[Late ventricular potentials. Clinical applications and relation to severe ventricular arrhythmias].

The recording of late ventricular potentials with high amplification cardiography (HAC) permits to identify patients presenting a risk of sudden death and ventricular tachycardia, especially in the later stage of myocardial infarction. Few authors have studied the prevalence of these potentials in other heart diseases presenting a risk of sudden death. Most series in the literature are too small to specify variations in the prevalence of these potentials according to the severity of the coronary disease. For this purpose, 835 patients including 535 coronary patients were evaluated with HAC compared to data from coronary angiography and Holter test. An automatic quantification method of the late potentials was used on 131 healthy subjects. The prevalence of late potentials is 32 p. cent after infarction, and 75 p. cent when a chronic ventricular tachycardia is present. These potentials retain their significance of tracers of ventricular arrhythmias in primary dilated myocardiopathies, with a prevalence of 25 p. cent reaching 50 p. cent in case of ventricular tachycardia. Their recording in the presence of idiopathic ventricular extrasystoles must be an indication to look for an underlying cardiopathy. It is possible to record them in other diseases especially in advanced valvular cardiopathies, as well as in right ventricular dysplasias with arrhythmia where their presence has a great diagnostic value.