Echocardiography has been one of the most significant advances in cardiology in the past two decades. It can provide anatomic, functional hemodynamic, and blood flow information. Conventional transtho racic echocardiography has limitations, particularly in certain patients such as those with obesity, chronic lung disease, or chest wall defor mity, or in those where a transthoracic approach is difficult for reasons including trauma, life support apparat uses, and surgical dressings. There are also certain disease states or conditions in which transtho racic echocardiography expectedly gives incomplete or inadequate in formation. Transesophageal echo cardiography has opened a unique "new window to the heart." The immediate proximity of the esophagus and the posterior heart permits exceptionally high resolution images, par ticularly of the left atrium, mitral valve, and intraatrial septum. Addi tionally, from the stomach (trans gastric views), the ventricles can be dependably imaged. Transesophageal echo cardiography presently is utilized in two environments: intraoperatively and for outpatient examinations. Intraoperatively, TEE is utilized to monitor cardiac function and de tect intracardiac air or debris, to diagnose or quantitate cardiac path ology, and to access operative results."