1. From the Division of Cardiovascular Diseases, Department of Internal Medicine (R.R., S.R.O., M.J.A., P.S., U.S.V., R.A.N., B.J.G.), Departments of Radiology (J.F.G., P.A.A.), Pediatrics (M.J.A.), and Molecular Pharmacology and Experimental Therapeutics (M.J.A.), and Windland Smith Rice Sudden Death Genomics Laboratory (M.J.A., J.M.B.), Mayo Clinic, Rochester, Minn; and Division of Cardiovascular Diseases (A.J.T.), Mayo Clinic, Scottsdale, Ariz.