1. Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
2. Internal Medicine, Pulmonary, University of Kentucky, Lexington, Kentucky, USA
3. CHI Saint Joseph Hospital, Lexington, Kentucky, USA
4. Electrophysiology Service, CHI Saint Joseph Medical Group, Lexington, KY, USA
5. Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA