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 .
Subclinical atrial fibrillation and the risk of stroke.
BACKGROUND One quarter of strokes are of unknown cause , and sub clinical atrial fibrillation may be a common etiologic factor . Pacemakers can detect sub clinical episodes of rapid atrial rate , which correlate with electrocardiographically documented atrial fibrillation . We evaluated whether sub clinical episodes of rapid atrial rate detected by implanted devices were associated with an increased risk of ischemic stroke in patients who did not have other evidence of atrial fibrillation . METHODS We enrolled 2580 patients , 65 years of age or older , with hypertension and no history of atrial fibrillation , in whom a pacemaker or defibrillator had recently been implanted . We monitored the patients for 3 months to detect sub clinical atrial tachyarrhythmias ( episodes of atrial rate > 190 beats per minute for more than 6 minutes ) and followed them for a mean of 2.5 years for the primary outcome of ischemic stroke or systemic embolism .  Patients with pacemakers  were r and omly assigned to receive or not to receive continuous atrial overdrive pacing . RESULTS By 3 months , sub clinical atrial tachyarrhythmias detected by implanted devices had occurred in 261 patients ( 10.1 % ) . Sub clinical atrial tachyarrhythmias were associated with an increased risk of clinical atrial fibrillation ( hazard ratio , 5.56 ; 95 % confidence interval [ CI ] , 3.78 to 8.17 ; P<0.001 ) and of ischemic stroke or systemic embolism ( hazard ratio , 2.49 ; 95 % CI , 1.28 to 4.85 ; P=0.007 ) . Of 51 patients who had a primary outcome event , 11 had had sub clinical atrial tachyarrhythmias detected by 3 months , and none had had clinical atrial fibrillation by 3 months . The population attributable risk of stroke or systemic embolism associated with sub clinical atrial tachyarrhythmias was 13 % . Sub clinical atrial tachyarrhythmias remained predictive of the primary outcome after adjustment for predictors of stroke ( hazard ratio , 2.50 ; 95 % CI , 1.28 to 4.89 ; P=0.008 ) . Continuous atrial overdrive pacing did not prevent atrial fibrillation . CONCLUSIONS Sub clinical atrial tachyarrhythmias , without clinical atrial fibrillation , occurred frequently in patients with pacemakers and were associated with a significantly increased risk of ischemic stroke or systemic embolism . ( Funded by St. Jude Medical ; ASSERT Clinical Trials.gov number , NCT00256152 . )
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 .