Clement J. Zablocki VA Medical Center 1 article published in JoVE Medicine Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery Paul S. Pagel1, Lonnie Dye III2, Graham E.D. Hill2, Juan L. Vega2, Justin N. Tawil2, Derek J. De Vry2, Kiran Chandrashekarappa1, Zafar Iqbal1, Brent T. Boettcher1, Julie K. Freed2 1Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, 2Department of Anesthesiology, Medical College of Wisconsin We describe a protocol to measure vortex formation time, an index of left ventricular filling efficiency, using standard transesophageal echocardiography techniques in patients undergoing cardiac surgery. We apply this technique to analyze vortex formation time in several groups of patients with differing cardiac pathologies.