Multimodality Noninvasive Imaging in the Monitoring of Pediatric Heart Transplantation

Orthotopic heart transplantation is a well-established and effective therapeutic option for children with end-stage heart failure. Multiple modalities, including noninvasive cardiac imaging, cardiac catheterization, angiography, and endomyocardial biopsy, are helpful to monitor these patients for graft dysfunction, rejection, and vasculopathy. Because of morbidities associated with invasive monitoring, noninvasive imaging plays a key role in the surveillance and evaluation of symptoms in pediatric transplant recipients. Echocardiography with or without stress augmentation may provide serial data on systolic and diastolic function, ventricular deformation, and tissue characteristics in children after transplantation. Although not perfectly sensitive or specific, advanced two- and three-dimensional echocardiographic detection of functional changes in cardiac grafts may allow early recognition of allograft rejection. Magnetic resonance imaging has shown promise for characterization of edema and scar and myocardial perfusion reserve, as well as potential application for the detection of microvasculopathic changes in the transplanted heart. Cardiac computed tomography is particularly well suited for the demonstration of coronary artery dimensions and anatomic residual lesions. In combination, these noninvasive imaging techniques help the transplantation cardiologist screen for graft dysfunction, detect critical graft events, and identify situations that require invasive testing of the transplanted heart. Advanced multimodality imaging techniques are likely to increasingly shape the monitoring practices for children following heart transplantation.