Left atrial enlargement. Echocardiographic assessment of electrocardiographic criteria.

Abstract

A comparison of electrocardiographic manifestations of left atrial enlargement (LAE) and left atrial size by echocardiography was made in 307 patients in sinus rhythm. Electrocardiographic criteria used were L:P wave duration in lead II equal to or greater than 0.12 s; Va: the ratio of the duration of negative terminal P in V1 to the P-R segment equal to or greater than 1.0; Vb: a negative P terminal force in V1 less than -0.03 mm s. The echocardiographic diagnosis of left atrial enlargement was based on transverse dimension greater than 4.0 cm, or a ratio of transverse atrial to transverse aortic root dimension greater than 1.17. In the presence of left atrial enlargement, a combination of criteria occurred more often than a single criterion. The overall predictive index of the electrocardiogram for left atrial enlargement was 63% (excluding criterion Vb raised probability to 80%); and that for absence of left atrial enlargement was 78%. The index of coarse vs. the fibrillary waves was unreliable in predicting left atrial enlargement. Changes in P wave morphology may be used as a resonably specific but less sensitive indicator of left atrial enlargement.