Harris K M, Malenka D J, Haney M F, Jayne J E, Hettleman B, Plehn J F, Griffin B P
Section of Cardiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
Am J Cardiol. 1997 Sep 15;80(6):741-5. doi: 10.1016/s0002-9149(97)00506-7.
This study sought to determine whether there is a quantitative improvement in mitral regurgitation (MR) after aortic valve replacement (AVR) for aortic stenosis (AS) and, if so, the mechanisms for this change. MR frequently accompanies AS. The addition of mitral valve replacement to AVR significantly increases the risk of surgery. Although previous studies have suggested a qualitative improvement in MR severity after AVR, semiquantitative analysis of this improvement has not been documented nor have the underlying mechanisms been examined. We evaluated 28 patients who had undergone 2-dimensional echo and color flow Doppler imaging an average of 1.5 +/- 2.5 months before and 2.5 +/- 4.2 months after AVR. Maximum MR area, MR percentage (MR area/left atrial area), mitral annular area, left atrial area, aortic gradient, and parameters of left ventricular geometry were measured to evaluate MR severity and to assess functional mechanisms for improvement in MR. There was a significant decrease in MR area (5.5 +/- 2.8 cm2 vs 2.5 +/- 1.9 cm2, p < or =0.0001) and MR percentage (25 +/- 11% vs 12 +/- 10% after operation, p < or =0.0001) between preoperative and postoperative studies. There was a significant reduction in aortic gradient, mitral annular area, left atrial area, and left ventricular length postoperatively. In univariate analysis, MR improvement was related to the lower preoperative left ventricular fractional area change (p = 0.027) and to the changes in fractional area change (p = 0.001) and left ventricular systolic area (p = 0.001). Thus, improvement in MR after AVR is related to changes in left ventricular function postoperatively. These data suggest that reduction in MR is due not only to decreased intraventricular pressure, but also to changes in ventricular morphology.
本研究旨在确定主动脉瓣置换术（AVR）治疗主动脉瓣狭窄（AS）后二尖瓣反流（MR）是否有定量改善，若有改善，其改变机制为何。MR常伴随AS。AVR联合二尖瓣置换术会显著增加手术风险。尽管既往研究提示AVR后MR严重程度有定性改善，但尚未有对这种改善的半定量分析记录，其潜在机制也未得到研究。我们评估了28例患者，这些患者在AVR术前平均1.5±2.5个月及术后2.5±4.2个月接受了二维超声心动图和彩色血流多普勒成像检查。测量最大MR面积、MR百分比（MR面积/左心房面积）、二尖瓣环面积、左心房面积、主动脉压差以及左心室几何形态参数，以评估MR严重程度并评估MR改善的功能机制。术前和术后研究之间，MR面积（5.5±2.8cm²对2.5±1.9cm²，p≤0.0001）和MR百分比（术后25±11%对12±10%，p≤0.0001）有显著降低。术后主动脉压差、二尖瓣环面积、左心房面积和左心室长度有显著减少。单因素分析中，MR改善与术前较低的左心室面积变化分数（p = 0.027）以及面积变化分数的改变（p = 0.001）和左心室收缩面积的改变（p = 0.001）有关。因此，AVR后MR的改善与术后左心室功能的变化有关。这些数据表明，MR的降低不仅归因于心室内压力降低，还与心室形态的改变有关。
