The Heart Rate Variability in Patients with Obesity and Heart Failure with a Preserved Ejection Fraction

The aim of our study was to investigate changes in the heart rate variability in patients with heart failure with a preserved ejection fraction, overweighting and obesity of various degrees. Materials and methods: During the study we examined 127 patients with obesity or overweight (68 males and 59 females) and heart failure with a preserved ejection fraction. All participants of the study had a general clinical examination, echocardiography, ECG monitoring, and the assessment of the N-terminal fragment of precursor protein brain-type natriuretic peptide. Results and discussion. There was a significant increase in daytime LF spectrum in patients with overweight and obesity of the 1st class. LF decreased with an increasing level of obesity. There was no significant decrease in the VLF, LF, and LFN spectrum at night at the surveyed patients. There was no significant increase in HF and HFN at night in comparison with the control group. The ratio of LF / HF didn`t significantly increase in patients with heart failure with preserver ejection fraction. NTproBNP correlated with SDNN (r=-0,327, p<0,05), LF (r=0,224, p<0,05). Ejection fraction correlate with SDNN (r=0,489, p<0,05). BMI correlate with LF (r=0,331, p<0,05), HF (r=-0,422, p<0,05), SDNN (r=−0,426, p<0,05). Age correlated with SDNN (r=−0,426, p<0,05), RMSSD (r=−0,287, p<0,05), HF (r=−0,477, p<0,05) and LF/HF (r=0,392, p<0,05). Connections between SDNN and age (VS 1.37 (0,97-1,71), p <0,05), SDNN and BMI (VS 1,24 (0,92-1,49), p <0,05) and SDNN and NTproBNP (VS 0,94 (0,82-1,22), p <0,05) were established in univariate regression analysis. Conclusions. There is a decrease of the activity of the parasympathetic autonomic nervous system and an increase of the sympathetic activity in patients with heart failure with a preserved ejection fraction and obesity of the 1st class or overweight in comparison with healthy individuals. There is a progressive decrease in the activity of both parts of the autonomic nervous system with an increase in the degree of obesity. According to results of univariant regression analysis, the relationships between SDNN and age, BMI, NTproBNP were established.