1. Duke Clinical Research Institute, Durham, NC (S.J.G.).
2. Division of Cardiology, Duke University School of Medicine, Durham, NC (S.J.G.).
3. Baylor Scott and White Research Institute, Dallas, TX (J.B.).
4. Department of Medicine, University of Mississippi, Jackson (J.B.).
5. Ahmanson–UCLA Cardiomyopathy Center, University of California, Los Angeles (G.C.F.).