Effects of Ang Ⅱ perfusion on transmural heterogeneous of Cx43 in acute myocardial ischemia reperfusion

Objective:To observe the effects of angiotensin Ⅱ(Ang Ⅱ) pefusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion(MIR),and investigate the role of rennin-angiotensin system in malignant ventricular arrhythmia induced by MIR.Methods:Twenty rabbits were randomly divided into MIR group(n=10) and Ang Ⅱ group(n=10).MIR model was produced with traditional ligation and opening of the anterior descending coronary artery in all animal.The hearts in vitro in the MIR group and the Ang Ⅱ group were perfused with simply improved Tyrode's solution and containing Ang Ⅱ Tyrode's solution respectively.90%monophasic action potential repolarization duration,transmural dispersion of repolarization.Cx43 protein(Cx43-pro) and mRNA(Cx43-Cq) expression in subepicardial,midmyocardial and subendocardial myocardium were measured in both groups.The greatest differences of Cx43-pro and Cx43-Cq among three myocardial layers were calculated and shown with △Cx43-pro and △Cx43-Cq respectively.Results:After Ang Ⅱ perfusion,90%monophasic action potential repolarization duration among three myocardial layer were significantly prolonged(P < 0.05 and P < 0.01),and transmural dispersion of repolarization also significantly increased compared with the MIR group(P < 0.05).Compare with the MIR group,three myocardial Cx43-pro and Cx43-Cq expression in the Ang Ⅱ group were significantly decreased(P < 0.05 and P < 0.01).but△Cx43-pro and △Cx43-Cq were significant increased.Conclusions:Renin-angiotensin system increases transmural heterogeneity of Cx43 expression in the rabbit model with MIR by Ang Ⅱ,and enlarge transmural dispersion of repolarization among three myocardial layers of left ventricular which induces malignant ventricular arrhythmia.

Experimental Study of the Effect of Autonomic Nervous System on the Transmural Dispersion of Ventricular Repolarization under Acute Myocardial Ischemia in Vivo

The effect of the autonomic nerves on the transmural dispersion of ventricular repolarization(TDR)under acute myocardial ischemia in intact canine was investigated.Using the monophasic action potential(MAP)recording technique,MAPs of the epicardium(Epi),midmyocardium(Mid)and endocardium(Endo)were recorded simultaneously by specially designed plunge-needle electrodes at the left ventricular free wall under acute myocardial ischemia in 12 open-chest dogs.MAPD 90 and TDR among three myocardial layers as well as the incidence of the early afterdepolarization(EAD)before autonomic nervous stimulation and during autonomic nervous stimulation were compared.It was found that 10 min after acute myocardial ischemia,TDR was increased from 55±8 ms to 86±15 ms during sympathetic stimulation(P<0.01).The TDR(53±9 ms)during parasympathetic stimulation was not significantly different from that of the control(55±8 ms)(P>0.05).The EAD was elicited in the Mid of 2 dogs(16%)10 min after acute myocardial ischemia,but the EAD were elicited in the Mid of 7 dogs(58%)during sympathetic stimulation(P<0.01).It was concluded that:(1)Sympathetic stimulation can increase the transmural dispersion of repolari-zation and induce early afterdepolarizations in the Mid under acute myocardial ischemia,which provide the opportunity for the ventricular arrhythmia developing;(2)Parasympathetic stimulation has no significant effect on the transmural dispersion of repolarization under myocardial ischemia.

EFFECT OF ACUPUNCTURE AT NEIGUAN POINT ON TRANSMEMBRANE POTENTIAL AND cAMP AND cGMP OF MYOCARDIAL CELL OF RABBITS WITH ACUTE MYOCARDIAL ISCHEMIA

28 health rabbits were divided into electroacupuncture group, and non-elec- troacupuncture. Effect of electrical needling "Neiguan" point on the action potintial and cAMP and cGMP of the ventricular cells of acute myocardial ischemia were observed.The main results are as follows: The RP, APA and maximun velecity of depolarization(Vmax) decrease, the APD prolongs in the electroacupuncture and non-electroacupuncture group, but the changes of non-electroacupuncture group are more evident than the electroacupuncture group.The attack rates of EAD and DAD in the nonelectroacupuncture group are higher than in elec troacupuncture group. cAMP in the acute myocardial ischemia cells increases, but the changes of which in nonelectroacupuncture group are more marked than the electroacupunct u re.The above mentioned results show that there is a protection effect of electrical needling "Neiguan"point on the action potential of the ventricular cell of acute myocardial ischemia rabbits. The effect might result from decreasing cAMP in the ischemia cells by electrical needling "Neiguan" point.

