Background: Left ventricular cavity dimension, wall thickness, relaxation, and filling increase with exercise training and have a role in enhancing physical performance. We probed whether changes in diastole may develop separately from those in cardiac morphometry and still contribute to improve physical performance. Challenging diastole by preload reduction with standing and integrating mitral flow analysis with the pulmonary venous flow analysis were viewed as a means for detecting fine diastolic variations. Methods: Patterns of mitral, tricuspid, and pulmonary venous flow were evaluated by echo Doppler imaging in the supine and standing positions in 11 long-distance runner women athletes participating in training programs and having no or very mild cardiac morphologic alterations and were compared with those in 11 healthy women active in daily life not participating in training programs. Maximal exercise tolerance was tested in both groups with a treadmill with use of the standard Bruce protocol. Results: Echocardiographic left ventricular mass index and mitral and pulmonary flow patterns in athletes and controls were similar while they were supine. Major (P <.01) percent variations and differences between athletes and controls with standing were smaller decrease in right (-12% ± 5% vs -29% ± 5%) and left ventricular (-3% ± 1% vs -9% ± 2%) dimensions and stroke volume (-7% ± 4% vs -23% ± 4%), smaller lengthening of early mitral deceleration (+7% ± 4% vs + 18% ± 5%), and isovolumic relaxation (-3% ± 5% vs +15% ± 7%) times. Athletes showed greater reduction in pulmonary S wave peak velocity (-25% ± 10% vs -12.5% ± 7%) and time velocity integral (Si) (-50% ± 9% vs -21% ± 8%), greater increases in pulmonary venous diastolic (D) wave peak velocity(+20% ± 9% vs +12% ± 10%, meters per second), and time velocity integral (Di) (+81% ± 16% vs +27% ± 14%) and greater decrease of S/D(-30% ± 6% vs -18% ± 5%) and Si/Di (-70% ± 10% vs -33% ± 5%) ratios. At multivariate analysis standing Si/Di was the strongest independent predictor of better exercise tolerance (peak exercise time 1035 ± 88 sec in athletes, 751 ± 20 in controls). Conclusions: Pulmonary flow analysis in athletes while standing can detect changes in diastolic function that are dissociated from apparent left ventricular morphologic alterations, are undetected in the supine position, and may, in part, determine exercise performance.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine