An initial application of transesophageal Doppler echocardiography in experimental small animal models. Journal   Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. Citation   J Am Soc Echocardiogr. 18(6):626-31 Publication date   2005 Jun Authors   Gao Z Li J Kehoe V Davidson WR Sinoway L Pu M Investigators   William R. Davidson, Jr. Jianhua Li Min Pu Lawrence I. Sinoway Grant agencies   National Heart, Lung, and Blood Institute Grants   NHLBI R01 HL0060800 Abstract   This study examined whether an intracardiac echocardiography catheter could be used for transesophageal echocardiography (TEE) examinations in normal rats, and intraoperative TEE in small animal models of disease. The study used 30 Sprague-Dawley normal rats, 10 rats undergoing coronary artery ligation, and 10 rats with experimentally induced mitral regurgitation. The rats were anesthetized with isoflurane and intubated. An intracardiac echocardiographic catheter was inserted into the esophagus. M-mode, 2-dimensional, and Doppler studies were performed in multiple views. TEE probe insertions were successful in all animals. Intraoperative TEE was safely performed in the rat models of myocardial infarction or mitral regurgitation. Mitral regurgitation was well assessed using color Doppler and pulmonary venous flow. This study demonstrates that TEE (including intraoperative TEE) can be safely performed in rats using an intracardiac echocardiographic catheter. It provides a new approach to the assessment of cardiac function and valvular regurgitation in small animals.