1. Division of Cardiology, Duke University, Durham, NC
2. Duke Clinical Research Institute, Duke University, Durham, NC
3. Division of Cardiology, University of Colorado, and CPC Clinical Research, Aurora, CO
4. Saint Luke's Mid America Heart Institute, University of Missouri‐Kansas City, Kansas City, MO
5. Ahmanson‐UCLA Cardiomyopathy Center, University of California Los Angeles, CA