Echocardiographic determination of mitral disc valve excursion.

Disc excursion and opening and closing velocities of prosthetic disc valves can be measured accurately by diagnostic echocardiography. The ultrasound beam is projected along the longitudinal axis of the valve and the echoes arising from the struts, disc, and suture ring are displayed on the oscilloscope. Twenty-four patients with normally functioning mitral Beall valves of various sizes and three patients with prosthetic valve dysfunction (one Beall, two Kay-Shiley) were studied. Table 1 lists the disc excursions with standard deviations of Beall valves measured by ultrasound. The 0.06-0.09 cm difference in excursion between models no. 103 and no. 104 valves was detected by ultrasound without prior knowledge of change in design of the valve and demonstrates the extreme accuracy of this technic. The opening and closing disc velocity averaged 22 cm/sec and 40 cm/sec, respectively. Decrease in-expected disc excursion and abnormal motion patterns were found in three patients with prosthetic dysfunction secondary to thrombus formation, and verified at operation. With continuous changes in valve designs it is important to obtain a baseline excursion and motion pattern for each patient immediately postoperatively. Echocardiography is a useful, noninvasive, reproducible technic for accurate assessment of prosthetic mitral disc valve movement.