmias following segmental PVI are focal atrial tachycardias, as opposed to macroreentrant flutter circuits, and are often successfully treated with repeat isolation of the PVs. Other Other complications with their respective incidences are summarized: Phrenic nerve injury (<1 percent) [57,58] in patients receiving RFA (and up to 6.3 percent in those receiving cryoablation). (See 'Comparison of radiofrequency and cryothermal ablation' above.) Periesophageal vagal injury (gastric hypomotility) [48,83]. Acute coronary artery occlusion/injury (<1 percent) [65,84]. Iatrogenic atrial septal defect after cryoballoon ablation without clinical consequence (20 percent) [85]. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 14/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate PREVENTION OF RECURRENCE The following therapies have been evaluated for their ability to prevent late recurrent AF; only treatment of obstructive sleep apnea (OSA) seems to be beneficial: Glucocorticoid therapy We do not believe there is sufficient evidence to recommend the use of prophylactic glucocorticoid therapy. Two observations raise the possibility that corticosteroid therapy might be useful for the prevention of early recurrence. Firstly, inflammation is associated with the development of AF, and systemic and local inflammatory responses may result from radiofrequency ablation (RFA) [86] (see "Epidemiology, risk factors, and prevention of atrial fibrillation",

the preferred tests in suspected cases [65]. A ventilation/perfusion lung scan can also be used to diagnose PV stenosis. Stent placement is a more effective therapy for PV stenosis compared with balloon angioplasty [69]. It is associated with a significant and almost immediate improvement in symptoms and pulmonary blood flow [62-64]. In series of patients who underwent balloon angioplasty with or without stenting, in-segment or in-stent stenosis requiring repeat intervention developed in approximately 50 percent of patients [63,64]. The roles of either elective stenting or surgery are not well defined [65]. However, the incidence of PV stenosis has significantly decreased due to improvement in ablative techniques, especially with moving the ablation lesions toward the atrial side of the PV-atrial junction. Periprocedural embolic events Patients undergoing CA to prevent recurrent AF are at risk for embolic events before, during, and after the procedure. The incidence of clinical stroke or transient ischemic attack is between 0 and 2 percent [9]. The role of anticoagulant therapy in this setting is discussed in detail separately. (See "Catheter ablation to prevent recurrent atrial fibrillation: Anticoagulation".) MRI-detected brain lesions and cognitive impairment Stroke and transient ischemic attack are not the only neurologic sequelae of CA. Multiple MRI studies performed within 24 hours https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 12/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate after RFA have demonstrated new cerebral lesions in 7 to 44 percent of asymptomatic patients [70-72]. However, in a study of 60 AF patients at relatively low risk for stroke who underwent CA, only one patient developed new asymptomatic lesions on MRI soon after the procedure [73]. These lesions were presumed secondary to microemboli [74]. Studies of the impact of these lesions on neurocognitive function have come to differing conclusions as to the significance of these lesions, as illustrated by the following studies: The prevalence of cognitive impairment after RFA was evaluated in a study of 150 patients: 60 undergoing ablation for paroxysmal AF, 30 for persistent AF, 30 for supraventricular tachycardia, and 30 matched AF patients awaiting RFA (the control group) [75]. All RFA patients received periprocedural enoxaparin, and most patients with AF had a CHADS 2 score of 0 or 1 ( table 3). All patients underwent eight neuropsychological tests at baseline and at 2 and 90 days after RFA. The prevalence of neurocognitive dysfunction at day 90 was 13, 20, 3, and 0 percent, respectively. In a study of 37 patients with paroxysmal AF who underwent 41 ablation procedures, MRI performed within 48 hours showed new brain lesions in 41 percent of patients and 44 percent of procedures [72]. Follow-up MRI at six months found glial scar in about 12 percent of those with lesions. However, there was no decline of neurocognitive function on testing. Vascular complications Vascular complications are among the most common adverse events related to AF ablation, likely due to the number and size of intravascular sheaths and the need for anticoagulation both during and immediately following the procedure. These complications include hematoma at the sites of catheter insertion, pseudoaneurysm, arteriovenous fistula, or retroperitoneal bleeding. Pseudoaneurysm and arteriovenous fistulae rates of 0.53 and 0.43 percent, respectively, have been reported [57,58]. This risk can be significantly reduced by the use of vascular ultrasound, which was demonstrated, in one study of 689 patients, to reduce the risk of vascular access complications from 5.3 to 1.1 percent [76]. Conservative management alone is usually sufficient for large hematomas and retroperitoneal bleeding, though anticoagulation may need to be held, and transfusion may be necessary in those patients where the risks of such interventions are warranted. Echo-guided manual compression and percutaneous intervention are usually effective treatments of femoral pseudoaneurysms or arteriovenous fistula, but direct surgical intervention is sometimes required [77]. Atrial esophageal fistula This is a potentially life-threatening medical emergency for which the exact mechanism is unknown. The overall incidence is 0.3 to 0.54 percent, and mortality is between 50 and 83 percent [78]. Early recognition can be missed due to the low awareness of https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 13/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate this rare complication. It is important for patients to be educated as to warning signs and to contact their AF ablation center should any suggestive symptoms develop. Clinical manifestations usually present one to four weeks post-ablation (range of 2 to 60 days), and the most common symptoms are fever, chest pain, and recurrent neurologic events from septic emboli. Chest computed tomography is the preferred diagnostic modality. Endoscopy with air insufflation should not be performed. Arrhythmic complications New reentrant circuits created by the ablation lesions can lead to atypical left atrial (LA) flutter. These circuits tend to develop around regions of LA scar and often involve the perimitral region. Due to anatomic variability and technical challenges, successful ablation is more difficult than that for typical right atrial flutter involving the isthmus of the inferior vena cava and tricuspid annulus. A significant percentage of LA flutter following PVI may also involve the musculature of the coronary sinus or the roof of the left atrium [79]. (See "Electrocardiographic and electrophysiologic features of atrial flutter".) Typical atrial flutter may also occur after LA ablation due to alterations in activation patterns of the LA and may have an unusual electrocardiographic morphology. LA flutter appears to be more common following circumferential (as opposed to segmental) PVI [49,79-82]. In a randomized comparison of circumferential and segmental PVI, LA flutter developed in 9 of the 50 patients undergoing circumferential PVI, and in 1 of the 50 patients in the segmental PVI group [49]. In addition, many of the recurrent LA arrhythmias following segmental PVI are focal atrial tachycardias, as opposed to macroreentrant flutter circuits, and are often successfully treated with repeat isolation of the PVs. Other Other complications with their respective incidences are summarized: Phrenic nerve injury (<1 percent) [57,58] in patients receiving RFA (and up to 6.3 percent in those receiving cryoablation). (See 'Comparison of radiofrequency and cryothermal ablation' above.) Periesophageal vagal injury (gastric hypomotility) [48,83]. Acute coronary artery occlusion/injury (<1 percent) [65,84]. Iatrogenic atrial septal defect after cryoballoon ablation without clinical consequence (20 percent) [85]. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 14/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate PREVENTION OF RECURRENCE The following therapies have been evaluated for their ability to prevent late recurrent AF; only treatment of obstructive sleep apnea (OSA) seems to be beneficial: Glucocorticoid therapy We do not believe there is sufficient evidence to recommend the use of prophylactic glucocorticoid therapy. Two observations raise the possibility that corticosteroid therapy might be useful for the prevention of early recurrence. Firstly, inflammation is associated with the development of AF, and systemic and local inflammatory responses may result from radiofrequency ablation (RFA) [86] (see "Epidemiology, risk factors, and prevention of atrial fibrillation", section on 'Inflammation and infection'). Secondly, glucocorticoid prophylaxis reduces the risk of the development of perioperative AF in patients undergoing coronary artery bypass graft surgery. (See "Atrial fibrillation and flutter after cardiac surgery", section on 'Ineffective or possibly effective therapies'.) The possible benefit from prophylactic glucocorticoid therapy was evaluated in a study of 125 patients with paroxysmal AF who were randomly assigned to either three days of glucocorticoid therapy or placebo starting immediately after the procedure [87]. The rate of AF recurrence (primary endpoint) was significantly lower in the glucocorticoid group at one month (27 versus 49 percent), with most of the benefit occurring during the first three days (7 versus 31 percent). Treatment of OSA OSA is a predictor of recurrent AF after RFA. Patients with OSA who undergo CA should be encouraged to be evaluated for treatment with continuous positive airway pressure [88,89]. (See "Clinical presentation and