Longitudinal analysis of systemic ventricular function and atrioventricular valve function after the Norwood procedure.

This article focuses on the longitudinal evaluation of systemic ventricular function (VF) and atrioventricular valve (AVV) regurgitation in neonates with hypoplastic left heart syndrome (HLHS) and its variants following the Norwood procedure, comparing two shunt types: the modified Blalock–Taussig shunt (MBTS) and the right ventricle to pulmonary artery conduit (RVPAC). Analysis of 335 patients and 4,352 echocardiograms revealed that after the Norwood procedure, ventricular function was initially worse but later better in the RVPAC group compared to MBTS, while AVV regurgitation was more frequent in the MBTS group before stage II palliation (bidirectional cavopulmonary shunt, BCPS). After BCPS, ventricular function declined more in the RVPAC group, and AVV regurgitation differences between groups were no longer significant. The study suggests that the hemodynamic impact of shunt type varies with the stage of palliation, with MBTS associated with poorer early ventricular function and AVV regurgitation but better long-term ventricular function compared to RVPAC.