Isolated left ventricular non-compaction

Isolated left ventricular noncompaction is a genetically heterogeneous congenital disorder characterized by an altered structure of the myocardial wall. This cardiomyopathy is thought to be due to an arrest of intrauterine compaction of the myocardial fibers in the absence of any other structural heart disease. Noncompaction of the left ventricular myocardium is an uncommon finding and remains frequently overlooked even by experienced echocardiographers. However, a correct diagnosis of noncompaction has important implications due to the possible association with other cardiac abnormalities and/or muscle disorders, progressive left ventricular dysfunction, risk of thromboembolism, and life-threatening arrhythmias. Furthermore, because of the familial association described with ventricular noncompaction, screening with echocardiography of first relatives is recommended. Since echocardiography is the diagnostic technique of choice, missed diagnoses may be due to nonoptimal imaging of the lateral and apical myocardium, and/or insufficient disease awareness by echocardiographers. To increase awareness of left ventricular noncompaction, the present paper reviews embryology, genetics, clinical features and pathophysiology, diagnosis, treatment and prognosis of patients affected by isolated left ventricular noncompaction.