This study examined right-ventricular-pulmonary arterial (RV-PA) coupling and pulmonary vascular mechanics during acute exercise in 12 middle-aged men with a long-standing history of endurance training. Subjects underwent simultaneous right-heart catheterization and echocardiography, with measures obtained at steady state heart rates of 100, 130 and 150 beats/min. Subjects were highly trained and displayed RV remodeling of endurance-trained athletes. During exercise at 100 beats/min, systolic, diastolic, and mean pulmonary artery pressure increased significantly from rest, as did pulmonary capillary wedge pressure. The slope of pooled mean pulmonary pressure indexed to cardiac output was 1.436 mmHg⋅min-1⋅L-1 with a distensibility index of 0.112 ± 0.048 mmHg-1. The pulmonary arterial elastance-RV end-systolic elastance ratio (Ea:Ees) decreased from rest to exercise at 130 beats/min (P < 0.01). These results suggest that Ea:Ees becomes favourable for RV function during exercise, indicative of a pulmonary vasculature that is highly distensible and well matched to RV output.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/42857 |
| Date | 26 November 2013 |
| Creators | Gray, Taylor |
| Contributors | Goodman, Jack |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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