Noninvasive Cardiac Event Monitoring to Detect Atrial Fibrillation After Ischemic Stroke: A Randomized, Controlled Trial Detection of atrial fibrillation in patients with acute stroke. Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL AF): design and rationale. A Structured Reading Algorithm Improves Telemetric Detection of Atrial Fibrillation After Acute Ischemic Stroke Detection of atrial fibrillation in patients with embolic stroke of undetermined source by prolonged monitoring with implantable loop recorders. Intermittent atrial fibrillation may account for a large proportion of otherwise cryptogenic stroke: a study of 30-day cardiac event monitors. Atrial fibrillation and paroxysmal atrial fibrillation detection in patients with acute ischemic stroke. Pilot Randomized Trial of Outpatient Cardiac Monitoring After Cryptogenic Stroke Holter monitoring in the diagnosis of stroke mechanism. Uncovering Atrial Fibrillation Beyond Short-Term Monitoring in Cryptogenic Stroke Patients: Three-Year Results From the Cryptogenic Stroke and Underlying Atrial Fibrillation Trial Cryptogenic stroke and underlying atrial fibrillation. Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective study Frequent Atrial Premature Beats Predict Paroxysmal Atrial Fibrillation in Stroke Patients: An Opportunity for a New Diagnostic Strategy Continuous monitoring versus HOLTER ECG for detection of atrial fibrillation in patients with stroke. Detection of atrial fibrillation after stroke and the risk of recurrent stroke. 96 hours ECG monitoring for patients with ischemic cryptogenic stroke or transient ischaemic attack Optimal timing and duration of continuous electrocardiographic monitoring for detecting atrial fibrillation in stroke patients.
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 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 Patients with atrial fibrillation ( AF ) are at increased risk for ischemic stroke . In patients who have suffered a stroke , screening for AF is routinely performed only for a short period after the stroke as part of the evaluation for possible causes . If AF is detected after an ischemic stroke , oral anticoagulation therapy is recommended for secondary stroke prevention . In 25 % to 30 % of stroke patients , the stroke mechanism can not be determined ( cryptogenic stroke ) . The incidence of paroxysmal AF undetected by short-term monitoring in patients with cryptogenic stroke is unknown , but has important therapeutic implication s on patient care . The optimum monitoring duration and method of AF detection after stroke are unknown . The purpose of this study is to evaluate the incidence of AF and time to AF detection in patients with cryptogenic stroke using an insertable cardiac monitor . STUDY DESIGN The CRYSTAL AF trial is a r and omized prospect i ve study to evaluate a novel approach to long-term monitoring for AF detection in patients with cryptogenic stroke . Four hundred fifty cryptogenic stroke patients ( by definition , without a history of AF ) will be enrolled at approximately 50 sites in Europe , Canada , and the United States . Patients will be r and omized in a 1:1 fashion to st and ard arrhythmia monitoring ( control arm ) or implantation of the subcutaneous cardiac monitor ( Reveal XT ; Medtronic , Inc , Minneapolis , MN ) ( continuous monitoring arm ) . OUTCOMES The primary end point is time to detection of AF within 6 months after stroke . The clinical follow-up period will be at least 12 months . Study completion is expected at the end of 2012 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 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 INTRODUCTION Despite extensive inpatient workup including telemetry monitoring , a significant proportion of stroke is classified as cryptogenic at hospital discharge . It is possible that a significant proportion of cryptogenic stroke is a result of intermittent atrial fibrillation ( AF ) . Thirty-day cardiac event monitors ( 30-DEM ) may increase the rate of AF detection compared with st and ard investigations that include a combination of electrocardiography , cardiac telemetry , and short-term Holter monitoring . METHODS Charts were review ed of patients who were admitted to a university stroke center or who were evaluated in the outpatient clinic during a 9-month period to determine whether the cause of stroke was cryptogenic . As a matter of protocol , such patients typically underwent 30-DEM and the results of such monitoring were documented along with the duration of inpatient cardiac monitoring if relevant . RESULTS In all , 218 patients with a diagnosis of ischemic stroke or transient ischemic attack were identified . Of the strokes , 36 ( 16.5 % ) were classified as cryptogenic . Twenty patients with cryptogenic stroke or transient ischemic attack were evaluated with 30-DEM . Four ( 20 % ) were found to have AF , and all 4 patients were treated with warfarin . CONCLUSION The 30-DEM changed the medical treatment of 20 % of patients with otherwise cryptogenic stroke because of the detection of intermittent AF despite no detection of AF on electrocardiography and inpatient telemetry monitoring in the majority of patients . Further prospect i ve studies of extended cardiac event monitors in the setting of cryptogenic stroke are warranted BACKGROUND Studies about continuous electrocardiographic ( ECG ) monitoring in detection of paroxysmal atrial fibrillation ( PAF ) in Asian patients with acute ischemic stroke are very limited . We looked for the prevalence and associated factors of atrial fibrillation ( AF ) and PAF in Thai patients with acute ischemic stroke . METHODS In all , 204 patients with acute ischemic stroke were prospect ively included .  