Improvement of Sympathovagal Balance by Regular Exercise May Counteract the Ageing Process. A Study by the Analysis of QT Variability

Abstract

QT interval (QT) variability analysis provides pathophysiological and prognostic information utilized in cardiac and non-cardiac diseases, complementary to those obtained from the analysis of heart period (HP) variability. An increased QT variability has been associated to a higher risk for cardiac events and poorest prognosis. Autonomic cardiovascular adaptation to internal and external challenges, such those occurring in athletes exposed to high levels of physical stress and in ageing could also be deepen by analyzing QT variability, searching for early prognostic signatures. The aim of the study was to analyze the QT variability and cardiac control complexity in a group of middle-aged half-marathon runners at baseline (B) and at a 10-year follow-up (FU). We found that the overall QT variability decreased at FU, despite the inescapable increase in age (52.3 ± 8.0 years at FU). This change was accompanied by an increase of the HP variability complexity without changes of the QT variability complexity. Of notice, over the years, the group of athletes maintained their regular physical activity by switching to a moderate intensity rather than strenuous. In conclusion, regular and moderate exercise over the years was beneficial for this group of athletes, as reflected by the decreased overall QT variability that is known to be associated to lower cardiovascular risk. The concomitant enhanced cardiac control complexity also suggests a trend opposite to what usually occurs with ageing, resulting in a more flexible cardiac control, typical of younger people.

Transfer Function Gain Between Heart Period and QT Interval Variability Decreases at a 10-year Follow-up in Half-Marathon Runners

“…This finding suggests that in the group of studied athletes the maintenance of regular physical exercise through the year, moving from strenuous to moderate activity, resulted in a lower sympathetic control. This observation is in keeping with previous studies [6,7] pointing out that reduction of physical exercise from strenuous to moderate implies a reduced sympathetic regulation and enhanced vagal cardiac modulation at FU, lowering the overall cardiovascular risk. This trend is opposite to those occurring with physiological ageing [21].…”

“…In this scenario, there is increasing attention in addressing this topic studying the effect of physical exercise on the cardiovascular system exploiting the heart period (HP) variability analysis [4][5][6]. More recently, the evaluation of QT interval (QT) variability analysis has been proposed as a complementary evaluation with respect to the more traditional HP variability one to better typify the cardiac sympathetic modulation also for the study of the cardiac control of athletes [7,8].…”

Whole-Body Cryostimulation in Post-COVID Rehabilitation for Patients with Obesity: A Multidisciplinary Feasibility Study

“…Exercise-based rehabilitation is a therapeutic approach that may play an important role in improving sympathovagal balance and normalizing sympathetic index levels [49].…”