After clinical training in internal medicine and cardiology, Dr. Rosenzweig trained as a molecular biologist in the laboratory of Drs. Jonathan and Christine Seidman, Department of Genetics at Harvard Medical School, from 1988 to 1991. His major focus in the Seidman laboratory was studying the molecular basis of cardiac hypertrophy through work on inherited hypertrophic cardiomyopathy and transcriptional control of hypertrophy-responsive genes.
Between 1991 and 1994, Dr. Rosenzweig trained in cell biology and experimental pathology with Dr. Michael A. Gimbrone, Jr., in the Vascular Research Division of the Brigham and Women's Hospital studying inflammatory signaling.
From 1994 to 2006, Dr. Rosenzweig was an independent investigator in the Cardiovascular Research Center (CVRC) at Massachusetts General Hospital, where he also served as the Director of the Program in Cardiovascular Gene Therapy.
In 2006, Dr. Rosenzweig became the Director of Cardiovascular Research and Associate Chief of Cardiology at the Beth Israel Deaconess Medical Center (BIDMC).