Ning X
Zhonghua Yi Xue Za Zhi. 1990 Feb;70(2):68-71, 6.
Mongrel dogs were instrumented with 4 pairs of Sonomicrometers to measure ventricular wall thickness (WT) and a Konigsberg (PT) high fidelity micromonometer to measure left ventricular pressure (LVP). Two weeks after surgical operation, studies were conducted. The dWT/dT-WT loop, dP/dt-LVP loop and dP/dt-dP/dt loop, etc. were used to observe the changes in cardiac dynamics. In 6 dogs, the circumflex artery was occluded with hydraulic occluder for three minutes under conscious condition. Three dogs were ventilated with hypoxic gas to reduce the arterial blood oxygen saturation to near 45%. The heart rate increased markedly under both hypoxia and ischemia. During coronary arterial occlusion contraction and relaxation tended to decrease and the ischemic myocardium was in a dysfunctional condition. During hypoxia, contraction and relaxation increased and myocardial movement was enhanced. Only under severe hypoxia, a decrease in heart rate occurred and contraction and relaxation began to be inhibited. These indicated that cardiac function under hypoxia is different from that under ischemia.
杂种犬被植入4对超声心动图仪以测量心室壁厚度（WT），并植入一台柯尼斯堡（PT）高保真微测压计以测量左心室压力（LVP）。手术操作两周后进行研究。使用dWT/dT-WT环、dP/dt-LVP环和dP/dt-dP/dt环等来观察心脏动力学的变化。在6只犬中，在清醒状态下用液压阻塞器将回旋动脉阻塞三分钟。三只犬用低氧气体通气，使动脉血氧饱和度降至接近45%。在缺氧和缺血状态下心率均显著增加。在冠状动脉阻塞期间，收缩和舒张趋于减弱，缺血心肌处于功能失调状态。在缺氧期间，收缩和舒张增强，心肌运动增强。仅在严重缺氧时，心率才会下降，收缩和舒张开始受到抑制。这些表明缺氧状态下的心脏功能与缺血状态下不同。
