Ando H, Tomoike H, Kurita J I, Nakamura M
Research Institute of Angiocardiology and Cardiovascular Clinic, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Jpn Circ J. 1993 Dec;57(12):1164-72. doi: 10.1253/jcj.57.1164.
The role of changes in preload in maintaining stable hemodynamics during coronary obstruction was assessed in the presence of myocardial ischemia due to occlusions of the left anterior descending (LAD) and left circumflex (LCX) coronary arteries. Changes in preload (mean left atrial pressure) to maintain a constant stroke volume after coronary occlusion were examined in 18 anesthetized dogs (LAD occlusion in 9 dogs, LCX occlusion in 9 dogs). The level of ischemia was assessed sonomicrometrically. Ventricular function curves relating left atrial pressure to stroke volume were assessed during a control state and after 1 min of coronary occlusion. The extent of preload reserve after coronary occlusion was examined on the ventricular function curves and was defined as the change in mean left atrial pressure required to maintain stroke volume at the level of the control state under conditions of regional ischemia. Ischemic size was determined by a stereo-angiogram after the animals were sacrificed. The extent of preload reserve (X) was linearly related to the ischemic size (Y) in both LAD (Y = 0.90 + 0.16X, r = 0.76, p < 0.001) and LCX (Y = -1.79 + 0.19X, r = 0.79, p < 0.001) occlusions. The slopes of the regression lines in LAD and LCX occlusions were the same. The X intercepts of these lines were -5.6% and 9.4% of the left ventricular weight in LAD and LCX ischemia (p < 0.001), respectively. Thus, the presence of systolic wall motion abnormalities due to coronary occlusion can be compensated for hemodynamically by changes in the preload reserve.(ABSTRACT TRUNCATED AT 250 WORDS)
在因左前降支（LAD）和左旋支（LCX）冠状动脉闭塞导致心肌缺血的情况下，评估了前负荷变化在冠状动脉阻塞期间维持稳定血流动力学中的作用。在18只麻醉犬中（9只犬进行LAD闭塞，9只犬进行LCX闭塞），研究了冠状动脉闭塞后为维持恒定心搏量而发生的前负荷（平均左心房压力）变化。通过超声测微法评估缺血程度。在对照状态和冠状动脉闭塞1分钟后，评估左心房压力与心搏量的心室功能曲线。在心室功能曲线上检查冠状动脉闭塞后的前负荷储备程度，并将其定义为在局部缺血条件下将心搏量维持在对照状态水平所需的平均左心房压力变化。在动物处死后通过立体血管造影确定缺血面积。在LAD（Y = 0.90 + 0.16X，r = 0.76，p < 0.001）和LCX（Y = -1.79 + 0.19X，r = 0.79，p < 0.001）闭塞中，前负荷储备程度（X）与缺血面积（Y）呈线性相关。LAD和LCX闭塞中回归线的斜率相同。这些线在LAD和LCX缺血中的X轴截距分别为左心室重量的-5.6%和9.4%（p < 0.001）。因此，冠状动脉闭塞引起的收缩期壁运动异常可通过前负荷储备的变化在血流动力学上得到代偿。（摘要截断于250字）
