Optimal timing and duration of continuous electrocardiographic monitoring for detecting atrial fibrillation in stroke patients.

BACKGROUND: Several studies have suggested that after ischemic stroke, continuous electrocardiographic (ECG) monitoring (CEM) increases the atrial fibrillation (AF) detection rate. However, optimal CEM terms of use are not clear. The aim of our study was to evaluate the usefulness of CEM in detecting AF and define optimal terms of the use of CEM.
METHODS: We prospectively enrolled consecutive patients with acute ischemic stroke who were admitted to the stroke unit without AF on baseline ECG. We compared 2 strategies of AF detection: the first using CEM and the second with routine clinical practice (24-hour Holter ECG and additional ECGs). Adjusted odds ratios for the association between AF diagnosis and the use of CEM stratified by monitoring duration were calculated using multivariate logistic regression analysis.
RESULTS: Of the 1166 patients included, 220 (18.87%) had AF on baseline ECG and were excluded. Of the 946 remaining patients, 592 underwent CEM. The prevalence of AF using CEM was 12.50% compared 2.26% using the routine strategy. After adjustment (demographic data, vascular risk factors, and National Institutes of Health Stroke Scale scores), using CEM increased 5.29 fold the odds of finding AF (95% confidence interval [CI] 2.43-11.55) compared to the routine strategy. The adjusted odds ratio (9.82; 95% CI 3.01-32.07) was maximum for the first day of monitoring and decreased later. Beyond 5 days, CEM usefulness was not significantly higher than the routine strategy.
CONCLUSIONS: We suggest that in order to enhance the detection rate of AF, CEM could be generalized in the stroke unit. It must be started early in patients with acute stroke and prolonged over a minimum of 4 days.