1. Division of Cardiology, Department of Medicine (M.I.A., V.S.H., S.H., K.S., D.A.K.), The Johns Hopkins University, The Johns Hopkins School of Medicine, Baltimore, MD.
2. Department of Biomedical Engineering (V.J., D.A.K.), The Johns Hopkins University, The Johns Hopkins School of Medicine, Baltimore, MD.
3. Department of Pharmacology and Molecular Sciences (D.A.K.), The Johns Hopkins University, The Johns Hopkins School of Medicine, Baltimore, MD.