He stayed on in that city for internship and residency at the University of Pennsylvania's Children's Hospital of Philadelphia (CHOP), the oldest children's hospital in the United States . In Philadelphia, he met and married Judy as they began their life together 34 years ago.
A year in London, as Senior Registrar in Intensive Care / Pulmonary Medicine at the world's oldest children's facility, The Hospital for Sick Children, was followed by fellowship in Pediatric Cardiology back in New Haven at Yale.
In 1979, Dr. Gewitz became Assistant Professor of Pediatrics at Penn and the first Director of Noninvasive Pediatric Cardiology at CHOP. In 1983, he was recruited by Westchester Medical Center - New York Medical College as Chief of Pediatric Cardiology for the institutions. A cooperative effort has led to an extensive academic and clinical program now centered at the Maria Fareri Children's Hospital, serving 9 practice sites in the tri-state area and all NYMC affiliates.
Pediatric Cardiology has grown to13 full time physicians plus a nurse clinician and technical staff, one of the largest services in the region. In 1989, Dr. Gewitz became Director of Pediatrics at Westchester Medical Center and in association with Dr. Leonard Newman, Chair of Pediatrics at New York Medical College , has built a Pediatrics Department of nearly 100 full-time faculty, which has become a leading force for children's health in the tri-state area. When Maria Fareri Children's Hospital opened in 2004 he became its first Executive Director and Physician-in-Chief.
Dr. Gewitz has edited a textbook, Primary Pediatric Cardiology , and has also been author or co-author of over 130 scientific publications and reports plus chapters in 15 major textbooks. He serves as reviewer and editorial board member for several scientific journals and is chair-elect of the Executive Committee of the American Heart Association's Council of Cardiovascular Disease in the Young and immediate past Chairman of its Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease.
He was co-author of the recent AHA guideline statement on endocarditis prophylaxis. He has been Associate Editor of the Journal Heart Disease , and is section co-editor for Cardiovascular Review . Dr. Gewitz is a fellow of numerous state and national societies including AOA, the medical school honor society, the NY Academy of Medicine, the Pediatric Academic Societies, the American Heart Association, and the American College of Cardiology. He served for 10 years as a member of the New York State Cardiac Advisory Committee, the group that advises the Commissioner of Health on cardiovascular practices and policies throughout New York .
His educational and clinical interests extends beyond America and has been furthered with trips to help children in Kiev, Ukraine and El Salvador where the team he headed received a Presidential medal for their efforts in cardiac treatment of children there. Former students and trainees are now Pediatric Cardiologists and pediatric academic and community leaders at major centers around the United States and in Europe . Dr. Gewitz has participated as faculty in the Salzburg Seminars training pediatric specialists from Central Europe in modern approaches to congenital heart care.
Dr. Gewitz credits the strong support of his family for providing the energy and inspiration he has needed over the years. He is the strongest supporter of his wife Judy, who has a successful career as Guidance Counselor at The Alternative School in the White Plains school system, of his daughter Emily, a public relations specialist, and his son Andrew, a PhD student at Stanford.