Abstract
Recent attention has been focused on possible unique features of the right ventricular
response to exercise. This study investigated a) the responses of right ventricular
cardiac dynamics and myocardial function to a standard bout of progressive cycle exercise
in healthy young males, and b) the effect of level of aerobic fitness on these responses.
14 athletically-trained males (20.4±1.5 years) and 11 normally-active males (21.1±1.3 years)
underwent a progressive upright cycle test to exhaustion with measurement of gas exchange
variables and assessment of right ventricular stroke volume, systolic and diastolic
myocardial velocities, and tricuspid inflow velocities by standard Doppler echocardiographic
techniques at rest, submaximal and peak exercise. Stroke volume rose initially by
approximately 27% in each group, followed by stable values to exhaustion. Values of
maximal stroke index and maximal oxygen uptake were significantly greater in the trained
group than the normally-active males (62±10 ml m−2, 54.3±4.0 ml kg−1 min−1; 49±7 ml m−2, 40.3±5.6 ml kg−1 min−1, respectively). No significant differences were observed in increases in systolic
or diastolic myocardial velocities, peak pulmonary outflow velocity, systolic ejection
rate, or tricuspid inflow velocity between the 2 groups. The magnitude of change of
these variables was similar to those previously described for left ventricular responses
to similar exercise. This study revealed no unique features of right ventricular functional
responses to an acute exercise challenge in young males.
Key words
stress testing - heart function - echocardiography