diagnosis of obstructive sleep apnea in adults".) Colchicine Colchicine, another drug with antiinflammatory properties, has been shown to decrease the risk of postoperative AF after cardiac surgery, particularly in patients with post-pericardiotomy syndrome. However, pending additional studies showing benefit, we do not use prophylactic colchicine. (See "Post-cardiac injury syndromes", section on 'Prevention'.) The potential ability of colchicine to reduce the incidence of early recurrent AF after pulmonary vein isolation was evaluated in a study of 206 individuals with paroxysmal AF who were randomly assigned to colchicine 0.5 mg twice daily or placebo beginning on the day of CA and continuing for three months [90]. After follow-up of about 15 months, there https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 15/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate was a lower recurrence rate of AF in patients taking colchicine (31.1 versus 49.5 percent; odds ratio [OR] 0.46, 95% CI 0.26-0.81). Angiotensin inhibition The data are mixed as to whether angiotensin converting enzyme inhibitors/angiotensin II receptor blockers reduce AF after CA procedures. This issue is discussed elsewhere. (See "ACE inhibitors, angiotensin receptor blockers, and atrial fibrillation", section on 'Catheter ablation of atrial fibrillation'.) Periprocedural weight reduction Some studies suggest that periprocedural weight reduction may be a helpful adjunct to CA. Pre-procedure weight reduction In a retrospective study of 600 patients, weight reduction before CA was associated with reduced AF occurrence [91]. Freedom from AF was observed in 420 patients (70 percent) at 15 months. Percent weight loss during the year before CA independently predicted freedom from AF through the next 15 months (OR 1.17, 95% CI 1.11-1.23). Post-procedure weight reduction The SORT-AF Study compared one-year AF burden in patients with obesity participating in a weight loss program versus usual care after CA [92]. The intervention group had a small reduction in weight loss (5 versus 1 kg in controls). AF burden (measured with implantable loop recorder) after ablation did not differ between the two groups (OR 1.14, 95% CI 0.37-3.6). However, a reduction in body mass index was associated with a decrease in AF recurrence in persistent compared with paroxysmal AF patients. FOLLOW-UP Surveillance for recurrence of atrial arrhythmias is important in patients who have undergone CA. We agree with the joint Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society expert consensus statement of catheter and surgical ablation of AF [65], which recommends the following: First visit with electrophysiologist at a minimum of three months, and then every six months for at least two years. Electrocardiograms (ECGs) at all visits; symptomatic (eg, palpitations) patients should be evaluated with some form of event monitoring. The optimal method for screening for episodes of AF after ablation is not known. In the above studies, late recurrent AF was detected by patient symptoms, serial ECGs, 24- to 48-hour Holter https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 16/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate monitoring, and implantable cardiac monitor [10,16,93,94]. Rhythm transmitters were also used in the first few months [94]. With the exceptions of implantable cardiac monitor, preexisting dual-chamber pacemaker, or implantable cardioverter-defibrillator with AF detection capabilities, these methods may underestimate the incidence of recurrence due to sampling error [95]. In addition, as has been well demonstrated, patients with AF have a high rate of asymptomatic episodes. (See "Paroxysmal atrial fibrillation", section on 'Natural history' and 'Efficacy' above.) MANAGEMENT OF RECURRENCE Some patients with symptomatic AF after CA are candidates for a repeat procedure. The decision to do so is usually based on a patient's assessment of the potential benefit and risks. Other patients may choose a trial of antiarrhythmic drug therapy to reduce symptoms. The most common reason for recurrence of paroxysmal AF is reconnection of previously ablated electrically active tissue. Based upon the recurrence rates of AF after ablation, many patients are candidates for repeat ablation. We tell our patients that the success rate is in the range of 50 to 85 percent for a single procedure based primarily on AF type and anatomy, and that about 20 percent of patients have at least a second procedure. Success rates after a second procedure can be as high as 90 percent. Some experts and patients have agreed to repeat the procedure a third time. Patients with a history of persistent AF have a lower success rate and are less often felt to be good candidates for repeat procedures. The issue of whether patients with AF recurrence should undergo a repeat procedure or be placed on antiarrhythmic drug therapy was addressed in a study that randomly assigned 154 patients with symptomatic, paroxysmal AF recurrence to either repeat ablation or antiarrhythmic drugs [96]. During three-year follow-up, fewer patients in the repeat ablation group demonstrated AF progression, defined as an increase in AF burden >30 percent relative to baseline based on insertable cardiac monitor (also sometimes referred to as implantable cardiac monitor or implantable loop recorder) data or development of persistent AF (25 versus 79 percent; p<0.01). Despite limitations of this study, it supports our approach of offering a second ablation procedure to most patients. CONTRAINDICATIONS While there are few absolute contraindications, the risks and benefits of AF ablation should be carefully considered in each patient. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 17/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Contraindications to AF ablation include preexisting left atrial or left atrial appendage thrombus, inability to safely administer anticoagulation during or after the procedure, inability to tolerate sedation, patients with atrial septal defect closure devices in whom transseptal access cannot be performed, and those with interruption of the inferior vena cava. While not contraindicated, ablations performed on those with very long-standing persistent AF (ie, >2 years), severe mitral stenosis or regurgitation, or large left atria are expected to have lower success rates. (See 'Predictors of recurrence' above.) SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Atrial fibrillation" and "Society guideline links: Arrhythmias in adults".) INFORMATION FOR PATIENTS UpToDate offers two types of patient education materials, The Basics and Beyond the Basics. th th The Basics patient education pieces are written in plain language, at the 5 to 6 grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more th th sophisticated, and more detailed. These articles are written at the 10 to 12 grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon. Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on patient info and the keyword(s) of interest.) Beyond the Basics topics (see "Patient education: Atrial fibrillation (Beyond the Basics)") SUMMARY AND RECOMMENDATIONS Role of catheter ablation (CA) CA for atrial fibrillation (AF) leads to symptom improvement in many patients. However, it has not convincingly been shown to decrease the risks of embolization (eg, stroke) or death. (See 'Efficacy' above.) https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 18/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Efficacy Current techniques for CA should lead to one-year freedom from symptomatic AF while off antiarrhythmic drug therapy in about 75 to 90 percent of patients with drug- resistant paroxysmal AF and no significant structural heart disease. (See 'Efficacy' above.) Complications Important complications of CA include death, cardiac tamponade, stroke, vascular trauma, and phrenic nerve palsy ( table 1). Specific signs and symptoms can help identify complications ( table 2). (See 'Complications' above.) Recurrence For patients who have recurrent AF after a first ablation, there are two reasonable management strategies: a clinical trial of an antiarrhythmic agent or proceeding directly to a second ablation. Patients may have a preference for one or the other. (See 'Management of recurrence' above.) 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Randomized study comparing combined pulmonary vein-left atrial junction disconnection and cavotricuspid isthmus ablation versus pulmonary vein-left atrial junction disconnection alone in patients presenting with typical atrial flutter and atrial fibrillation. Circulation 2003; 108:2479. 39. Waldo AL, Cooper TB. Spontaneous onset of type I atrial flutter in patients. J Am Coll Cardiol 1996; 28:707. 40. Waldo AL. Mechanisms of atrial flutter and atrial fibrillation: distinct entities or two sides of a coin? Cardiovasc Res 2002; 54:217. 41. Steinberg JS, Romanov A, Musat D, et al. Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: the PReVENT AF Study I. Heart Rhythm 2014; 11:1567. 42. Lang CC, Santinelli V, Augello G, et al. Transcatheter radiofrequency ablation of atrial fibrillation in patients with mitral valve prostheses and enlarged atria: safety, feasibility, and efficacy. J Am Coll Cardiol 2005; 45:868. 43. Nair M, Shah P, Batra R, et al. Chronic atrial fibrillation in patients with rheumatic heart disease: mapping and radiofrequency ablation of flutter circuits seen at initiation after cardioversion. Circulation 2001; 104:802. 44. Steinberg JS, Shabanov V, Ponomarev D, et al. Effect of Renal Denervation and Catheter Ablation vs Catheter Ablation Alone on Atrial Fibrillation Recurrence Among Patients With Paroxysmal Atrial Fibrillation and Hypertension: The ERADICATE-AF Randomized Clinical Trial. JAMA 2020; 323:248. 45. Bertaglia E, Stabile G, Pappone A, et al. Updated national multicenter registry on procedural safety of catheter ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2013; 24:1069. 46. Pappone C, Oral H, Santinelli V, et al. Atrio-esophageal fistula as a complication of percutaneous transcatheter ablation of atrial fibrillation. Circulation 2004; 109:2724. