“Supranormal” Cardiac Function in Athletes Related to Better Arterial and Endothelial Function

Objective: Athlete's heart is associated with left ventricular (LV) hypertrophy (LVH), and “supranormal” cardiac function, suggesting that this is a physiological process. Hypertrophy alone cannot explain increase in cardiac function, therefore, other mechanisms, such as better ventriculo‐arterial coupling might be involved. Methods: We studied 60 male (21 ± 3 years) subjects: 27 endurance athletes, and a control group of 33 age‐matched sedentary subjects. We assessed global systolic and diastolic LV function, short‐ and long‐axis myocardial velocities, arterial structure and function and ventriculo‐arterial coupling, endothelial function by flow‐mediated dilatation, and amino‐terminal pro‐brain natriuretic peptide (NT‐proBNP) and biological markers of myocardial fibrosis and of oxidative stress. Results: Athletes had “supranormal” LV longitudinal function (12.4 ± 1.0 vs 10.1 ± 1.4 cm/s for longitudinal systolic velocity, and 17.4 ± 2.6 vs 15.1 ± 2.4 cm/s for longitudinal early diastolic velocity, both P < 0.01), whereas ejection fraction and short‐axis function were similar to controls. Meanwhile, they had better endothelial function (16.7 ± 7.0 vs 13.3 ± 5.3%, P < 0.05) and lower arterial stiffness (pulse wave velocity 7.1 ± 0.6 vs 8.8 ± 1.1 m/s, P = 0.0001), related to lower oxidative stress (0.259 ± 0.71 vs 0.428 ± 0.88 nmol/mL, P = 0.0001), with improved ventriculo‐arterial coupling (37.1 ± 21.5 vs 15.5 ± 13.4 mmHg.m/s3× 103, P = 0.0001). NT‐proBNP and markers of myocardial fibrosis were not different from controls. LV longitudinal function was directly related to ventriculo‐arterial coupling, and inversely related to arterial stiffness and to oxidative stress. Conclusions: “Supranormal” cardiac function in athletes is due to better endothelial and arterial function, related to lower oxidative stress, with optimized ventriculo‐arterial coupling; athlete's heart is purely a physiological phenomenon, associated with “supranormal” cardiac function, and there are no markers of myocardial fibrosis. (Echocardiography 2010;27:659‐667)