[Diagnostic value of transesophageal echocardiography in diseases of the heart valve system].

Due to high resolution transesophageal echocardiography has been proven to have additional diagnostic benefits in valvular heart disease. The quantification of aortic and mitral valve insufficiency is possible by the use of semiquantitative methods. In aortic valve insufficiency the relation of the regurgitant jet width to the left ventricular outflow tract and in mitral valve insufficiency the relation of the regurgitant jet area to the left atrium are the parameters with the most accurate sensitivity. The main advantage of the method in this point is the rapid detection of morphological pathology at the valves. The development of multiplane transducers enhanced the quantification of aortic valve stenosis which is performed by planimetry of the orifice area in an ideal cross-section of the valve reached at a mean angle of 46 degrees. The high resolution image of mitral valve anatomy leads to the intraoperative use of the method during valve repair identifying inadequate surgical correction, which can be revised instantly. Visualization of the valvular and subvalvular mitral apparatus enables a more reliable indication for valvuloplasty by detecting the presence or absence of atrial thrombi and assessing the severity of calcification, the guide catheter and the balloon placement. Transesophageal echocardiography is the method of choice in the detection and measurement of vegetations and abscesses in infective endocarditis. Imaging an increasing extent of a vegetation during follow-up investigations can lead to the necessity of surgical intervention for preventing embolic events. The transesophageal approach especially in combination with color-doppler flow imaging is superior to the transthoracic method in the detection of abscesses and secondary complications like communication to adjacent structures or implication of the mitral valve. In this point the use of multiplane probes permits a more accurate assessment of the extent and the spatial configuration of additional masses. Concerning valve prostheses the detection rate of vegetations, abscesses as well as degenerations of bioprostheses is higher using the transesophageal method than the transthoracic approach. Abscesses located near the right coronary sinus or in the ventricular septum are difficult to detect due to shadowing caused by prosthetic artefacts. The visualization of bioprostheses allows the measurement of the thickness of the leaflets which is necessary for the diagnosis of valve sclerosis or degeneration. In combination with color-doppler flow imaging the method allows the differentiation of transvalvular and perivalvular regurgitation. The movements of the occluder can be imaged leading to a more reliable diagnosis of obstruction in combination with the trans-thoracic use of doppler-methods.