Fig. 2

Ventricular phenotypes in HLHS. a posterior view of heart with slit-like ventricle. The apex (*) is formed by the right ventricle (RV) and inter-ventricular coronary arteries (arrowheads) indicate the extent of the left ventricular cavity (LV), which has been opened with a longitudinal incision. The free wall is thin (arrows) and there is no endocardial fibroelastosis (EFE) within the cavity. b Miniaturised left ventricle. Although the apex (*) is formed by the right ventricle (RV) the left ventricular cavity is large as is the mitral valve. The left ventricular free wall is of similar thickness to the right ventricular free wall (arrows) and there is no EFE. c Heart with thick-walled (arrows) left ventricle. The right ventricle, containing coarse trabeculations, wraps around this to form the apex (*). There is prominent EFE (arrowheads) which also involves the mitral valve (MV). d Heart with slit-like ventricle in which the thin but long LV cavity (arrows) has been exposed by cutting longitudinally through the entire heart. There is no connection (arrowhead) with the left atrium (*). e EFE (arrowheads) with investment of left ventricular trabeculations (arrow). f Measurements of left ventricular length in relation to right ventricular length and g left ventricular free wall thickness in relation to right free wall thickness. h The ratio of LV/RV lengths of hearts with mitral atresia/aortic atresia (MA/AA), mitral stenosis/aortic atresia (MS/AA) and mitral stenosis/aortic stenosis (MS/AS) were the same (median and interquartile range). However, the miniature ventricles had longer ventricular cavities. i The LV/RV wall ratio in slit-like ventricles was reduced in comparison with other groups. Hearts with mitral stenosis/aortic atresia and mitral stenosis/mitral stenosis demonstrated LV wall thickening of similar extent. The LV and RV wall thicknesses were equal in hearts with miniaturised ventricles. *p < 0.05, **p < 0.01, ****p < 0.001