[Doppler echocardiography in the evaluation of prosthetic valve function].

The limitations of invasive and noninvasive procedures, including M-mode and 2-D echocardiography, in the follow-up of patients with prosthetic heart valve replacement, are numerous and well known. Doppler echocardiography helps the functional evaluation of prosthetic valves by reliable detection of valvular regurgitation through a malfunctioning prosthetic valve or due to paravalvular leaks. On the other hand, serial determinations of the values of pressure drops or effective valve orifice areas, calculated from the half-time pressure, enables the diagnosis of prosthetic valve obstruction or dehiscence. The results in the assessment of prosthetic valve function by Doppler echocardiography in a group of operated patients, are reported. Signs of prosthetic valve malfunction were not present in 6 patients with mitral valve prostheses and two patients with two-valve-prostheses (mitral and aortic) in the group ob 13 evaluated patients. In two patients with Björk mitral valves mitral regurgitation was found. It was due to valvular leakage in one patient and to paravalvular leakages in the other. In both patients with aortic prosthetic dysfunction a paravalvular leak was diagnosed. There was an invasive proof of prosthetic regurgitation in the same four patients. The only patient with biologic mitral valve prosthesis presented a significant flow obstruction.