1. Department of Medicine, Division of Cardiovascular Medicine, UCSD Cardiovascular Institute, University of California, San Diego, CA, U.S.A.
2. Department of Pediatrics, Division of Cardiology, University of California, San Diego, CA, U.S.A.
3. Department of Anesthesiology, Veterans Affairs San Diego Healthcare System, San Diego, CA, U.S.A.
4. Department of Anesthesiology, University of California San Diego, La Jolla, CA, U.S.A.