下丘脑背内侧核传出冲动和正中神经传入冲动对左心室跨壁血流的影响

THE EFFECTS OF DORSAL MEDIAN HYPOTHALAMUS EFFERENT IMPULSES AND MEDIAN NERVOUS AFFERENT IMPULSES ON THE LEFT VENTRICULAR TRANSMURAL BLOOD FLOW

心内膜下心肌缺血是目前医学界研究较活跃的问题之一。因心内膜下缺血往往涉及范围广泛,且易引起电不稳定,若治疗不当,其远期预后与穿壁型心肌梗塞者相同。但内膜下心肌梗塞往往在梗塞区内含有较多的存活心肌,因此,若处理及时,可望较好的恢复。临床上早就认识到中枢神经功能紊乱,能引起内膜下心肌缺血或梗塞,但其机理尚不清楚,一般认为,心电图 S-T段下移代表内膜下心肌缺血,但缺乏直接根据。Hoffman 和 buckberg

Thirty-two rabbits were anaesthetized with mixture of α-chloralose and urethane and ventilated with a volume controlled respirator.After midsternal thoractomy the heat was suspended in an open pericardical cradle.Left ventricular (LV) pressure was recorded through a fluid-filled catheter inserted into the left ventricle through LV apex.Aortic pressure was recordedthrough a fluid-filled catheter introduced into the ascending aorta through left carotid artery.Each catheter was connected to a blood pressure tranducer Pso.The epicardial electrocardiogram (EECG) was measured by a cotton wick—normal saline electrode.The LV and aortic pressure as well as EECG were recorded simultaneously on a polygraph RM-6000 at a paper speed of 100mm/sec.The diastolic pressure time index (DPTI)/tension time index (TTI) ratio and EECG S-T Segment changes were taken as the indices of LY transmural blood flow.DPTI/TTI and EECG S-T segment markedly depressed (P<0.01) duringstimulation of dorsal median hypothalamus (DMH) with a pair of concentric electrode,with persisted at least 60 minutes after stopped stimulation of DMH.And this effect can be relived by synchronous stimulation of MN (P>0.05).This study indicated that DMH takes an important role in both inducing subendomyocardial ischemia and reliving subendomyocardial ischemia through stimulation of MN.