THE RELATIONSHIP BETWEEN LOWER SERUM MAGNESIUM LEVELS AND HEART RATE VARIABILITY INDICES

Introduction: Magnesium is required in muscular contraction, neuromuscular conduction, heart functions, and vascular tone. Heart rate variability (HRV) is a non-invasive assessment method of the autonomic nervous system activity which regulates heart rate (HR). Time-domain, frequency-domain and non-linear analysis of the HRV can establish the autonomic tone balance. Objectives: The purpose of this study was to investigate the relationship between lower serum magnesium levels and HRV indices, and to observe if magnesium supplementation can corrected autonomic functions. Methods: We analyzed HRV parameters in 30 patients with hypomagnesaemia and 20 age-related healthy subjects. Results: In control group we found lower values for HR, LF nu and LF/HF ratio (p< 0.0002) and higher values for HF nu, SD1 when compare with patients with magnesium deficiency, resulting that in supine position there is an enhanced heart rate. In magnesium deficiency group we found increase LF nu, LF/HF ratio suggesting that the sympathovagal balance was affected with a sympathetic overactivity. After magnesium supplementation the HR, LF/HF ratio decrease and RMIMSD, pNN50%, HF, SD1 increase in these patients. Conclusions: Findings from the current study suggest that Mg supplementation may enhance parasympathetic activity and therefore presenting a positive impact on cardiac autonomic function.