Endurance athletes generate significantly higher stroke volumes and cardiac outputs during exercise (p<0.001) by producing greater reductions in LV ejection and diastolic filling times.
Does endurance athletic status alter cardiac filling dynamics and stroke volume during exercise compared to controls?
Endurance athletes exhibit distinct cardiac adaptations that allow greater reductions in ejection and diastolic filling times, generating higher stroke volumes and cardiac output during exercise.
Absolute Event Rate: 0% vs 0%
Introduction: Cardiac filling is constrained by a reduced ejection time and diastolic period as heart rate increases during exercise. We compared cardiac filling dynamics in endurance athletes and controls during exercise to determine how athletic status influences hemodynamic constraints during exercise. Methods: Thirty-two participants (21 endurance athletes, 11 controls) underwent exercise echocardiography at 20%, 40%, and 60% of peak power output. We measured cardiac timing, stroke volume (SV), and flow rates (SV indexed to body surface area and phase duration). Data was analyzed using linear mixed models. Results: Athletes demonstrated resting bradycardia (44±8 vs 68±14 bpm, p<0.001), through an extended ejection time (296±38 vs 247±30 ms, p<0.001) and diastolic filling (811±229 vs 560±161 ms, p=;0.005). Pre-exercise cardiac outputs were matched (p=0.969). During exercise, there was a significant group x exercise interaction for LV ejection time (P<0.001) and Diastolic period (p<0.001), indicating distinct athletic adaptations. Although the systolic to diastolic (S/D) ratio was similar at rest, a significant interaction occurred during exercise (p=0.013). Athletes also achieved a greater cardiac output response (Group x Exercise interaction: p<0.001). Indexed stroke volume increased similarly in both groups (interaction p=0.271) yet remained significantly higher in athletes (Group effect p<0.001). Consequently, athletes maintained superior absolute volumes throughout the protocol, resulting in greater high-intensity stroke volumes. Conclusion: Athletes are able to produce greater reductions in both LV ejection and diastolic filling time and generate higher stroke volumes during exercise, permitting greater cardiac outputs and a greater exercise response.
Spencer et al. (Thu,) reported a other. Endurance athletes generate significantly higher stroke volumes and cardiac outputs during exercise (p<0.001) by producing greater reductions in LV ejection and diastolic filling times.