Snapshot 12-lead ECG and continuous ECG monitoring for at least the first 24 hours were performed . Multivariate analyses were performed to find out the associated factors of AF and PAF . RESULTS AF was diagnosed in 31 patients ( 15 % ) and PAF in 15 patients ( 7 % ) . Twelve and 3 patients with PAF were diagnosed by continuous ECG monitoring and snapshot 12-lead ECG , respectively . Mean duration of continuous ECG monitoring and mean time to detect PAF were 55 and 23 hours , respectively . Multivariate analysis revealed that age of 70 years or older ( odds ratio [ OR ] 3.52 , 95 % confidence interval [ CI ] 1.68 - 7.35 , P = .001 ) and heart diseases ( OR 4.26 , 95 % CI 1.14 - 15.95 , P = .031 ) were associated with AF and PAF . CONCLUSIONS AF/PAF was one of the common causes of ischemic stroke in Thai patients . Most PAF was detected by continuous ECG monitoring . Snapshot 12-lead ECG and continuous ECG monitoring should be recommended in all patients with acute ischemic stroke Background and Purpose — Observational studies indicate that outpatient cardiac monitoring detects previously undiagnosed atrial fibrillation ( AF ) in 5 % to 20 % of patients with recent stroke . However , it remains unknown whether the yield of monitoring exceeds that of routine clinical follow-up . Methods — In a pilot trial , we r and omly assigned 40 patients with cryptogenic ischemic stroke or high-risk transient ischemic attack to wear a Cardionet mobile cardiac outpatient telemetry monitor for 21 days or to receive routine follow-up alone . After thorough investigation , we excluded patients with documented AF or other apparent stroke pathogenesis . We contacted patients and their physicians at 3 months and at 1 year to ascertain any diagnoses of AF or recurrent stroke or transient ischemic attack . Results — The baseline characteristics of our cohort broadly matched those of previous observational studies of monitoring after stroke . In the monitoring group , patients wore monitors for 64 % of the assigned days , and 25 % of patients were not compliant at all with monitoring . No patient in either study arm received a diagnosis of AF . Cardiac monitoring revealed AF in zero patients ( 0 % ; 95 % confidence interval , 0%–17 % ) , brief episodes of atrial tachycardia in 2 patients ( 10 % ; 95 % confidence interval , 1%–32 % ) , and nonsustained ventricular tachycardia in 2 patients ( 10 % ; 95 % confidence interval , 1%–32 % ) . Conclusions — In the first reported r and omized trial of cardiac monitoring after cryptogenic stroke , the rate of AF detection was lower than expected , incidental arrhythmias were frequent , and compliance with monitoring was suboptimal . Our findings highlight the challenges of prospect ively identifying stroke patients at risk for harboring paroxysmal AF and ensuring adequate compliance with cardiac monitoring . Clinical Trial Registration — URL : http:// clinical trials.gov . Unique Identifier : 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 Background —Atrial fibrillation ( AF ) can be a cause of previously diagnosed cryptogenic stroke . However , AF can be paroxysmal and asymptomatic , thereby making detection with routine ECG methods difficult . Oral anticoagulation is highly effective in reducing recurrent stroke in patients with AF , but its initiation is dependent on the detection of AF . Cryptogenic Stroke and Underlying Atrial Fibrillation ( CRYSTAL AF ) is the first r and omized study to report the detection of AF in cryptogenic stroke patients using continuous long-term monitoring via insertable cardiac monitors ( ICM ) . Methods and Results — Patients with prior cryptogenic stroke were r and omized to control ( n=220 ) or ICM ( n=221 ) and followed for ⩽36 months . Cumulative AF detection rates in the ICM arm increased progressively during this period ( 3.7 % , 8.9 % , 12.4 % , and 30.0 % at 1 , 6 , 12 , and 36 months , respectively ) , but remained low in the control arm ( 3.0 % at 36 months ) . This result ed in oral anticoagulation prescription in 94.7 % of ICM patients with AF detected at 6 months , 96.6 % at 12 months , and 90.5 % at 36 months . Among ICM patients with AF detected , the median time to AF detection was 8.4 months , 81.0 % of first AF episodes were asymptomatic , and 94.9 % had at least 1 day with > 6 minutes of AF . Conclusions —Three-year monitoring by ICM in cryptogenic stroke patients demonstrated a significantly higher AF detection rate compared with routine care . Given the frequency of asymptomatic first episodes and the long median time to detection , these findings highlight the limitations of using traditional AF detection methods . The majority of patients with AF were