Electrocardiographic Changes Reflecting Left Atrial Abnormality in Hypertension

To separate the effects of hypertension and atherosclerosis on the left atrium, the electrocardiograms of 76 hypertensive patients and 76 normal control subjects, matched for age and sex, were studied. Four established criteria for left atrial abnormality were used. One or more positive criteria were satisfied in 45 of the 76 patients and 28 had two or more positive criteria. In contrast, only four of the 76 normal subjects had one abnormal criterion; none had more than one. In 37 patients selective coronary cinearteriography was performed and five of these with abnormal P waves had no arteriographic evidence of atherosclerosis. Eleven of 45 patients with left atrial abnormality had repeated episodes of atrial arrhythmias, whereas only one of the 31 patients with normal P waves had an atrial arrhythmia, demonstrating that repeated atrial arrhythmias are more frequent in patients with left atrial abnormality. Left atrial abnormality was, therefore, a frequent finding in hypertension; it may occur even in the absence of cardiac enlargement and coronary arterial disease. It was, at times, the sole sign of cardiac abnormality in hypertension.