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 22/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate 47. Scanavacca MI, D' vila A, Parga J, Sosa E. Left atrial-esophageal fistula following radiofrequency catheter ablation of atrial fibrillation. J Cardiovasc Electrophysiol 2004; 15:960. 48. Shah D, Dumonceau JM, Burri H, et al. Acute pyloric spasm and gastric hypomotility: an extracardiac adverse effect of percutaneous radiofrequency ablation for atrial fibrillation. J Am Coll Cardiol 2005; 46:327. 49. Karch MR, Zrenner B, Deisenhofer I, et al. Freedom from atrial tachyarrhythmias after catheter ablation of atrial fibrillation: a randomized comparison between 2 current ablation strategies. Circulation 2005; 111:2875. 50. Oral H, Scharf C, Chugh A, et al. Catheter ablation for paroxysmal atrial fibrillation: segmental pulmonary vein ostial ablation versus left atrial ablation. Circulation 2003; 108:2355. 51. Deshmukh A, Patel NJ, Pant S, et al. In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures. Circulation 2013; 128:2104. 52. Gupta A, Perera T, Ganesan A, et al. Complications of catheter ablation of atrial fibrillation: a systematic review. Circ Arrhythm Electrophysiol 2013; 6:1082. 53. Spragg DD, Dalal D, Cheema A, et al. Complications of catheter ablation for atrial fibrillation: incidence and predictors. J Cardiovasc Electrophysiol 2008; 19:627. 54. Zado E, Callans DJ, Riley M, et al. Long-term clinical efficacy and risk of catheter ablation for atrial fibrillation in the elderly. J Cardiovasc Electrophysiol 2008; 19:621. 55. Cappato R, Calkins H, Chen SA, et al. Prevalence and causes of fatal outcome in catheter ablation of atrial fibrillation. J Am Coll Cardiol 2009; 53:1798. 56. Cappato R, Calkins H, Chen SA, et al. Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circ Arrhythm Electrophysiol 2010; 3:32. 57. Maan A, Shaikh AY, Mansour M, et al. Complications from catheter ablation of atrial fibrillation: a systematic review. Crit Pathw Cardiol 2011; 10:76. 58. Cappato R, Calkins H, Chen SA, et al. Worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circulation 2005; 111:1100. 59. Zeljko HM, Mont L, Sitges M, et al. Entrapment of the circular mapping catheter in the mitral valve in two patients undergoing atrial fibrillation ablation. Europace 2011; 13:132. 60. Kesek M, Englund A, Jensen SM, Jensen-Urstad M. Entrapment of circular mapping catheter in the mitral valve. Heart Rhythm 2007; 4:17. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 23/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate 61. Taylor GW, Kay GN, Zheng X, et al. Pathological effects of extensive radiofrequency energy applications in the pulmonary veins in dogs. Circulation 2000; 101:1736. 62. Saad EB, Marrouche NF, Saad CP, et al. Pulmonary vein stenosis after catheter ablation of atrial fibrillation: emergence of a new clinical syndrome. Ann Intern Med 2003; 138:634. 63. Packer DL, Keelan P, Munger TM, et al. Clinical presentation, investigation, and management of pulmonary vein stenosis complicating ablation for atrial fibrillation. Circulation 2005; 111:546. 64. Qureshi AM, Prieto LR, Latson LA, et al. Transcatheter angioplasty for acquired pulmonary vein stenosis after radiofrequency ablation. Circulation 2003; 108:1336. 65. European Heart Rhythm Association (EHRA), European Cardiac Arrhythmia Scoiety (ECAS), American College of Cardiology (ACC), et al. HRS/EHRA/ECAS expert Consensus Statement on catheter and surgical ablation of atrial fibrillation: recommendations for personnel, policy, procedures and follow-up. A report of the Heart Rhythm Society (HRS) Task Force on catheter and surgical ablation of atrial fibrillation. Heart Rhythm 2007; 4:816. 66. Saad EB, Rossillo A, Saad CP, et al. Pulmonary vein stenosis after radiofrequency ablation of atrial fibrillation: functional characterization, evolution, and influence of the ablation strategy. Circulation 2003; 108:3102. 67. Arentz T, Weber R, Jander N, et al. Pulmonary haemodynamics at rest and during exercise in patients with significant pulmonary vein stenosis after radiofrequency catheter ablation for drug resistant atrial fibrillation. Eur Heart J 2005; 26:1410. 68. Di Biase L, Fahmy TS, Wazni OM, et al. Pulmonary vein total occlusion following catheter ablation for atrial fibrillation: clinical implications after long-term follow-up. J Am Coll Cardiol 2006; 48:2493. 69. Fender EA, Widmer RJ, Hodge DO, et al. Severe Pulmonary Vein Stenosis Resulting From Ablation for Atrial Fibrillation: Presentation, Management, and Clinical Outcomes. Circulation 2016; 134:1812. 70. Gaita F, Caponi D, Pianelli M, et al. Radiofrequency catheter ablation of atrial fibrillation: a cause of silent thromboembolism? Magnetic resonance imaging assessment of cerebral thromboembolism in patients undergoing ablation of atrial fibrillation. Circulation 2010; 122:1667. 71. Schrickel JW, Lickfett L, Lewalter T, et al. Incidence and predictors of silent cerebral embolism during pulmonary vein catheter ablation for atrial fibrillation. Europace 2010; 12:52. 72. Herm J, Fiebach JB, Koch L, et al. Neuropsychological effects of MRI-detected brain lesions after left atrial catheter ablation for atrial fibrillation: long-term results of the MACPAF study. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 24/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Circ Arrhythm Electrophysiol 2013; 6:843. 73. Verma A, Debruyne P, Nardi S, et al. Evaluation and reduction of asymptomatic cerebral embolism in ablation of atrial fibrillation, but high prevalence of chronic silent infarction: results of the evaluation of reduction of asymptomatic cerebral embolism trial. Circ Arrhythm Electrophysiol 2013; 6:835. 74. Haines DE. ERACEing the risk of cerebral embolism from atrial fibrillation ablation. Circ Arrhythm Electrophysiol 2013; 6:827. 75. Medi C, Evered L, Silbert B, et al. Subtle post-procedural cognitive dysfunction after atrial fibrillation ablation. J Am Coll Cardiol 2013; 62:531. 76. Sharma PS, Padala SK, Gunda S, et al. Vascular complications during catheter ablation of cardiac arrhythmias: A comparison between vascular ultrasound guided access and conventional vascular access. J Cardiovasc Electrophysiol 2016; 27:1160. 77. Waigand J, Uhlich F, Gross CM, et al. Percutaneous treatment of pseudoaneurysms and arteriovenous fistulas after invasive vascular procedures. Catheter Cardiovasc Interv 1999; 47:157. 78. Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary. J Arrhythm 2017; 33:369. 79. Chugh A, Oral H, Good E, et al. Catheter ablation of atypical atrial flutter and atrial tachycardia within the coronary sinus after left atrial ablation for atrial fibrillation. J Am Coll Cardiol 2005; 46:83. 80. Kanagaratnam L, Tomassoni G, Schweikert R, et al. Empirical pulmonary vein isolation in patients with chronic atrial fibrillation using a three-dimensional nonfluoroscopic mapping system: long-term follow-up. Pacing Clin Electrophysiol 2001; 24:1774. 81. Cummings JE, Schweikert R, Saliba W, et al. Left atrial flutter following pulmonary vein antrum isolation with radiofrequency energy: linear lesions or repeat isolation. J Cardiovasc Electrophysiol 2005; 16:293. 82. Gerstenfeld EP, Callans DJ, Dixit S, et al. Mechanisms of organized left atrial tachycardias occurring after pulmonary vein isolation. Circulation 2004; 110:1351. 83. Dumonceau JM, Giostra E, Bech C, et al. Acute delayed gastric emptying after ablation of atrial fibrillation: treatment with botulinum toxin injection. Endoscopy 2006; 38:543. 84. Roberts-Thomson KC, Steven D, Seiler J, et al. Coronary artery injury due to catheter ablation in adults: presentations and outcomes. Circulation 2009; 120:1465. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 25/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate 85. Sieira J, Chierchia GB, Di Giovanni G, et al. One year incidence of iatrogenic atrial septal defect after cryoballoon ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2014; 25:11. 86. Koyama T, Sekiguchi Y, Tada H, et al. Comparison of characteristics and significance of immediate versus early versus no recurrence of atrial fibrillation after catheter ablation. Am J Cardiol 2009; 103:1249. 87. Koyama T, Tada H, Sekiguchi Y, et al. Prevention of atrial fibrillation recurrence with corticosteroids after radiofrequency catheter ablation: a randomized controlled trial. J Am Coll Cardiol 2010; 56:1463. 88. Fein AS, Shvilkin A, Shah D, et al. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol 2013; 62:300. 89. Naruse Y, Tada H, Satoh M, et al. Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy. Heart Rhythm 2013; 10:331. 90. Deftereos S, Giannopoulos G, Efremidis M, et al. Colchicine for prevention of atrial fibrillation recurrence after pulmonary vein isolation: mid-term efficacy and effect on quality of life. Heart Rhythm 2014; 11:620. 91. Peigh G, Wasserlauf J, Vogel K, et al. Impact of pre-ablation weight loss on the success of catheter ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2021; 32:2097. 92. Gessler N, Willems S, Steven D, et al. Supervised Obesity Reduction Trial for AF ablation patients: results from the SORT-AF trial. Europace 2021; 23:1548. 93. Pappone C, Rosanio S, Augello G, et al. Mortality, morbidity, and quality of life after circumferential pulmonary vein ablation for atrial fibrillation: outcomes from a controlled nonrandomized long-term study. J Am Coll Cardiol 2003; 42:185. 94. Verma A, Wazni OM, Marrouche NF, et al. Pre-existent left atrial scarring in patients undergoing pulmonary vein antrum isolation: an independent predictor of procedural failure. J Am Coll Cardiol 2005; 45:285. 95. Senatore G, Stabile G, Bertaglia E, et al. Role of transtelephonic electrocardiographic monitoring in detecting short-term arrhythmia recurrences after radiofrequency ablation in patients with atrial fibrillation. J Am Coll Cardiol 2005; 45:873. 96. Pokushalov E, Romanov A, De Melis M, et al. Progression of atrial fibrillation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation: a randomized comparison of drug therapy versus reablation. Circ Arrhythm Electrophysiol 2013; 6:754. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 26/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Topic 949 Version 66.0 https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 27/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate GRAPHICS Signs and symptoms of complications of catheter ablation to prevent atrial fibrillation within a month post-ablation Sign/symptom Differential Suggested evaluation

