Modifications of long-term heart rate variability produced in an experimental model of diet-induced metabolic syndrome

Abstract

Metabolic syndrome (MetS) has been linked to a higher prevalence of cardiac arrhythmias, the most frequent being atrial fibrillation, but the mechanisms are not well understood. One possible underlying mechanism may be an abnormal modulation of autonomic nervous system activity, which can be quantified by analysing heart rate variability (HRV). Our aim was to investigate the modifications of long-term HRV in an experimental model of diet-induced MetS to identify the early changes in HRV and the link between autonomic dysregulation and MetS components. NZW rabbits were randomly assigned to control ( n = 10) or MetS ( n = 10) groups, fed 28 weeks with high-fat, high-sucrose diet. 24-hour recordings were used to analyse HRV at week 28 using time-domain, frequency-domain and nonlinear analyses. Time-domain analysis showed a decrease in RR interval and triangular index (Ti). In the frequency domain, we found a decrease in the low frequency band. Nonlinear analyses showed a decrease in DFA-α1 and DFA-α2 (detrended fluctuations analysis) and maximum multiscale entropy. The strongest association between HRV parameters and markers of MetS was found between Ti and mean arterial pressure, and Ti and left atrial diameter, which could point towards the initial changes induced by the autonomic imbalance in MetS.

Electrifying insights into cardiac arrhythmias: from molecular mechanisms to therapeutic translations

“…The studies presented in this special edition of Interface Focus represent a broad spectrum of approaches that add to our body of arrhythmic knowledge and understanding. They include in vivo [1,2], in silico [3][4][5][6][7], in vitro [8] and ex vivo [7,9] studies covering animal [1,7,9] and human [3,8] models and clinical imaging [2]. Most consider implications for the atria [1,2,[4][5][6], reflecting the dominant morbidity and mortality burden of atrial fibrillation in many parts of the world, with the balance studying ventricular electrical function [3,7,9].…”

“…They include in vivo [1,2], in silico [3][4][5][6][7], in vitro [8] and ex vivo [7,9] studies covering animal [1,7,9] and human [3,8] models and clinical imaging [2]. Most consider implications for the atria [1,2,[4][5][6], reflecting the dominant morbidity and mortality burden of atrial fibrillation in many parts of the world, with the balance studying ventricular electrical function [3,7,9]. The motivating pro-arrhythmic disease states are similarly varied and include metabolic syndrome [1], atrial fibrillation [2,4,6,8], long-QT syndrome [3], pulmonary arterial hypertension [5] and myocardial induced heart failure [9].…”

“…Most consider implications for the atria [1,2,[4][5][6], reflecting the dominant morbidity and mortality burden of atrial fibrillation in many parts of the world, with the balance studying ventricular electrical function [3,7,9]. The motivating pro-arrhythmic disease states are similarly varied and include metabolic syndrome [1], atrial fibrillation [2,4,6,8], long-QT syndrome [3], pulmonary arterial hypertension [5] and myocardial induced heart failure [9]. While some of the studies explicitly consider a range of scales or dimensions [3,5,6], others focus on the cellular or subcellular space [7,9], the whole heart [2,4,8] or non-invasive torso-scale signals [1].…”

“…The motivating pro-arrhythmic disease states are similarly varied and include metabolic syndrome [1], atrial fibrillation [2,4,6,8], long-QT syndrome [3], pulmonary arterial hypertension [5] and myocardial induced heart failure [9]. While some of the studies explicitly consider a range of scales or dimensions [3,5,6], others focus on the cellular or subcellular space [7,9], the whole heart [2,4,8] or non-invasive torso-scale signals [1].…”

“…Together, the studies reported in this special edition of Interface Focus are a taster of the exciting research tracks currently pursued in the cardiac arrhythmia field. Some of these works are poised for clinical and health science translation [1,2], others present tantalizing new mechanistic insights and patient-specific pathways across complexity scales with digital models [3][4][5][6][7], while the final two studies seek to bridge from bench to bedside by examining the links between clinically accessible tissue structure and detailed function [8], as well as pharmaceutical interventions and outcomes [9].…”