The Relationship Between Daily Atrial Tachyarrhythmia Burden From Implantable Device Diagnostics and Stroke Risk: The TRENDS Study A Structured Reading Algorithm Improves Telemetric Detection of Atrial Fibrillation After Acute Ischemic Stroke Diagnosis of paroxysmal atrial fibrillation in patients with implanted pacemakers: relationship to symptoms and other variables. Stroke event rates in anticoagulated patients with paroxysmal atrial fibrillation. Frequent Atrial Premature Beats Predict Paroxysmal Atrial Fibrillation in Stroke Patients: An Opportunity for a New Diagnostic Strategy Multicenter randomized study of anticoagulation guided by remote rhythm monitoring in patients with implantable cardioverter-defibrillator and CRT-D devices: Rationale, design, and clinical characteristics of the initially enrolled cohort The IMPACT study. Association between atrial fibrillation and appropriate implantable cardioverter defibrillator therapy: results from a prospective study. Rationale and design of the Apixaban for the Reduction of Thrombo‐Embolism in Patients With Device‐Detected Sub‐Clinical Atrial Fibrillation (ARTESiA) trial Detection of atrial fibrillation in patients with embolic stroke of undetermined source by prolonged monitoring with implantable loop recorders. Detection of atrial high-rate events by continuous Home Monitoring: clinical significance in the heart failure–cardiac resynchronization therapy population Holter monitoring in the diagnosis of stroke mechanism. Focused 2012 update of the Canadian Cardiovascular Society atrial fibrillation guidelines: recommendations for stroke prevention and rate/rhythm control. Long-term risk of recurrent atrial fibrillation as documented by an implantable monitoring device: implications for optimal patient care. Prognostic importance of atrial fibrillation in implantable cardioverter-defibrillator patients. Detection of atrial fibrillation in patients with acute stroke. Noninvasive Cardiac Event Monitoring to Detect Atrial Fibrillation After Ischemic Stroke: A Randomized, Controlled Trial A prospective, multicenter evaluation of ablating complex fractionated electrograms (CFEs) during atrial fibrillation (AF) identified by an automated mapping algorithm: acute effects on AF and efficacy as an adjuvant strategy.
Background —It is unknown if brief episodes of device-detected atrial fibrillation ( AF ) increase thromboembolic event ( TE ) risk . Methods and Results —TRENDS was a prospect i ve , observational study enrolling patients with ≥1 stroke risk factor ( heart failure , hypertension , age ≥65 years , diabetes , or prior TE ) receiving pacemakers or defibrillators that monitor atrial tachycardia (AT)/AF burden ( defined as the longest total AT/AF duration on any given day during the prior 30-day period ) . This time-varying exposure was up date d daily during follow-up and related to TE risk . Annualized TE rates were determined according to AT/AF burden subsets : zero , low ( < 5.5 hours [ median duration of subsets with nonzero burden ] ) , and high ( ≥5.5 hours ) . A multivariate Cox model provided hazard ratios including terms for stroke risk factors and time-varying AT/AF burden and antithrombotic therapy . Patients ( n=2486 ) had at least 30 days of device data for analysis . During a mean follow-up of 1.4 years , annualized TE risk ( including transient ischemic attacks ) was 1.1 % for zero , 1.1 % for low , and 2.4 % for high burden subsets of 30-day windows . Compared with zero burden , adjusted hazard ratios ( 95 % CIs ) in the low and high burden subsets were 0.98 ( 0.34 to 2.82 , P=0.97 ) and 2.20 ( 0.96 to 5.05 , P=0.06 ) , respectively . Conclusions —The TE rate was low compared with patients with traditional AF with similar risk profiles . The data suggest that TE risk is a quantitative function of AT/AF burden . AT/AF burden ≥5.5 hours on any of 30 prior days appeared to double TE risk . Additional studies are needed to more precisely investigate the relationship between stroke risk and AT/AF burden Background and Purpose — Anticoagulation is a highly effective secondary prevention in patients with cardioembolic stroke and atrial