Restrictive right ventricular physiology and right ventricular fibrosis as assessed by cardiac magnetic resonance and exercise capacity after biventricular repair of pulmonary atresia and intact ventricular septum

Abstract

Background: The hypertrophic myocardium, myocardial fiber disarray, and endocardial fibroelastosis in pulmonary atresia and intact ventricularseptum(PAIVS)may provide anatomic substrates for restrictivefilling of the right ventricle. Hypothesis: Restrictiveright ventricle (RV) physiology is relatedto RV fibrosis and exercise capacity in patients after biventricular repair of PAIVS. Methods: A total of 27 patients, age 16.5 ± 5.6 years, were recruited after biventricular repair of PAIVS. Restrictive RV physiology was defined by the presence of antegrade diastolic pulmonary flow and RV fibrosis assessedby late gadoliniumenhancement (LGE) cardiacmagnetic resonance. Their RV functionwas compared with that of 27 healthy controls and related to RV LGE score and exercise capacity. Results: Compared with controls, PAIVS patients had lower tricuspid annular systolic and early diastolic velocities, RV global longitudinal systolic strain, systolic strain rate, and early and late diastolic strain rates (all P < 0.05). A total of 22 (81%, 95%confidence interval: 62%-94%) PAIVS patients demonstrated restrictive RV physiology. Compared to those without restrictive RV physiology (n=5), these 22 patients had lower RV global systolic strain, lower RV systolic and early diastolic strain rates, higher RV LGE score, and a greater percent of predicted maximum oxygen consumption (all P < 0.05). Conclusion: Restrictive RV physiology reflects RV diastolic dysfunction and is associatedwith more severe RV fibrosis but better exercise capacity in patients after biventricular repair of PAIVS. © 2010 Wiley Periodicals, Inc.