Noninvasive cardiac monitoring for detecting paroxysmal atrial fibrillation or flutter after acute ischemic stroke: a systematic review.

BACKGROUND AND PURPOSE Identifying paroxysmal atrial fibrillation/flutter is an essential part of the etiological workup of patients with ischemic stroke. However, there is controversy in the literature regarding the use of noninvasive cardiac rhythm monitoring with previous reviews reporting a low detection rate with routine monitoring. We performed a systematic review to determine the frequency of occult atrial fibrillation/flutter detected by noninvasive methods of continuous cardiac monitoring after acute ischemic stroke or transient ischemic attack. METHODS Studies were identified from comprehensive searches of PubMed, EMBASE, Science Citation Index, and bibliographies of relevant articles. Only English language articles were included. Randomized controlled trials and prospective cohort studies of consecutive patients with acute ischemic stroke that fulfilled predefined criteria were eligible. Two authors conducted searches and abstracted data from eligible studies independently. RESULTS Sixty studies were deemed potentially eligible. After application of eligibility criteria, 5 studies (736 participants) were included in the analysis. All studies evaluated Holter monitoring; 2 also evaluated event loop recording. In studies that evaluated Holter monitoring (588 participants), new atrial fibrillation/flutter was detected in 4.6% (95% CI: 0% to 12.7%) of consecutive patients with ischemic stroke. Duration of monitoring ranged from 24 to 72 hours. Two studies (140 participants) evaluated event loop recorders after Holter monitoring. New atrial fibrillation/flutter was detected in 5.7% and 7.7% of consecutive patients in these 2 studies. CONCLUSIONS Screening consecutive patients with ischemic stroke with routine Holter monitoring will identify new atrial fibrillation/flutter in approximately one in 20 patients. Although based on limited data, extended duration of monitoring may improve the detection rate. Further research is required before definitive recommendations can be made.