Doppler-Derived Gradients in Normally Functioning Monostrut Bjِrk-Shiley Prostheses

Doppler echocardiography is an established technique for the routine assessment of prosthetic heart valve function; its accuracy in the estimation of pressure valve gradients has been demonstrated in comparative studies with invasive data.1,2 Ultrasound examination therefore is an important aid in the clinical follow-up of these patients. Nevertheless, the variability of normal values for transprosthetic Doppler gradients is relatively wide, depending basically on the model and size of the valve.3,4 For this reason, the availability of reference values for different valve sizes of a particular model is necessary for a correct assessment of the prosthetic function in every patient. This study reports the normal range of Doppler gradients in a large series of patients with clinically normal-functioning Monostrut Bjِrk-Shiley valves5 (Shiley, Inc., Irvine, California) in the aortic or mitral position, obtained either postoperatively or over a long-term follow-up.