Ronald Berger, M.D., Ph.D., is professor of medicine and biomedical engineering at Johns Hopkins University. Dr. Berger is also director of the electrophysiology fellowship program and co-director of the electrophysiology service at The Johns Hopkins Hospital. He serves on the editorial boards of three major journals in the cardiovascular field, has authored more than 250 articles and book chapters, and holds more than 30 patents on methods and devices used in electrophysiology diagnosis and treatment. Dr. Berger and his colleagues perform approximately 3,500 electrophysiology procedures and 500 atrial fibrillation ablation procedures each year.