Abstract 1941: Changes in Ventricular Strain Pattern in Infants With Hypoplastic Left Heart Syndrome
Background: The long-term outcome of hypoplastic left heart syndrome (HLHS) is limited by progressive ventricular dysfunction. Longitudinal strain dominates in the normal RV, while circumferential strain plays a greater role in the LV. In adults with a biventricular circulation and systemic RV the strain pattern resembles the LV suggesting mechanical adaptation. The aims of this study were to identify changes in strain pattern in HLHS between the Norwood and Bidirectional cavopulmonary anastomosis (BCPA) evaluation.
Method: In this prospective, cross-sectional study, infants with HLHS underwent speckle tracking imaging (STI) analysis of peak strain and strain rate (SR) in the longitudinal and circumferential planes at pre-Norwood and pre-BCPA stages. Comparisons of longitudinal and circumferential strain and SR were made between the 2 groups and within each group (p<0.05).
Results: In the 20 pre-Norwood infants (5±4 days), longitudinal and apical circumferential strain and SR were significantly greater than basal strain and SR (Fig 1⇓). In the 14 pre-BCPA infants (5±3 months) no strain parameter dominated. Comparison of pre-Norwood and pre-BCPA infants showed a reduction of both longitudinal and circumferential SR. Moderate to severe tricuspid regurgitation (TR) was present in 1 pre-Norwood and 4 pre-BCPA infants.
Conclusions: Reduction in longitudinal and circumferential SR and increased TR at the pre-BCPA evaluation suggests RV function is impaired compared to pre-Norwood patients. Reduction in the relative contribution of longitudinal strain and SR to ventricular contraction at the pre-BCPA evaluation may reflect adaptation to long-term systemic pressures.