Poster de conférence
Résumé : Exercise is associated with an increase in pulmonary arterial pressure (PAP) with cardiac output (Q) elevation. However, because of the distensibility of the arteriolar pulmonary vasculature, the mPAP (mean PAP)-Q relationship is not strictly linear. A curvilinear model allows the calculation of the distensibility coefficient α, as percentage change of vessel diameter per mmHg of mPAP increase. It remains unknown how much endurance training affects the α distensibility coefficient of the pulmonary circulation. We hypothesize that greater pulmonary vascular distensibility α allows for a higher pulmonary vascular reserve and allows a higher Qmax and thus a higher aerobic exercise capacity (VO2max), probably observable in trained athletes. 34 male volunteers, nonsmokers and free of cardiovascular or lung disease, participated in our study: 17 professional football players (24±3 years old, BMI 24±2, VO2max 41,3±5,4 ml/min/kg) were compared to body-dimension and age matched sedentary volunteers (VO2max 34,5±5,5 ml/min/kg). All underwent a semi-recumbent cyclo-ergometer incremental cardiopulmonary exercise test (CPET) with stress echocardiography for non-invasive PAP, left and right atrial pressure, and Q measurements. Pulmonary distensibility α index was calculated from multipoint mPAP-Q plots from rest to maximal exercise. The present results confirmed the hypothesis as athletes exhibited a significative increase of the α distensibility coefficient in athletes vs controls (1.37±0.41%/mmHg vs 1.02±0.31%/mmHg, p=0.017). Therefore, endurance athletes have a greater distensibility of the pulmonary arteriolar vessels as compared to sedentary people, which might contribute to develop higher Qmax and enhance VO2max.