[Signal-averaged ECG and left-ventricular function in patients with severe ventricular arrhythmia in ischemic heart...

In 35 patients with ischemic heart disease we evaluated the incidence of ventricular late potentials and left ventricular function. The patients were divided into two groups: group A consisting of 15 patients (14 men, 1 woman) aged from 40 to 71 years (mean age 56) with previously documented ventricular tachycardia or fibrillation, and into group B comprising 20 subject (16 men, 4 women) aged from 35 to 62 years (mean age 50) with ischemic heart disease without the above-mentioned arrhythmias. Time from the development of ventricular tachycardia or fibrillation was 3 weeks to 4 years. The incidence of arterial hypertension and previous myocardial infarction was similar in both groups. Body surface late potentials were recorded by signal averaging technique according to Simson using Frank's orthogonal XYZ lead system. In addition, in all the patients 24-hour ECG monitoring was performed to reveal any ventricular rhythm disturbances and echocardiography was used to evaluate left ventricular function. The presence of the ventricular late potentials meeting at least two of the Simson's--Dene's criteria was found in 13 (87%) patients in group A and in 2 (10%) patients from group B. In the patients after ventricular tachycardia or fibrillation the mean values of th total QRS duration (QRS-D) and the low amplitude signal duration (LAS40) were higher whereas the root mean square voltage of the last 40 ms of th vector magnitude QRS (RMS) was lower (154 ms, 56 ms, 15 muV, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)