Changes of Doppler Echocardiographic Findings After Mitral Valve Operation

ABSTRACT

Pulsed Doppler echocardiography was performed before and five to fifteen days (mean, 9.3 days) after mitral valve surgery to evaluate the change of pulmonary arterial pressure in 80 patients (29 males and 51 females) with mitral valve disease by preejection period (PEP)/acceleration time (AT) ratio at the right ventricular outflow tract. In 13 patients with pulmonary hypertension (mean pulmonary arterial pressure equal to or greater than 20mmHg), Doppler echocardiography was followed three to twelve months after operation. In 76 patients with a mitral valve prosthesis (15 patients with the Bjork-Shiley valve, 28 patients with the Ionescu-Shiley valve, and 33 patients with the St. Jude valve), mean transmitral pressure gradient and pressure-half time were estimated by continuous wave Doppler echocardiography five to fifteen days after operation. 1) PEP/AT Ratio by pulsed Doppler echocardiography correlated well with the mean pulmonary arterial pressure gradient by cardiac catheterization (r=0.83, p<0.001). 2) After mitral valve surgery, PEP/AT ratio decreased significantly (p<0.001). In group with mean pulmonary arterial pressure equal to or greater than 40mmHg, immmediate postoperative PEP/AT ratio was greater (P<0.05) than that in group with mean pulmonary arterial pressure less than 20 mmHg, but, difference between the preoperative and postoperative PEP/AT ratio was much greater (P<0.001) than that in group with mean pulmonary arterial pressure between 20 and 39 mmHg. 3) In 13 patients, on whom repeated Doppler echocardiography performed, PEP/AT ratio decreased immediately after mitral valve surgery (p<0.001). After then, it decreased further, but, the amount of the decrease was much smaller than immediate one (p<0.001). 4) There was no significant difference in postoperative PEP/AT ratio among the different prosthesis. Mean transmitral pressure gradient and pressure half-time of the Bjork-Shiley, Ionescu-Shiley, and St, jude valves were 3.1 mmhg and 67.3 msec, 2.9 mmHg and 65.3 msec, and 2.7 mmhg and 60.2 msec, repectively. The St.Jude valve had somewhat smaller mean transmitral pressure gradient and pressure half-time, but there was no statistical significance. In conclusion, elevated pulmonary arterial pressure in patients with mitral valve disease decreased greatly within 15 days after operation, and Doppler echocardiography was a useful method in the follow-up of prosthetic mitral valve function.