Comparison of blood velocity profile in the left ventricle at rest and during exercise between endurance trained and sedetary control subjects

The purpose of the present study was to compare between healthy male endurance trained athletes (T, n = 6) and sedentary control subjects (S, n = 6) for the blood velocity profile in left ventricle at rest and during exercise. Peak velocity of blood injection into the left ventricle at diastole (dV), peak velocity of blood ejection out of the left ventricle at systole (sV), duration of blood injection (dD) and duration of blood ejection (sD) were measured by pulsed Doppler sonography at rest and during cyclic ergometer exercise at intensity of 40, 60 and 80% maximal O₂ uptake (V̇o₂max). The dV tended to be higher T than S at rest and during exercise at all intensities, and statistical significance existed at rest and during exercise at 80%V̇o₂max. However, there was no significant differences in the sV between T and S. In addition, the dV/sV in T was significantly highter than that in S at rest and during exercise at all intensities. These results indicate that fulling velocity on the left ventricle in T was faster than that in S. In other words, these indicate that preload on the left ventricle in T was larger than that in S. Moreover, the relationship between stroke volume and dV (r=0.50, p<0.001) was closer than that between stroke volume and sV (r=0.30) in all subjects at rest and during exercise. These data suggest that the contribution of enhanced dV was stronger than that of sV to the larger stroke volume observed in dV.