胸内负压增大对家兔实验性冠脉供血不足的治疗作用

本实验首先以22只家兔为对象用垂体后叶素制造心肌供血不足模型（模型组），待家兔完全恢复正常以后，再同样制造模型，同时增大胸内负压（低胸内压组）。发现低胸内压组心电图缺血性ST-T改变恢复，P-R间期缩短，心率增快（P＜0．05），心肌供血不足比模型组减轻。另外用垂体后叶素造成心功能降低后，增大胸内负压时，左室最大收缩压、左室压最大上升和下降速率均明显增大（P＜0．01），左室舒张末期压降低（P＜0.05）。心功能的增强是由于冠脉血流增加，心肌等长自身调节结果。本研究为临床上呼吸训练治疗心肌缺血提供了科学依据。

Curative Effect on Experimental Myocardial Ischemia Rabbits By Increasing Intrathoracic Nagetive Pressure

In 22 rabbits, myocardial ischemia models were established by the use of pituitrin(model group).After the rabbits recovered completly, the same model were established and their intrathoracic pressure (ITP) were descended at the same time (low ITP group). In low ITP group, the electrocardiogram ST-T were recovered, P -R period were smaller and heart rates were higher than than of model group (P<0. 05). This showed that the coronary artery blood supply of low ITP group became better. After the rabbits cadiac function were weakened by the use of pituitrin, the ITP of rabbits were made descent. This made rabbits left ventricular systolic pressure(LVSP), left ventricular pressure maximal ascending rate (dp/dtmax) and maximal descending rate (-dp/dtmax) increased significantly (P<0. 01), left ventricular end diastolic pressure (LVEDP) decreased (P< 0. 05). This result suggested that the heart function were promoted by the equal - length self - regulation of myocardium.