1. Department of Internal Medicine, Gundersen Health System, La Crosse, WI 54601, USA
2. Department of Cardiology, Gundersen Health System, La Crosse, WI 54601, USA
3. Department of Cardiothoracic Surgery, Gundersen Health System, La Crosse, WI 54601, USA
4. Department of Pathology, Gundersen Health System, La Crosse, WI 54601, USA