Lifestyle Intervention Improves Parasympathetic Activity in Hypertrophic Cardiomyopathy

Abstract

Background A limited number of studies have investigated the effects of lifestyle interventions in hypertrophic cardiomyopathy (HCM). This study evaluated the effect of a novel lifestyle intervention incorporating physical activity (PA) and dietary nitrate supplementation on heart rate variability (HRV) and haemodynamic measures in HCM. Methods Twenty-eight individuals with HCM were randomised into either the intervention or control group. Frequency-domain HRV measures including low frequency power (LF), high frequency power (HF) and LF/HF were recorded at rest using bioimpedance. Non-invasive haemodynamic variables were recorded at rest using bioreactance. Participants in the intervention group consumed 6 mmol of nitrate daily (concentrated beetroot juice) and were instructed to increase and maintain daily PA by ≥ 2000 steps/day above baseline for 16 weeks. Control group participants retained their usual lifestyle and monitored daily step counts. Results There was a significant increase in post-intervention HF power (7.54 ± 2.14 vs 8.78 ± 1.60 ms2, P < .01) and LF power (6.89 ± 2.33 vs 8.17 ± 1.55, P < .01) in the intervention but not in the control group. Resting mean arterial blood pressure (MABP) in the intervention group significantly reduced at follow-up (108 ± 6 vs 102 ± 7 mmHg, P < .01). Conclusions A novel lifestyle intervention including PA and dietary nitrate supplementation enhanced parasympathetic activity and resting MABP in HCM.