American College of Cardiology (ACC), et al. HRS/EHRA/ECAS expert Consensus Statement on catheter and surgical ablation of atrial fibrillation: recommendations for personnel, policy, procedures and follow-up. A report of the Heart Rhythm Society (HRS) Task Force on catheter and surgical ablation of atrial fibrillation. Heart Rhythm 2007; 4:816. 66. Saad EB, Rossillo A, Saad CP, et al. Pulmonary vein stenosis after radiofrequency ablation of atrial fibrillation: functional characterization, evolution, and influence of the ablation strategy. Circulation 2003; 108:3102. 67. Arentz T, Weber R, Jander N, et al. Pulmonary haemodynamics at rest and during exercise in patients with significant pulmonary vein stenosis after radiofrequency catheter ablation for drug resistant atrial fibrillation. Eur Heart J 2005; 26:1410. 68. Di Biase L, Fahmy TS, Wazni OM, et al. Pulmonary vein total occlusion following catheter ablation for atrial fibrillation: clinical implications after long-term follow-up. J Am Coll Cardiol 2006; 48:2493. 69. Fender EA, Widmer RJ, Hodge DO, et al. Severe Pulmonary Vein Stenosis Resulting From Ablation for Atrial Fibrillation: Presentation, Management, and Clinical Outcomes. Circulation 2016; 134:1812. 70. Gaita F, Caponi D, Pianelli M, et al. Radiofrequency catheter ablation of atrial fibrillation: a cause of silent thromboembolism? Magnetic resonance imaging assessment of cerebral thromboembolism in patients undergoing ablation of atrial fibrillation. Circulation 2010; 122:1667. 71. Schrickel JW, Lickfett L, Lewalter T, et al. Incidence and predictors of silent cerebral embolism during pulmonary vein catheter ablation for atrial fibrillation. Europace 2010; 12:52. 72. Herm J, Fiebach JB, Koch L, et al. Neuropsychological effects of MRI-detected brain lesions after left atrial catheter ablation for atrial fibrillation: long-term results of the MACPAF study. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 24/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Circ Arrhythm Electrophysiol 2013; 6:843. 73. Verma A, Debruyne P, Nardi S, et al. Evaluation and reduction of asymptomatic cerebral embolism in ablation of atrial fibrillation, but high prevalence of chronic silent infarction: results of the evaluation of reduction of asymptomatic cerebral embolism trial. Circ Arrhythm Electrophysiol 2013; 6:835. 74. Haines DE. ERACEing the risk of cerebral embolism from atrial fibrillation ablation. Circ Arrhythm Electrophysiol 2013; 6:827. 75. Medi C, Evered L, Silbert B, et al. Subtle post-procedural cognitive dysfunction after atrial fibrillation ablation. J Am Coll Cardiol 2013; 62:531. 76. Sharma PS, Padala SK, Gunda S, et al. Vascular complications during catheter ablation of cardiac arrhythmias: A comparison between vascular ultrasound guided access and conventional vascular access. J Cardiovasc Electrophysiol 2016; 27:1160. 77. Waigand J, Uhlich F, Gross CM, et al. Percutaneous treatment of pseudoaneurysms and arteriovenous fistulas after invasive vascular procedures. Catheter Cardiovasc Interv 1999; 47:157. 78. Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary. J Arrhythm 2017; 33:369. 79. Chugh A, Oral H, Good E, et al. Catheter ablation of atypical atrial flutter and atrial tachycardia within the coronary sinus after left atrial ablation for atrial fibrillation. J Am Coll Cardiol 2005; 46:83. 80. Kanagaratnam L, Tomassoni G, Schweikert R, et al. Empirical pulmonary vein isolation in patients with chronic atrial fibrillation using a three-dimensional nonfluoroscopic mapping system: long-term follow-up. Pacing Clin Electrophysiol 2001; 24:1774. 81. Cummings JE, Schweikert R, Saliba W, et al. Left atrial flutter following pulmonary vein antrum isolation with radiofrequency energy: linear lesions or repeat isolation. J Cardiovasc Electrophysiol 2005; 16:293. 82. Gerstenfeld EP, Callans DJ, Dixit S, et al. Mechanisms of organized left atrial tachycardias occurring after pulmonary vein isolation. Circulation 2004; 110:1351. 83. Dumonceau JM, Giostra E, Bech C, et al. Acute delayed gastric emptying after ablation of atrial fibrillation: treatment with botulinum toxin injection. Endoscopy 2006; 38:543. 84. Roberts-Thomson KC, Steven D, Seiler J, et al. Coronary artery injury due to catheter ablation in adults: presentations and outcomes. Circulation 2009; 120:1465. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 25/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate 85. Sieira J, Chierchia GB, Di Giovanni G, et al. One year incidence of iatrogenic atrial septal defect after cryoballoon ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2014; 25:11. 86. Koyama T, Sekiguchi Y, Tada H, et al. Comparison of characteristics and significance of immediate versus early versus no recurrence of atrial fibrillation after catheter ablation. Am J Cardiol 2009; 103:1249. 87. Koyama T, Tada H, Sekiguchi Y, et al. Prevention of atrial fibrillation recurrence with corticosteroids after radiofrequency catheter ablation: a randomized controlled trial. J Am Coll Cardiol 2010; 56:1463. 88. Fein AS, Shvilkin A, Shah D, et al. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol 2013; 62:300. 89. Naruse Y, Tada H, Satoh M, et al. Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy. Heart Rhythm 2013; 10:331. 90. Deftereos S, Giannopoulos G, Efremidis M, et al. Colchicine for prevention of atrial fibrillation recurrence after pulmonary vein isolation: mid-term efficacy and effect on quality of life. Heart Rhythm 2014; 11:620. 91. Peigh G, Wasserlauf J, Vogel K, et al. Impact of pre-ablation weight loss on the success of catheter ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2021; 32:2097. 92. Gessler N, Willems S, Steven D, et al. Supervised Obesity Reduction Trial for AF ablation patients: results from the SORT-AF trial. Europace 2021; 23:1548. 93. Pappone C, Rosanio S, Augello G, et al. Mortality, morbidity, and quality of life after circumferential pulmonary vein ablation for atrial fibrillation: outcomes from a controlled nonrandomized long-term study. J Am Coll Cardiol 2003; 42:185. 94. Verma A, Wazni OM, Marrouche NF, et al. Pre-existent left atrial scarring in patients undergoing pulmonary vein antrum isolation: an independent predictor of procedural failure. J Am Coll Cardiol 2005; 45:285. 95. Senatore G, Stabile G, Bertaglia E, et al. Role of transtelephonic electrocardiographic monitoring in detecting short-term arrhythmia recurrences after radiofrequency ablation in patients with atrial fibrillation. J Am Coll Cardiol 2005; 45:873. 96. Pokushalov E, Romanov A, De Melis M, et al. Progression of atrial fibrillation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation: a randomized comparison of drug therapy versus reablation. Circ Arrhythm Electrophysiol 2013; 6:754. https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 26/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Topic 949 Version 66.0 https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 27/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate GRAPHICS Signs and symptoms of complications of catheter ablation to prevent atrial fibrillation within a month post-ablation Sign/symptom Differential Suggested evaluation Back pain Musculoskeletal, retroperitoneal hematoma Physical exam, CT imaging Chest pain Pericarditis, pericardial effusion, Physical exam, chest coronary stenosis (ablation radiograph, ECG, related), pulmonary vein stenosis, musculoskeletal (after echocardiogram, stress test, cardiac catheterization, chest CT cardioversion), worsening reflux Cough Infectious process, bronchial irritation (mechanical, Physical exam, chest radiograph, chest CT cryoballoon), pulmonary vein stenosis Dysphagia Esophageal irritation (related to Physical exam, chest CT, MRI transesophageal echocardiography), atrioesophageal fistula Early satiety, nausea Gastric denervation Physical exam, gastric emptying study Fever Infectious process, pericarditis, atrioesophageal fistula Physical exam, chest radiograph, chest CT, urinalysis, laboratory blood work Fever, dysphagia, neurological symptoms Atrial esophageal fistula Physical exam, laboratory blood work, chest CT or MRI; avoid endoscopy with air insufflation Groin pain Pseudoaneurysm, AV fistula, hematoma Ultrasound of the groin, laboratory blood work; consider CT scan if ultrasound negative Hypotension Pericardial effusion/tamponade, bleeding, sepsis, persistent Echocardiography, laboratory blood work vagal reaction Hemoptysis Pulmonary vein stenosis or Chest radiograph, chest CT or occlusion, pneumonia MR scan, VQ scan Neurological symptoms Cerebral embolic event, atrial Physical exam, brain imaging, esophageal fistula chest CT or MRI https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 28/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Shortness of breath Volume overload, pneumonia, Physical exam, chest pulmonary vein stenosis, radiograph, chest CT, laboratory phrenic nerve injury blood work CT: computed tomography; ECG: electrocardiogram; MRI: magnetic resonance imaging; AV: atrioventricular. Adapted from: Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial brillation: Executive summary. J Interv Card Electrophysiol 2017; 50:1. Available at: https://link.springer.com/article/10.1007%2Fs10840-017-0277-z. Copyright 2017 The Authors. Reproduced under the terms of the Creative Commons Attribution License 4.0. Graphic 127127 Version 1.0 https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 29/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Intraprocedural risks of ablation for atrial fibrillation Complication Incidence Diagnostic