Is there a role for ischemia detection after an acute myocardial infarction?

Coronary angiography and eventual revascularization have become the most common approaches for patients with acute coronary syndromes.Ischemia detection in this scenario is usually regarded as unnecessary for most of the patients.In fact,current guidelines recommend complete revascularization for patients with multivessel disease in the context of ST-elevation myocardial infarction,although it is in contrast with previous recommendations.However,some recent data suggested that ischemia could have a role for the decision of revascularization in these patients.The CROSS-AMI study randomized patients with ST-elevation myocardial infarction treated with primary angioplasty and who also had multivessel disease to a complete anatomic revascularization of the non-infarct related artery lesions vs subsequent revascularization of the noninfarct related artery lesions only if ischemia was demonstrated by stress echocardiography.The main findings were that only 30%of the patients in the ischemia arm needed a second revascularization and that the outcome was similar in both arms.Regarding non-ST-elevation acute coronary syndrome,coronary angiography is in general warranted for most of the patients.However,recent long-term published studies on patients randomized to an invasive or less aggressive approach based on ischemia detection have found no differences in outcome.The ultimate study in non-ST-elevation acute coronary syndrome comparing ischemia detection with an invasive approach is pending.Therefore,ischemia detection might have a role for stratifying these subjects.This is particularly true in the current era of imaging of high quality and sensitivity,last generation stents,radial access and modern antithrombotic therapy.

Effect of electroacupuncture "Shenmen" on the expression of cAMP and cGMP in the myocardium, hippocampus and serum of rats with acute myocardial ischemia

Objective:Discussion on the protectiion of electroacupuncture"Shenmen"on heart and brain injury induced by acute myocardial ischemia in rats from the perspective of the expression of cyclic adenosine monophosphate(cAMP)and cyclic guanosine monophosphate(cGMP).Methods:Thirty male SD rats were randomly divided into normal group,model group,and electroacupuncture group.The electrocardiogram was recorded by the Powerlab 8-lead physiological recording system.The left anterior descending coronary artery was ligated to replicate the rat myocardial ischemia model.The acupuncture group was treated with electroacupuncture on the second day after the model was replicated.After the last electroacupuncture treatment,rat myocardium,hippocampus tissue and abdominal aortic blood were collected,and enzyme-linked immunosorbent assay was used to detect the levels of cAMP and cGMP in myocardium,hippocampus tissue and serum content.Results:Compared with the normal group,the cAMP content in the myocardial tissue of the model group was significantly increased,and the cAMP content in the hippocampus tissue and serum was significantly reduced;compared with the model group,the cAMP content in the myocardial tissue of the electroacupuncture group was decreased,and the hippocampus tissue Compared with the normal group,the content of cGMP in the myocardial tissue and serum of the model group increased,and the content of cGMP in the hippocampus decreased.Compared with the model group,the content of cGMP in the hippocampus of the electroacupuncture group was increased.The cGMP content increased,the serum cGMP content was significantly reduced,and the difference in the cGMP content in myocardial tissue was not statistically significant.Conclusion:Electroacupuncture at"Shenmen"acupoint can significantly improve the expression of cAMP,cGMP and myocardial cAMP in the serum and hippocampus of model rats with acute myocardial ischemia-induced heart and brain injury,but has a lower effect on myocardial cGMP content.

