[Functional transvalvular regurgitation in patients with Björk-Shiley aortic valves: a pulsed Doppler echocardiographic study].

It is well known that a small amount of regurgitation occurs through Björk-Shiley valves. Obviously, this functional regurgitation is related to the construction of the Björk-Shiley valve, wherein the disc does not overlap the ring, but fits within its orifice, leaving a minimal space between the edge of the disc and the ring. The aim of this study was to evaluate the clinical significance of regurgitation in patients having Björk-Shiley valves in the aortic position by pulsed Doppler echocardiography. The study group consisted of 46 patients with normally functioning valves and five patients with malfunctioning valves. Valve dysfunction resulted from paravalvular regurgitation in three, and thrombosed valves in two (confirmed by surgery and angiography). Using pulsed Doppler echocardiography, aortic regurgitation was observed in 29 of the 46 normally functioning Björk-Shiley aortic valves. Among these, regurgitant flow signals were constantly located in the vicinity of the valve ring in the left ventricular outflow tract. Therefore, these regurgitant flow signals were considered to represent functional regurgitation of the Björk-Shiley valve. Aortography was performed for 11 of the 46 normally functioning Björk-Shiley valves, and there was minimal transvalvular regurgitation in all. In all of the five malfunctioning Björk-Shiley aortic valves, aortic regurgitant flow signals were detected by pulsed Doppler echocardiography, and the maximal distance of the regurgitant flow signals from the Björk-Shiley valve ring was more than 0.5 cm. However, it was difficult to differentiate transvalvular regurgitation from paravalvular regurgitation using pulsed Doppler technique alone.(ABSTRACT TRUNCATED AT 250 WORDS)