RV adaptation to increased afterload in congenital heart disease and pulmonary hypertension

PLoS One. 2018 Oct 24;13(10):e0205196. doi: 10.1371/journal.pone.0205196. eCollection 2018.

Abstract

Background: The various conditions causing a chronic increase of RV pressure greatly differ in the occurrence of RV failure, and in clinical outcome. To get a better understanding of the differences in outcome, RV remodeling, longitudinal function, and transverse function are compared between patients with pulmonary stenosis (PS), those with a systemic RV and those with pulmonary hypertension (PH).

Materials and methods: This cross-sectional study prospectively enrolled subjects for cardiac magnetic resonance imaging (CMR), functional echocardiography and cardiopulmonary exercise testing. The study included: controls (n = 37), patients with PS (n = 15), systemic RV (n = 19) and PH (n = 20). Statistical analysis was performed using Analysis of Variance (ANOVA) with posthoc Bonferroni.

Results: PS patients had smaller RV volumes with higher RV ejection fraction (61.1±9.6%; p<0.05) compared to controls (53.8±4.8%). PH and systemic RV patients exhibited dilated RVs with lower RV ejection fraction (36.9±9.6% and 46.3±10.1%; p<0.01 versus controls). PH patients had lower RV stroke volume (p = 0.02), RV ejection fractions (p<0.01) and VO2 peak/kg% (p<0.001) compared to systemic RV patients. Mean apical transverse RV free wall motion was lower and RV free wall shortening (p<0.001) was prolonged in PH patients-resulting in post-systolic shortening and intra-ventricular dyssynchrony. Apical transverse shortening and global longitudinal RV deformation showed the best correlation to RV ejection fraction (respectively r = 0.853, p<0.001 and r = 0.812, p<0.001).

Conclusions: RV remodeling and function differed depending on the etiology of RV pressure overload. In contrast to the RV of patients with PS or a systemic RV, in whom sufficient stroke volumes are maintained, the RV of patients with PH seems unable to compensate for its increase in afterload completely. Key mediators of RV dysfunction observed in PH patients, were: prolonged RV free wall shortening, resulting in post-systolic shortening and intra-ventricular dyssynchrony, and decreased transverse function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cardiac Output
  • Echocardiography
  • Exercise Test
  • Female
  • Heart Defects, Congenital / diagnostic imaging
  • Heart Defects, Congenital / physiopathology*
  • Heart Ventricles / diagnostic imaging
  • Heart Ventricles / physiopathology*
  • Humans
  • Hypertension, Pulmonary / diagnostic imaging
  • Hypertension, Pulmonary / physiopathology*
  • Linear Models
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Pulmonary Valve Stenosis / diagnostic imaging
  • Pulmonary Valve Stenosis / physiopathology*
  • Ventricular Dysfunction, Right / diagnosis
  • Ventricular Dysfunction, Right / diagnostic imaging
  • Ventricular Dysfunction, Right / physiopathology
  • Ventricular Function, Right
  • Ventricular Remodeling*

Grants and funding

Funding for this research was supported by unrestricted grants from Actelion Pharmaceuticals Ltd. and ICIN-NHI, which is a non-commercial scientific institution. These companies were not involved in the writing, data analysis or conclusions of this manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.