56-76: External Loop Recording for 7 Days Detects More Patients with Atrial Fibrillation Compared to 2-Day Holter Recording in Patients with Ischemic Stroke or Transient Ischemic Attack

Atrial fibrillation (AF) is the most important cardiac cause for ischemic stroke and transient ischemic attacks (TIA) and the detection of AF has important therapeutic consequences in these patients. AF is, however, often paroxysmal and asymptomatic and the optimal method for detection of AF in patients with stroke/TIA is not yet defined in the guidelines. The external loop recorder (ELR), R.Test Evolution 4®, is a new device that continuously monitors and automatically analyses heart rhythm. The method is significantly less resource demanding compared to a traditional Holter analyses, but the diagnostic value of the ELR with regard to detection of AF compared to Holter is unknown. Aim: To compare the diagnostic value of a 7-day ELR recording to a 2-day Holter recording with regard to the detection of AF in a consecutive population of patients with ischemic stroke/TIA and without a history of AF. Material and methods: Consecutive patients with stroke/TIA within the previous week were included from the department of Neurology in our hospital during April 2014 to January 2015. Inclusion criteria were age ≥ 60 years, no AF on surface ECG and no history of AF, no pacemaker, no active cancer or expected low compliance. The 2-day Holter recording and the 7-day ELR were started simultaneously. Atrial fibrillation was defined as absolutely irregular intervals between two R waves, in the absence of P-waves and lasting more than 30 seconds. Results: We included 190 patients, mean (s.d.) age was 71.1 (7.6) years and 57% were male. The 2-day Holter analysis primarily detected four patients with AF, one of whom was missed by the ELR. The Holter recording of this patient was scrutinised and it turned out, that the patient had an atrial tachycardia and not AF. The 7-day ELR detected the same three patients with AF as the three true positive on the 2-day Holter and further six patients with AF after the 2-day Holter period. The prevalence of AF was 1.6 % using the 2-day Holter versus 4.7 % using the 7-day ELR. The 7-day ELR recording thus detected significantly more patients with AF compared to the 2-day Holter recording (p = 0.031, Exact McNemar). Conclusion: A 7-day ELR analysis detects significantly more patients with AF than a 2-day Holter recording. These finding have clinical implications because the ELR analysis is less resource demanding than Holter recording analysis.