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在麻醉开胸犬,用电起搏维持心率恒定,研究了电刺激颈迷走神经(VNS)及冠状动脉内注入乙酰胆碱(ACh)对缩窄的冠状动脉的节段阻力及血流量的影响。在左旋支主干造成不同程度的冠状动脉缩窄。分别测定左旋支血流量(CBF_(cx))、主动脉压和主旋支远端冠状动脉压,记录心电图。实验发现,在冠状动脉临界狭窄和重度狭窄时,VNS 或冠脉给ACh 引起心外膜大冠状动脉阻力及冠状动脉主旋支总阻力增大,CBF_(cx)减少;随着缩窄程度加重,这些改变也愈明显,然而,心肌内小冠状动脉阻力却无显著改变。
In anesthetized thoracodorsal dogs, electrical pacemaker was used to maintain constant heart rate. The effects of electrical stimulation of cervical vagus nerve (VNS) and intracoronary injection of acetylcholine (ACh) on segmental resistance and blood flow of narrowed coronary arteries were studied. In the left circumflex artery causes varying degrees of coronary artery narrowing. Left ventricular blood flow (CBF_ (cx)), aortic pressure and distal coronary artery pressure were measured and electrocardiogram was recorded. The experiment found that in critical critical and severe coronary artery stenosis, VNS or coronary artery to ACh caused by epicardial coronary resistance and coronary aortic total resistance increased, CBF_ (cx) decreased; with the degree of constriction increased , These changes are also more obvious, however, there is no significant change in myocardial resistance of small coronary arteries.