title: Right Ventricular Functional Reserve in Pulmonary Arterial Hypertension.
abstract: Right ventricular (RV) functional reserve affects functional capacity and prognosis in patients with pulmonary arterial hypertension (PAH). PAH associated with systemic sclerosis (SSc-PAH) has a substantially worse prognosis than idiopathic PAH (IPAH), even though many measures of resting RV function and pulmonary vascular load are similar. We therefore tested the hypothesis that RV functional reserve is depressed in SSc-PAH patients.
  
  
  
  RV pressure-volume relations were prospectively measured in IPAH (n=9) and SSc-PAH (n=15) patients at rest and during incremental atrial pacing or supine bicycle ergometry. Systolic and lusitropic function increased at faster heart rates in IPAH patients, but were markedly blunted in SSc-PAH. The recirculation fraction, which indexes intracellular calcium recycling, was also depressed in SSc-PAH (0.32±0.05 versus 0.50±0.05; P=0.039). At matched exercise (25 W), SSc-PAH patients did not augment contractility (end-systolic elastance) whereas IPAH did (P<0.001). RV afterload assessed by effective arterial elastance rose similarly in both groups; thus, ventricular-vascular coupling declined in SSc-PAH. Both end-systolic and end-diastolic RV volumes increased in SSc-PAH patients to offset contractile deficits, whereas chamber dilation was absent in IPAH (+37±10% versus +1±8%, P=0.004, and +19±4% versus -1±6%, P<0.001, respectively). Exercise-associated RV dilation also strongly correlated with resting ventricular-vascular coupling in a larger cohort.
  
  
  
  RV contractile reserve is depressed in SSc-PAH versus IPAH subjects, associated with reduced calcium recycling. During exercise, this results in ventricular-pulmonary vascular uncoupling and acute RV dilation. RV dilation during exercise can predict adverse ventricular-vascular coupling in PAH patients.
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Steven
authors.initials: S
authors.lastname: Hsu
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Houston
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Tampakakis
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Anita C
authors.initials: AC
authors.lastname: Bacher
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Parker S
authors.initials: PS
authors.lastname: Rhodes
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Mathai
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Damico
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Kolb
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Hummers
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Ami A
authors.initials: AA
authors.lastname: Shah
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: McMahan
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Celia P
authors.initials: CP
authors.lastname: Corona-Villalobos
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Stefan L
authors.initials: SL
authors.lastname: Zimmerman
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Fredrick M
authors.initials: FM
authors.lastname: Wigley
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hassoun
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD. ryan.tedford@jhmi.edu dkass@jhmi.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Kass
authors.affiliation: From Divisions of Cardiology (S.H., B.A.H., E.T., A.C.B., P.S.R., D.A.K., R.J.T.), Pulmonary and Critical Care (S.C.M., R.L.D., T.M.K., P.M.H.), and Rheumatology (L.K.H., A.A.S., Z.M., F.M.W.), Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD; and Departments of Radiology (C.P.C.-V., S.L.Z.) and Biomedical Engineering (D.A.K.), Johns Hopkins Medical Institutions, Baltimore, MD. ryan.tedford@jhmi.edu dkass@jhmi.edu.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Tedford
mesh_terms: D015331:Cohort Studies; D005080:Exercise Test / Q000379:methods; D065627:Familial Primary Pulmonary Hypertension / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000502:physiology
keywords: force-frequency response; heart ventricles; hypertension; pulmonary artery; pulmonary heart disease; scleroderma, systemic; sports nutritional physiological phenomena