实验性颅内压升高对狗心肌收缩性的影响

Effect of elevated intracranial pressure on canine cardiac contractility

作者观察12只健康狗颅内压(ICP)升高对心肌收缩性的影响.用硬脑膜外套囊法使ICP阶梯升高,分别升至6.7,13.3和20.0kPa.结果ICP升至6.7kPa时,除心率显著减慢外,其它指标无明显改变.ICP升至13.3 kPa时,血压升高,心率减慢,心输出量由1.83 L/min升至2.51L/min,LVSP由15 kPa升至22kPa(P<0.01),+dp/dt_(max)由236 kPa /s升至306kPa/s(P<0.01),-dp/dt_(max)由167 kPa/s升至262kPa/s(P<0.01),t—dp/dt_(max)时间由82.ms缩短至62ms(P<0.01),说明心肌收缩性增强.ICP继续升至20.0kPa时,上述指标均继续增高,作者认为这是机体代偿的结果.

The effect of elevated intracranial pressure (ICP)on cardiac contractility was studied in 12 dogs .The ICPwas elevated in gradient by placing a balloon in epidural space to 6.7, 13.3 and 2(10 kPa . When ICP was elevated to 6.7 kPa, the blood pressure (BP )increased slightly and heart rate (HR )slowed significantly When ICP was de-vated to 13.3 kPa, the BP increased and HR slowed (P<0.05), cardiac output increased from 1.83 to 151 L/min , LVSP from 15 to 22 kPa (P<a01)+dp/dtmax from 236 to 306 kPa/s (P<0.01)-dp/dtmax from 167 to 262 kPa/s (P<0.01)and 5-dp/dtmax shortened from 82 to 62 ms(P<0.01). These change indicated that the cardiac contractility was enhanced . When ICP was elevated to 20.0 kPa , all indices above mentioned increased further . The reason for the increased cardiac contractility was thought to be a compensatory mechanism .