title: Very short paroxysms account for more than half of the cases of atrial fibrillation detected after stroke and TIA: a systematic review and meta-analysis.
abstract: BACKGROUND
  Guidelines suggest that only poststroke atrial fibrillation episodes lasting 30 s or longer should be considered for anticoagulation. However, little evidence supports this recommendation.
  
  
  OBJECTIVE
  We performed a systematic review and meta-analysis to investigate the frequency of poststroke atrial fibrillation lasting less than 30 s in stroke and transient ischemic attack patients.
  
  
  METHODS
  We searched PubMed, Embase, and Scopus from 1980 to June 30, 2014 for studies reporting the detection of poststroke atrial fibrillation of less than 30 s and of 30 s or longer. The primary endpoint was the proportion of screened patients diagnosed with poststroke atrial fibrillation lasting less than 30 s. The secondary endpoint was the proportion of patients diagnosed with poststroke atrial fibrillation shorter than 30 s among the overall number of patients in whom a poststroke atrial fibrillation was detected after stroke or transient ischemic attack.
  
  
  RESULTS
  From 28 290 titles, we included nine studies in the random-effects meta-analysis. Among stroke and transient ischemic attack patients without a history of atrial fibrillation, 9·0% (95% confidence interval: 4·9-14·3) experienced episodes of poststroke atrial fibrillation shorter than 30 s. An additional 6·5% (95% confidence interval: 3·2-10·9) experienced episodes of poststroke atrial fibrillation longer than 30 s. Among all patients with poststroke atrial fibrillation, 56·3% (95% confidence interval: 37·7-74·0) had poststroke atrial fibrillation episodes shorter than 30 s during diagnostic evaluation.
  
  
  CONCLUSIONS
  The clinical and prognostic significance of poststroke atrial fibrillation episodes shorter than 30 s is unknown. The high frequency of poststroke atrial fibrillation episodes shorter than 30 s justify further investigation into the risk of stroke recurrence and the risk-benefit profile of anticoagulation for this patient population.
authors.affiliation: Department of Clinical Neurological Sciences, London Health Sciences Centre. Western University, London, ON, Canada.
authors.forename: Luciano A
authors.identifier: http://orcid.org/0000-0001-6425-9343
authors.initials: LA
authors.lastname: Sposato
authors.affiliation: Ivey Business School, Western University, London, ON, Canada.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Cipriano
authors.affiliation: Department of Clinical Neurological Sciences, London Health Sciences Centre. Western University, London, ON, Canada.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Riccio
authors.affiliation: Department of Clinical Neurological Sciences, London Health Sciences Centre. Western University, London, ON, Canada.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Hachinski
authors.affiliation: Stroke Outcomes Research Center, Division of Neurology, Department of Medicine, St. Michael's Hospital and Institute of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.|Li Ka Shing Knowledge Institute, Toronto, ON, Canada.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Saposnik
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*; D020521:Stroke / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*; D013997:Time Factors
keywords: atrial fibrillation; cardiac embolism; cardio-aortic embolism; meta-analysis; screening; transient ischemic attack