Silent Atrial Fibrillation after Ischemic Stroke or Transient Ischemic Attack: Interest of Continuous ECG Monitoring

Background: Since atrial fibrillation (AF) may be undiagnosed when asymptomatic and paroxysmal, we aimed to investigate the incidence and determinants of silent AF in patients with acute ischemic stroke or transient ischemic attack (TIA). Methods: Consecutive patients admitted to the Stroke Unit of the University Hospital of Dijon, France, for acute ischemic stroke or TIA were prospectively enrolled from March to December 2012. Silent AF was assessed by continuous electrocardiography (ECG) monitoring for 24 h after admission. An echocardiography was performed at day 2 +/- 1 to measure left ventricular ejection fraction (LVEF) and left auricular (LA) dimensions. Results: Among the 187 patients included, 19 (10%) developed silent AF. Patients with silent AF were markedly older (76 vs. 66 years, p < 0.002), with lower creatinine levels (90 vs. 80 mu mol/l, p = 0.030) and were less often smokers (5 vs. 24%, p = 0.058) than patients without silent AF. They also showed a trend towards more frequent hypertension and a recent history of infection. Patients with silent AF had a larger indexed LA volume (37.4 vs. 30.8 ml/m(3), p = 0.057) and LA diameter (23.2 vs. 20.8 mm/m(2), p = 0.059). LVEF in the two groups was similar. In multivariate analysis, only age remained an independent estimate of silent AF. Conclusion: Silent AF detected by continuous ECG monitoring is common and closely associated with older age. Further studies are needed to investigate the interest of systematically screening for silent AF for secondary prevention after ischemic stroke/TIA. (C) 2014 S. Karger AG, Basel