Isolated Noncompaction of the Left Ventricle in Adults.

Isolated left ventricular noncompaction (ILVNC) is a cardiomyopathy that was first described in 1926 as a "spongy myocardium." The disorder results from intrauterine arrest of compaction of the loose interwoven meshwork of the fetal myocardial primordium and subsequent persistence of deep trabecular recesses in the myocardial wall. The classical clinical presentation is a triad of heart failure, arrhythmias, and embolic events from mural thrombi. ILVNC has been associated with several autosomal dominant, X-linked, and mitochondrial genetic mutations that are also shared among other cardiomyopathies. Over the past decade, ILVNC has been subject to intensive research, as it increases the risk for sudden cardiac death. This review focuses on the current understanding of ILVNC in adult populations and attempts to provide organized insight into the disease process, screening, diagnosis, management, role of device therapy, and prognosis.