fibrillation/flutter ( AF ) . However , the condition remains underdiagnosed , because paroxysmal AF may be missed by diagnostic tests in the acute phase . In this study , the sensitivity of AF detection was assessed for serial electrocardiographic recordings and continuous stroke unit telemetric monitoring with or without a structured algorithm to analyze telemetric data ( SEA-AF ) . Methods — Three hundred forty-six consecutive patients with acute ischemic stroke were prospect ively included and subjected to st and ard telemetric monitoring . In addition , telemetric data were separately analyzed following SEA-AF , consisting of a structured evaluation of episodes with high risk for AF and a chronological beat-to-beat screening of the full registration . Serial electrocardiograms  were conducted in 24-hour intervals . Results — Median effective telemetry monitoring time was 75.5 hours ( interquartile range 64–86 hours ) . Overall , AF was diagnosed in 119 of 346 patients ( 34.4 % ) . The structured reading algorithm was the most sensitive method to detected AF . Conventional telemetry and serial electrocardiographic assessment s were less effective . However , only 35 % of patients with previously documented paroxysmal AF and negative baseline electrocardiogram demonstrated AF episodes during monitoring . Conclusions — Continuous stroke unit telemetry using SEA-AF shows a significantly higher detection rate for AF compared with daily electrocardiographic assessment s and st and ard telemetry without structured reading . The low overall probability to detect paroxysmal AF with either method during the first days after stroke demonstrates the urgent need for complementary diagnostic strategies such as long-term monitoring and frequent follow-up assessment s. Clinical Trial Registration — URL : www . clinical trials.gov . Unique identifier : NCT01177748 BACKGROUND Atrial fibrillation ( AF ) is not always accompanied by clear-cut symptoms and symptoms suggestive of AF may not correspond to a genuine AF episode . The study prospect ively evaluated the burden of asymptomatic AF episodes in pacemaker patients ( for sick sinus syndrome ) with a history of documented paroxysmal AF . METHODS Consecutive patients were enrolled and implanted with dual-chamber pacemakers equipped with diagnostic features for AF monitoring .  Each patient was instructed about typical AF symptoms and was asked to keep a detailed log of symptoms . Stored pacemaker data were analyzed using only AF episodes > 30 s. RESULTS The mean follow-up was 16 + /- 6 months and 102 patients were enrolled ( 73 + /- 7 years , 59 M ) . Thirteen patients ( 13 % ) dropped out with the development of permanent AF and their data were discarded . Twenty-three patients ( 26 % ) without device-stored AF episodes all reported at least one annotated AF episode . There were 1,245 device-stored AF episodes in 66 ( 74 % ) out of 89 patients . Patients reported 1,141 episodes of AF-related symptoms . Only 240 ( 21 % ) corresponded to a genuine device-stored AF event . The sensitivity and positive predictive value of symptoms to detect AF were respectively 19 % and 21 % . Episode duration , rate increase at the onset of the arrhythmia , heart disease , or antiarrhythmic drug therapy showed no statistically significant differences comparing symptomatic and asymptomatic episodes . CONCLUSIONS Many pacemaker patients with paroxysmal AF can develop AF-like symptoms in the absence of device-stored AF . AF-related symptoms have low sensitivity and low positive predictive value in patients with permanent pacemakers AIMS To test the hypothesis that stroke and systemic embolic events ( SEE ) in the stroke prevention using an oral thrombin inhibitor in atrial fibrillation ( SPORTIF ) III and V trials are different between paroxysmal and persistent atrial fibrillation ( AF ) . METHODS Data analysis from two cohorts of patients enrolled in the prospect i ve SPORTIF III and V clinical trials ( n = 7329 ) ; 836 subjects ( 11.4 % ) with paroxysmal AF [ mean age 70.1 years ( SD = 9.5 ) ] were compared with 6493 subjects with persistent AF for this ancillary study . RESULTS The annual event