Effects of electroacupuncture of acupoints of the neiguan and ximen on ischemic myocardium energy metabolism with acute myocardial ischemia rats

Objective:To observe the effect of Electroacupuncture of Acupoints of the Neiguan(PC6)and Ximen(PC4)on its myocardial energy metabolism with acute myocardial ischemia rats caused by coronary artery ligation.Methods:Forty standard Spargue-Dawely(SD)rats were divided into four groups randomly,namely,group of Neiguan,group of Ximen,model group,sham group.The group of rats of myocardial ischemia were induced by coronary ligation,and the model rat of acute myocardial ischemia was prepared.The sham group had no ligation of the needle.After anesthesia was awakened,acupuncture was applied bilateral at Neiguan and Ximen of the group of Neiguan and Ximen,once a day at a fixed time for 14 days.The rats of model group and the sham group were not given acupunctured,but use the samely methods of Neiguan and Ximen groups to grap the rats at the same time everyday.After 14 days the experiment was over,observed the pathological changes of myocardial tissue by HE staining,detected the levels of free fatty acid(FFA),adenosine triphosphate(ATP)content,and the activities of Na^(+)-K^(+)-ATPase according to the reagents´demand.Results:Pathological results showed that acupuncuted at Neiguan and Ximen could improve the ischemic cardiomyocyte injury.Compared with the sham group,the levels of FFA in model group were increased(p<0.01),the levels of ATP,the activities of Na^(+)-K^(+)-ATPase were all decreased(p<0.01);Compared with the model group,the levels of FFA were decreased(p<0.05,p<0.01),the levels of ATP,the activities of Na^(+)-K^(+)-ATPase were improved.Conclusion:Acupuncturing at the Pericardium Meridian can alleviate the cell injury by myocardial ischemia,and also can improve the myocardial energetic metabolism in acute myocardial ischemia.

Potassium variability during hospitalization and outcomes after discharge in patients with acute myocardial infarction

BACKGROUND The variability of metabolic biomarkers has been determined to provide incremental prognosis information,but the implications of electrolyte variability remained unclear.METHODS We investigate the relationships between electrolyte fluctuation and outcomes in survivors of acute myocardial infarction(n=4386).Ion variability was calculated as the coefficient of variation,standard deviation,variability independent of the mean(VIM)and range.Hazard ratios(HR)were estimated using the multivariable-adjusted Cox proportional regression method.RESULTS During a median follow-up of 12 months,161(3.7%)patients died,and heart failure occurred in 550(12.5%)participants after discharge,respectively.Compared with the bottom quartile,the highest quartile potassium VIM was associated with increased risks of all-cause mortality(HR=2.35,95%CI:1.36–4.06)and heart failure(HR=1.32,95%CI:1.01–1.72)independent of cardiac troponin I(c Tn I),N terminal pro B type natriuretic peptide(NT-pro BNP),infarction site,mean potassium and other traditional factors,while those associations across sodium VIM quartiles were insignificant.Similar trend remains across the strata of variability by other three indices.These associations were consistent after excluding patients with any extreme electrolyte value and diuretic use.CONCLUSIONS Higher potassium variability but not sodium variability was associated with adverse outcomes post-infarction.Our findings highlight that potassium variability remains a robust risk factor for mortality regardless of clinical dysnatraemia and dyskalaemia.

Surgical Management for a Broken Delivery Shaft in <i>Vivo</i>during PCI Following Acute Myocardial Infarction in a Complex LAD Artery Lesion: A Case Report and Literature Review

Stuck up and fracture of coronary angioplasty hardware are unwonted complications of percutaneous coronary interventions (PCI) for which surgical retrieval and management is once in a while required. We present one case of a 59-year-old diabetic, a hypertensive gentleman who attended the emergency room (ER) with central chest pain for 2 hours. After evaluation of the patient by physical and noninvasive diagnostic tests, he was diagnosed as a case of acute myocardial infarction (AMI) with stable hemodynamic. For the aforementioned findings, the patient was treated first with a thrombolytic agent in ER and then shifted to Cardiology Department for monitoring and further coronary evaluation by coronary angiography (CAG). CAG revealed essentially single vessel disease (SVD) with complex left anterior descending (LAD) artery lesion, so PCI was attempted but failed with an unfortunate incidence of the broken delivery shaft and left in vivo. Immediate decision making and surgical management for retrieval of lost angioplasty device and correction coronary lesion with revascularization save the patient from grave complication. All the series of events and management approaches of this very complex coronary artery lesion are discussed in this article.

When is The Best Time of Stem Cell Transplantation for Treating Acute Myocardial Infarction──A Brief Meta-analysis of Current Clinic Trials

The best time of stem cells transplantation for treating acute myocardial infarction (AMI) is still to be followed with interest and a focus issue for clinical cardiologist. A brief meta-analysis of clinical trials about timing-window and therapeutic effects of stem cell transplantation for treating AMI will be made out in this article.

Spontaneous Coronary Artery Dissection with Clinical Presentation of Acute Myocardial Infarction

SCAD （spontaneous coronary artery dissection） proves to be a pathology of several manifestations, whose clinical diagnosis is a challenge for emergency departments. Therefore, their early identification and knowledge of the various forms of presentation are mandatory for optimal medical therapy. We present a case report of a 45-year-old patient who was admitted to the coronary unit showing symptoms and laboratory tests compatible with myocardial infarction. Complete diagnosis was obtained only with more specific exams. The manifestations of the disease in the case described and the main features of the disease are discussed.

Acute myocardial infarction and extensive systemic thrombosis in thrombotic thrombocytopenic purpura: A case report and review of literature

BACKGROUND Thrombotic thrombocytopenic purpura(TTP)is a thrombotic microangiopathy characterized by the pentad of hemolytic anemia,fever,thrombocytopenia,renal failure,and neurological dysfunction.The formation of microthrombi in the arterioles and capillaries of various organs is one of the main pathophysiological mechanisms.Clinical manifestations of cardiac involvement in TTP patients are variable.Acute myocardial infarction has been reported as a complication with TTP as the secondary thrombotic event.Its emergence as the initial thrombotic event is extremely rare.CASE SUMMARY A 49-year-old previously healthy man was admitted for fever,typical angina chest pain 3 d prior to presentation,and newly onset left lower limb pain.The electrocardiogram illustrated ST-elevation acute myocardial infarction of the anterolateral wall of the left ventricle.Transthoracic echocardiography depicted two large thrombi at the apex of the left ventricle and moderately reduced ejection fraction(40%).Venous Doppler ultrasound showed occlusion of the left popliteal artery.Laboratory tests showed severe thrombocytopenia,mild hemolytic anemia,elevated D-dimers,and high troponin and creatine kinase-MB.Abdominal computed tomography revealed other thrombotic sites(superior mesenteric artery,posterior aortic wall,spleen and renal infarction,and ileum necrosis).He was immediately started on steroids and addressed to surgery for acute abdominal pain.After an initial stabilization of the hematological deficit,he went into general surgery for resection of the necrotic ileum but died soon after the intervention due to multiple organ failure.CONCLUSION Cardiac involvement in TTP patients is common,challenging and more often fatal,especially when other thrombotic complications coexist.

The Safety of Autologous Peripheral Blood Stem Cell Transplantation by Intracoronory Infusion in Patients with Acute Myocardial Infarction

Objectives Bone-marrow stem-cell transplantation has been shown to improve cardiac function in patients with acute myocardial infarction (AMI) , but the safety of intracoronory infusion of autologous peripheral blood stem-cell (PBSCs) in patients with AMI is unknown. For this reason, we observe the feasibility and safety of PBSCs transplantation by intracoronory infusion in such patients. Methods 41 patients with AMI were allocated to receive granulocyte colony-stimulating factor (G- CSF: Filgrastim,300μg) with the dose of 300μg~ 600μg/day to mobilize the stem cell, and the duration of applying G-CSF was 5 days. On the sixth day, PBSCs were separated by Baxter CS 3000 blood cel 1 separator into suspend liquid 57 ml. Then the suspend liquid was infused into the infarct related artery (IRA) by occluding the over the wire balloon and infusing artery through balloon center lumen. In the process of the intracoronary infusion of PBSCs, the complications should be observed, which were arrhythmias including of bradycardia, sinus arrest or atrial ventricular block, premature ve. ntricular beats ,ven~icular tachycardia, ventricular fibrillation; and hypotention, etc. Results There were total 10 cases with complications during the intracoronary infusion of PBSCs. The incidence of complications was 24.4% (10/41), including bradyca- rdia was 2.4 % (1/41), sinus arrest or atrial ventri- cular block was 4.0% (2/41), ventricular fibrillation was 2.4 % (1/41), hypotention was 14.6 % (6/41). Conclusions In patients with AMI, intracoronary infusion of PBSCs is feasible and safe.

