Birkeland S, Westby J, Faerestrand S, Grong K
Surgical Research Laboratory, University of Bergen, Haukeland Hospital, Norway.
Am J Physiol. 1993 Feb;264(2 Pt 2):H533-40. doi: 10.1152/ajpheart.1993.264.2.H533.
We studied the effect of inferior cardiac nerve stimulation on global and regional left ventricular function before and after circumflex coronary arterial (CFX) occlusion in 12 pentobarbital-anesthetized cats. Regional function was evaluated by orthogonal sonomicrometry in the anterior midwall of the left ventricle and by two-dimensional short-axis echocardiography. CFX occlusion provoked hypokinesis in the nonischemic free wall adjacent to the dyskinetic ischemic region (17.6 +/- 2.3 vs. 34.6 +/- 2.2% preocclusion wall thickening; P < 0.01) and gradually improved systolic wall thickening toward the contralateral remote region, where the maximal hyperkinetic response was measured (52.9 +/- 4.4 vs. 32.5 +/- 3.3% preocclusion wall thickening; P < 0.001). In the anterior wall, remote region, hyperkinesis was predominant in longitudinal segments (8.1 +/- 0.8 vs. 2.3 +/- 0.6% preocclusion ejection shortening; P < 0.001) and slight in circumferential segments (11.0 +/- 0.7 vs. 9.1 +/- 0.6% preocclusion ejection shortening; P < 0.01). The postocclusion systolic wall thickening and segment-shortening pattern were not modified by sympathetic nerve stimulation, which increased cardiac output less after coronary occlusion, although contractility (dP/dt) increased markedly. In conclusion, the myocardial contraction pattern in ischemic and nonischemic regions after CFX occlusion is not much modified by sympathetic cardiac nerve stimulation.
我们研究了在12只戊巴比妥麻醉的猫中，左旋冠状动脉（CFX）闭塞前后，刺激心下神经对左心室整体和局部功能的影响。通过正交超声测微法评估左心室前壁中层的局部功能，并通过二维短轴超声心动图进行评估。CFX闭塞导致运动障碍的缺血区域相邻的非缺血游离壁运动减弱（闭塞前室壁增厚为34.6±2.2%，闭塞后为17.6±2.3%；P<0.01），并朝着对侧远隔区域逐渐改善收缩期室壁增厚，在该区域测量到最大的运动亢进反应（闭塞前室壁增厚为32.5±3.3%，闭塞后为52.9±4.4%；P<0.001）。在前壁远隔区域，纵向节段以运动亢进为主（闭塞前射血缩短率为2.3±0.6%，闭塞后为8.1±0.8%；P<0.001），圆周节段则轻微增加（闭塞前射血缩短率为9.1±0.6%，闭塞后为11.0±0.7%；P<0.01）。闭塞后交感神经刺激未改变收缩期室壁增厚和节段缩短模式，尽管冠状动脉闭塞后心输出量增加较少，但收缩性（dP/dt）显著增加。总之，CFX闭塞后缺血和非缺血区域的心肌收缩模式未因交感心脏神经刺激而有太大改变。
