Abstract
Ventricular noncompaction is a cardiomyopathy that results from a disturbed compaction of the loose meshwork of myocardial fibers during organogenesis. Hence, deep intertrabecular recesses covered by ventricular endocardium and communicating with the latter remain under these conditions.2 Nevertheless, echocardiographic and patho-anatomical studies revealed that the epicardial layer of the myocardium is always compacted, generating a 2-layer appearance of the affected myocardial segments: a noncompacted endocardial layer and a compact epicardial layer. This 2-layer structure is particularly important, because the relative thickness of the 2 layers represents one of the diagnostic criteria for ventricular noncompaction.2 It can only be applied, however, when the imaging plane is oriented perpendicular to the plane of the compacted myocardial layer.
The study by Gelberg1 is very important, because it would represent the first observation of a ventricular noncompaction in the cat. Indeed, the presence of trabeculated myocardium lined by ventricular endocardium and separated by interconnecting clear spaces is demonstrated in Fig. 2. However, the section presented does not show any compacted myocardial layer; it is, rather, oriented in a parallel or an oblique manner relative to the compacted layer. Hence, no information on the thickness of the trabecular layer, both in absolute numbers and relative to the thickness of the compacted layer, can be derived from this preparation. Thus, in view of the diagnostic criteria for noncompaction, we believe that it is not possible to prove the presence of ventricular noncompaction based on this analysis and suggest an additional section that demonstrates the relative thickness of both myocardial layers.