Electrocardiographic left atrial abnormalities and risk of ischemic stroke

Background and Purpose - We evaluated the association between electrocardiographic left atrial abnormality (ECG-LAA) and ischemic stroke, especially whether ECG-LAA provides additional prognostic information to that provided by echocardiography. Methods - A population-based, case-control study included 146 patients with first ischemic stroke and 195 age-, gender-, and race/ethnicity-matched community control subjects. ECG-LAA was defined as either P-wave duration >120 ms or P-terminal force in precordial lead V₁ (PTFV₁) >40 ms·mm. Results - PTFV₁ >40 ms·mm was associated with ischemic stroke after adjustment for other stroke risk factors (odds ratio [OR], 2.32; 95% CI, 1.29 to 4.18). The association remained significant after adding echocardiographic left atrial diameter to the model (OR, 2.31; 95% CI, 1.28 to 4.17). PTFV₁ was independently associated with stroke in patients in the upper half of echocardiographically determined left ventricular mass (adjusted OR, 4.5; 95% CI, 2.20 to 9.15) but not in those in the lower half (OR, 0.58; 95% CI, 0.20 to 1.65; P=0.0008). Conclusions - ECG-LAA can supplement 2D echocardiography in assessing the risk of ischemic stroke, especially in subjects with increased left ventricular mass.