Left Ventricular Noncompaction

Abstract

Left ventricular noncompaction (LVNC) is accepted as an unclassified (the American Heart Association) or a genetic cardiomyopathy (the European Society of Cardiology), but some argue that this phenotype may be a morphologic trait shared by different cardiomyopathies. This chapter covers the state of the art on the pathology, underlying mechanisms, its clinical manifestations, and diagnosis and treatment modalities of LVNC. LVNC may be defined as follows: an inner non-compacted layer with prominent left ventricular trabeculae and deep intertrabecular recesses and a thin outer compacted layer. Mechanisms are still debatable, with the hypothesis of compaction arrest during embryogenesis as the most accepted theory. Genetic data support LVNC as a distinct cardiomyopathy, although evidence for LVNC as a shared morphological trait is not ruled out, since LVNC may be associated with other cardiomyopathies, congenital heart diseases and in some cases may be acquired. Diagnosis is based on imaging and may be confirmed by the use of genetics. Clinical picture and prognosis and the management options are discussed.