[Use of signal averaging system in the study of ventricular late potentials]

Signal-averaged electrocardiograms (SAECGs) were performed in 93 patients with various heart diseases and 20 dogs with experimental acute myocardial infarction. SA-ECGs were recorded with a high-pass bidirectional digital filter Mode FDS which was made by Shanghai Fudan University and Suzhou Medical College. All the patients and dogs were also examined with ART 1200 EPX recorder. Ventricular late potentials (VLPs) were directly recorded from the epicardium with experimental infarction by using composite electrodes and signal averaging system in late stage of coronary ligation. The results showed: VLPs were detected by body surface SA-ECG only in half of the dogs with VLPs detected by the real time mapping on infarction region, but the abnormal SAECGs did reveal the delayed ventricular activity; the data obtained with FDS or ART SA-ECG were similar.