Cardiomyopathy Caused by Isolated Noncompaction of the Left Ventricle in Adults

J. Willis Hurst, MD


January 25, 2002


Noncompacted left ventricle is currently listed as an unclassified cardiomyopathy by the World Health Organization. In a recent study, Oechslin and colleagues describe their observations and follow-up of 35 adult patients with noncompacted left ventricle. The authors conclude that this condition might now be classified as a specific type of cardiomyopathy.

This type of idiopathic cardiomyopathy is caused by the intrauterine arrest of compaction of the left ventricular endocardial myocytes in the absence of other cardiac abnormalities. The recesses and clefts formed by noncompaction of the endocardial tissue become filled with blood that is derived from the left ventricular cavity. The authors believe this entity is different from the condition known as persistent sinusoids, which may be associated with congenital right and left ventricular outflow tract obstruction.

Noncompacted myocardium can be identified by echocardiomyopathy. The authors express the view that the echocardiographer must be familiar with this type of condition because prominent left ventricular trabeculation may occur normally in patients with hypertrophy of the left ventricle from other causes. It appears that the clinical findings in patients with noncompaction are similar to those found in other types of cardiomyopathy, and even an expert echocardiographer may misdiagnose the condition.

Patients with noncompaction of the left ventricle can develop heart failure, embolic events from left ventricular thrombi, and ventricular arrhythmias. The mortality rate for the condition is high, as it is with other types of cardiomyopathy. Management includes treatment of heart failure, arrhythmia, and emboli. Some patients may need an implanted internal defibrillator, and others may need cardiac transplantation.