LEFT-VENTRICULAR DIASTOLIC FUNCTION IN TRIATHLETES AND UNTRAINED SUBJECTS - A STRESS DOPPLER-ECHO STUDY

To assess changes of left ventricular diastolic function (LV-DF) induced by endurance training Doppler mitral flow was derived in 17 male triathletes (TRI, swimming, running, cycling) and 19 healthy untrained subjects (UT) during bicycle exercise (EX) in supine position. Mitral flow is characterized by the early passive (E wave) and late, by atrial contraction caused inflow (A wave) into the LV during diastole. In particular atrial filling fraction (AFF) as the relative atrial contribution to LV filling was considered. In UT AFF increased from 29% at rest to 40% during EX. Two min post EX the value fell to 38% and reached nearly baseline values (32%) only ten min post EX. In TRI AFF also increased from 25% at rest to 32% during EX. However, AFF decreased already two min post EX to 25% and so was significantly lower than in UT (p < 0.05). Ten min post EX TRI reached an AFF of 24% which was lower compared to baseline values (p = 0.0552). TRI had a significantly higher LV-mass-index than UT (133 g/m2 vs. 80 g/m2; p < 0.001). Performing a multiple regression analysis there was no influence of heart rate during EX on the differences of Doppler-parameters between both groups. Conclusion: Both UT and TRI show a significant increase of AFF during EX. In EA these changes return earlier to baseline as compared to UT. This indicates a beneficial effect of endurance training on LV-DF despite significant LV-hypertrophy.