[The characteristics of the autonomic regulation of the heart rate in patients with IHD and ventricular arrhythmias under obzidan therapy].

Propranolol hydrochloride was administered to 30 patients with stable angina pectoris suffering from coronary heart disease (CHD). Of them 18 patients had ventricular extrasystole, 12 had ventricular tachycardia. All the patients underwent resting ECG, bicycle ergometry, transesophageal pacing, 24-h ECG monitoring. Vegetative cardiac regulation was determined using mathematical analysis of at least 100 successive intervals R-R at rest before and after therapy (120 mg day of propranolol hydrochloride). The authors estimated characteristics of the variance analysis and two secondary values--stress index and centralization index calculated by spectral characteristics of the rhythm. Only in CHD patients with ventricular tachycardia the treatment shifted the vegetative tone in the direction of parasympathetic nervous system. It is concluded that propranolol hydrochloride affects cardiac rhythm depending on the initial condition of vegetative regulation of cardiac activity.