Exercise electrocardiography in athletes: diagnostic accuracy and pathophysiological background

This thesis gives insight in the value of exercise testing used during pre-participation screening in asymptomatic athletes. Exercise testing is commonly used to detect coronary heart disease. This thesis shows that exercise testing combined with analysis of inspiratory and expiratory breath gasses increased the accuracy of exercise testing to detect any form of dysfunction of the heart. The athletes with abnormal test results were referred to the department of Cardiology for further diagnostic evaluation. The majority of these athletes didn’t show any signs of coronary heart disease. In order to explain the abnormal exercise test results, the geometry of the heart of the athletes was evaluated. Athletes with abnormal exercise test results did not shown the typical signs of the so-called athlete’s heart. However, the function of the smallest arteries (microcirculation) of athletes was attenuated. Therefore, it can be hypothesized that at least a part of the athletes with abnormal exercise test results without obstructive coronary heart disease show signs of premature coronary heart disease together with an attenuated microvascular function. These athletes could be at risk for the development of exercise-induced myocardial ischemia and subsequently for the development of a myocardial infarction and/or sudden cardiac death. Therefore, the findings of this thesis may have important clinical implications for athletes with abnormal test results without obstructive coronary heart disease, as a new potential substrate for the occurrence of sudden cardiac death in athletes is identified.