Objective Norwood and hybrid procedure are two options available for initial palliation of patients with hypoplastic left heart syndrome (HLHS). Our study aimed to assess potential differences in right ventricular (RV) function and pulmonary artery dimensions using cardiac magnetic resonance (CMR) in survivors with HLHS.
Methods 42 Norwood (mean age 2.4±0.8) and 44 hybrid (mean age 2.0±1.0 years) patients were evaluated by CMR after stage II palliation prior to planned Fontan completion. Initial stage I Norwood procedure was performed using a modified Blalock-Taussig shunt, while the hybrid procedure consisted of bilateral pulmonary artery banding and arterial duct stenting. Need for reinterventions and subsequent outcomes were also assessed.
Results Norwood patients had larger RV end-diastolic dimensions (91±23 vs 80±31 mL/m2, p=0.004) and lower heart rate (90±15 vs 102±13, p<0.001) than hybrid patients. Both Norwood and hybrid patients showed preserved global RV pump function (59±9 vs 59%±10%, p=0.91), while RV strain, strain rate and intraventricular synchrony were superior in the Norwood group. Pulmonary artery size was reduced (lower lobe index 135±74 vs 161±62 mm2/m2, p=0.02), and reintervention rate was significantly higher in the hybrid group whereas subsequent outcome did not differ significantly (p=0.24).
Conclusions Norwood and hybrid strategy were associated with equivalent and preserved global RV pump function while development of the pulmonary arteries and reintervention rate were superior using the Norwood approach. Impaired RV myocardial deformation as a potential marker of early RV dysfunction in the hybrid group may have a negative long-term impact in this population.
- cardiac magnetic resonance (CMR) imaging
- Congenital heart disease surgery
- Complex congenital heart disease
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Contributors HL, HB-R, TH, CA, CY, DS and GG have contributed to the conception and design of the study. HL, MSN, JW, PH, CS, CA, DA, RR and HA have contributed to the acquisition of data, analysis and interpretation of the data. HL, JB, TH, DS and GG have contributed to the drafting of the article and have revised it critically for important intellectual content.
Funding This study was supported by the Doris-Haag Stiftung, Frankfurt am Main, Germany and the Willy Robert Pitzer Stiftung, Bad Nauheim, Germany. This study has also received funding by the Department of Health through the National Institute for Health Research comprehensive Biomedical Research Centre award to Guy’s & St Thomas' NHS Foundation Trust in partnership with King’s College London and King’s College Hospital NHS Foundation Trust. The Division of Imaging Sciences receives also support as the Centre of Excellence in Medical Engineering (funded by the Wellcome Trust and EPSRC; grant number WT 088641/Z/09/Z) as well as the BHF Centre of Excellence (British Heart Foundation award RE/08/03).
Competing interests None declared.
Ethics approval Local medical ethics board Justus-Liebig University Giessen, Germany and local ethic board Evelina Children’s Hospital (08/H0810/058), London, UK.
Provenance and peer review Not commissioned; externally peer reviewed.
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