1 From the Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey (A.J.R.); and Departments of Physiology and Medicine, New York Medical College, Valhalla (J.M.S.). aross1@hmc.psu.edu.
2 From the Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey (A.J.R.); and Departments of Physiology and Medicine, New York Medical College, Valhalla (J.M.S.).