1. Department of Internal Medicine, Marshfield Clinic Health System, Marshfield, Wisconsin, USA
2. Department of Cardiovascular Diseases, Rush University, Chicago, Illinois, USA
3. Department of Cardiovascular Diseases, Marshfield Clinic Health System, Marshfield, Wisconsin, USA
4. Department of Clinical Cardiac Electrophysiology, Aurora Health Care, Milwaukee, Wisconsin, USA
5. Division of Cardiac MRI, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA