As the mitral valve disease becomes long-standing, the patient may develop pulmonary hypertension. It was reported that after surgical correction, the elevated pulmonary vascular resistance(PVR) would fall quickly in association with the fall in
left
atrial pressure(LAP). This study was performed to evaluate the changes in mean pulmonary artery pressure(PAP) and PVR immediately after mitral valve replacement(MVR).
Fifty six patients undergoing mitral valve replacement(MVR) were divided into two groups on the basis of the basis of the presence or absence of significant pulmonary hypertension, defined as a resting mean pulmonary arterial pressure greater
than
30mmHg. After induction of anesthesia, PAP, PVR, cardiac output(CO) were measured and compared with values in postbypass period.
PAP and PVR were significantly decreased(PAP from 39.64(1.88 to 29.18(1.65 mmHg P<0.001, PVR from 6.16(1.14 to 3.53(0.62 units, P<0.05) in Group II(PAP(30mmHg, n=23), whereas not changed in Group I(APA<30 mmHg, n=33)(P<0.05).
Persistance of an elevated PVR is needed postoperatiavely. This study demonstrated that the PAP and PVR fall significantly after MVR especially in patients with severe pulmonary hypertension.
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