The expression of oxidative stress genes related to myocardial ischemia reperfusion injury in patients with ST-elevation myocardial infarction

BACKGROUND:We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury(MIRI)in patients with acute ST-elevation myocardial infarction(STEMI)using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism.METHODS:The mononuclear cells were separated by ficoll centrifugation,and plasma total antioxidant capacity(T-AOC)was determined by the ferric reducing ability of plasma(FRAP)assay.The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction(qRT-PCR).Additionally,gene ontology(GO)enrichment analysis was performed on DAVID website to analyze the potential mechanism further.RESULTS:The total numbers of white blood cells(WBC)and neutrophils(N)in the peripheral blood of STEMI patients(the AMI group)were significantly higher than those in the control group(WBC:11.67±4.85×10^(9)/L vs.6.41±0.72×10^(9)/L,P<0.05;N:9.27±4.75×10^(9)/L vs.3.89±0.81×10^(9)/L,P<0.05),and WBCs were significantly associated with creatine kinase-myocardial band(CK-MB)on the first day(Y=8.945+0.018X,P<0.05).In addition,the T-AOC was significantly lower in the AMI group comparing to the control group(12.80±1.79 U/mL vs.20.48±2.55 U/mL,P<0.05).According to the gene analysis,eight up-regulated differentially expressed genes(DEGs)included GADD45A,PRDX2,HSPD1,DNAJB1,DNAJB2,RAD50,TNFSF6,and TRADD.Four down-regulated DEGs contained CCNG1,CAT,CYP1A1,and ATM.TNFSF6 and CYP1A1 were detected by polymerase chain reaction(PCR)to verify the expression at different time points,and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression.GO and kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response(UPR)and apoptosis.CONCLUSIONS:WBCs,especially neutrophils,were the critical cells that mediating reperfusion injury.MIRI was regulated by various genes,including oxidative metabolic stress,heat shock,DNA damage and repair,and apoptosis-related genes.The underlying pathway may be associated with UPR and apoptosis,which may be the novel therapeutic target.

EFFECT OF ELECTROACUPUNCTURE ON MYOCARDIAL ISCHEMIA INDUCED CHANGES OF CARDIAC SYMPATHETIC ACTIVITY AND INVOLVEMENT OF SPINIAL δ-OPIOID, NMDA-AND NON-NMDA RECEPTORS IN THE RABBIT

