Nagatsu M, Ishihara K, Zile M R, Tsutsui H, Tagawa H, DeFreyte G, Tanaka R, Cooper G, Carabello B A
Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, SC.
J Thorac Cardiovasc Surg. 1994 Feb;107(2):416-23.
Severe mitral regurgitation (regurgitant fraction 0.75 +/- 0.02) was created in eight dogs by our closed-chest chordal rupture technique. After 3 months of chronic mitral regurgitation all indices of contractile function were depressed. Mitral valve repair was then attempted. Postoperative regurgitant fraction was reduced compared with the preoperative value in all eight dogs. Concomitantly, forward cardiac output increased in all dogs and pulmonary capillary wedge pressure fell in all dogs. However, in some dogs, significant regurgitation persisted despite repair. Postoperative regurgitant fraction ranged from 0% to 60%. Postoperative residual regurgitant fraction was related significantly to postoperative cardiac output (r = 0.99), pulmonary capillary wedge pressure (r = 0.77), ejection fraction (r = 0.75), and two indices of contractile function--the mass-corrected end-systolic stress volume relationship (r = 0.87) and end-systolic stiffness (r = 0.93). In general, these parameters returned to their normal values before mitral regurgitation when postoperative regurgitant fraction was less than 30%. Myocytes isolated from the ventricles at the end of study also demonstrated normal contractile function when regurgitant fraction was less than 30%.
通过我们的闭胸腱索断裂技术，在8只犬中造成了严重二尖瓣反流（反流分数为0.75±0.02）。在慢性二尖瓣反流3个月后，所有收缩功能指标均降低。然后尝试进行二尖瓣修复。与术前值相比，所有8只犬术后的反流分数均降低。同时，所有犬的心输出量增加，肺毛细血管楔压下降。然而，在一些犬中，尽管进行了修复，仍存在明显的反流。术后反流分数范围为0%至60%。术后残余反流分数与术后心输出量（r = 0.99）、肺毛细血管楔压（r = 0.77）、射血分数（r = 0.75）以及两个收缩功能指标——质量校正的收缩末期应力容积关系（r = 0.87）和收缩末期硬度（r = 0.93）显著相关。一般来说，当术后反流分数小于30%时，这些参数恢复到二尖瓣反流前的正常值。在研究结束时从心室分离的心肌细胞在反流分数小于30%时也表现出正常的收缩功能。
