Right ventricular myocardial adaptation to different training protocols in top-level athletes

Abstract

Objective: The aim of this study was to analyze right ventricular (RV) myocardial function in competitive athletes with left ventricular (LV) hypertrophy induced by either endurance or strength training.

Methods: Standard Doppler echo, maximal electrocardiogram (ECG) ergometric test, and pulsed tissue Doppler (TD) of LV mitral annulus and of RV tricuspid annulus were performed in 32 competitive endurance athletes (long-distance swimmers; ATE) and in 26 strength-trained athletes (short-distance swimmers; ATS), all males. By use of TD, the following parameters of myocardial function were assessed: systolic peak velocities (Sm), precontraction time, contraction time, early (Em) and late (Am) diastolic velocities, Em/Am ratio, and relaxation time.

Results: The two groups were comparable for age, but ATS at rest exhibited higher heart rate, systolic blood pressure, and body surface area. LV mass index did not significantly differ between the two groups. However, ATS characterized increased wall thickness and relative wall thickness, whereas LV stroke volume and both LV and RV end-diastolic diameters were greater in ATE. All transmitral and transtricuspid Doppler indexes were higher in ATE, with increased E/A ratios. TD analysis demonstrated in ATE higher Em and Em/Am ratio as well as longer relaxation time both at mitral and at tricuspid annulus level. In the overall population, distinct multiple linear regression models evidenced independent positive association between RV peak Em velocity and LV end-diastolic diameter (P < 0.001) as well as independent direct correlation of the same RV peak Em velocity with both LV stroke volume and maximal workload achieved by bicycle ergometer (both P < 0.001).

Conclusions: Right ventricular early diastolic myocardial function is positively influenced by preload increase in athletes, and represents an independent determinant of cardiac performance during physical effort. Therefore, pulsed TD may be taken into account to distinguish different cardiac adaptation to either endurance or strength sport activities, and eventually to quantify RV adaptation degree to long-term training.