Lai D T, Timek T A, Dagum P, Green G R, Glasson J R, Daughters G T, Liang D, Ingels N B, Miller D C
Department of Cardiovascular and Thoracic Surgery and Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, USA.
J Thorac Cardiovasc Surg. 2000 Nov;120(5):966-75. doi: 10.1067/mtc.2000.110186.
The perturbed mitral leaflet geometry that leads to acute ischemic mitral regurgitation during acute left ventricular ischemia has not been quantified, nor is it known whether annuloplasty rings affect these detrimental changes in leaflet geometry.
Radiopaque markers were implanted on both mitral leaflets and around the anulus in 3 groups of sheep: one group without rings served as the control group (n = 7); the others underwent Duran (n = 6; Medtronic Heart Valve Division, Minneapolis, Minn) or Carpentier-Edwards Physio (n = 5; Baxter Cardiovascular Division, Santa Ana, Calif) ring annuloplasty. After recovery, 3-dimensional marker coordinates were obtained by means of biplane videofluoroscopy before and during acute posterolateral left ventricular ischemia. Leaflet geometry was defined by measuring distances between annular and leaflet markers and perpendicular distances to the leaflet markers from a best-fit annular plane.
In all control animals, left ventricular ischemia was associated with acute ischemic mitral regurgitation and apical displacement (away from the annular plane) of the posterior leaflet edge and base markers by 0.6 +/- 0.4 mm (P =.01) and 0.7 +/- 0.2 mm (P <.001), respectively. The distance between the posterior leaflet markers and the mid-posterior anulus did not change significantly during ischemia. The anterior leaflet edge marker extended 1.0 +/- 0. 5 mm (P =.01) away from the mid-anterior anulus during ischemia, but compared with its nonischemic position, the anterior leaflet was not displaced apically away from the annular plane. In all animals in the Duran and Physio groups, leaflet geometry was unchanged during ischemia, and acute ischemic mitral regurgitation was not detected.
Acute ischemic mitral regurgitation was associated with restricted motion of the posterior leaflet and extension of the anterior leaflet. Annuloplasty rings prevented these geometric perturbations of the mitral leaflets during acute left ventricular ischemia and preserved valvular competence.
导致急性左心室缺血期间急性缺血性二尖瓣反流的二尖瓣叶几何形状改变尚未得到量化，也不清楚瓣环成形环是否会影响叶几何形状的这些有害变化。
在3组绵羊的二尖瓣叶和瓣环周围植入不透射线的标记物：一组不植入环作为对照组（n = 7）；其他组分别接受杜兰（Duran）（n = 6；美敦力心脏瓣膜部，明尼阿波利斯，明尼苏达州）或卡彭蒂埃 - 爱德华兹生理（Carpentier-Edwards Physio）（n = 5；百特心血管部，圣安娜，加利福尼亚州）瓣环成形术。恢复后，在急性左后外侧心室缺血前和缺血期间通过双平面视频荧光透视法获取三维标记坐标。通过测量瓣环和叶标记物之间的距离以及从最佳拟合瓣环平面到叶标记物的垂直距离来定义叶几何形状。
在所有对照动物中，左心室缺血与急性缺血性二尖瓣反流以及后叶边缘和基部标记物向心尖移位（远离瓣环平面）有关，分别为0.6±0.4毫米（P = 0.01）和0.7±0.2毫米（P <0.001）。缺血期间后叶标记物与后瓣环中部之间的距离无明显变化。缺血期间前叶边缘标记物远离前瓣环中部延伸1.0±0.5毫米（P = 0.01），但与非缺血位置相比，前叶未向心尖远离瓣环平面移位。在杜兰组和生理组的所有动物中，缺血期间叶几何形状未改变，未检测到急性缺血性二尖瓣反流。
急性缺血性二尖瓣反流与后叶运动受限和前叶延伸有关。瓣环成形环可防止急性左心室缺血期间二尖瓣叶的这些几何形状改变，并保持瓣膜功能。
