Abstract 17241: Electrocardiographic Left Atrial Abnormalities and Risk of Stroke in Patients with Atrial Fibrillation

Introduction: Mounting evidence suggests that left atrial (LA) structural remodeling plays an important role in the mechanism of stroke in patients with a history of atrial fibrillation (AF). We evaluated the association among the severity of LA abnormality on electrocardiogram (ECG), the severity of LA structural remodeling by cardiac magnetic resonance (CMR), and a history of stroke or transient ischemic attack in patients with AF referred for catheter ablation. Methods: A total of 229 consecutive patients (age 60±10 years, 72% male) referred for catheter ablation of AF who were in sinus rhythm at the time of pre-ablation ECG recording and CMR were included, with (n=21; the stroke group) and without (n=208; control group) a history of stroke or TIA. The severity of LA abnormality on ECG was quantified from the P wave terminal force in lead V 1 (PTFV 1 ). Results: In the stroke group, PTFV 1 was significantly higher compared with the control group (8,107±5,921 vs. 4,865±3,205μV*ms; p 2 ) and decrease in left ventricular ejection fraction (%) were associated with an increase in PTFV 1 (47.7 and 74,1μV*ms; p=0.027 and 0.005, respectively). Multivariable analysis demonstrated that the PTFV 1 and LA emptying fraction were associated with a history of stroke (odds ratio 1.23 and 0.94; p=0.002 and 0.037, respectively) after adjusting for the CHA 2 DS 2 -VASc score and the LA minimum volume. Conclusions: PTFV 1 is an independent marker of stroke, and provides an incremental value to the CHA 2 DS 2 -VASc score in patients with AF. Evaluation of LA abnormalities by 12-lead ECG may improve the current risk stratification of stroke in patients with AF.