prescribed oral anticoagulation therapy . Clinical Trial Registration — Clinical trials.gov ; Unique identifier : NCT00924638 BACKGROUND Current guidelines recommend at least 24 hours of electrocardiographic ( ECG ) monitoring after an ischemic stroke to rule out atrial fibrillation . However , the most effective duration and type of monitoring have not been established , and the cause of ischemic stroke remains uncertain despite a complete diagnostic evaluation in 20 to 40 % of cases ( cryptogenic stroke ) . Detection of atrial fibrillation after cryptogenic stroke has therapeutic implication s. METHODS We conducted a r and omized , controlled study of 441 patients to assess whether long-term monitoring with an insertable cardiac monitor ( ICM ) is more effective than conventional follow-up ( control ) for detecting atrial fibrillation in patients with cryptogenic stroke . Patients 40 years of age or older with no evidence of atrial fibrillation during at least 24 hours of ECG monitoring  underwent r and omization within 90 days after the index event . The primary end point was the time to first detection of atrial fibrillation ( lasting > 30 seconds ) within 6 months . Among the secondary end points was the time to first detection of atrial fibrillation within 12 months . Data were analyzed according to the intention-to-treat principle . RESULTS By 6 months , atrial fibrillation had been detected in 8.9 % of patients in the ICM group ( 19 patients ) versus 1.4 % of patients in the control group ( 3 patients ) ( hazard ratio , 6.4 ; 95 % confidence interval [ CI ] , 1.9 to 21.7 ; P<0.001 ) . By 12 months , atrial fibrillation had been detected in 12.4 % of patients in the ICM group ( 29 patients ) versus 2.0 % of patients in the control group ( 4 patients ) ( hazard ratio , 7.3 ; 95 % CI , 2.6 to 20.8 ; P<0.001 ) . CONCLUSIONS ECG monitoring with an ICM was superior to conventional follow-up for detecting atrial fibrillation after cryptogenic stroke . ( Funded by Medtronic ; CRYSTAL AF Clinical Trials.gov number , NCT00924638 . ) Purpose Ischemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality . There are several causes of stroke , affecting prognosis , outcomes , and management , but in many cases , the etiology remains undetermined . We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by st and ard methods . The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months . The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation . Methods and results We prospect ively enrolled 24 patients under 75 years of age , 15 men and 9 women of mean age 49 years , who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism . All causes of stroke were excluded by normal 12-lead ECG , 24-h Holter monitoring , echocardiography , cervical Doppler , hematological , and inflammatory tests . All patients underwent electrophysiological study . Of the patients , 37.5 % had latent atrial vulnerability , and 33.3 % had inducible sustained arrhythmia . Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months . No sustained arrhythmia was found . Only one patient had non-significant episodes of atrial fibrillation . Conclusion In this study , symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder  in patients under 75 years with unexplained cerebral ischemia . The use of this device should not be generalized in the systematic evaluation of these patients . In addition , this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients 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 BACKGROUND AND PURPOSE Detection of atrial fibrillation is of vital importance because oral anticoagulation decreases the risk of a stroke by 64 % . Current st and ards for stroke unit treatment require continuous electrocardiogram ( ECG ) monitoring for at least 24 h. Additionally , a 24-h HOLTER ECG ( HOLTER ) should be performed in selected patients . It remains unclear whether continuous monitoring at the bedside is equivalent to HOLTER for the detection of atrial fibrillation . Furthermore , we investigate how many additional patients with paroxysmal atrial fibrillation can be identified as a result of a longer duration of continuous monitoring . METHODS In this study , we prospect ively compared the detection rates of HOLTER and 24-h monitoring at the Stroke Unit at the University of Heidelberg over a period of 9 months . Continuous monitoring was analyzed by trained nurses , HOLTER by cardiologists . RESULTS We included 370 patients with ischemic stroke or transient ischemic attack ( TIA ) in our study . Of these , 192 patients underwent HOLTER . Previously unknown atrial fibrillation was detected in 44 patients , 13 patients had no atrial fibrillation in baseline ECG , but  atrial fibrillation  was detected by continuous monitoring . In two patients , the HOLTER showed atrial fibrillation ; both patients had also been detected by continuous monitoring . Median time to detection of the atrial fibrillation during continuous monitoring was 43 h after hospitalization . CONCLUSION In this study , use of HOLTER does not give any additional benefit in comparison with continuous monitoring with intermittent analysis by trained staff alone . The median detection