Barry L. Zaret, M.D. is Robert W. Berliner Professor of Medicine and professor of radiology, Yale University School of Medicine. Dr. Zaret served as chief of the section of cardiology at Yale from 1978 - 2004 and has been a pioneer in developing the field of noninvasive diagnosis in cardiovascular disease, with an emphasis on nuclear cardiology. Genell Subaksharpe, M.S., is president of G. S. Sharpe Communications, Inc. and has produced or collaborated on more than forty books in health and medicine.