The Heart of Trained Athletes

Young competitive athletes are widely regarded as a special subgroup of healthy individuals with a unique lifestyle who are seemingly invulnerable and often capable of extraordinary physical achievement.1–3 For more than 100 years, there has been considerable interest in the effects of intense athletic conditioning on the cardiovascular system.4–27 The advent of echocardiography more than 30 years ago provided a noninvasive quantitative assessment of cardiac remodeling associated with systematic training, and consequently, a vast body of literature has been assembled that is focused on the constellation of alterations known as “athlete’s heart.”4–27Athlete’s heart is generally regarded as a benign increase in cardiac mass, with specific circulatory and cardiac morphological alterations, that represents a physiological adaptation to systematic training.1,6–27 However, the clinical profile of athlete’s heart has expanded considerably over the last several years as a result of greater accessibility to large populations of trained athletes studied systematically with echocardiography, ECG, cardiac magnetic resonance, and ambulatory Holter ECG monitoring. As a consequence, there is increasing recognition of the impact that prolonged conditioning has on cardiac remodeling, which may eventually mimic certain pathological conditions with the potential for sudden death or disease progression.Over the last several years, sudden deaths of trained athletes, usually associated with exercise, have become highly visible events fueled by news media reports and with substantial impact on both the physician and lay communities.1,28–36 Interest in these tragic events has accelerated owing to their increased recognition; awareness that underlying, clinically identifiable cardiovascular diseases are often responsible; and the availability of treatments to prevent sudden death for high-risk athlete-patients. In the present review, we offer a comprehensive assessment of many issues that target the interrelation of intense physical exertion with cardiac structure and function, as well as the rare, potentially adverse consequences of …