1. Bradenton Cardiology Center, Manatee Memorial Hospital, FL (S.J.M.).
2. Columbia University Irving Medical Center, New York, NY (S.A.P.).
3. North Carolina Heart and Vascular Research, Raleigh (W.W.).
4. Wellmont Holston Valley Medical Center, Kingsport, TN (D.C.M.).
5. Metropolitan Heart and Vascular, Minneapolis, MN (J.W.C.).
6. Mercy Medical Des Moines, IA (M.G.H.G.).
7. University of Michigan Health West, Wyoming (M.J.S.).
8. St. Joseph Hospital – Orange, CA (B.C.K.).
9. Beth Israel Deaconess Medical Center, Boston, MA (D.S.P.).
10. Cedars-Sinai Medical Center, Los Angeles, CA (S.D.).