1. Division of Cardiothoracic Surgery, New York Presbyterian Hospital - College of Physicians and Surgeons of Columbia University, New York, New York;
2. Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania;
3. Division of Cardiology, New York Presbyterian Hospital - College of Physicians and Surgeons of Columbia University, New York, New York; and
4. Department of Anesthesiology, Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, New York