testing Air embolism <1% Nothing or cardiac catheterization Asymptomatic cerebral emboli 2 to 15% Brain MRI Cardiac tamponade 0.2 to 5% Echocardiography Coronary stenosis/occlusion <0.1% Cardiac catheterization Death <0.1 to 0.4% N/A Mitral valve entrapment <0.1% Echocardiography Permanent phrenic nerve paralysis 0 to 0.4% Chest radiograph, sniff test Radiation injury <0.1% None Stroke or TIA 0 to 2% Head CT/MRI, cerebral angiography Vascular complications 0.2 to 1.5% Vascular ultrasound, CT scan MRI: magnetic resonance imaging; TIA: transient ischemic attack; CT: computed tomography. Adapted from: Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial brillation: Executive summary. J Interv Card Electrophysiol 2017; 50:1. Available at: https://link.springer.com/article/10.1007%2Fs10840-017-0277-z. Copyright 2017 The Authors. Reproduced under the terms of the Creative Commons Attribution License 4.0. Graphic 127125 Version 1.0 https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 30/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate CHADS score, thromboembolic risk, and effect of warfarin anticoagulation 2 Clinical parameter Points Congestive heart failure (any history) 1 Hypertension (prior history) 1 Age 75 years 1 Diabetes mellitus 1 Secondary prevention in patients with a prior ischemic stroke or a transient 2 ischemic attack; most experts also include patients with a systemic embolic event Events per 100 person-years* CHADS score 2 NNT Warfarin No warfarin 0 0.25 0.49 417 1 0.72 1.52 125 2 1.27 2.50 81 3 2.20 5.27 33 4 2.35 6.02 27 5 or 6 4.60 6.88 44 NNT: number needed to treat to prevent 1 stroke per year with warfarin. The CHADS score estimates the risk of stroke, which is defined as focal neurologic signs or symptoms that persist for more than 24 hours and that cannot be explained by hemorrhage, trauma, 2 or other factors, or peripheral embolization, which is much less common. Transient ischemic attacks are not included. All differences between warfarin and no warfarin groups are statistically significant, except for a trend with a CHADS score of 0. Patients are considered to be at low risk with a score of 0, at intermediate risk with a score of 1 or 2, and at high risk with a score 3. One exception is that most experts would consider patients with a prior ischemic stroke, transient ischemic attack, or 2 systemic embolic event to be at high risk, even if they had no other risk factors and, therefore, a score of 2. However, the great majority of these patients have some other risk factor and a score of at least 3. Data from: Go AS, Hylek EM, Chang Y, et al. Anticoagulation therapy for stroke prevention in atrial brillation: how well do randomized trials translate into clinical practice? JAMA 2003; 290:2685; and CHADS2 score from Gage BF, Waterman AD, Shannon W, et al. Validation of clinical classi cation schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA 2001; 285:2864. Graphic 61615 Version 8.0 https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 31/32 7/5/23, 8:10 AM Atrial fibrillation: Catheter ablation - UpToDate Contributor Disclosures Rod Passman, MD, MSCE Grant/Research/Clinical Trial Support: Abbott [Ablation]; AHA [Ablation]; NIH [Stroke prevention]. Consultant/Advisory Boards: Abbott [Ablation]; iRhythm [Monitoring]; Janssen [Atrial fibrillation detection]; Medtronic [Implantable cardiac monitors]. Speaker's Bureau: iRhythm [Monitoring]. All of the relevant financial relationships listed have been mitigated. Bradley P Knight, MD, FACC Grant/Research/Clinical Trial Support: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; MDT [Electrophysiology]; Philips [Electrophysiology]. Consultant/Advisory Boards: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; CVRx [Heart failure]; MDT [Electrophysiology]; Philips [Electrophysiology]; Sanofi [Arrhythmias]. Speaker's Bureau: Abbott [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Transeptal catheterization]; BSCI [Electrophysiology]; MDT [Electrophysiology]. All of the relevant financial relationships listed have been mitigated. N A Mark Estes, III, MD Consultant/Advisory Boards: Boston Scientific [Arrhythmias]; Medtronic [Arrhythmias]. All of the relevant financial relationships listed have been mitigated. Nisha Parikh, MD, MPH No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/atrial-fibrillation-catheter-ablation/print 32/32

7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate Official reprint from UpToDate www.uptodate.com 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved. Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists : Rod Passman, MD, MSCE : Bradley P Knight, MD, FACC, N A Mark Estes, III, MD : Nisha Parikh, MD, MPH All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Jun 2023. This topic last updated: Jun 13, 2022. INTRODUCTION The primary trigger for most episodes of atrial fibrillation (AF) is an electrical discharge(s) within one of the four pulmonary veins (see "Mechanisms of atrial fibrillation", section on 'Triggers of AF'). The cornerstone of any procedure aimed at reducing AF burden is the electrical isolation of the pulmonary veins so that these discharges do not trigger the initiation of AF. In those with persistent and longstanding persistent AF, and in some patients with paroxysmal AF, additional areas, often in one or both of the atria or surrounding structures, are targeted for ablation, as they may also serve as a source of AF triggers or maintenance. Catheter ablation (CA) is the procedure that is used to prevent the initiation of AF by electrically isolating these triggers from the rest of the atrial chamber tissue. This topic is intended to be viewed primarily by non-electrophysiologists. Electrophysiologists may be more interested in other topics: (See "Overview of catheter ablation of cardiac arrhythmias".) (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy".) (See "Atrial fibrillation: Catheter ablation".) (See "Invasive diagnostic cardiac electrophysiology studies".) https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 1/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate (See "Catheter ablation to prevent recurrent atrial fibrillation: Anticoagulation".) PATIENT SELECTION A major clinical goal of CA is a reduction in AF-related symptoms. CA is superior to medical therapy at improving quality of life. Therefore, it is generally reserved for individuals with symptoms attributable to the arrhythmia, which most often include palpitations, shortness of breath, or generalized fatigue [1,2]. Even if they have no AF-related symptoms, older individuals with early AF (duration <1 year) and additional cardiovascular conditions also benefit from therapies aimed at maintaining sinus rhythm; these therapies include CA [3]. (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy", section on 'Recommendations of others'.) Patients should be considered for ablation for AF after the history and physical exam have been reviewed and there is documentation of symptomatic correlation with AF on electrocardiogram (ECG) or other forms of monitoring. Modifiable risk factors including obesity, excessive alcohol intake, and sleep apnea should be addressed, as they are important components of AF treatment and impact the success of any rhythm control intervention [4-8]. AF CA may be appropriate in the following groups: Patients with paroxysmal or persistent AF who have tried a class I or III antiarrhythmic drug ablation can be considered if such medications are either unsuccessful or are not tolerated. Some individuals may choose ablation as first-line therapy. For patients with long-standing persistent AF, a trial of one or more class I or III antiarrhythmic drugs is recommended. Ablation as first-line therapy can be considered in those with contraindications to drugs. Asymptomatic younger individuals and patients with heart failure due to reduced ejection fraction may also benefit from ablation [9,10]. We do not perform CA in: Individuals who are too frail to safely undergo the procedure. Patients with a left atrial appendage thrombus. Individuals with bleeding diathesis who cannot receive intra- and postprocedural anticoagulation. PREPROCEDURAL PREPARATION https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 2/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate Once a patient has been selected for AF ablation, the clinician performing the procedure or their designee should obtain informed consent from the patient. This involves shared decision- making after discussing the indications, benefits, risks, and alternatives of the planned procedure. Sedation options include general anesthesia that requires an endotracheal tube or monitored anesthesia care with sedation but not requiring intubation. Most procedures are performed under general anesthesia. Medication management Most physicians performing ablation will discontinue antiarrhythmic drugs prior to the ablation with the rationale that it may help to identify the triggers of the AF at the time of the procedure. We acknowledge that many other electrophysiologists will continue them. There are no well-performed studies to guide practice. With regard to oral anticoagulation, randomized trials have demonstrated superior efficacy and safety of uninterrupted anticoagulation throughout the ablation procedure compared with temporary discontinuation of anticoagulation and bridging with low molecular weight heparin. Most operators, including the authors, perform the procedure on uninterrupted or minimally interrupted direct-acting oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) such as warfarin. A meta-analysis of 17,434 patients from 12 observational trials and one randomized trial compared uninterrupted warfarin with interrupted warfarin and heparin bridging at the time of AF ablation. Uninterrupted warfarin was associated with significant reductions in stroke and major and minor bleeding [11]. Studies have shown that patients on uninterrupted DOACs have either lower (dabigatran, edoxaban [12,13]) or similar (rivaroxaban, apixaban) [14,15] bleeding risks compared with those