부산대학교 도서관

Athleteʼs heart is associated with left ventricular hypertrophy (LVH) and “supranormal” cardiac function, suggesting that this LVH is a physiological compensatory process. Hypertrophy alone can not explain increase in cardiac function, therefore, other mechanisms, such as better arterial function, might be involved. Our study uses new and complex methods, such as 2D speckle tracking imaging (STI), to evaluate deformation and rotation of the LV, in order to test ventriculo-arterial coupling and its benefits on cardiac function.Methods: 40 subjects (20±4 years, 23 male) were enrolled: 20 competitive athletes and a control group of 20 sex- and age- matched sedentary, normal subjects. Conventional echo was used to assess LV geometry and EF. STI was used to measure LV systolic rotation: peak apical rotation (RotA), peak basal rotation (RotB), LV twist (LVT), and twist rate (LVTR); and also LV systolic deformation: radial strain (rS) and strain rate (rSR), and longitudinal strain (LS) and strain rate (LSR). Arterial function was assessed from augmentation index (Aix), β index, and carotido-femoral pulse wave velocity (PWV); and ventriculo-arterial coupling from amplitude of the compression wave (CW) from the carotid wave-intensity tracings. Endothelial function was measured from flow mediated dilatation (FMD), at the level of the brachial artery.Results: Although athletes had LVH (128±38 vs. 100±32 g/m2, p<0.01), they showed “supranormal” longitudinal and radial deformation, and also increased LV rotation, whereas EF was similar with controls. They also had better endothelial and arterial functions, with improved ventriculo-arterial coupling (table). Univariate analysis showed that LS was related to FMD (r=0.79, r2=0.43), to AIx (r=−0.59, r2=0.33), and to PWV (r=−0.67, r2=0.37)(all p<0.01).Conclusions: LVH in athletes is a pure physiological adaptive phenomenon, associated with “supranormal” LV deformation and rotation, due to better endothelial and arterial function, with optimized ventriculo-arterial coupling.