The non-invasive recognition of left atrial enlargement: comparison of electro- and echocardiographic measurements.

The aim of this study was to compare the ability of electro- and echocardiography to detect enlargement of the left atrium. Seventy-four patients, divided into three groups (eighteen normal, thirty-six valvular disease, twenty hypertension and/or coronary artery disease) were studied. The P wave terminal force in lead V1 (PTF-V1) was measured from a standard 12 lead electrocardiogram, and the internal left atrial dimension (LAD) was measured from time-motion echocardiograms. Linear regression analysis showed a small but significant linear correlation between PTF-V1 and LAD (r = 0-32, P less than 0-01). Both methods would separate patients with diseases known to cause left atrial enlargement from normals, but echocardiography showed greater "specificity" (100% v. 94+) and "sensitivity" (75% v. 67%). It was much superior to the ECG in detecting milder grades of left atrial enlargement and for following serial changes.