Hypertrophic Cardiomyopathy: An unexpected finding in a surgical variant of Heterotopic Heart Transplantation

A 42 years old woman was admitted to the Cardiology Department for heart failure. The woman had a diagnosis of Idiopathic Restrictive Cardiomyopathy. At the age of 29 she underwent a variant of the traditional intervention of Heterotopic Heart Transplantation (HHT). The donor Left Ventricular (dLV)was implanted towork as a biologic left ventricular device in series with the recipient Left Ventricular (rLV). This variant of the traditional intervention (Fig. 1 Panel A; G; H) was necessary to prevent the failure of the donor Right Ventricular (dRV) because the patient at the time of transplantation had a pulmonary resistance of 12Wood Unit. The patient had an abdominal pacemaker with three epicardial electrodes to allow the counter pulsation of the two hearts (Fig. 1 Panel A; B; C; D; F). The atrial electrode was added four years after the transplantation because the patient developed a third-degree atrioventricular block in the native heart. At the echocardiography examination the donor heart showed a severe hypertrophy (maximum 30 mm; anterior-septum; Video 1; transthoracic echocardiography) and a severe hypertrophy of papillary muscles, maximum 26 mm (Video 2; transesophageal echocardiography). The angiography showed normal coronary arteries. The patient underwent endomyocardial biopsy specimens that reveal no evidence of active myocarditis or amyloid but myocardial fiber disarray (Fig. 1 Panel I). Inside the heterogeneity of presentation of heart failure after HHT, Hypertrophic Cardiomyopathy of the donor heart can be a possibility which needs a knowledge of the type of intervention (traditional or variant) for a proper evaluation and a correct diagnosis.