Exercise type in left atrial remodeling and incident atrial fibrillation

Date
2021
DOI
Authors
Heimlich, Brent Adam
Version
OA Version
Citation
Abstract
BACKGROUND: The adaptive plasticity of the heart enables it to maintain sufficient cardiac output under a wide array of physiological and pathological states. When metabolic demands are imposed on a chronic basis, such as during a long-term exercise regimen, the heart adapts to meet those demands. When these adaptations are due to exercise, physiological and, therefore, reversible remodeling occurs, as opposed to the irreversible process of pathological remodeling secondary to cardiac injury. While sharing similarities, endurance and resistance exercise engage the heart, and more specifically, the left atrium in vastly different manners, leading to dissimilar patterns of remodeling and disparate outcomes in the subsequent incidence of atrial fibrillation. LITERATURE REVIEW: Existing research has largely centered around defining the limits of physiological remodeling to accurately differentiate it from pathological remodeling. Not only is there a great deal of overlap between the two, but these phenomena can often coexist, making it difficult to distinguish which process is at play. It is largely agreed upon in the scientific community that chronic high intensity endurance exercise results in reversible left atrial enlargement and the most credible evidence shows it is indeed associated with an increased incidence of atrial fibrillation. Reliable data for resistance athletes, however, is less convincing. PROPOSED PROJECT: This will be a prospective cohort study of 3,600 student athletes engaged in either endurance or resistance training (with a non-athlete control group) to be followed over 120 days to assess for differences in their patterns of left atrial remodeling. A second phase will consist of a 10-year follow-up to compare the incidence of atrial fibrillation in each cohort. We hypothesize that both the remodeling patterns and the subsequent incidence of atrial fibrillation will be different between the three groups. CONCLUSION: In performing this study, we will compile one of the largest study populations to date in order to accurately detect clinically significant changes in cardiac structure and function which, while largely adaptive and beneficial, can also lead to life threatening arrhythmias later in life. Exercise type unquestionably plays a key role in the reason why and the rate at which these physiological processes occur. A deeper understanding is imperative to fully determine the consequences of high intensity training. SIGNIFICANCE: These findings will allow athletes to better understand the effects training has on cardiovascular health. As atrial fibrillation is the most common arrhythmia in athletes, the clinical ramifications of this study are immense.
Description
License
Attribution 4.0 International