Article Text
PDF
Statistics from Altmetric.com
Isolated left ventricular non-compaction (IVNC) was first described just over a decade ago,1 and is now gaining prominence as a rare, but important, differential in the diagnosis of patients presenting with cardiac failure. This unclassified cardiomyopathy, previously known as “spongy left ventricular myocardium”, is characterised by prominent myocardial trabeculations and deep intertrabecular recesses which lie in continuity with the left ventricular cavity. Although prominent trabeculae are seen in the normal right ventricle, the persistence of prominent left ventricular trabeculation is not normally apparent after birth. This failure in the normal compaction of the ventricular endomyocardium results from an arrest in cardiac embryogenesis (fig 1).
Parietal views of sagitally dissected human embryonic left ventricles showing the process of normal trabecular compaction. During early embryogenesis ventricular trabeculation develops in the apical region soon after looping, and serves primarily as a means to increase myocardial oxygenation in the absence of coronary circulation. Concomitant with ventricular septation, the trabeculae start to compact in their portions adjacent to the outer compact myocardium, adding substantially to its thickness. (A) Abundant fine trabeculae are present at six weeks. (B) The trabeculae start to solidify at their basal area, contributing to added thickness of the compact layer, at 12 weeks when ventricular septation is completed. (C) The compact layer forms most of the myocardial mass after completion of compaction in the early fetal period. Scale bars 100 μm (A, …