Implications of Exercise-Induced Pulmonary Arterial Hypertension
Purpose: To characterize the hemodynamic and ventilatory responses to exercise in a group of patients with unexplained dyspnea, increased risk for pulmonary arterial hypertension (PAH), and an elevated mean pulmonary artery pressure (mPAP; >30 mm Hg) on exercise.
Methods: A total of 37 symptomatic patients at risk of PAH and 20 healthy controls underwent a cardiopulmonary exercise test and were assessed for quality of life (QOL). Patients had a pulmonary artery catheter in situ during the exercise test.
Results: Seventeen subjects had exercise-induced PAH (EIPAH), which we defined as mPAP <= 25 mm Hg at rest, and mPAP > 30 mm Hg and pulmonary artery wedge pressure <20 mm Hg on exercise. These subjects had reduced peak exercise cardiac output (72% ± 19% predicted). Further, compared with matched controls, subjects with EIPAH had reduced peak oxygen consumption (1.2 ± 0.4 vs 1.7 ± 0.5 L·min-1, P < 0.05), an elevated ventilatory equivalent for carbon dioxide (41.0 ± 7.3 vs 31.0 ± 2.9, P < 0.05) and reduced end-tidal carbon dioxide tension (32.6 ± 3.6 vs 39.4 ± 2.7 mm Hg, P < 0.05) at the anaerobic threshold. These exercise abnormalities were associated with impaired QOL (P < 0.05).
Conclusions: Elevated pulmonary artery pressure on exercise can be associated with hemodynamic and ventilatory abnormalities typical of PAH, along with impaired exercise capacity and reduced QOL.
Fowler, R., Maiorana, A., Jenkins, S., Gain, K., O'Driscoll, G., & Gabbay, E. (2011). Implications of exercise-induced pulmonary arterial hypertension. Medicine and Science in Sports and Exercise, 43(6), 983-989. doi:10.1249/MSS.0b013e318204cdac