Examination of isolated ventricular noncompaction (hypertrabeculation) as a distinct entity in adults.

Three patients (2 women) 36, 45, and 49 years of age underwent cardiac transplantation for what was diagnosed clinically as nonischemic dilated cardiomyopathy. Examination of the transthoracic echocardiogram and explanted heart in each disclosed marked hypertrabeculation involving the free wall of the very dilated left ventricle, a finding consistent with what has been termed "isolated ventricular noncompaction" (IVNC). Although these 3 cases anatomically fulfilled the echocardiographic definition of IVNC, review of previous publications containing gross photographs of the heart suggests that IVNC is overdiagnosed at least morphologically.