Regurgitant flow in apparently normal valve prostheses: improved detection and semiquantitative analysis by transesophageal two-dimensional color-coded Doppler echocardiography.

In 128 patients with apparently normally functioning prosthetic valves (n = 136) in the aortic position (n = 79) and the mitral position (n = 57), the prevalence of transprosthetic regurgitant flow was studied by use of transthoracic and transesophageal two-dimensional color-coded Doppler echocardiography. With the transthoracic approach, regurgitant flow was detected in early systole or diastole for 28% of the mitral prostheses and for 29% of the aortic prostheses. With transesophageal color-coded Doppler echocardiography, regurgitant jets were visualized for 95% of the mitral prostheses and for 44% of the aortic prostheses. In 40% of the Björk-Shiley prostheses and 88% of the St. Jude Medical prostheses in the mitral position, more than one jet with an eccentric origin was detected, whereas in bioprostheses only one centrally localized regurgitant jet was noted. The regurgitant jet length was 22 +/- 2 mm in mitral prostheses and 12 +/- 2 mm in aortic prostheses. The jet area was 154 +/- 31 mm2 in mitral prostheses and 61 +/- 26 mm2 in aortic prostheses. Jets of this size and frequency have to be considered a normal finding and the equivalent of regurgitant flow known from in vitro studies. We conclude that only transesophageal color-coded Doppler echocardiography seems to be a reliable method for following up mitral valve prostheses to detect and differentiate regurgitant jets. For aortic valve prostheses the advantage of transesophageal color-coded Doppler echocardiography does not seem to be as obvious as the advantage for mitral prostheses.