Right Ventricular Functional Reserve in Pulmonary Arterial Hypertension

• DOI: 10.1161/circulationaha.116.022082
• Publication Date: 2016-05-12T04:19:05Z
• Authors: Steven Hsu; Brian A. Houston; Emmanouil Tampakakis; Anita C. Bacher; Parker S. Rhodes; Stephen C. Mathai; Rachel L. Damico; Todd M. Kolb; Laura K. Hummers; Ami A. Shah; Zsuzsanna McMahan; Celia P. Corona-V...; Stefan L. Zimmerman; Fredrick M. Wigley; Paul M. Hassoun; David A. Kass; Ryan J. Tedford
• Keywords: Cohort Studies; Male; Ventricular Dysfunction, Right; Exercise Test; Ventricular Function, Right; Humans; Familial Primary Pulmonary Hypertension; Female; Heart; Prospective Studies; Prognosis

Right ventricular (RV) functional reserve affects capacity and prognosis in patients with pulmonary arterial hypertension (PAH). PAH associated systemic sclerosis (SSc-PAH) has a substantially worse than idiopathic (IPAH), even though many measures of resting RV function vascular load are similar. We therefore tested the hypothesis that is depressed SSc-PAH patients.RV pressure-volume relations were prospectively measured IPAH (n=9) (n=15) at rest during incremental atrial pacing or supine bicycle ergometry. Systolic lusitropic increased faster heart rates patients, but markedly blunted SSc-PAH. The recirculation fraction, which indexes intracellular calcium recycling, was also (0.32±0.05 versus 0.50±0.05; P=0.039). At matched exercise (25 W), did not augment contractility (end-systolic elastance) whereas (P<0.001). afterload assessed by effective elastance rose similarly both groups; thus, ventricular-vascular coupling declined Both end-systolic end-diastolic volumes to offset contractile deficits, chamber dilation absent (+37±10% +1±8%, P=0.004, +19±4% -1±6%, P<0.001, respectively). Exercise-associated strongly correlated larger cohort.RV subjects, reduced recycling. During exercise, this results ventricular-pulmonary uncoupling acute dilation. can predict adverse patients.