Implications of Exercise-Induced Pulmonary Arterial Hypertension

Robin M. Fowler
Andrew J. Maiorana
Sue C. Jenkins
Kevin R. Gain
Gerry O'Driscoll, University of Notre Dame Australia
Eli Gabbay Mbbs

Abstract

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) (>30mmHg) on exercise.

Methods: Thirty-seven symptomatic patients, at risk of PAH, and 20 healthy controls, underwent a cardiopulmonary exercise test and were assessed for quality of life (QoL). Patient subjects had a pulmonary artery catheter in situ during the exercise test.

Results: Seventeen subjects had exercise-induced pulmonary arterial hypertension (EIPAH), which we defined as mPAP <=25mmHg at rest, and mPAP >30mmHg and pulmonary artery wedge pressure <20mmHg 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, 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+/-2.7mmHg, p<0.05) at the anaerobic threshold. These exercise abnormalities were associated with impaired QoL (p<0.05).

Conclusion: 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.

 

Link to Publisher Version (DOI)

http://doi.org/10.1249/MSS.0b013e318204cdac