on uninterrupted VKA. Studies of DOACS with lower bleeding risks compared with VKA: The RE-CIRCUIT trial randomized 704 patients undergoing AF ablation to uninterrupted dabigatran or VKA. The incidence of major bleeding events during and up to eight weeks after ablation was lower with dabigatran than with warfarin (1.6 versus 6.9 percent) [12]. In a trial of 614 patients undergoing CA, participants were randomly assigned to uninterrupted edoxaban or VKA. Major bleeds were nonsignificantly lower in persons assigned to edoxaban compared with VKA (0.2 versus 2 percent; hazard ratio 0.16; 95% CI 0.02-1.73) [13]. Studies of DOACS with similar bleeding risks compared with VKA: https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 3/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate In a trial of rivaroxaban or VKA in people undergoing AF ablation, bleeding events were similar in the two study arms [14]. In a trial that compared uninterrupted apixaban with placebo, the rates of clinically significant and major bleeding were also similar for both groups (10.6 versus 9.8 percent) [15]. Imaging All patients with AF, not just those being considered for CA, should undergo transthoracic echocardiography (TTE) to evaluate for factors that may affect treatment including the presence and extent of valvular disease, chamber size, and ventricular function. (See "Atrial fibrillation: Overview and management of new-onset atrial fibrillation", section on 'Echocardiogram'.) Transesophageal echocardiography (TEE), which is superior to TTE for finding atrial thrombus, is often performed within 24 hours prior to ablation since the presence of thrombus in the left atrium or left atrial appendage is a contraindication to AF ablation. Some operators may choose to forego TEE in patients with a low risk of stroke (ie, CHA DS -VASc 1) who are expected to be 2 2 in sinus rhythm at the time of the procedure and who have been and will be maintained on uninterrupted anticoagulation throughout the periprocedural timeframe. Some operators will individualize the need for preprocedure TEE and tend to only perform it in higher-risk patients. Risk factors for left atrial appendage thrombus prior to ablation include hypertrophic cardiomyopathy, ejection fraction <30 percent, persistent or longstanding persistent AF, and elevated CHA DS -VASc score [16]. In a study of 1058 preprocedure TEEs, the rate of detection of 2 2 left atrial thrombus or prethrombus was 1 percent in patients with paroxysmal AF in sinus rhythm and 2 percent for patients with paroxysmal AF who were in AF at the time of the procedure. The risk increased with increasing CHADS score [17]. 2 Computed tomography (CT) or cardiac magnetic resonance imaging (cMRI) may be performed preablation to define the left atrial anatomy, specifically the number, size, and location of the pulmonary veins ( figure 1). Data are emerging to suggest that these imaging techniques are also highly sensitive for left atrial thrombus, and many operators use CT or cMRI to evaluate for left atrial thrombus instead of TEE in low-risk individuals. A comparison of cMRI with TEE to evaluate preablation left atrial appendage thrombus demonstrated 100 percent sensitivity and 99.2 percent specificity for equilibrium phase delayed enhancement CMR with a long inversion time [18]. New high-dimensional mapping catheters used during the procedure can create high- definition structural geometry, and for many operators has obviated the need for preprocedure imaging. PROCEDURAL ISSUES https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 4/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate Ablation for AF is among the most complicated procedures performed by electrophysiologists. The procedure should be performed in centers with experience with complex electrophysiologic procedures and capabilities in managing acute complications. Advancements in procedural technologies and techniques have significantly shortened the duration of ablation procedures for AF. Total procedure time typically ranges from 1.5 to 4 hours [19]. The ablation is performed using uni- or bilateral femoral venous access and transseptal puncture for accessing the left atrium. Anesthesia Ablation for AF is performed in the fasting state with general anesthesia or monitored anesthesia care (MAC) using sedation. In a retrospective cohort study of CA performed under either general anesthesia or conscious sedation, conscious sedation had shorter total procedure times and equivalent success rates compared with general anesthesia [20]. In a retrospective cohort study of CA performed under either general anesthesia or MAC, MAC had shorter total procedure times and equivalent success rates with general anesthesia [19]. Agents typically used for conscious sedation include short-acting benzodiazepines (eg, midazolam) and opioids (eg, fentanyl) in divided doses [21]. The type of anesthesia used for AF ablation procedures is dependent on several variables including the expected complexity and duration of the procedure, energy source being utilized, patient comorbidities, patient preference, and availability of anesthesia support. Patient immobility is important to optimize catheter contact and reduce movement error in the anatomic mapping systems. Paralytics should not be used when testing for phrenic nerve capture during ablation. High frequency ventilation, also called jet ventilation, which utilizes a respiratory rate greater than four times the normal value. (>150 [Vf] breaths per minute) and very small tidal volumes, is used in some centers to aid catheter stability and has been associated with improved outcomes [22]. Intraprocedural medications In addition to anesthetic agents, intravenous heparin is administered throughout the AF ablation procedure to reduce the risk of thrombus formation on the catheters, sheaths, left atrium and left atrial appendage, and at ablation sites. Heparin is administered prior to or immediately after transseptal access has been achieved with a targeted activated clotting time (ACT) of >300 seconds. Target ACT may be reached faster and with lower loading doses in patients undergoing ablation on uninterrupted vitamin K antagonists (VKA) compared with non-vitamin K antagonist oral anticoagulants (NOACs; also referred to as direct acting oral anticoagulants [DOAC]) [23]. Additionally, time to target ACT varies amongst the NOACs, with average time in minutes required to achieve a target ACT of >300 seconds https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 5/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate significantly longer in those receiving uninterrupted dabigatran or apixaban compared with those receiving rivaroxaban [24]. Protamine can be used to reverse anticoagulation at the time of sheath removal post-procedure. Esophageal imaging and temperature monitoring The proximity of the esophagus to the posterior left atrium makes it susceptible to thermal injury (see 'Complications' below). Atrioesophageal fistula, typically occurring one to four weeks post-ablation, is a potentially lethal consequence of AF ablation, with a reported incidence of 0.02 to 0.11 percent. To minimize risk, operators will limit energy delivery in the posterior wall in areas adjacent to the esophagus. As the esophagus can have a highly variable position that can vary throughout the procedure, visualization of the esophagus can be performed using electroanatomic mapping, intracardiac ultrasound (ICE), or barium paste. Many operators use an esophageal temperature probe to assess the effects of ablation on intraluminal temperature, though this practice has not yet been shown to reduce the risk of fistula formation given the low incidence of these events. Given the very low overall incidence of fistula, there have been no randomized data to demonstrate superiority of one esophageal monitoring strategy over another. Consequently, minimization of power delivery to the atrial tissue adjacent to the esophagus or minimization of temperature elevation remain surrogates for procedural safety Vascular ultrasound CA for AF requires multiple sheaths with large diameters in one or both femoral veins in patients receiving oral and intravenous anticoagulation. These issues make vascular complications the most common complications of AF ablation. Access can be obtained through the modified Seldinger approach. Vascular ultrasound has been used for venipuncture guidance and postprocedural evaluation. In a cohort study of 1435 patients undergoing cryoballoon ablation for AF, major clinical events occurred in 1.7 percent of those patients who had their procedure performed without ultrasound guidance versus 0 percent in those that did have ultrasound guidance [25]. In a multicenter, randomized trial, 320 patients were randomized to ultrasound guided versus conventional venipuncture. Major complications were low and not significantly different between groups. Puncture time, inadvertent arterial puncture, and need for extra puncture attempts were all significantly reduced in the ultrasound arm [26]. Intracardiac ultrasound Intracardiac ultrasound allows for real-time imaging of cardiac anatomy. The probe is placed in the right atrium via the inferior vena cava. Common uses of ICE include the identification of intra- and extracardiac anatomic structures such as the esophagus, facilitation of transseptal puncture, guidance of catheter placement, and recognition of https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 6/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate complications including thrombus formation on sheaths and catheters and early recognition of pericardial effusion. Fluoroscopy Mapping and ablation of AF requires precise navigation of catheters within the left atrium and localization of intra- and extracardiac structures. Fluoroscopy is used to assess catheter placement, to visualize catheter movement, and to assess proximity to adjacent structures such as the esophagus when marked by an intraluminal catheter or barium paste. Patient and physician exposure to ionizing radiation during AF ablation are