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.
BACKGROUND
The hypertrophic myocardium, myocardial fiber disarray, and endocardial fibroelastosis in pulmonary atresia and intact ventricular septum (PAIVS) may provide anatomic substrates for restrictive filling of the right ventricle.


OBJECTIVE
Restrictive right ventricle (RV) physiology is related to 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 assessed by late gadolinium enhancement (LGE) cardiac magnetic resonance. Their RV function was 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).


CONCLUSIONS
Restrictive RV physiology reflects RV diastolic dysfunction and is associated with more severe RV fibrosis but better exercise capacity in patients after biventricular repair of PAIVS.
Liang
Xue-Cun
XC
Division of Pediatric Cardiology, Department of Pediatrics and Adolescent Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China.
Lam
W W M
WW
Cheung
E W Y
EW
Wu
A K P
AK
Wong
Sophia J
SJ
Cheung
Yiu-Fai
YF
D000293:Adolescent; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D002313:Cardiomyopathy, Restrictive / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016022:Case-Control Studies; D002404:Catheterization; D003287:Contrast Media; D015150:Echocardiography, Doppler; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D018633:Pulmonary Atresia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011652:Pulmonary Circulation; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016278:Ventricular Function, Right; D055815:Young Adult
D003287:Contrast Media; D019786:Gadolinium DTPA