Electrocardiographic diagnosis of left atrial enlargement. Role of the P terminal force in lead V1.

The ability of the electrocardiographic criterion, P terminal force in lead V1 (PTF-V1), to diagnosis left atrial enlargement (LAE) is evaluated in a group of 317 men. A left atrial index greater than 2.2 cm/m2, determined by echocardiography, is used as the standard for LAE. The value for this criterion of 0.04 mm-sec performs best, although there is no significant difference in percent correct diagnosis for values of PTF-V1 ranging from 0.03 to 0.09 mm-sec.