highly variable, and radiation injury to the patient is reported in <0.1 percent of cases. Efforts to reduce patient and physician exposure to ionizing radiation have successfully relied on alternative imaging modalities, including ICE and electroanatomic mapping. (See "Radiation-related risks of imaging".) Electroanatomic mapping Electroanatomic mapping systems combine real-time, detailed information of the anatomy and electrical properties of the cardiac structures under evaluation. These systems (Carto [Biosense Webster], NAVX [Abbott], and Rhythmia [Boston Scientific]) use diagnostic and ablation catheters and navigation patches on the patient's skin to create a three- dimensional anatomical map used to help localize critical sites for ablation. ABLATION TECHNIQUES AND TARGETS Energy sources There are three US Food and Drug Administration (FDA)-approved energy sources for AF ablation: radiofrequency energy, cryothermal energy in the form of cryoballoon, and laser balloon. This issue is discussed in detail elsewhere. (See "Overview of catheter ablation of cardiac arrhythmias", section on 'Energy sources used for ablation'.) The commonly used and approved energy sources for CA are radiofrequency and cryothermal. The efficacy and safety associated with these two energy sources have been found to be similar in multiple studies. This issue is discussed elsewhere. (See "Atrial fibrillation: Catheter ablation", section on 'Comparison of radiofrequency and cryothermal ablation'.) Pulmonary vein isolation Complete electrical isolation of all PVs using circumferential, wide area pulmonary vein isolation (PVI) is the goal of most procedures. The following explains the rationale. The initiation of AF requires a trigger either within or near the atrium (eg, PVs, crista terminalis, superior vena cava), and substrate within the atrium to maintain AF [9] (see "Mechanisms of atrial fibrillation", section on 'Basic atrial electrophysiology'). The anatomic significance of https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 7/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate triggers and substrate differs somewhat, depending upon whether the AF is paroxysmal, persistent, or permanent (see "Paroxysmal atrial fibrillation", section on 'Introduction'). In patients with paroxysmal AF, PV triggers are the primary stimulus in most cases. As AF becomes more persistent, non-PV sources become more important [27]. The following important observations regarding triggers came from early studies of patients with paroxysmal AF and have guided the development of successful ablation techniques for AF [28-30]. AF is commonly triggered by ectopic beats from muscle fibers (fascicles) extending from the left atrium into the PVs ( figure 1). Ectopic foci are localized to the PVs in approximately 90 percent of patients with predominantly structurally normal hearts [31]. Most patients have multiple foci that can act as triggers. Most (94 percent) of the foci are 2 to 4 cm inside the PVs, with the left superior vein being the most common site [28]. The remaining foci are usually in the right or left atrium. The superior vena cava is a much less common site of triggering ectopic beats [28]. Because of these observations, early attempts at ablation targeted these focal ectopic beats within the PV [28]. This approach was limited by: Inconsistent ability to identify the triggering beats during electrophysiology study. Difficulties with precise localization of appropriate ablation sites. The risk of PV stenosis, which can occur following ablation within the PVs. (See "Atrial fibrillation: Catheter ablation".) These limitations lead to the adoption of ablative techniques focused on the complete electrical isolation of all PVs using circumferential wide area PVI. The majority of ablations performed use radiofrequency energy or cryothermy (cryoballoon ablation). Infrared laser received FDA approval in 2018. Circumferential PVI involves the creation of confluent ablation lesions that encircle the ostia of all four PVs, usually in two pairs (ie, a left- and right-sided circles) [32-34]. The goal is to electrically isolate the PVs from the left atrium. For ablation using radiofrequency energy, power, duration, and the catheter contact force determine the size and the depth of the lesion created. It is generally felt that some lesions create edema but not scars, leading to temporary but not permanent ablation, and this ultimately leads to electrical reconnection of the left atrium to the https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 8/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate PVs. Greater power, longer duration, and greater contact force improve the efficacy of the procedure but lead to an increase in complications such as cardiac perforation [35,36]. The efficacy and safety of high-power, short-duration ablation, which creates larger, shallower, and more homogeneous lesions, is under evaluation [37]. Circumferential PVI results in extensive ablation across a wider area of the left atrium. Because of the more extensive ablation, this technique may provide additional methods for preventing AF, including autonomic denervation, elimination of triggering foci outside the PVs, and alteration of the left atrial substrate necessary for perpetuating AF. However, more extensive ablation, particularly in the posterior left atrium, may increase the rate of complications, including the development of left atrial tachycardias or flutters months or years after the ablation. The relative efficacy and safety of these methods are discussed elsewhere. (See "Atrial fibrillation: Catheter ablation", section on 'Efficacy'.) Use of a contact force-sensing catheter We use a contact force-sensing catheter in all patients with AF undergoing radiofrequency CA (RFA). The TOCCASTAR study found that patients who underwent CA with this catheter and who received a higher force ( 10 grams) had significantly lower rates of AF recurrence at one year. Use of adenosine-guided pulmonary vein isolation The administration of intravenous adenosine can be used to unmask dormant conduction at the time of CA. Reconnection rates are high in RFA, with three large studies finding rates of 21 (ADVICE), 27 (UNDER-ATP), and 34 percent [38-40]. The use of adenosine to guide additional CA has been shown to improve arrhythmia-free survival in some studies using RFA. Some technical aspects of the procedure are discussed separately. (See 'Ablation techniques and targets' above.) In the ADVICE study, 534 patients with paroxysmal AF who had failed drug therapy underwent a standard PV isolation procedure using radiofrequency energy [38]. Patients were observed for spontaneous recovery of conduction over 20 minutes to allow for reconnected PVs to be reisolated before adenosine administration. Intravenous adenosine was then given to all patients. The 284 patients in whom dormant conduction (evidence of persistent PV conduction) was unmasked by adenosine were randomly assigned to additional adenosine-guided ablation to abolish dormant conduction or to no additional ablation. Among the 250 patients without dormant conduction, 117 were enrolled in a registry. The primary endpoint of the time to first recurrence of symptomatic electrocardiographically documented atrial tachyarrhythmia was between 91 and 365 days. The following findings were noted: Dormant PV conduction was present in 284 (53 percent) of patients. https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 9/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate Freedom from symptomatic atrial tachycardia occurred more often with adenosine-guided further ablation (69.4 versus 42.3 percent; hazard ratio [HR] 0.44, 95% CI 0.31-0.64). Among patients in the registry, approximately 56 percent remained free from symptomatic atrial tachyarrhythmia. The rate of serious adverse events was similar in both groups. Limitations of this study include lack of generalizability (does not apply to patients undergoing cryoablation), lack of use of force-sensing catheters, which are used by many of our experts, and the use of "dormant connection" as an endpoint rather than AF recurrence. In the UNDER-ATP trial, 2113 patients with paroxysmal, persistent, or long-lasting AF were randomly assigned to either adenosine-guided PV isolation (1112 patients) or conventional PV isolation (1001 patients) [39]. The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 seconds or those requiring repeat ablation, hospital admission, or usage of Vaughan Williams class I or III antiarrhythmic drugs at one year with the blanking period of 90 days post-ablation. Among patients assigned to adenosine-guided PV isolation, adenosine provoked dormant PV conduction in 307 patients (27.6 percent). Additional radiofrequency energy applications successfully eliminated dormant conduction in 302 patients (98.4 percent). At one year, 68.7 percent of patients in the adenosine-guided PV isolation group and 67.1 percent of patients in the conventional PV isolation group were free from the primary endpoint, with no significant difference (adjusted HR 0.89; 95% CI 0.74-1.09; p = 0.25). The results were consistent across all the prespecified subgroups. Also, there was no significant difference in the one-year event-free rates from repeat ablation for any atrial tachyarrhythmia between the groups (adjusted HR 0.83; 95% CI 0.65-1.08; p = 0.16). Based on these studies, the use an adenosine in patients undergoing CA with radiofrequency energy is at the discretion of the operator. Confirmation of complete isolation Unlike many other cardiac ablation procedures, AF does not need to be present or induced at the time of the ablation procedure nor is termination of AF or inability to reinduce the arrhythmia a required endpoint of the procedure. For PVI, acute procedural success is defined as electrical isolation of all PVs [41]. This is defined by entry block or the inability to electrically capture PV myocardial tissue distal to the area of ablation when pacing is performed proximal to the ablation line. To do this, a circular catheter is positioned just