Saumil J Patel1, John G Augoustides2. 1. Cardiovascular and Thoracic Division, Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. 2. Cardiovascular and Thoracic Division, Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Electronic address: yiandoc@hotmail.com.