Contribution of the high amplitude electrocardiography to the detection of ventricular late potentials in several cardiovascular diseases.
The criteria for detection of ventricular late potentials (VLP) by high amplitude electrocardiography (ECG) in the frequency domain were evaluated in 75 patients with cardiovascular diseases, mostly men (85%), with a mean age of 57 years, distributed by disease type into three subgroups: (1) with a history of myocardial infarction (MI)--53 cases; (2) with syncopes, episodes of prolonged ventricular arrhythmias--18 cases; (3) with unobstructive, primary cardiomyopathies--4 cases. Complete clinical examination, standard ECG, continuous 24 hr Holter ECG, high amplitude ECG (Corazonix system) for detection of VLP by analyses in the time domain (TD) and in the frequency one (FD) were performed in all the cases. The VLP incidence was evidently high in all the cases. By association of the analyses in TD and FD, the accuracy of VLP detection increased by 17.3% in the whole group (from 64% to 81.3%). The incidence of severe ventricular arrhythmias (class 4-5 Lown, i.e., doubled and/or trebled ventricular extrasystoles, salvos of unsustained ventricular tachycardia) was evidently higher in the patients with VLP (88% compared with 77% in the absence of VLP), thus demonstrating the presence, in most of the patients studied, of an arrhythmogenic mechanism by ventricular reentry.