Hemodynamics and Endothelial Function of Perioperative Myocardial Ischemia

To determine whether the stimulation of parasymapthetic nerve could evoke the coroanry constriction，我们承担两个研究包括intracoronary acetylcholine stress test in dogs and theedrohpnium stress test in patients with ischemic heart disease.1)动物实验：To investigate that the coronary vascular tone possibly modulate the response of intracoronaryacethylcholine (Ach) injection. Methods：6 successful experiments were accomplished in 10 dogs. dogs were anesthetized with thiopental（5mg/kg） and morphine (3mg/kg) and maintained with inhalation of sevoflurane. Coronary shunt fromcarotid artery to LAD was installed. EM flow probe was incorporated and measured the toal coronaryflow to LAD.HR was controlled by ventricula pacing after the accomplishion fo AV block (123 bpm). .血压maintaine with the pressurized Blood reservor (mmHg / mmHg). the graded doses ofintracoronary Ach (0.01-1Omicrog) injected through this cannula. LAD flow arid coronary perfusionpres……Intracoronary endotheline-t (ET-1) was More sure were monitored following the Ach injection. Intracoronary endotheline-t （ET-1）infused to redue 30% of co ronary flow fromthe baseline value. Ach压力测试是重复的前and after introcoronary in fusion of ET-1. ResultsLAD flow increased with intracoronary Ach indose dependent. mannaer.ET-1 inhibited LAD flow responseLAD flow decreased below contorl value at the recoveryphase after reactive hyperemia to Achwith ET-1, but not without ET-1. Conclusion：High coronary vascular tone possibly need to induce the coronary constriction with the action ofparasympathetic nerve.2)临床研究：To study whether the activation of parasympathetic nerve induce myocardial ischemia due To thecoronary spasm. Material and methods：我们研究15 patients with coronary artery disease scheduled for elective coronary artery surgery（CABG）. A bolus dose of Edr (0.25mg kg-1) was injected through A central venous catheterl duringharvesting of left internal thoracic artery. Edr successfully induced sinus bradycardia in allpatients. Heart rate (HR) reached the maximum reduction at 3 minutes (-15.3*6.8 beat·smin-1，p< O1). The maximum reduction of HR was proportionally amplified with an increasing baseline HR(r = -0.80,p<O.001). Systemic and pulmonary arterial pressures did not change during this period. Prolongationof PQ duration appeared on lead II EGG for 1分钟after Edr injection (p<O.0 1). No new deviationof ST segments was observed on leads II or V5 for 20分钟. Conclusion：Only the activation of parasympathetic nerve less possibly induce coronary spasm in the patientswith ischemic heart disease. Less

To determine whether the stimulation of parasymapthetic nerve could evoke the coroanry constriction, we conducted two studies including the intracoronary acetylcholine stress test in dogs and the edrohpnium stress test in patients with ischemic heart disease.1)Animal experiment : To investigate that the coronary vascular tone possibly modulate the response of intracoronary acethylcholine (Ach) injection. Methods : 6 successful experiments were accomplished in 10 dogs. Dogs were anesthetized with thiopental (5mg/kg) and morphine (3mg/kg) and maintained with inhalation of sevoflurane. Coronary shunt from carotid artery to LAD was installed. EM flow probe was incorporated and measured the toal coronary flow to LAD.HR was controlled by ventricula pacing after the accomplishion fo AV block (123 bpm). Blood pressure maintaine with the pressurized blood reservor (84mmHg). The graded doses of intracoronary Ach (0.01-1Omicrog) injected through this cannula. LAD flow arid coronary perfusion pres … More sure were monitored following the Ach injection. Intracoronary endotheline-t (ET-1) was infused to redue 30% of co ronary flow fromthe baseline value. Ach stress test was repeated before and after introcoronary in fusion of ET-1. Results : LAD flow increased with intracoronary Ach indose dependent. mannaer.ET-1 inhibited LAD flow response to Ach. LAD flow decreased below contorl value at the recoveryphase after reactive hyperemia to Ach with ET-1, but not without ET-1. Conclusion : High coronary vascular tone possibly need to induce the coronary constriction with the activation of parasympathetic nerve.2)Clinical study : To study whether the activation of parasympathetic nerve induce myocardial ischemia due to the coronary spasm. Material and methods : We studied 15 patients with coronary artery disease scheduled for elective coronary artery surgery (CABG). A bolus dose of Edr (0.25mg・kg-1) was injected through a central venous catheterl during harvesting of left internal thoracic artery. Edr successfully induced sinus bradycardia in all patients. Heart rate (HR) reached the maximum reduction at 3 minutes (-15.3*6.8 beat・smin-1, p<O.O1). The maximum reduction of HR was proportionally amplified with an increasing baseline HR (r=-0.80, p<O.001). Systemic and pulmonary arterial pressures did not change during this period. Prolongation of PQ duration appeared on lead II EGG for 1 minute after Edr injection (p<O.0 1). No new deviation of ST segments was observed on leads II or V5 for 20 minutes. Conclusion : Only the activation of parasympathetic nerve less possibly induce coronary spasm in the patients with ischemic heart disease. Less