Daytime-related arterial pressure fluctuations, heart rate cause myocardial arrhythmogenity. The goal of the study was to establish correlative connections between chronotropic-inotropic heart activity, positive baroreflector reactions of cardiovascular system, type of supraventricular and ventricular arrhythmias by Singh in patients with ischemic heart disease and hypertension. An object of study were 70 patients with the above mentioned pathology. Parametric and nonparametric correlation analysis of obtained results of investigation showed that heart rate increase and systolic arterial pressure combination at night time is a risk factor for myocardial arrhythmogenity.