Echocardiographic and electrocardiographic criteria for diagnosing left atrial enlargement.

Electrocardiographic criteria for left atrial enlargement (LAE) were evaluated in a group of 100 patients with a wide spectrum of cardiovascular diseases and compared with the echocardiographic measurement of left atrial dimension (LAD). Data analysis showed a high degree of correlation between the echocardiographic measurement of LAD and the EKG criteria for LAE. The magnitude of the P terminal force in lead V1 was the most specific of the EKG criteria evaluated, while the P/P-R segment ratio was least specific. Concordance between the two methods of measuring left atrial size increased when multiple positive EKG criteria were present.