Fatiga cardíaca en los deportistas: una realidad en la que hay que pensar

Prolonged and intense physical exercise can produce acute cardiovascular changes that may impact on the athletes’ health and performance. Echocardiography has allowed the discovery and understanding of the morphological and functional response experienced by the trained heart, contributing to assess the possible cardiac injury triggered by high intensity exercise. The athlete heart is characterized by global chamber remodeling, with a preserved biventricular systolic function, or in the lower limit of normality, and normal, or even improved, relaxation. There is some debate about whether the athlete systolic function at rest is a reliable parameter of left ventricular (LV) contractile capacity. Some authors support that a low left ventricular ejection fraction (LVEF) in athletes is not equivalent to systolic dysfunction, as the myocardium preserves the ability to increase its contractility with the increased preload elicited by exercise in response to the Frank-Starling law. New myocardial strain imaging techniques with speckle tracking have allowed to study cardiac function, providing additional information beyond ejection fraction. Caselli et al. (1) defined the characteristics of LV myocardial mechanics with 2D speckle tracking in 200 Olympic Italian athletes. They showed normal global longitudinal strain (GLS) values, though slightly below that of controls (–18.1%±2,2% vs. –19.4%±2.3%, P <0.001). Systolic strain rate (SRS) and early diastolic strain rate (SRE) were not different between athletes and controls and late diastolic strain rate (SRA) was lower in athletes. However, this reduction was not clinically relevant and should not be misinterpreted as reduced function. Athletes participating in resistance disciplines presented higher LV chamber diameter, wall thickness and mass index, as well as higher left atrial size compared with other disciplines, which represents adaptation to high hemodynamic load. Conversely, the differences in strain and strain rate related with the type of sport practiced were only slight, suggesting that, although LV morphological remodeling is associated