Parameters of the spectral analysis of the heart rate variability in treating depression

The objective of this work was to study circadian rhythms of the indicators of the spectral analysis of the heart rate variability in case of depression.
Materials and methods. A total of 37 patients, with a mean age of 46.7±10.3 years, were examined. According to the International Classification of Disease, 10th revision (ICD-10), endogenous depression was diagnosed for all of them (F 31.3–31.4, F 32.0–32.2, F 33.0–33.2). To assess the variability of the heart rhythm, the spectral analysis was used. The patients were examined at 1 AM, 7 AM, 1 PM, 7 PM prior to the beginning of treatment, following one week, and upon leaving the inpatient department. The control group consisted of 15 mentally healthy people.
Results. Before the beginning of treatment, desynchronization of circadian rhythms of the indicators studied and the sleep-wake cycle, the increase in the spectrum power within lowfrequency (LF) range, and the decrease in the spectrum power within high-frequency (HF) range were observed. Reduction of depression symptoms was followed by resynchronization of the rhythms under study, with a spectrum power within LF range being increased and that within HF range – decreased.
Conclusions. Changes in depression symptoms and chronobiological disorders testify to their close pathogenetic link.