1. Division of Cardiology, Hunter Holmes McGuire Veterans Affairs Medical Center (VAMC), Richmond, VA 23249, USA
2. Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
3. Department of Radiological Sciences, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
4. Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University (VCU) Medical Center, Richmond, VA 23219, USA