The parameters of heart rate variability are known to be widely used for screening the occurrence of ventricular arrhythmia in patients with post-infarction left ventricular aneurysm. However, in literature, there are not much data on changes in heart rate variability in patients with post-infarction left ventricular aneurysm depending on different therapeutic approaches, and this issue is not sufficiently studied. The objective of the research was to study the peculiarities of heart rate variability in patients with post-infarction left ventricular aneurysms depending on therapeutic approach.Materials and methods. We analyzed heart rate variability of 238 patients with post-infarction left ventricular aneurysm. All patients were divided into 3 groups depending on therapeutic approach: optimal basic therapy, patients who underwent percutaneous coronary interventions and those after coronary artery bypass grafting. All patients underwent 24-hours standard ECG monitoring with the analysis of heart rate variability.Results. The study showed that heart rate variability of patients with post-infarction left ventricular aneurysm depended on treatment tactics; hypersympathicotonia was typical. The values of the low-frequency range in patients of Group I and Group III constituted 3103±93.6 ms2 and 3295±45.4 ms2, respectively, which was higher compared to those in the control group and Group II, р<0.05. Parasympathetic influences in patients with post-infarction left ventricular aneurysm were weakened. The analysis of the integral parameters showed that in patients with post-infarction left ventricular aneurysm the autonomous mechanisms of regulation predominated over the central ones. The centralization index was the lowest in patients of Group I and Group II, 2.9±0.3 and 2.3±0.1, respectively, being lower compared to the control group, р<0.05. The other peculiarities were detected as well.Conclusions. The parameters of heart rate variability in patients with post-infarction left ventricular aneurysm were found to depend on treatment tactics. The patients with non-surgical treatment tactics had the most unfavorable heart rate variability characteristics. They developed hypersympathicotonia and high humoral regulatory influences. The application of revascularization when treating patients with post-infarction left ventricular aneurysm using percutaneous coronary interventions can reduce the aggressive sympathetic influences, as well as the value of the Baevsky index. Revascularization with the use of coronary artery bypass grafting does not allow optimizing the autonomous imbalance, although it reduces stress index.