[Late right and left ventricular potentials using inter-cardiac recording in patients with ischemic heart disease--methodologic and clinical problems].

The aim of the study was to compare detection frequency of late inter-cardiac potentials recorded from the right and left ventricle. There was also estimated relationship between their incidence and ventricular tachycardia or fibrillation occurrence. 41 patients with ischemic heart disease underwent the study. Electrophysiologic examination were performed because of ventricular tachycardia and/or fibrillation attacks or complex ventricular arrhythmias recorded in ECG Holter monitoring. In 11 patients intracardiac electrocardiograms were recorded from both ventricles, in 29 only from the right and in 1 from the left one. All patients underwent programmed right and/or left ventricular stimulation. Left ventricular end-diastolic diameter, segmental contractility and ejection fraction were echocardiographically estimated. Study results were statistically analyzed by means of CHI2 and t-Student tests for unpaired variables. Late potentials were more frequently observed in patients with left ventricular dyskinesis (p less than 0.01) and decreased ejection fraction. Late potentials recorded in patients with a history of ventricular tachycardia or fibrillation were more delayed to proceeded QRS complex and had a greater amplitude. This prolongation of ventricular activation can make an anatomic substrate for dangerous ventricular arrhythmias occurrence. Since the presence of late potentials in patients with contractility disorders is connected with more frequent incidence of spontaneous and provoked ventricular arrhythmias, endocardial late potentials recording may be of a prognostic value, if it is performed from both ventricles.