Transesophageal two-dimensional echocardiography and color Doppler flow velocity mapping in the evaluation of cardiac valve prostheses

Abstract

To determine the value of transesophageal ultrasound in the assessment of cardiac valve prostheses, 14 patients with clinically suspected mitral prosthesis malfunction were studied by transthoracic and transesophageal two-dimensional imaging as well as by color Doppler flow velocity mapping (color Doppler). Patients underwent left ventricular angiography (n = 13), surgery (n = 11), or both angiography and surgery (n = 10). Nine patients had only mitral valve replacement, four patients had both mitral and aortic valve replacement, and one patient had mitral, aortic, and tricuspid valve replacement. There were 16 biological and four mechanical prostheses. The degree of mitral regurgitation was graded by both transthoracic and transesophageal color Doppler according to the area of the regurgitant jet visualized and was compared with a three-point classification of mitral regurgitation by left ventricular angiography judged by observers blinded to the echocardiographic results. All transesophageal studies were performed without complication and were well tolerated. The pathological morphology of the mitral prosthesis was additionally or more clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery in three patients with flail leaflets and one patient with a vegetation compared with images obtained by the transthoracic approach. Valvular regurgitation was graded by the transthoracic approach as absent in four patients, mild in two patients, moderate in five patients, and severe in only three patients. The transesophageal assessment showed absence of mitral regurgitation in two patients, moderate regurgitation in two patients, and severe regurgitation in 10 patients. Left ventricular angiography done in 13 of the 14 patients revealed no regurgitation in two patients, mild regurgitation in one patient, moderate regurgitation in one patient, and severe mitral regurgitation in nine patients. This corresponded to the grading by transesophageal echocardiography in 12 of the 13 patients with the 13th patient graded as mild regurgitation by angiography and moderate regurgitation by transesophageal echocardiography. We conclude that in patients with biological mitral prosthesis malfunction, transesophageal two-dimensional imaging, as well as color Doppler, can provide reliable diagnostic information beyond that available from the transthoracic approach with the degree of mitral regurgitation corresponding to that found on left ventricular angiography.