Relation of Electrocardiographic Left Atrial Abnormalities to Risk of Stroke in Patients with Atrial Fibrillation

Abstract

The P-wave terminal force in lead V₁ (PTFV₁) on the 12-lead electrocardiogram (ECG) quantifies left atrial (LA) structural and electrophysiologic abnormalities. We aimed to evaluate the association between PTFV₁ and cerebrovascular accident (CVA) as well as LA structure and function in patients with atrial fibrillation (AF). We conducted a cross-sectional study of 229 patients with AF (60 ± 10years, 72% men) with (n = 21) and without (n = 208) a history of CVA, who underwent preablation ECG and cardiac magnetic resonance in sinus rhythm. PTFV₁ was defined as the duration (in milliseconds) of the downward deflection of the P wave in lead V₁ multiplied by the absolute value of its amplitude (in microvolts) on ECG. PTFV₁ is associated with LA minimum volume (V_min) and left ventricular ejection fraction but not associated with the extent of LA fibrosis quantified by cardiac magnetic resonance late gadolinium enhancement. In addition, PTFV₁ is associated with CVA independent of the CHA₂DS₂-VASc score and LA V_min (odds ratio 1.23; 95% confidence interval 1.08 to 1.40; p = 0.002). Furthermore, PTFV₁ has an incremental value over the CHA₂DS₂-VASc score as a marker of CVA (p <0.001). In conclusion, ECG-defined PTFV₁ is independent marker of stroke in patients with AF and reflects the underlying LA remodeling. Our findings suggest that evaluation of PTFV₁ can improve the current risk stratification of stroke.