DIAGNOSTIC-ACCURACY OF THE RESTING ELECTROCARDIOGRAM IN DETECTION AND ESTIMATION OF LEFT ATRIAL ENLARGEMENT - AN ECHOCARDIOGRAPHIC CORRELATION IN 551 PATIENTS

The identification of LA enlargement may have important clinical implications. Previous correlations of ECG P wave morphologies associated with LA enlargement and echocardiography have been limited by the use of small numbers of patients and by the employment of M-mode echocardiography without the benefit of two-dimensional guidance. The purpose of this study was to further examine the sensitivity and specificity of various P wave morphologies (P wave ≥110 msec, notched P ≥ 40 msec, and PTFV1 ≥ 40 msec · mm) for the diagnosis of LA enlargement and to determine if these waveforms may be predictive of LA size. ECGs and surface echocardiograms obtained within 1 week of each other were evaluated in 551 patients (140 normal and 411 study subjects). The various P wave morphologies were found to be poorly sensitive (30% to 60%) but very specific (90%) for LA enlargement. Combinations of P wave morphologies did not improve sensitivity or specificity. ECG features did give an estimate of the degree of LA enlargement. When PTFV1 is ≥40 msec · mm, 95% of patients had LA size ≥ 40 mm; and when this parameter was ≥60 msec · mm, 75% had LA size ≥60 mm. These criteria for LA enlargement on the ECG are specific and predictive of the degree of LA enlargement measured by echocardiography. © 1991.