Impact of Staged Palliation on Somatic Growth in Patients with Hypoplastic Left Heart Syndrome

Background. Somatic growth pattern in infants undergoing staged palliation for hypoplastic left heart syndrome (Norwood procedure [NP], stage 2 palliation [S2P], and Fontan procedure [FP]) during transition toward a more energy efficient series circulation is not well understood. Objectives. We sought to determine growth pattern in these infants and factors influencing it. Methods. Patients who underwent NP since 2001 and survived at least 1 year after S2P were followed until FP or death/heart transplantation (n = 46). Weight for age z-scores (WAZ) were measured prior to NP; at initial discharge; prior to S2P; at four time periods after S2P; and prior to FP. Impact of gender, race, era of NP, anatomic subtype, NP shunt type, gastrostomy, home-surveillance program (daily weights and pulse oximetry), and interstage oxygen saturation on WAZ was evaluated. Results. Repeated measures anova showed a significant change in WAZ across time periods (P < 0.0005), with a significant decline from Pre-NP to Pre-S2P (P < 0.0005) and steady increase from Pre-S2P to Pre-FP (P= 0.016). None of the factors evaluated had a significant effect on this growth pattern. Length of hospital stay after NP was negatively correlated with WAZ at discharge (P= 0.001), but not for other time periods. Intervals from discharge to S2P and NP to S2P interval did not correlate with WAZ. Conclusion. Somatic growth is significantly impaired after NP but recovers steadily following S2P, as the patient transitions toward separated series circulation. Earlier S2P may lead to earlier resumption of normal growth in this critical period of early infancy.