[Diagnostic value of the transesophageal Doppler echocardiography]

Transesophageal echocardiography has been proven to be of particular value in all patients with transthoracic echocardiograms of low quality related to pulmonary emphysema, obesity and chest deformation as well as in intensive care unit patients. Similarly, transesophageal Doppler echocardiography is of particular value in all cases in which the transthoracic Doppler, due to methodological problems, is of limited value. Mitral regurgitation can be detected and quantified and flow direction described. Only in 12/25 patients with mild, 11/12 patients with moderate and 5/8 patients with severe insufficiency was regurgitation detected by transthoracic echocardiography as compared to transesophageal echocardiography with which the lesion was consistently detected. In two patients with severe and clinically-inapparent mitral regurgitation related to papillary muscle rupture, the diagnosis was established only by the transesophageal approach in an emergency situation. Atrial septal defects were detected in 8/15 patients and the size of the defect analyzed. With transesophageal Doppler echocardiography, the relation of left-to-right and right-to-left shunts could be described. In 7/16 patients with aortic dissection, true and false lumen were differentiated by analysing the flow pattern within both lumina. In 9/16 patients differentiation was enabled through delineation of the false lumen which was filled with thrombotic material. Detection of aortic regurgitation and tricuspidal regurgitation is possible but analysis of flow patterns is difficult because flow direction is nearly orthogonal to the ultrasound beam. First attempts to quantify cardiac output have been performed. For the future, transesophageal color flow Doppler mapping appears to be a most promising method.