Dr. Brian H. Negus

Dr. William F. Oellerich earned his medical degree from the University of Tennessee at Memphis while concurrently earning a doctorate in philosophy in its Department of Pharmacology. He completed his internship and residency in internal medicine and served as chief resident at Barnes-Jewish Hospital at the Washington University School of Medicine in St. Louis, Missouri. He also completed his fellowship in cardiology at Washington University School of Medicine.Dr. Oellerich is board certified in cardiology and echocardiography. He has had specialized training in nuclear cardiology, diagnostic cardiac catheterization, cardiac magnetic resonance imaging, autonomic pharmacology, cardiovascular pharmacology, and echocardiography. He has been published in the American Journal of Roentgenology, Neuroscience and The Journal of Pharmacology and Experimental Therapeutics.He is the director of the echocardiography lab and CT cardiovascular program at Memorial Hospital. He plays an instrumental part in the ongoing progress of the cardiovascular CT program. He is helping to coordinate the introduction of a valve clinic to The Chattanooga Heart Institute. Dr. Oellerich is rated as a Distinguished provider by MediFind in the treatment of Carotid Artery Disease. His top areas of expertise are Coronary Heart Disease, Atherosclerosis, Aortic Valve Stenosis, and Angina.

Dr. William (Bill) Warren is a cardiologist specializing in non-invasive and imaging cardiology. He is board-certified in Internal Medicine, Cardiovascular Disease, Nuclear Cardiology, and Echocardiography. Dr. Warren graduated summa cum laude from Princeton University, earned his Doctor of Medicine degree at Harvard Medical School, completed his internal medicine internship and residency at Massachusetts General Hospital, and finished a cardiology fellowship at Johns Hopkins Hospital. His areas of focus include a wide range of cardiovascular conditions and treatments, with expertise in non-invasive diagnostic studies.Since joining The Chattanooga Heart Institute in 2003, Dr. Warren has become a valued leader at CHI Memorial and in the Chattanooga medical community. He currently serves as managing partner of The Chattanooga Heart Institute, where he collaborates with over 30 colleagues. He previously chaired the CHI Memorial Board of Directors.Dr. Warren possesses a broad range of clinical interests and expertise. His dedication to patient care stems from a deep love of science combined with a genuine ability to connect with patients on a personal level. The complexity and diverse treatment options within cardiovascular care drew him to this field, allowing him to help critically ill patients recover and thrive. He was the recipient of CHI Memorial’s inaugural St. Luke’s Healer’s Heart award which recognizes physicians and providers for demonstrating compassion, inclusion, integrity, excellence and collaboration.Dr. Warren's commitment extends beyond clinical practice. He has conducted research studies which have been published in prestigious journals including the American College of Cardiology Current Journal Review, Circulation, Journal of Infectious Diseases, Journal of Clinical Microbiology, and Journal of Clinical Research.Away from work, Dr. Warren enjoys nature photography and travel. He has visited all seven continents. Dr. Warren is rated as a Distinguished provider by MediFind in the treatment of Carotid Artery Disease. His top areas of expertise are Coronary Heart Disease, Atherosclerosis, Angina, Pacemaker Implantation, and Heart Bypass Surgery.

Dr. Lehman is board certified in Cardiovascular Disease and specializes in imaging cardiology. He came to Chattanooga Heart from Duke University Health System in Durham, NC. Dr. Lehman completed a fellowship and residency in Cardiovascular Disease at Duke University. He received his medical degree from Duke University School of Medicine and a Master’s of Public Policy, Concentration in Health Policy from Duke University Sanford School of Public Policy. He graduated summa cum laude from Georgetown University with a Bachelor’s of Science, Biology, where he had the highest GPA for all bachelor of science degrees. He served as a congressional aid on Capitol Hill. Dr. Lehman is rated as a Distinguished provider by MediFind in the treatment of Carotid Artery Disease. His top areas of expertise are Mitral Valve Regurgitation, Aortic Regurgitation, Necrosis, and Arterial Embolism.