Frequency indicators of heart rate variability in assessing the effectiveness of antihypertensive therapy in patients with metabolic disoders
Authors: Irina Kurnikova, Shirin Gulova, Tatiana Nikishova, Nikolay Kislyy, Sofia Buturlina, Oksana Demina
Abstract: Introduction. Modern computer technologies that allow analyzing the dispersion of signals from biological objects significantly expand the diagnostic capabilities of medicine. Heart rate variability analysis (HRV) is a very promising technology that allows us to evaluate not only the function of the cardiovascular system, but also the state of the mechanisms of autonomic regulation (AR) in general. Purpose: to identify the relationship between the initial autonomous status and the effectiveness of the use of antihypertensive drugs (AHT) in patients with metabolic disorders by comparative analysis of HRV. Materials and methodsThe study included 87 patients with diabetes (DM) and arterial hypertension (HTN). Clinical examination included metabolic status, hemoglobin A1c. 49 people (observation group - 1) had unsatisfactory glycemic control (HbA1c=11±3.1%), including 19 patients (32±6.7y.) with type 1 diabetes-DT1 (1а) and 30 patients (52±7.1y) with type 2 – DT2 (1b). The comparison group (2) included 38 patients with compensated diabetes (HbA1c=6.2±4.3%), 22 people had DT1– 2a (29.5±4.9y.), 16 - DT2 – 2b (55±4.4y.). As AHT, patients took moxonidine (0.2-0.4 mg/day). Holter ECG monitoring complex "Valenta"MN-08 (Russia) with a set of computer programs. The HRV spectral analysis: total power of the frequency spectrum – TC (ms2); LF (%) - the low-frequency component - waves of 0.04-0.15 Hz (reflects activity of the sympathetic system); HF (%) - high-frequency waves from 0.15 to 0.40 Hz (activity of the parasympathetic nervous system at the segmental level); ULF (%) - ultra-low frequency - waves up to 0.0033 Hz, (activity of the higher centers of HR regulation); VLF (%) – very low frequency - 0.0033-0.04 Hz (functional state of suprasegmental structures). Index of Centre (IC) - ratio of the activity of the central regulation loop to the autonomous = (LF+VLF)/HF; Index vagosympathetic balance (IVB) – ratio LF/HF.Results.There were significant changes in HRV, but the direction and severity of disorders in different types of DM was not the same. IC in patients with DT2 was low - 1.19 ± 0.08, which is possible only with a pronounced disturbance of central and autonomic links of HR regulation. The power of the low-frequency (LF-24.2±2.1%, VLF-23.4±3.7%, ULF-30.8±8.4%) prevailed over of HF-21.6±2.9%, which is characteristic of disruption of AR. Group 1a didn’t affect IC (1.32 ± 0.17), but was accompanied by decrease of TC, the predominance of ULF-36.5 ± 11%, VLF-33.9±4.7%, LF-17.4 ± 6.9% over the high-frequency (HF-11.7 ± 1.5%). LF/HF was higher than the average, confirming hypersympathicoton. Autonomous imbalance was observed in 1b, but against the background of increased activity of the parasympathetic nervous system (LF/HF=0.86±0.07). Pronounced clinical efficacy of moxonidine was observed in 92.7% of patients 2a regardless of compensation and 87.5% - 2b. After the appointment to group 1a, TC increased, which indicated the restoration of autonomous balance. The HF increased (18.4±1.9%) and LF/HF normalized - 1.23±0.14. VLF decreased, LF and ULF didn’t significantly change. The clinical efficacy of moxonidine in monovariant didn’t exceed 46.7% and combination therapy with other pharmacological groups was required. Conclusion. Insufficient effectiveness of therapy in patients of this group was associated with pronounced changes in autonomic regulation.
Keywords: Holter Ecg Monitoring, Heart Rate Variability, Autonomous Regulation, Antihypertensive Therapy, Diabetes
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