time of 43 h emphasizes the importance of longer continuous monitoring Failure to expeditiously diagnose atrial fibrillation ( AF ) as the cause of ischemic stroke has unclear consequences . We studied the association between detection of AF after discharge and the risk of recurrent stroke . We followed a prospect ively assembled cohort of patients hospitalized for stroke for 1 year for new diagnoses of AF and recurrent stroke . We compared rates of recurrent stroke in patients with a new diagnosis of AF and those without a new diagnosis of AF after discharge using Kaplan-Meier survival statistics . We conducted Cox proportional hazards analysis of the diagnosis and timing of AF and recurrent stroke after adjustment for age , sex , race , preexisting AF , hypertension , dyslipidemia , diabetes , previous stroke , and use of antithrombotic and statin medications . Among 5575 patients with stroke , 113 ( 2.0 % ) received a new diagnosis of AF after discharge , and 221 ( 4.0 % ) had recurrent stroke . At 1 year , the Kaplan‒Meier rate of recurrent stroke was 18.9 % in those with a new diagnosis of AF and 4.5 % in others , including those with AF diagnosed before or during the index hospitalization ( P = .001 ) . The association between a new diagnosis of AF and stroke recurrence persisted after adjustment for potential confounders ( hazard ratio , 5.6 ; 95 % confidence interval , 3.4 - 9.1 ) . A new diagnosis of AF after discharge for stroke is associated with an increased risk of recurrent stroke , even compared with patients with known AF . These findings identify a subset of patients at high risk for recurrent stroke and highlight the importance of timely detection of AF in patients with stroke Atrial fibrillation ( AF ) is intermittent in 30 % of patients with cardioembolic stroke and , therefore , might not be seen in a single st and ard ECG recording . The aim of this study was to evaluate if prolonged ECG monitoring ( 96 h ) finds episodes of intermittent AF beyond the 24 h ECG monitoring in patients with cryptogenic stroke or transient ischemic attack ( TIA ) . We prospect ively evaluated consecutive patients affected by cryptogenic stroke or TIA who had sinus rhythm on a 12-lead ECG on admission , and during ECG monitoring performed in the acute phase ( for at least 24 h ) . Patients had continuous 96 h Holter ECG monitoring within 30 days from stroke onset . 114 patients were included in the study ( mean age 63.1 ± 15.1 , 59 males ) .  AF was found in 29 patients ( 24.3 % ) . In 20 patients , AF was found in the first 24 h of recording , and in nine patients after 24 h. In addition , several other dysrhythmias such as supraventricular ectopic activity ( 33 ) , ventricular tachycardia ( 10 ) , sinus pause ( 4 ) and sinus-atrial block ( 1 ) were found . In patients with cryptogenic stroke or TIA , 96 h ECG monitoring detected a high rate of AF . One-third of AF was seen beyond 24 h of ECG monitoring BACKGROUND Several studies have suggested that after ischemic stroke , continuous electrocardiographic ( ECG ) monitoring ( CEM ) increases the atrial fibrillation ( AF ) detection rate . However , optimal CEM terms of use are not clear . The aim of our study was to evaluate the usefulness of CEM in detecting AF and define optimal terms of the use of CEM . METHODS We prospect ively enrolled consecutive patients with acute ischemic stroke who were admitted to the stroke unit without AF on baseline ECG . We compared 2 strategies of AF detection : the first using CEM and the second with routine clinical practice ( 24-hour Holter ECG and additional ECGs ) . Adjusted odds ratios for the association between AF diagnosis and the use of CEM stratified by monitoring duration were calculated using multivariate logistic regression analysis . RESULTS Of the 1166 patients included , 220 ( 18.87 % ) had AF on baseline ECG and were excluded . Of the 946 remaining patients , 592 underwent CEM . The prevalence of AF using CEM  was 12.50 % compared 2.26 % using the routine strategy . After adjustment ( demographic data , vascular risk factors , and National Institutes of Health Stroke Scale scores ) , using CEM increased 5.29 fold the odds of finding AF ( 95 % confidence interval [ CI ] 2.43 - 11.55 ) compared to the routine strategy . The adjusted odds ratio ( 9.82 ; 95 % CI 3.01 - 32.07 ) was maximum for the first day of monitoring and decreased later . Beyond 5 days ,  CEM usefulness was not significantly higher than the routine strategy . CONCLUSIONS We suggest that in order to enhance the detection rate of AF , CEM could be generalized in the stroke unit . It must be started early in patients with acute stroke and prolonged over a minimum of 4 days
Longer duration of electrocardiographic monitoring after cryptogenic stroke is associated with a greater detection of AF .
BACKGROUND Atrial fibrillation ( AF ) is a major cause of stroke .
Although st and ard investigations after an event include electrocardiographic monitoring , the optimal duration to detect AF is unclear .
We performed a systematic review and meta- analysis to determine whether the duration of electrocardiographic monitoring after an ischemic event is related to the detection of AF .