distal to the PV ostium for the purpose of recording electrograms within the PVs. Confirmation is attempted after a 30-minute waiting period after isolation. https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 10/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate Some operators also test for exit block, defined by the inability to capture atrial myocardium when pacing is performed within the PV distal to the ablation line. There is a high correlation between AF recurrences and the demonstration of persistent or recurrent conduction between the PVs and left atrium (see "Atrial fibrillation: Catheter ablation", section on 'Efficacy'). Recurrent PV conduction explains most cases of recurrence; it is thought to be due to recovery of function of tissue that has been acutely injured (ie, edema and inflammation) but not permanently scarred. Administration of adenosine has been shown to identify PVs with dormant conduction by transiently restoring excitability and conduction across circumferential ablation lines at risk of reconnection [38]. However, improvements in ablation tools and techniques have significantly reduced the routine use of adenosine. It is used at the discretion of the operator. (See "Atrial fibrillation: Catheter ablation", section on 'Efficacy'.) Ablation targets in persistent atrial fibrillation In contrast to patients with paroxysmal AF, patients with persistent AF (and in particular longstanding persistent AF) often have multiple triggers distributed throughout the atria in addition to triggers within the PV [42]. It is thought that mechanisms that maintain rather than trigger the arrhythmia are more important in these individuals. These observations may explain the reduced efficacy of CA procedures that are limited to PVI in patients with longstanding persistent AF seen in most studies. In these patients, additional lesions are often needed to prevent recurrence of AF. These lesions are often placed anatomically in the left atrial posterior wall and roof, in the left atrial appendage, coronary sinus, or in the right atrium. Additional targets include sites of complex fractionated electrograms and rotors [43,44] (see "Mechanisms of atrial fibrillation", section on 'Mechanisms of atrial fibrillation: triggers and substrates'). Though the goal of additional lesion sets are to modify the AF substrate, these approaches may also result in proarrhythmia through the creation of new reentrant circuits. Data supporting the benefits and optimal approach for the treatment of persistent AF are inconclusive and are often individualized by patient and operator. Additional ablation targets/techniques outside the PVs include: Non-PV triggers (eg, coronary sinus, posterior left atrium, crista terminalis) Complex fractionated electrograms (CFAEs) Linear ablation (LA roof, mitral isthmus) Other thoracic veins (superior vena cava, coronary sinus) Posterior wall isolation Left atrial appendage isolation Ablation of cardiac autonomic nerves (ganglionic plexi) Focal impulse and rotor modulation (FIRM) phase mapping-guided ablation Stepwise approach (PVI, CFAE, linear, coronary sinus) https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 11/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate POSTPROCEDURAL ISSUES After the procedure, patients usually remain supine for a fixed period (usually two to four hours) following sheath removal to promote hemostasis at the venous puncture sites. Vascular closure devices allow for more rapid hemostasis and shorter time to ambulation. Most centers keep patients overnight following the procedure. Same-day discharge has become increasingly common given the shorter procedure times and use of venous closure techniques [45,46]. Post-discharge medications Oral anticoagulation is usually continued [47] for at least two months to ensure that the increased risk of embolization associated with the procedure has returned to a baseline risk, regardless of CHADS VA Sc score. This also allows for adequate time 2 2 to document an absence of recurrence of AF for those patients in whom practitioners and patients are contemplating discontinuing anticoagulation [48]. Importantly, there are no randomized data on the safety of discontinuing anticoagulation post-ablation for patients who have presumably maintained sinus rhythm. The risk of AF recurrence, the recognized proportional increase in the burden of asymptomatic AF, and the uncertainty surrounding the causal association between the arrhythmia itself and stroke all support the recommendation to risk stratify patients for oral anticoagulation use based on CHA DS -VASc no differently than if an 2 2 ablation had not been performed. (See "Catheter ablation to prevent recurrent atrial fibrillation: Anticoagulation", section on 'Postprocedural anticoagulation'.) Antiarrhythmic medications may or may not be continued after the procedure. Our preference is to stop them after the procedure. Patients in whom consideration should be given to continuing them include patients with long-standing persistent AF or patients with debilitating AF symptoms. Post-discharge follow-up At the time of discharge, patients are given instructions on activity and what potential complications to look for. They should refrain from heavy physical activity, including exercise and weight lifting, for the week post-procedure to allow for complete healing of the vascular access sites. Baths should also be avoided for one week to reduce infection risk. In patients without identified post-procedural complications such as vascular access site problems, we wait three months to reevaluate the patient [9] (see 'Complications' below). Patients with potential complications should be seen immediately. Patients who develop symptoms should contact either their primary care physician, general cardiologist, or electrophysiologist to discuss the need for early evaluation. Yearly follow-up with a physician thereafter is also recommended. These ongoing interactions with the medical profession allow the patient's clinical status to be evaluated, including an https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 12/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate assessment of the presence or absence of AF, as well as their stroke risk profile and anticoagulation needs. These interactions also provide an opportunity to focus on the treatment of associated diseases and lifestyle modifications [9]. Routine ECG should be performed at the time of follow-up visits, and more intense monitoring may be performed as dictated by patient symptoms and the clinical impact of AF detection [41]. Evaluation for recurrent atrial fibrillation The primary purpose of the first follow-up visit around the three-month mark is to determine the success of the procedure. Screening for post- procedure AF is discussed separately. (See "Atrial fibrillation: Catheter ablation", section on 'Follow-up'.) In general, we do not evaluate the patient for the presence of AF prior to three months, as early episodes do not necessarily predict the long-term success or failure of the procedure. They can often be managed with antiarrhythmic drugs or cardioversion. Repeat ablation during this time is rarely necessary. During this three-month healing phase, there is resolution of inflammation and consolidation of lesion formation. This time period is referred to in clinical research trials as the "post-procedure blanking period." Anticoagulants are continued throughout this period regardless of the patient's CHA DS -VASc score ( table 1). Antiarrhythmic drugs and/or electrical cardioversion 2 2 are used during this blanking period at the discretion of the treating physician and usually reserved for those with debilitating symptoms or recurrent persistent AF. Success rates The success rate of AF ablation is dependent on multiple factors including patient selection, technique, definition of success, and the intensity and duration of rhythm monitoring post-ablation. For research purposes, the primary endpoint of AF ablation trials is freedom from recurrent AF/ atrial tachycardia (AT) defined as the absence of any recurrent AF/AT >30 seconds without antiarrhythmic drugs. Using this strict definition, the one-year success rate for paroxysmal AF is approximately 70 to 80 percent and 60 to 70 percent for persistent AF at most experienced centers. However, a greater proportion of patients will derive an improvement in AF-related symptoms from ablation, and studies using implantable cardiac monitors or other devices that can record all episodes of AF have shown an AF burden reduction of over 98 percent [49]. (See "Maintenance of sinus rhythm in atrial fibrillation: Catheter ablation versus antiarrhythmic drug therapy", section on 'Patients with prior antiarrhythmic drug treatment'.) Complications Complications are discussed in detail separately. (See "Atrial fibrillation: Catheter ablation", section on 'Complications'.) https://www.uptodate.com/contents/catheter-ablation-for-the-treatment-of-atrial-fibrillation-technical-considerations-for-non-electrophysiologists/print 13/27 7/5/23, 8:11 AM Catheter ablation for the treatment of atrial fibrillation: Technical considerations for non-electrophysiologists - UpToDate SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Atrial fibrillation" and "Society guideline links: Arrhythmias in adults".) INFORMATION FOR PATIENTS UpToDate offers two types of patient education materials, The Basics and Beyond the Basics. th th The Basics patient education pieces are written in plain language, at the 5 to 6 grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more th th sophisticated, and more detailed. These articles are written at the 10 to 12 grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon. Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on patient info and the keyword(s) of interest.) Beyond the Basics topics (see "Patient education: Atrial fibrillation (Beyond the Basics)") SUMMARY AND RECOMMENDATIONS Pulmonary vein origin of atrial fibrillation (AF) The primary trigger for most episodes

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