He specializes in pediatric heart failure, heart transplant, and pulmonary hypertension. He is actively involved in multiple national and international transplant organizations including the International Society for Heart and Lung Transplantation (ISHLT), the Americal Society for Transplantation, and the International Pediatric Transplant Assocation. His primary research involves outcomes of cardiac transplantation in children with complex congenital heart disease, treatment of antibody medited rejection, treatment of acute heart failure, innovative noninvasive measurements of systolic and diastolic function in children with cardiomyopathies and heart transplant, and cost analysis of heart transplantation. He participates in multicenter research studies through the Pediatric Heart Transplant Study and ISHLT.