Diagnostic Usefulness of Histological Examination of the Left Ventricular "Core" Excised to Insert a Left Ventricular Assist Device in Patients With Severe Heart Failure.

The left ventricular assist device (LVAD) has proven to be beneficial for patients with severe heart failure poorly responsive to anti heart failure medicine. To examine both grossly and histologically the portion of left ventricular (LV) free wall excised ("the left ventricular core") to insert a LVAD in 337 patients with severe heart failure from a variety of causes. We collected together all photographs of LV "cores" and the histologic sections prepared from them and reexamined both. Despite the fact that these LV cores usually weighed >100 times the quantity of myocardium available to examine compared with that available by biotome inserted via a transvenous catheter, the number in which histologic study allowed an unequivocal diagnosis was limited. Examination of the clinical records usually was required to establish the definitive diagnosis. Although the presence of a scarred myocardial wall usually suggested ischemic cardiomyopathy (IC), the scarring may not have involved the LV apex resulting in a nonscarred portion of myocardium simulating idiopathic dilated cardiomyopathy (IDC). Moreover, about 10% of the patients with IDC have myocardial scars thus simulating IC. Involvement of the LV core by amyloid, sarcoid, myocarditis, and acute infarction, of course, allowed a specific anatomic diagnosis. Despite the presence of ample tissue to secure a definitive diagnosis, the combination of clinical input and morphologic assessment was required to arrive at a definite diagnosis in most patients.