The purpose of the study was to estimate the intensity of the proarrhythmic indices in patients with hypertensive disease and to evaluate the effect of the angiotensin-converting enzyme inhibitor perindopril on proarrhythmic factors. Out of 42 patients with stages I-II hypertensive disease, 28 (66.6 %) were observed to have cardiac arrhythmia. Patients with the signs of left ventricular hypertrophy were significantly more frequently found to have ventricular arrhythmias, including high-grade ones and decreased cardiac rhythm variability A significant decrease in both systolic and diastolic blood pressures was recorded alter therapy with perindopril in a dose of 4-8 mg for 6-10 months. At the same time, there was a significant reduction in the average daily number of premature ventricular beats and in the left ventricular myocardial mass index, and an increase in CRV. Evaluation of the effectiveness and tolerance of perindopril revealed that as main as6 patients had side effects that were not a reason for discontinuing the drug.