Arrhythmogenesis of Sports: Myth or Reality?

Abstract

Regular exercise confers health benefits with cardiovascular mortality risk reduction through a variety of mechanisms. At a population level, evidence suggests that undertaking more exercise has greater benefits. In the modern era of sport, there has been an exponential rise in professional and amateur athletes participating in endurance events, with a progressively better understanding of the associated cardiac adaptations, collectively termed ‘athletes heart’. However, emerging data raise questions regarding the risk of potential harm from endurance exercise, with an increased risk of arrhythmia from adverse cardiac remodelling. Cross-sectional studies have demonstrated that athletes may exhibit a higher burden of AF, conduction tissue disease, ventricular arrhythmias, a cardiomyopathy-like phenotype and coronary artery disease. In an attempt to separate myth from reality, this review reports on the evidence supporting the notion of ‘too much exercise’, the purported mechanisms of exercise-induced cardiac arrhythmia and complex interplay with sporting discipline, demographics, genetics and acquired factors.

Wide Spectrum of Bradyarrhythmias and Supraventricular Tachyarrhythmias in Sportsmen: Run Forrest, Run?!

“…The risk of AF is estimated to be two- to five-fold greater in endurance athletes than in non-athletic individuals. Evidence indicates that AF is influenced by factors such as the intensity, duration, and type of exercise or sport [ 18 ]. The well-established dose–response relationship between exercise and AF risk is notable, with athletes diagnosed with AF demonstrating higher weekly training volumes, engaging in longer training sessions, and participating in slightly more sports events per year [ 7 ].…”

“…Both mixed and endurance exercises have been associated with an increased risk of atrial fibrillation [ 18 ]. While observational studies have widely represented endurance athletes such as runners, joggers, cyclists, and skiers, there has been less emphasis on non-aerobic disciplines like weightlifting [ 20 ].…”

Exercise-Induced Arrhythmia or Munchausen Syndrome in a Marathon Runner?

“…Though regular exercise training is considered an important health-promoting and disease-preventive measure, strenuous long-lasting exercise may lead to unfavorable changes, including heart rate (HR) disturbances [1,2]. Many cardiologists are of the opinion that extreme endurance exercises performed by professional and even ambitious leisure-time athletes could be dangerous [3,4] and even provoke sudden cardiac death [5,6]. Wearable HR monitors (HRMs) are increasingly used by professional and leisure-time athletes, as well as by cardiac patients, to monitor HR during exercise [7][8][9].…”

Does Myocardial Atrophy Represent Anti-Arrhythmic Phenotype?

“…It appears that distinguishing between athlete’s heart and a hypertensive heart can be challenging [ 9 ], while hypertension is more prevalent in athletes [ 10 ]. Nevertheless, due to genetic background (cardiomyopathy), “athletes heart” is susceptible to developing ventricular arrhythmias, which are mostly benign premature beats due to repolarization (ion channels) abnormalities [ 11 ]. Moreover, the occurrence of malignant arrhythmias, such as ventricular fibrillation (VF) or polymorphic ventricular tachycardia, are promoted by structural remodelling [ 11 ] with a potential risk for sudden cardiac death [ 7 , 12 , 13 ].…”

“…Nevertheless, due to genetic background (cardiomyopathy), “athletes heart” is susceptible to developing ventricular arrhythmias, which are mostly benign premature beats due to repolarization (ion channels) abnormalities [ 11 ]. Moreover, the occurrence of malignant arrhythmias, such as ventricular fibrillation (VF) or polymorphic ventricular tachycardia, are promoted by structural remodelling [ 11 ] with a potential risk for sudden cardiac death [ 7 , 12 , 13 ]. Thus, it is believed that there is a risk of cardiac arrhythmias regardless of the “physiological” or “pathological” aetiology of myocardial structural remodelling.…”