Using transesophageal echocardiography, cardiac structures can be imaged with high resolution. The aim of our study was to evaluate whether transesophageal echocardiography is superior in detecting mitral valve prolapse and other cardiac abnormalities compared with transthoracic echocardiography in an age-matched control group and in young patients with cerebral ischemic events (patient group). Forty patients with cerebral ischemic events (mean age 35.2 years) and 29 controls (mean age 30.4 years) were examined using both methods. Transthoracic and transesophageal echocardiography showed a significantly higher incidence of mitral valve prolapse in the patient group compared with the control group (p<0.001). By means of transesophageal echocardiography, it was possible to measure highly significant bulging in both the anterior and the posterior mitral leaflet in the patient group compared with the control group (p<0.001), and the thickness of the mitral leaflets was significantly higher in the patient group. In 9 of 20 (45%) patients with normal transthoracic echocardiograms, transesophageal echocardiography showed pathologic findings. We found transesophageal echocardiography to be a sensitive method for detecting mitral valve prolapse as well as valve changes and other cardiac abnormalities not detectable by conventional echocardiography. Our study underlines the role of mitral valve prolapse in young stroke patients as a relevant risk factor and emphasizes the importance of changed mitral valve morphology. {Stroke 1988;19:345-348)A series of studies has demonstrated an association of mitral valve prolapse (MVP) with cerebral ischemic events in younger patients.1 " 4 In 1980, Barnett and coworkers, by means of M-mode echocardiography, pointed out that the incidence of MVP in stroke patients <45 years of age was significantly higher (40%) than in age-matched controls.5 An increasing number of reports indicate that it is necessary to differentiate between "normal" MVP and a pathologic form with valve thickening and a high degree of myxomatous tissue change. 67 Some clinical retrospective studies address the possibility that the extent of valve involvement may influence the risk of embolic stroke. 8 -9 Transesophageal echocardiography (TEE) is a recently developed imaging technique with a very high degree of reliability and excellent resolution of the cardiac structures, especially the mitral valve.10 Until now, it has not been used for the cardiologic examination of younger patients with cerebral ischemic events.Our investigation examined whether TEE can provide additional diagnostic information in comparison with conventional transthoracic echocardiography ( r i b ) in patients with cerebral ischemic events and in Received March 14, 1987; accepted November 25, 1987. age-matched controls. In addition, we were also interested in analyzing the incidence of MVP by TEE, in quantifying the bulging of the mitral leaflets over the valve plane in normal and changed valves, and in performing measurements related to va...