Iguchi A, Tabayashi K, Ninomiya M
Department of Thoracic and Cardiovascular Surgery, Tohoku University School of Medicine, Sendai, Japan.
Tohoku J Exp Med. 1996 Jul;179(3):157-66. doi: 10.1620/tjem.179.157.
Conventional mitral valve replacement (MVR) for patients with chronic mitral regurgitation (MR) is usually associated with decrease in left ventricular (LV) ejection fraction (EF). This study investigated the effect of preoperative LV size on LV performance and examined loading conditions before and after conventional MVR. Echocardiographic study was performed on 13 and 9 patients with LV end-systolic dimension of less than 26 mm/m2 (group A) or greater than 26 mm/m2 (group B), respectively. Postoperatively, the LV end-diastolic dimension and EF decreased significantly in both groups. There was a decrease in end-systolic wall stress after MVR. Preoperative LV forward flow estimated by the normalized aortic peak velocity increased significantly in both groups after surgery. The decrease in EF after MVR is not the result of increased systolic loading, and LV performance may not decrease after conventional MVR. Preoperative echocardiographic evaluation can provide important prognostic information in patients with MR undergoing MVR.
对于慢性二尖瓣反流（MR）患者，传统二尖瓣置换术（MVR）通常会导致左心室（LV）射血分数（EF）降低。本研究调查了术前左心室大小对左心室功能的影响，并检查了传统MVR前后的负荷情况。分别对13例和9例左心室收缩末期内径小于26mm/m²（A组）或大于26mm/m²（B组）的患者进行了超声心动图研究。术后，两组的左心室舒张末期内径和EF均显著降低。MVR后收缩末期壁应力降低。手术后两组通过标准化主动脉峰值速度估计的术前左心室前向血流均显著增加。MVR后EF降低并非收缩期负荷增加的结果，传统MVR后左心室功能可能不会降低。术前超声心动图评估可为接受MVR的MR患者提供重要的预后信息。
