1. Division of Cardiovascular Disease, Department of Internal Medicine, MercyOne North Iowa Medical Center , 1000 4th St SW, Mason City, IA 50401 , USA
2. Division of Haematology-Oncology, Department of Internal Medicine, UMass Chan-Baystate , 759 Chestnut St, Springfield, MA 01199 , USA
3. Division of Cardiology, Department of Internal Medicine, University of California Davis , 4150 V Street, Suite 3100, Sacramento, CA 95817 , USA
4. Department of Cardiology, Department of Internal Medicine, University of Maryland , 620 W Lexington St, Baltimore, MD 21201 , USA
5. Division of Cardiology, Cardiovascular Institute of South , 441 Heymann Blvd, Lafayette, LA 70503 , USA
6. Division of Cardiology, Department of Internal Medicine, University of California San Diego , 9500 Gilman Dr. La Jolla, CA 92093 , USA
7. Department of Cardiology, University of Iowa , 200 Hawkins Dr, Iowa City, IA 52242 , USA
8. Division of Cardiology, St George's University of London , Cranmer Terrace, London SW17 0RE , UK