rates for stroke/SEE are 1.73 % for persistent AF and 0.93 % for paroxysmal AF . In a multivariate analysis , after adjusting for stroke risk factors , gender and aspirin usage , the differences remained statistically significant with a higher hazard ratio ( HR ) for stroke/SEE in persistent AF [ vs. paroxysmal AF , HR 1.87 , 95 % confidence interval ( CI ) 1.04 - 3.36 ; P = 0.037 ] . In ' high risk ' patients ( with > or=2 stroke risk factors ) annual event rates for stroke/SEE were 2.08 % for persistent AF and 1.27 % for paroxysmal AF ( adjusted HR = 1.68 , 95 % CI 0.91 - 3.1 , P = 0.098 ) . Elderly patients had annual event rates for stroke/SEE of 2.38 % for persistent AF and 1.13 % for paroxysmal AF ( adjusted HR = 2.27 , 95 % CI 0.92 - 5.59 , P = 0.075 ) . Vitamin K antagonist (VKA)-naive paroxysmal AF patients had a 1.89%/year stroke/SEE rate , compared with 0.61 % for previous VKA takers ( HR = 0.33 , 95 % CI 0.11 - 1.01 , P = 0.052 ) . CONCLUSION In this large clinical trial cohort of anticoagulated AF patients , those with paroxysmal AF had stroke rates which were lower than for patients with persistent AF , although both groups had broadly similar stroke risk factors . Subjects with paroxysmal AF at ' high risk ' had stroke/SEE rates that were not significantly different to persistent AF subjects Background and Purpose — For patients having suffered ischemic stroke , the current diagnostic strategies often fail to detect atrial fibrillation as a potential cause of embolic events . The aim of the study was to identify paroxysmal atrial fibrillation in stroke patients . We hypothesized that patients with frequent atrial premature beats ( APBs ) recorded in 24-hour ECG will show more often atrial fibrillation when followed by repeated long-term ECG recordings than patients without or infrequent APBs . Methods — 127 patients with acute ischemic stroke and without known AF were enrolled in a prospect i ve study to detect paroxysmal AF . Patients were stratified according to the number of APBs recorded in a 24-hour ECG ( ≥70 APBs versus < 70 APBs ) . Subsequently , they all underwent serial 7-day event-recorder monitoring at 0 , 3 , and 6 months . Results — Serial extended ECG monitoring  identified AF in 26 % of patients with frequent APBs but only in 6.5 % when APBs were infrequent ( P=0.0021 ) . A multivariate analysis showed that the presence of frequent APBs in the initial 24-hour ECG was the only independent predictor of paroxysmal AF during follow-up ( odds ratio 6.6 , 95 % confidence intervals 1.6 to 28.2 , P=0.01 ) . Conclusions — In patients with acute ischemic stroke , frequent APBs ( ≥70/24 hours ) are a marker for individuals who are at greater risk to develop or have paroxysmal AF . For such patients , we propose a diagnostic workup with repeated prolonged ECG monitoring to diagnose paroxysmal AF Atrial fibrillation and atrial flutter are common cardiac arrhythmias associated with an increased risk of stroke in patients with additional risk factors .  Anticoagulation ameliorates stroke risk , but because these arrhythmias may occur intermittently without symptoms , initiation of prophylactic therapy is often delayed until electrocardiographic documentation is obtained . The IMPACT study is a multicenter , r and omized trial of remote surveillance technology in patients with implanted dual-chamber cardiac resynchronization therapy defibrillator ( CRT-D ) devices design ed to test the hypothesis that initiation and withdrawal of oral anticoagulant therapy guided by continuous ambulatory monitoring of the atrial electrogram improve clinical outcomes by reducing the combined rate of stroke , systemic embolism , and major bleeding compared with conventional clinical management . For those in the intervention group , early detection of atrial high-rate episodes ( AHRE ) generates an automatic alert to initiate anticoagulation based on patient-specific stroke risk stratification . Subsequently , freedom from AHRE for predefined periods prompts withdrawal of anticoagulation to avoid bleeding . Patients in the control arm are managed conventionally , the anticoagulation decision prompted by incidental detection of atrial fibrillation or atrial flutter during routine clinical follow-up . The results will help define the clinical utility of wireless remote cardiac rhythm surveillance and help establish the critical threshold of AHRE burden warranting anticoagulant therapy in patients at risk of stroke . In this report , we describe the study design and baseline demographic and clinical features of the initial cohort ( 227 patients ) INTRODUCTION  Atrial fibrillation ( AF ) is associated with significant morbidity and mortality that may be related to hemodynamic impairment , thromboembolic events , or enhanced electrical instability of the ventricular myocardium . There is , however , a lack of data concerning the association of AF and ventricular tachyarrhythmias . METHODS AND RESULTS Consecutive patients with indication for an implantable cardioverter defibrillator ( ICD ) were classified for the presence or absence of persistent AF at the time of device implantation .  Incidence of device therapy , stored electrograms , and clinical events during follow-up were evaluated prospect ively . Two hundred fifty patients were included . During follow-up ( 20+/-14 months ) , patients in AF experienced appropriate device therapy for recurrent ventricular arrhythmias more frequently compared with patients in sinus rhythm ( SR ) ( 63 % vs 38 % , P = 0.01 ) . On multivariate analysis , AF was an independent predictor of appropriate ICD therapy ( relative risk 1.8 ; 95 % confidence interval [ CI ] 1.2 to 2.9 ) and inappropriate device therapy ( relative risk 2.3 ; 95 % CI 1.2 to 4.5 ) . Predefined clinical events ( cluster endpoint : death , syncope , and hospitalizations ) were observed more frequently in AF than in SR patients ( 55 % vs 31 % , P = 0.01 ) . Analysis of device-stored electrograms revealed a higher incidence of short-long-short cycles preceding ventricular arrhythmias in AF compared with SR patients ( 50 % vs 16 % , P = 0.002 ) . Baseline heart rate preceding ventricular arrhythmias did not differ between the two groups . CONCLUSION AF is an independent predictor of recurrent ventricular arrhythmias in ICD recipients . The underlying electrophysiologic mechanism seems to be irregular rather than rapid ventricular activation , with a high incidence of short-long-short sequences preceding ventricular tachyarrhythmias in AF patients Background Device‐detected sub clinical atrial fibrillation ( AF ) refers to infrequent , short‐lasting , asymptomatic AF that is detected only with long‐term continuous monitoring . Sub clinical AF is common and associated with an increased risk of stroke ; however , the risk of stroke with sub clinical AF is lower than for clinical AF , and very few patients with sub clinical AF alone have been included in large AF anticoagulation trials . The net benefit of anticoagulation in patients with sub clinical AF is unknown . Design ARTESiA is a prospect i ve , multicenter , double‐blind , r and omized controlled trial , recruiting patients with sub clinical AF detected by an implanted pacemaker , defibrillator , or cardiac monitor , and who have additional risk factors for stroke . Patients with clinical AF documented by surface electrocardiogram will be excluded from the study . Participants will be r and omized to receive either apixaban ( according to st and ard AF dosing ) or aspirin 81 mg daily . The primary outcome is the composite of stroke , transient ischemic attack with diffusion‐weighted magnetic resonance imaging evidence of cerebral infa rct ion , and systemic embolism . Approximately 4,000 patients will be enrolled from around 230 clinical sites , with an anticipated mean follow‐up of 36 months until 248 adjudicated primary outcome events have occurred . Summary ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with sub clinical AF and additional risk factors Recently , the clinical entity embolic stroke of undetermined source ( ESUS ) has been defined for patients with ischemic strokes , where neither a cardioembolic nor a non-cardiac source can be detected . These patients may suffer from asymptomatic atrial fibrillation ( AF ) , terminating spontaneously