Early myocardial changes in experimental chick model of hypoplastic left heart syndrome (547.10)

Abstract

Hypoplastic left heart syndrome (HLHS) is a complex congenital heart defect in which the left ventricle of the heart is critically underdeveloped and unable to effectively supply blood to the body. Early reloading of the hypoplastic left ventricle can induce its growth and maturation and lead to rescue. To analyze the early changes during development of HLHS, we used an experimental chick model of left atrial ligation (LAL). Fertilized eggs were incubated at 37.5 °C. Partial ligation of the left atrium of chick embryonic hearts was performed at the ED4. At ED6, we performed ultrasound biomicroscopy examination of control and ligated hearts, followed by confocal microscopy 3D reconstruction of the left ventricle. Only those LAL hearts with clear phenotype, defined as apex‐forming right ventricle, were included in the quantitative evaluation. The hypoplastic left ventricle was significantly smaller in cross‐section with a total tissue volume less than half that of matched controls. In ovo analysis of circumferential strain from ultrasound showed no difference between the control and LAL group. This data indicate that although there is a clear morphological phenotype at this stage, the myocardial performance is still within normal limits, strengthening the point of early, possibly fetal, intervention for HLHS.Grant Funding Source: Supported by PRVOUK‐P35/LF1/5, RVO: 67985823, GACR P302/11/1308, and Bucknell University PUR grant