title: Improved detection of silent atrial fibrillation using 72-hour Holter ECG in patients with ischemic stroke: a prospective multicenter cohort study.
abstract: OBJECTIVE
  Adequate diagnosis of atrial fibrillation (AF), including paroxysmal AF, is an important part of stroke workup. Prolonged ECG monitoring may improve the detection of paroxysmal, previously undiagnosed AF (unknown AF). Therefore, we evaluated systematic 72-hour Holter ECG monitoring to detect unknown AF for the workup of patients with stroke.
  
  
  METHODS
  Unselected survivors of a stroke or transient ischemic attack (TIA) without known AF were enrolled in a prospective, multicenter cohort study of 72-hour Holter ECG monitoring in 9 German secondary and tertiary stroke centers between May 2010 and January 2011. In addition to standardized workup of stroke pathogenesis according to the German Stroke Unit protocol, all patients underwent 72-hour Holter ECG monitoring directly after admission. All ECGs were centrally analyzed by 2 independent observers. We determined the proportion of unknown AF and compared the detection rates of 72- and 24-hour monitoring.
  
  
  RESULTS
  A total of 1135 patients were enrolled (mean age, 67 years [SD, 13.1 years], 45% women, 29% TIA). Unknown AF was detected in 49 out of 1135 patients (4.3%, [95% confidence interval, 3.4-5.2%]) by 72-hour ECG monitoring. Unknown AF was diagnosed in 29 patients (2.6%) within the first 24 hours of ECG monitoring, and in 20 more patients only by 72 hours of ECG monitoring. The number needed to screen by 72-hour ECG was 55 patients (95% confidence interval [35-123]) for each additional AF diagnosis. Patients with unknown AF were significantly older and had more often a history of previous stroke. Patients with unknown AF were equally distributed within categories of pathogenesis according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification.
  
  
  CONCLUSIONS
  In unselected survivors of stroke or TIA, 72-hour ECG monitoring is feasible and improves the detection rate of silent paroxysmal AF.
authors.affiliation: From the Department of Neurology, Kreisklinikum Siegen, Siegen, Germany (M.G.); Department of Neurology, Hainich Klinikum, Mühlhausen, Germany (M.J.); Department of Neurology, HSK Klinik, Wiesbaden, Germany (G.H.); Department of Neurology, Klinikum Offenbach, Offenbach, Germany (E.S.); Department of Neurology, University of Heidelberg, Germany (R.V.); Department of Neurology, Vivantes Klinikum Neukölln, Berlin, Germany (D.N.); Department of Neurology, Klinikum Bad Hersfeld, Bad Hersfeld, Germany (M.H.); Department of Neurology, University of Essen, Germany (C.W.); Department of Neurology, University of Erlangen, Germany (M.K.); Department of Neurology, University of Göttingen, Germany (R.W.); Sanofi-Aventis Deutschland, Berlin, Germany (L.R.); and University of Birmingham Centre for Cardiovascular Sciences, Birmingham, UK, and Department of Cardiovascular Medicine and Atrial Fibrillation competence NETwork (AFNET), University Hospital Münster, Germany (P.K.).
authors.forename: Martin
authors.initials: M
authors.lastname: Grond
authors.forename: Marek
authors.initials: M
authors.lastname: Jauss
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hamann
authors.forename: Erwin
authors.initials: E
authors.lastname: Stark
authors.forename: Roland
authors.initials: R
authors.lastname: Veltkamp
authors.forename: Darius
authors.initials: D
authors.lastname: Nabavi
authors.forename: Markus
authors.initials: M
authors.lastname: Horn
authors.forename: Christian
authors.initials: C
authors.lastname: Weimar
authors.forename: Martin
authors.initials: M
authors.lastname: Köhrmann
authors.forename: Rolf
authors.initials: R
authors.lastname: Wachter
authors.forename: Ludger
authors.initials: L
authors.lastname: Rosin
authors.forename: Paulus
authors.initials: P
authors.lastname: Kirchhof
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D002545:Brain Ischemia / Q000150:complications* / Q000503:physiopathology; D015331:Cohort Studies; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000150:complications* / Q000503:physiopathology; D013997:Time Factors
keywords: Holter ECG; anticoagulation; atrial fibrillation; new oral anticoagulants; secondary prevention; stroke; vitamin K antagonists