Background: The benefits of exercise are well documented. Intensive exercise for more than 4 h per week is associated with cardiovascular remodelling, including increases in ventricular dimensions, wall thickness, and left ventricular mass. These changes are influenced by sex, ethnicity, and type and duration of exercise. In highly trained endurance athletes, exercise is often associated with electrocardiographic changes at rest.
Case summary: A well-trained endurance athlete underwent cardiac investigation after his 33-year-old brother died while jogging. A resting 12-lead electrocardiogram showed significant first degree atrioventricular block (AVB), and longer monitoring revealed advanced AVB. This led to further testing and exercise restrictions.
Discussion: Although most electrocardiographic changes are related to athletic performance, the distinction between normal variants, often exaggerated by the physiology of the conditioned athlete, and myocardial or electrical disease may be challenging. Athletes should undergo comprehensive cardiovascular evaluation, with management based on these results.
Keywords: Athlete; Case report; Endurance training; Heart; Sports cardiology; Sudden cardiac death.