John A. Kastor, M.D., a professor of medicine at the University of Maryland School of Medicine, is the former chief of the Cardiovascular Division at the University of Pennsylvania School of Medicine and former chair of the Department of Medicine at Maryland. He is the author of Arrhythmias; Mergers of Teaching Hospitals in Boston, New York, and Northern California; Governance of Teaching Hospitals: Turmoil at Penn and Hopkins; and Specialty Care in the Era of Managed Care: Cleveland Clinic versus University Hospitals of Cleveland, the last two published by Johns Hopkins.