David L. Hayes, MD, FACC, FHRS Dr. Hayes is a consultant for the Division of Cardiovascular Diseases and Professor of Medicine in the College of Medicine at the Mayo Clinic in Rochester, Minnesota, has lectured worldwide and is the author of multiple publications on cardiac pacing and defibrillation, including the widely read Cardiac Pacing and Defibrillation: A Clinical Approach, and A Case-Based Approach to Pacemakers, ICDs, and Cardiac Resynchronization.