[Noninvasive registration of spontaneous ventricular potentials in patients with healthy hearts and in patients with intraventricular impulsive conduction disorders. Method and results of the signal averaging technic].

For registration of delayed depolarizations 50 healthy persons (age: 49.4 +/- 6.2 years) and 43 patients with bundle-branch block (age: 65.1 +/- 11.8 years; 23 of them with right and 20 with left bundle-branch block) underwent high-resolution electrocardiography at the body surface using signal-averaging technique. The findings were compared with results obtained in the 24-hour long-term ECG. In 2 normal persons (4%), delayed depolarizations were recorded whose configuration, however, differed from that of pathological findings in patients with coronary heart disease. 2 other subjects evidenced repetitive ventricular arrhythmias. Detection of delayed depolarizations in patients with coronary heart disease is indicative of an increased risk of malignant or even fatal arrhythmias. The low prevalence in healthy subjects underlines the specificity of this finding and represents the prerequisite for identifying patients with an increased risk. Delayed depolarizations were found also in 3 patients with right and 4 patients with left bundle-branch block (16.3% in all). 8 patients had repetitive ventricular arrhythmias, and one of them with a left bundle-branch block also revealed delayed depolarizations. Thus delayed depolarizations can be registered in some patients with intraventricular conduction defects. The incidence rate corresponds to that found in patients with coronary heart disease, so that detection of delayed depolarizations in this patient group is not helpful in the assessment of prognosis.