Assessment of autonomic function with heart rate turbulence and heart rate variability in young obese patients

Abstract

Background: Sudden cardiac death (SCD) is a main cause of cardiovascular mortality in developed countries. Obesity-related impairment of the cardiovascular system may be exist even at the young age, and progress asymptotical for decades before clinical manifestations present in. Death may be sudden in obese individuals with or with- out arrhythmias Heart rate turbulence (HRT) and Heart rate variability (HRV) both of which reflects autonomic dysfunction is a proven non-invasive electrocardiographic predictor of cardiac death. Aims & Objectives: To evaluate autonomic function with Heart rate turbulence (HRT) and Heart rate variability (HRV) in young obese patients without comorbidities. Materials and Methods: 60 young patients with age ≤35 of body mass index (BMI) ≥30 (average 34.12 ± 2.59) and 40 young healthy patients with ≤35 of BMI <25 (23.25 ± 1.14) matched age and sex were divided in two groups (group 1: obese patients and group 2: Non-obese patients respectively). 24 hours ambulatory holter ECG recordings were obtained from all patients. Turbulence onset (TO), Turbulence slope (TS), Time domain HRV (SDNN, mean RR, RMSSD, sNN50 were analysed and compared between two groups. Results: RMSSD (ms) and Total sNN50 was decreased in obese patients compared to non- obese patients (32.57 ± 7.40 vs 40.15 ± 6.80; p: 0.003 and 8616 ± 5300 vs 10920 ± 6700; p<0,001 respectively) and SDNN (ms) was decreased in obese patients compared those with no-obese. (122.79±23.19 vs 164.52±15.48 p<0,001 respectively). TS and TO was different between groups (8.85 ± 6.67 vs. 15.96 ± 12.37; p < 0,001 and 0.45 ± 1.62 vs -0.22 ± 0.32 respectively). Conclusion: Autonomic dysfunction in young obese patients without comorbidities was impaired. These patients may be under risk of adverse cardiovascular outcome including fatal cardiac arrhythmias.