Multislice Computed Tomography Evaluation 21 Years After Heterotopic Heart Transplantation
A 47-year-old man was investigated in the heart transplantation unit of our hospital almost 21 years after he had undergone a heterotopic heart transplantation at the Harefield Hospital (England). This is probably the longest-living heterotopic heart transplantation patient ever. In June 1983, he received heart transplant for end-stage heart failure resulting from dilated cardiomyopathy. Nowadays, heterotopic heart transplantation is hardly performed but may be indicated when the patient has irreversible pulmonary hypertension or when the donor heart is believed to be too small to support the recipient’s circulation. This donor heart came from a 16-year-old boy, and a full heterotopic transplantation was performed with the donor pulmonary artery inserted into the recipient pulmonary artery. After a successful operation and some initial signs of rejection, this patient has been living a reasonably normal life. He was initially managed with triple-therapy immunosuppression; currently, he receives cyclosporine monotherapy. Since 1999, he has been known to have ventricular tachycardias of the native heart, which have been under control with amiodarone since 2002. He currently is under evaluation at our hospital because his physical condition has worsened in the last 6 months. For reasons of possible retransplantation in the future, a computed tomography (CT) scan was made (see Figure 1, Figure 2, Movie I, and Movie II in the Data Supplement). Parameters for the study were as follows: 16-slice CT (Philips MX8000) with a detector configuration of 16×0.75 mm and a gantry rotation time of 420 ms. To reduce heart rate and to improve image quality, 10 mg metoprolol was administered intravenously. Postprocessing techniques such as volume rendering can produce 3-dimensional images, which allow preoperational evaluation (see Figure 1a and 1b and movies IIa and IIb). Figure 2 shows a coronal image from the same CT data set.
Movie I shows the original CT data set in diastole; 2-dimensional transaxial sections of both hearts are displayed in a craniocaudal movie sequence. Movie II and III show rotating 3-dimensional volume-rendered multislice CT images of the anatomic situs. Digital removal of superimposing structures reveals a clear overview of the anatomy of both hearts. Note the direct connection of the superior vena cava to the right atrium of the donor heart. The donor left atrium is anastomosed to the recipient left atrium. Movie IV shows an overview of the donor and recipient hearts in a coronal cross-sectional plane. By reconstructing the CT data set at various phases of the RR interval, the movie is able to show both hearts pumping. The native heart (on the right) changes its shape during the heart cycle, but systolic and diastolic volumes remain almost identical, with a measured ejection fraction of &1%. Note the jet in the left ventricle caused by incompetence of the native aortic valve. Finally, Movie V shows an overview of the pumping donor and recipient hearts in a paraxial cross-sectional plane through both ventricles. There is a small diastolic jet from the aorta back into the native left ventricle. Note also the smaller diastolic jet (bright) from the native left atrium into the native left ventricle and the larger systolic jet (dark) back from the native left ventricle into the left atrium, indicating that there is actually a small de facto shunt from the aorta through the native left ventricle into the left atrium.
The online-only Data Supplement can be found at http://circ.ahajournals.org/cgi/content/full/113/4/e57/DC1.