Figure 4.

Gross and histological morphology. Four examples of cases showing focal non-compaction of the left ventricle. (a) and (b) Left ventricular wall of two cases with Ebstein’s anomaly of the tricuspid valve. The apical regions show a thick noncompacted layer when compared to the compacted myocardium. In (c), a case with a muscular trabecular ventricular septal defect shows a focal area of noncompaction at the left ventricular outlet free wall (* the membranous septum has been accidentally torn, but was originally intact); Ao—opened aorta. Panel (d) depicts the histological aspect of the apical region of a case with complete transposition of the great arteries, although histology was not used for measurements. The noncompacted layer (NC) is thicker than the compacted myocardium (C); Masson´s trichrome stain.