and thus eluding detection . Implantable loop recorders ( ILR ) with automatic AF detection algorithms can detect short-lasting , sub clinical AF . The aim of this study was to prospect ively assess and predict AF detection in patients with ESUS using ILR with daily remote interrogation . Patients with acute ESUS received an ILR , were seen every 6 months and additionally interrogated their ILR daily using remote monitoring . The incidence of AF detection was assessed and parameters which might predict AF detection ( clinical and from magnetic resonance tomography ) were analysed . ILR implantation was performed in 123 patients on average 20 days after stroke . During a mean follow-up of 12.7±5.5 months , AF was documented and manually confirmed in 29 of 123 patients ( 23.6 % ) . First AF detection occurred on average after 3.6±3.4 months of monitoring . Patients with AF were on average older , had a higher CHA2DS2-VASc score and more often cerebral microangiopathy . In conclusion , AF can be documented in approximately 25 % of patients with the diagnosis of ESUS after careful work-up within a year of monitoring by an ILR and daily remote interrogation . This had important therapeutic consequences ( initiation of anticoagulation for secondary stroke prevention ) in these patients Aims Uncertainty exists over the importance of device-detected short- duration atrial arrhythmias . Continuous atrial diagnostics , through home monitoring ( HM ) technology ( BIOTRONIK , Berlin , Germany ) , provides a unique opportunity to assess frequency and quantity of atrial fibrillation ( AF ) episodes defined as atrial high-rate events ( AHRE ) . Methods and results Prospect i ve data from 560 heart failure ( HF ) patients ( age 67 ± 10 years , median ejection fraction 27 % ) patients with a cardiac resynchronization therapy ( CRT ) device capable of HM from two multi-centre studies were analysed . Atrial high-rate events burden was defined as the duration of mode switch in a 24-h period with atrial rates of > 180 beats for at least 1 % or total of 14 min per day . The primary endpoint was incidence of a thromboembolic ( TE ) event . Secondary endpoints were cardiovascular death , hospitalization because of AF , or worsening HF . Over a median 370-day follow-up AHRE occurred in 40 % of patients with 11 ( 2 % ) patients developing TE complications and mortality rate of 4.3 % ( 24 deaths , 16 with cardiovascular aetiology ) . Compared with patients without detected AHRE , patients with detected AHRE>3.8 h over a day were nine times more likely to develop TE complications ( P= 0.006 ) . The majority of patients ( 73 % ) did not show a temporal association with the detected atrial episode and their adverse event , with a mean interval of 46.7 ± 71.9 days ( range 0–194 ) before the TE complication . Conclusion In a high-risk cohort of HF patients , device-detected atrial arrhythmias are associated with an increased incidence of TE events . A cut-off point of 3.8 h over 24 h was associated with significant increase in the event rate . Routine assessment of AHRE should be considered with other data when assessing stroke risk and considering anti-coagulation initiation and should also prompt the optimization of cardioprotective HF therapy in CRT patients BACKGROUND Atrial fibrillation ( AF ) , an important and treatable cause of ischaemic stroke , can occur as a sustained or a paroxysmal arrhythmia . Continuous cardiac rhythm monitoring ( Holter monitoring ) is often performed in stroke patients to identify paroxysmal AF , which is an indication for warfarin anti-coagulation in this patient population . AIM The aim of this study was to assess the clinical utility of Holter monitoring in detecting occult AF in patients with possible cardioembolic stroke . METHODS The medical records of ischaemic stroke patients consecutively hospitalized at a single academic centre during a one-year period were review ed . Data regarding patient demographics , stroke characteristics , electrocardiography and echocardiography results and duration and findings of Holter monitoring were abstract ed . The primary outcome was yield of newly diagnosed AF on Holter monitoring .  RESULTS Of 465 consecutive patients admitted with a diagnosis of new ischaemic stroke , 210 underwent Holter monitoring . The mean duration of monitoring was 22.8 + /- 4.0 h. Previously undiscovered AF was -identified in five cases ( 2.4 % ) , all of which represented non-rheumatic AF . In three cases , the Holter test was negative despite AF documented on an admission electro-cardiogram . CONCLUSIONS Holter monitoring can identify occult paroxysmal AF , assisting targeted secondary prevention in patients with new ischaemic stroke . However , the st and ard 24-h duration of monitoring probably under-estimates the prevalence of paroxysmal AF in this population . Prospect i ve studies are indicated to evaluate the value of longer monitoring periods in stroke population The Canadian Cardiovascular Society ( CCS ) published the complete set of 2010 Atrial Fibrillation ( AF ) Guidelines in the January , 2011 issue of the Canadian Journal of Cardiology . During its deliberations , the CCS Guidelines Committee engaged to a timely review of future evidence , with periodic composition of focused up date s to address clinical ly important advances . In 2011 , results were published from 3 pivotal AF trials : the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonist for Prevention of Stroke and Embolism Trial in Atrial Fibrillation ( ROCKET-AF ) , the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation ( ARISTOTLE ) study , and the Permanent Atrial Fibrillation Outcome Study Using Dronedarone on Top of St and ard Therapy ( PALLAS ) , comparing dronedarone with placebo in patients with permanent AF and additional cardiovascular disease risk-factor burden . Each of these large r and omized trials provided clear results with major implication s for AF management . Other important evidence that has emerged since the 2010 Guidelines includes findings about prediction instruments for AF-associated stroke and bleeding risk , stroke risk in paroxysmal-AF patients , risk-benefit considerations related to oral anticoagulation in patients with chronic kidney disease , and risk/benefit considerations in the use of antiplatelet agents , alone and in combination with each other or with oral anticoagulants , in AF patients . The Guidelines Committee judged that this extensive and important new evidence required focused updating of the 2010 Guidelines with respect to stroke prevention and rate/rhythm control . This report presents the details of the new recommendations , along with the background and rationale OBJECTIVES The present study determined the incidence and time course of atrial fibrillation ( AF ) recurrences  in patients with a history of AF and fitted with an implantable monitoring device .  BACKGROUND The long-term risk of undetected recurrence of AF in patients receiving stable antiarrhythmic therapy remains uncertain . METHODS In 110 patients with a class I indication for physiologic pacing and a history of AF , a pacemaker with dedicated functions for AF detection and electrogram storage was implanted , and antiarrhythmic drug treatment was optimized . Patients were regularly followed up with evaluation of AF-related symptoms , a  resting electrocardiogram ( ECG ) , and  interrogation of device memory .  The incidence of AF recurrences lasting > 48 h in asymptomatic patients presenting in sinus rhythm ( SR ) at the respective follow-up visit constituted the primary end point of this prospect i ve study . RESULTS During 19 + /- 11 months , 678 follow-up visits were performed . Atrial fibrillation was documented in 51 patients ( 46 % ) by ECG recording and in 97 patients ( 88 % ) by a review of stored electrograms ( p < 0.0001 ) . Device interrogation revealed AF recurrences lasting > 48 h in 50 patients , 19 of whom ( 38 % ) were completely asymptomatic and in SR at subsequent follow-up . In 11 ( 16 % ) of 67 patients with device-confirmed freedom from AF for > or =3 months , AF lasting > 48 h recurred subsequently . CONCLUSIONS This prospect i ve study demonstrates a high incidence of recurrent AF despite optimized antiarrhythmic therapy . Of particular note , AF relapses > 48 