New insights into resting and exertional right ventricular performance in the healthy heart through real-time pressure-volume analysis

William K. Cornwell, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Tomio Tran, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Lukasz Cerbin, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Greg Coe, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Akshay Muralidhar, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Kendall Hunter, Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Natasha Altman, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Amrut V. Ambardekar, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Christine Tompkins, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Matthew Zipse, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Margaret Schulte, Clinical and Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Katie O'Gean, Clinical and Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Morgan Ostertag, Clinical and Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Jordan Hoffman, Department of Cardiothoracic Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Jay D. Pal, Department of Cardiothoracic Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Justin S. Lawley, Department of Sport Science, University of Innsbruck, Innsbruck, Austria.
Benjamin D. Levine, University of Texas Southwestern Medical Campus, Dallas, TX, USA.
Eugene Wolfel, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Wendy M. Kohrt, Clinical and Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Peter Buttrick, Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.

Document Type

Article

Abstract

KEY POINTS: Despite growing interest in right ventricular form and function in diseased states, there is a paucity of data regarding characteristics of right ventricular function - namely contractile and lusitropic reserve, as well as ventricular-arterial coupling, in the healthy heart during rest, as well as submaximal and peak exercise. Pressure-volume analysis of the right ventricle, during invasive cardiopulmonary exercise testing, demonstrates that that the right heart has enormous contractile reserve, with a three- or fourfold increase in all metrics of contractility, as well as myocardial energy production and utilization. The healthy right ventricle also demonstrates marked augmentation in lusitropy, indicating that diastolic filling of the right heart is not passive. Rather, the right ventricle actively contributes to venous return during exercise, along with the muscle pump. Ventricular-arterial coupling is preserved during submaximal and peak exercise in the healthy heart. ABSTRACT: Knowledge of right ventricular (RV) function has lagged behind that of the left ventricle and historically, the RV has even been referred to as a 'passive conduit' of lesser importance than its left-sided counterpart. Pressure-volume (PV) analysis is the gold standard metric of assessing ventricular performance. We recruited nine healthy sedentary individuals free of any cardiopulmonary disease (42 ± 12 years, 78 ± 11 kg), who completed invasive cardiopulmonary exercise testing during upright ergometry, while using conductance catheters inserted into the RV to generate real-time PV loops. Data were obtained at rest, two submaximal levels of exercise below ventilatory threshold, to simulate real-world scenarios/activities of daily living, and maximal effort. Breath-by-breath oxygen uptake was determined by indirect calorimetry. During submaximal and peak exercise, there were significant increases in all metrics of systolic function by three- to fourfold, including cardiac output, preload recruitable stroke work, and maximum rate of pressure change in the ventricle (dP/dt ), as well as energy utilization as determined by stroke work and pressure-volume area. Similarly, the RV demonstrated a significant, threefold increase in lusitropic reserve throughout exercise. Ventricular-arterial coupling, defined by the quotient of end-systolic elastance and effective arterial elastance, was preserved throughout all stages of exercise. Maximal pressures increased significantly during exercise, while end-diastolic volumes were essentially unchanged. Overall, these findings demonstrate that the healthy RV is not merely a passive conduit, but actively participates in cardiopulmonary performance during exercise by accessing an enormous amount of contractile and lusitropic reserve, ensuring that VA coupling is preserved throughout all stages of exercise.

Medical Subject Headings

Activities of Daily Living; Heart; Heart Ventricles; Humans; Stroke Volume; Ventricular Dysfunction, Right; Ventricular Function, Right

Publication Date

7-1-2020

Publication Title

The Journal of physiology

E-ISSN

1469-7793

Volume

598

Issue

13

First Page

2575

Last Page

2587

PubMed ID

32347547

Digital Object Identifier (DOI)

10.1113/JP279759

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