Atrial fibrillation is the most frequent cause of the cardioembolic stroke but often remains underdiagnosed. It is often asymptomatic or intermittent and, thus, may not be detected on standard 12-lead ECG or even 24-hour Holter ECG recording. Jabaudon et al. in their study have hypothesized that 7-day ambulatory ECG monitoring using an event-loop recording (ELR) device would detect otherwise occult episodes of atrial fibrillation and flutter (AF) after acute stroke or transient ischemic attack (TIA).
Their analysis is based on the data of one hundred forty-nine consecutive patients, who were admitted to the neurology department with an acute stroke or TIA. These subjects were screened for embolismic arrhythmias using standard ECG methods. The screening protocol represented the goal of the study. At first, the patients had undergone standard short ECG measurement. Then, the absence of AF on this measurement, they underwent 24-hour Holter ECG recording. For patients with normal Holter it was followed by a 7-day ambulatory ECG monitoring (ELR). Patients with previously documented persistent AF, with primary hemorrhagic stroke, or with acute large vessel dissection were not included in the study. This approach allowed the authors to correctly compare the practiacl efficiency of different methods of AF detection.
AF was detected in 22 patients. Standard ECG identified AF in 2.7% of the cases at admission (4/149 patients) and in 4.1% of remaining patients within 5 days (6/145). Holter disclosed AF in 5% of patients with a normal standard ECG (7/139 patients), whereas ELR detected AF in 5.7% of patients with a normal standard ECG and normal Holter (5/88 patients).
Following an acute stroke or TIA, ELR identified patients with AF, which remained undetected with standard ECG and with Holter. The authors come to the conclusion that ELR should, therefore, be considered in every patient in whom a cardioembolic mechanism is suspected.