h remained totally asymptomatic in a significant proportion of patients . Freedom from AF for > or =3 months did not preclude subsequent long-lasting AF recurrence OBJECTIVES This study aim ed to assess the prevalence of different types of  atrial fibrillation ( AF ) and their prognostic importance in  implantable cardioverter-defibrillator ( ICD ) patients . BACKGROUND The prevalence of AF has taken epidemic proportions in the population with cardiovascular disease . The prognostic importance of different types of AF in ICD patients remains unclear . METHODS Data on 913 consecutive patients ( 79 % men , mean age 62 + or - 13 years ) receiving an ICD at the Leiden University Medical Center were prospect ively collected . Among other characteristics , the existence and type of AF ( paroxysmal , persistent , or permanent ) were assessed at implantation . During follow-up , the occurrence of appropriate or inappropriate device therapy as well as mortality was noted . RESULTS At implantation , 73 % of patients had no history of AF , 9 % had a history of paroxysmal AF , 7 % had a history of persistent AF , and 11 % had permanent AF . During 833 + or - 394 days of follow-up , 117 ( 13 % ) patients died , 228 ( 25 % ) patients experienced appropriate device discharge , and 139 ( 15 % ) patients received inappropriate shocks . Patients with permanent AF exhibited more than double the risk of mortality , ventricular arrhythmias triggering device discharge , and inappropriate device therapy .  Patients with paroxysmal or persistent AF did not show a significant increased risk of mortality or appropriate device therapy but demonstrated almost 3 times the risk of inappropriate device therapy . CONCLUSIONS In the population currently receiving ICD treatment outside the setting of clinical trials , a large portion has either a history of AF or permanent AF . Both types of AF have prognostic implication s for mortality and appropriate as well as inappropriate device discharge Atrial fibrillation ( AF ) and paroxysmal AF ( PAF ) are common causes of stroke which may not be detected by a single electrocardiogram ( EKG ) . We conducted a prospect i ve study to determine if 48 hours of telemetry monitoring increased the rate of detection of AF in patients with acute stroke and thus identified patients requiring anticoagulation . One hundred and fifty consecutive patients with acute ischemic stroke were placed on telemetry monitoring for 48 hours . Thirty-five patients had AF related strokes . There were 12 patients with AF related stroke who did not have a previous history of AF and were found to have AF following the stroke . Six of these 12 patients were found to have AF on their admission EKG . The remaining six patients had normal admission EKGs and were diagnosed with AF only during telemetry monitoring for 48 hrs . Patients with AF were older , had larger strokes , which were more likely to be non-lacunar , than patients without AF . Our study suggests that AF is sometimes undiagnosed until a stroke occurs . Improved methods of detection of AF are needed in high-risk patients for primary stroke prevention . Patients older than 65 years of age with non-lacunar strokes should have 48 hours of telemetry monitoring to detect previously undiagnosed AF Background and Purpose — Atrial fibrillation ( AF ) elevates risk of recurrent stroke but is incompletely identified by st and ard investigation after stroke , though detection rates correlate with monitoring duration . We hypothesized that 7 days of noninvasive cardiac-event monitoring early after stroke would accelerate detection of AF and thus uptake of effective therapy . Methods — We performed a pragmatic r and omized trial with objective outcome assessment among patients presenting in sinus rhythm with no AF history , within 7 days of ischemic stroke symptom onset . Patients were r and omized to st and ard practice investigations ( SP ) to detect AF , or SP plus additional monitoring ( SP-AM ) . AM comprised 7 days of noninvasive cardiac-event monitoring reported by an accredited cardiac electrocardiology laboratory . Primary outcome was detection of AF at 14 days . Results — One-hundred patients were enrolled from 2 centers . Within 14 days of stroke , sustained paroxysms of AF were detected in 18 % of patients undergoing SP-AM versus 2 % undergoing SP ( P<0.05 ) . Paroxysms of any- duration were detected in 44 % of patients undergoing SP-AM versus 4 % undergoing SP ( P<0.001 ) . These differences persisted at 90 days . Anticoagulant therapy was commenced within 14 days in 16 % of SP-AM patients versus none r and omized to SP ( P<0.01 ) . This difference persisted to 90 days ( 22 % versus 6 % ; P<0.05 ) . Conclusions — Routine noninvasive cardiac-event monitoring after acute stroke enhances detection of paroxysmal AF and early anticoagulation . Extended monitoring should be offered to all eligible patients soon after acute stroke . Guidelines on investigation for AF in stroke patients could be strengthened . Clinical Trial Registration — URL : http://www.controlled-trials.com/is rct n/. Unique identifier : IS RCT N97412358 BACKGROUND Complex fractionated electrograms ( CFEs ) are continuous electrograms ( EGMs ) of very short cycle length ( CL ) representing substrate for atrial fibrillation ( AF ) perpetuation . Ablation of CFEs may result in AF slowing , termination , and prevention , but identifying them can be subjective . OBJECTIVE The purpose of this study was to prospect ively assess ( 1 ) whether an automated algorithm can identify CFE regions , ( 2 ) the acute effects of ablating these regions on AF , and ( 3 ) the long-term efficacy as an adjuvant strategy to pulmonary vein antrum isolation ( PVAI ) . METHODS Thirty-five patients ( three centers , 61 + /- 9 years , left atrium [ LA ] 43 + /- 9 mm , ejection fraction 53 % + /- 7 % ) with symptomatic paroxysmal ( n = 21 ) or persistent ( n = 14 ) AF were studied . A decapolar lasso ( 2-mm spacing ) was used for mapping . A three-dimensional shell of the LA and pulmonary veins ( PVs ) was created . If not already in AF , AF was induced by burst pacing ( with or without isoproterenol ) . Atrial EGMs during AF were mapped/analyzed using an automated CFE algorithm . The algorithm measures the time between discrete deflections in a local EGM over 5 seconds ( based on selectable width and peak-to-peak [ > 0.03 mV ] criteria ) . The mean CL of the local EGM is projected onto the LA shell as a color-coded display . Regions of CL < 120 ms ( published criteria ) were targeted for ablation/elimination . Atrial fibrillation cycle length ( AFCL ) and regularity were measured from the CS . After CFE ablation , further ablation was done to achieve complete PVAI . RESULTS AF was spontaneous ( n = 20 ) or induced ( n = 15 ) in all patients . CFEs were most commonly found along the septum ( 97 % ) , anterior LA ( 97 % ) , PV antra ( 83 % ) , base of appendage ( 83 % ) , and annulus ( 71 % ) . CFE ablation alone prolonged the AFCL ( 171 + /- 27 vs. 304 + /- 41 ms ; P = .03 ) and regularized AF to left/right flutter ( AFL ) in 74 % of patients . CFE ablation terminated AF/AFL in 19 patients (54%)-the other 16 were cardioverted- and AF became noninducible in 77 % . CFE ablation alone did not cause PV isolation ( 0.1 + /- 0.3 PV isolated/patient ) . After combined CFE and PVAI ablation , the single-procedure , off-drug success rate was 83 % ( follow-up 13 + /- 4 months ) versus 71 % in matched controls who had PVAI alone ( P = .045 ) . CONCLUSIONS CFE ablation guided by an automated algorithm result ed in AFCL prolongation , regularization , and noninducibility in most patients . AF terminated in 54 % of cases . PVAI with adjuvant CFE ablation has a high efficacy and may be superior to PVAI alone
Conclusion Patients with an AHRE burden over 6 min have an increased risk for stroke .
Aims Atrial fibrillation ( AF ) patients have increased risk of stroke .
In paroxysmal AF , the combination of duration and frequency of episodes defines AF burden .
In patients with cardiac implantable electronic devices ( CIEDs ) , atrial high-rate episodes ( AHREs ) can be monitored continuously and are considered as a proxy for AF .
This systematic review aims to determine the relationship between AF burden and risk of thrombo-embolic events ( TBEs ) .