Guido E. Pieles, Dan-Mihai Dorobantu, Jessica E. Caterini, Barbara Cifra, Janette Reyes, Sara Roldan Ramos, Eilis Hannon, Craig A. Williams, Tilman Humpl, Luc Mertens, Greg D. Wells, Mark K. Friedberg
Hospital for Sick Children. University of Exeter.
Canada and United Kingdom
American Joural of Physiology Heart and Circulatory Physiology
Am J Physiol Heart Circ Physiol 2024;
DOI: 10.1152/ajpheart.00096.2024
Abstract
Despite exercise intolerance being predictive of outcomes in pulmonary arterial hypertension (PAH), its underlying cardiac mechanisms are not well described. The aim of the study was to explore the biventricular response to exercise and its associations with cardiorespiratory fitness in children with PAH. Participants underwent incremental cardio-pulmonary exercise testing and simultaneous exercise echocardiography on a recumbent cycle ergometer. Linear mixed models were used to assess cardiac function variance and associations between cardiac and metabolic parameters during exercise. Eleven participants were included with a mean age 13.4 ±2.9 years. Right ventricle (RV) systolic pressure (RVsp) increased from a mean of 59 ±25 mmHg at rest to 130 ±40 mmHg at peak exercise (p<0.001), while RV fractional area change (RV-FAC) and RV free wall longitudinal strain (RVFW-Sl) worsened (35.2% vs 27%, p=0.09 and -16.6% vs -14.6%, p=0.1, respectively). At low and moderate intensity exercise, RVsp was positively associated with stroke volume and O2 pulse (p<0.1). At high intensity exercise RV-FAC, RVFW-Sl and left ventricular longitudinal strain were positively associated with oxygen uptake and O2 pulse (p<0.1), while stroke volume decreased towards peak (p=0.04). In children with PAH, the increase of pulmonary pressure alone does not limit peak exercise, but rather the concomitant reduced RV functional reserve, resulting in RV-PA uncoupling, worsening of inter-ventricular interaction and LV dysfunction. A better mechanistic understanding of PAH exercise physiopathology can inform stress testing and cardiac rehabilitation in this population.
Category
Class I. Idiopathic Pulmonary Hypertension
Right Heart Dysfunction Associated with Pulmonary Vascular Disease
Diagnostic Testing for Pulmonary Vascular Disease. Non-invasive Testing
Diagnostic Testing for Pulmonary Vascular Disease. Risk Stratification
Age Focus: Pediatric Pulmonary Vascular Disease
Fresh or Filed Publication: Fresh (PHresh). Less than 1-2 years since publication
Article Access
Free PDF File or Full Text Article Available Through PubMed or DOI: Yes