Arrhythmias in an athlete: the effect of de-training

Symptomatic bradyarrhythmias in the athlete-Underlying mechanisms and treatments

Bradyarrhythmias including sinus bradycardia and atrioventricular (AV) block are frequently encountered in endurance athletes especially at night. While these are well tolerated by the young athlete, there is evidence that generally from the fifth decade of life onward, such arrhythmias can degenerate into pathological symptomatic bradycardia requiring pacemaker therapy. For many years, athletic bradycardia and AV block have been attributed to high vagal tone, but work from our group has questioned this widely held assumption and demonstrated a role for intrinsic electrophysiological remodeling of the sinus node and the AV node. In this article, we argue that bradyarrhythmias in the veteran athlete arise from the cumulative effects of exercise training, the circadian rhythm and aging on the electrical activity of the nodes. We consider contemporary strategies for the treatment of symptomatic bradyarrhythmias in athletes and highlight potential therapies resulting from our evolving mechanistic understanding of this phenomenon.

PECULIARITIES OF VASOR-REGULATING FUNCTIONS OF THE VASCULAR ENDOTHELIUM IN ADAPTATION OF THE YOUTH BODY TO SYSTEMATIC PHYSICAL LOADS

OBJECTIVE

The aim: To analyze the features of changes in the functional state of the vascular endothelium of handball players in the dynamics of the training process, at different levels of the body's hypoxic state.

PATIENTS AND METHODS

Materials and methods: Theoretical methods, the method of Corretti et al. with the use of high-resolution ultrasound, Fisher test with the calculation of the Fisher criterion and the Bland-Altman method. The study of the vasomotor function of the vascular endothelium was carried out of young men 18-20 y.o., who did not go in for sports and which were systematically played handball. The brachial artery diameter, maximum linear blood flow velocity, volumetric blood flow velocity were registered in the state of relative rest after artificially created reactive hyperemia.

RESULTS

Results: The primary results obtained showed that in the process of long-term adaptation to systematic muscular work, a pronounced vasodilation effect was observed. Subsequent analyze of changes in the functional state of the vascular endothelium of young sportsmen during the macrocycle preparation different levels of the body's hypoxic state manifested the following. The young men-athletes had more pronounced vasodilation effect, the values of the linear and volumetric blood flow velocity both in the state of relative rest and at the peak of the artificially created hyperemia were significantly higher than in the young men, who did not go in for sports.

CONCLUSION

Conclusions: Suggested that the systematic muscular work contributes to a significant intensification of the oxidation pathway of nitric oxide formation from L-arginine with the participation of endothelial NO-synthase.

Atrial fibrillation in athletes: Implicit literature-based connections suggest that overtraining and subsequent inflammation may be a contributory mechanism

Research on atrial fibrillation (AF), a common heart arrhythmia in the elderly, over many decades has resulted in a literature of more than 16,000 articles indexed in Medline. An exploratory Medline search was conducted in which the subheadings for epidemiology and etiology of AF were combined to form a small subset of the initial records. Further computer-assisted selection led to a few articles that reported an unexpectedly high prevalence of AF in groups of otherwise healthy middle-aged endurance runners and other athletes. Why athletes should be unusually susceptible to AF is mysterious and puzzling. Because relatively few articles are about both AF and endurance exercise, a computer was used first to create a list of important terms that these two separate literatures had in common. Several inflammation-related terms, including C-reactive protein (CRP) and interleukin-6, were on that list. Further searching and literature analysis revealed that excessive endurance exercise or overtraining can lead to chronic systemic inflammation and, separately, that there is a solid association between CRP and AF and that anti-inflammatory agents have been reported to lower CRP and ameliorate AF. No articles were found that brought together all three concepts - AF, inflammation, and exercise. The following hypothesis is plausible, readily testable, and apparently novel: Older athletes diagnosed with AF but otherwise healthy who have engaged in rigorous aerobic endurance exercise for more than a decade will have CRP levels that are higher than those of a similar population of athletes without AF. Corroboration of this hypothesis would then justify a prospective clinical trial of anti-inflammation therapy. It is of particular interest to extend recent studies of inflammation in AF to athletes; athletic behavior that can induce inflammation may contribute to understanding the origins of AF.