Changes of Right Ventricular Function and Longitudinal Deformation in Children with Hypoplastic Left Heart Syndrome before and after the Norwood Operation

Abstract

The purpose of this study was to investigate changes in right ventricular (RV) function and deformation parameters before and at steady state after the Norwood operation in neonates with hypoplastic left heart syndrome. A further aim was to delineate factors that affected these changes. On echocardiograms before and 21 days (range, 10-35 days) after the Norwood operation, the two-dimensional speckle-tracking parameters global and regional peak systolic longitudinal strain and strain rate were retrospectively compared in 33 patients with hypoplastic left heart syndrome. In addition, RV functional assessment included RV fractional area change and tricuspid annular plane systolic excursion. The associations between postoperative echocardiographic findings and preoperative or postoperative complications, prenatal diagnosis, postoperative heart rate, oxygen saturation, and medication use as well as cardiopulmonary bypass and aortic cross-clamp times were tested. Global strain (-18.3 ± 3.6% vs -16.8 ± 3.8%, P= .02) and global strain rate (-1.6 ± 0.3 vs -1.2 ± 0.3 sec(-1), P < .0001) decreased significantly. Regional strain decreased significantly in the apical and mid lateral segments, while regional strain rate decreased significantly in all but the basal septal segments. Tricuspid annular plane systolic excursion of the lateral annulus decreased significantly, while RV fractional area change remained the same. No significant associations were found between postoperative RV function and potential impact factors. Two-dimensional global and regional longitudinal strain and strain rate as well as tricuspid annular plane systolic excursion were reduced in patients with hypoplastic left heart syndrome after the Norwood operation. None of the examined preoperative and postoperative patient or surgical factors was found to explain this decrease.