Aim: To observe the effect of electroacupuncture (EA) on acute myocardial ischemia (AMI) induced changes of cardiac sympathetic discharges and the effects of some related receptors in the spinal cord. Methods: A total of 53 rabbits anesthetized with mixture solution of 25% urethane (420 mg/kg) and 1.5% chloralose (50 mg/kg) were used in this study. AMI was induced by occlusion of the ventricular branch of the left coronary artery. Discharges of the left cardiac sympathetic nerve were recorded by using a bipolar platinum electrode. Bilateral "Ximen"(PC 40) and "Kongzhui"(LU 6) were stimulated electrically by using an EA therapeutic apparatus or an electrical stimulator. DPDPE δ opiate receptor agonist, 20 nmol, 10 μL, n=8), Naltrindole Hydrochloride (δ opiate receptor antagonist, 20 nmol, 10 μL, n=8), DAP5 (NMDA receptor antagonist, 5 nmol, 10 μL, n=9) and CNQX (non NMDA receptor antagonist, 5 nmol, 10 μL, n=8) were respectively injected into the thoracic subarachnoid space of the spinal cord in different groups, followed by observing their effects on changes of sympathetic activity evoked by EA of the abovementioned acupoints. Results: ① After AMI, sympathetic discharges increased (200.56±79.89%) in 10 cases and decreased (-59.34 ±7.06%) in other 9 cases in comparison with their individual basal values. After EA of "Ximen" (PC 4) and "Kongzhui"(LU 6), AMI induced increase and decrease changes of the sympathetic activity were suppressed significantly, but the effect of EA of LU 6 was weaker than that of EA of PC 4. ② Following EA of PC 4 and LU 6, sympathetic discharges increased significantly in 2 and 4 cases, decreased apparently in 7 and 3 cases, and had no striking changes in 1 and 3 cases respectively. The mean reaction threshold of sympathetic activity after EA of PC 4 and LU 6 were 2.1±0.65 mA and 3.28±1.13 mA separately. ③ After pre treatment with DPDPE, the reaction threshold of the cardiac sympathetic activity to EA of PC 4 elevated significantly (35.89±6.12%); while after pre treatment with Naltrindole, this reaction threshold decreased considerably (84.88±26.58%). Following intrathecal injection of DAP5 (n=9) and CNQX (n=9) , the reaction thresholds of the cardiac sympathetic activity to EA of PC 4 increased obviously (142.06±60.27% and 112.54±28.58% separately). It suggests that spinal δ opioid receptor, NMDA and non NMDA receptors are involved in EA induced changes of sympathetic activity. Conclusion: ① EA could regulate AMI induced changes of cardiac sympathetic activity; and ② spinal δ opioid receptors, NMDA and non NMDA receptors participate in the effect of EA on the cardiac sympathetic activity.

Myocardial ischemia-reperfusion injury:Possible role of melatonin

Our knowledge and understanding of the pathophysiology of coronary atherosclerosis has increased enormously over the last 20 years.Reperfusion through thrombolysis or percutaneous coronary angioplasty is the standard treatment for preventing acute myocardial infarction.Early reperfusion is an absolute prerequisite for survival of the ischemic myocardium,but reperfusion itself may lead to accelerated and additional myocardial injury beyond that generated by ischemia alone.These outcomes,in a range of reperfusion-associated pathologies,are collectively termed "reperfusion injuries".Reactive oxygen species are known to be produced in large quantities in the first few minutes of the post-ischemia reperfusion process.Similarly,scientific evidence from the last 15 years has suggested that melatonin has beneficial effects on the cardiovascular system.The presence of vascular melatoninergic receptor binding sites has been demonstrated;these receptors are functionally linked to vasoconstrictor or vasodilatory effects of melatonin.It has been shown that patients with coronary heart disease have a low melatonin production rate,especially those with higher risk of cardiac infarction and/or sudden death.Melatonin attenuates molecular and cellular damage resulting from cardiac ischemia-reperfusion in which destructive free radicals are involved.

AMI患者PCI术后血清PAF、CK-MB、sCD40L水平变化及其与再缺血的关系

目的探究急性心肌梗死(AMI)患者经皮冠状动脉介入(PCI)术后血清血小板活化因子(PAF)、肌酸激酶同工酶(CK-MB)、可溶性白细胞分化抗原40配体(sCD40L)水平的变化,并分析其与术后再缺血的关系。方法前瞻性选取2019年10月至2022年10月郑州大学第一附属医院收治的225例AMI患者作为研究对象,检测围手术期(术前、术后3 d、术后14 d)所有患者的血清PAF、CK-MB、sCD40L水平,术后接受为期1年随访,根据PCI术后有无再缺血发生分为再缺血发生组30例和再缺血未发生组195例。比较两组患者的临床资料及血清PAF、CK-MB、sCD40L水平;采用Logistic回归方程分析AMI患者PCI术后再缺血影响因素;绘制受试者工作特征曲线(ROC)分析血清PAF、CK-MB、sCD40L水平对AMI患者PCI术后再缺血的预测价值。结果再缺血发生组患者的中国冠心病患者抗血小板治疗优选方案(OPT-CAD)评分为(102.41±15.83)分,明显高于再缺血未发生组的(82.37±10.69)分,差异有统计学意义(P<0.05);再缺血发生组患者术后3 d、14 d的血清PAF水平分别为(89.15±20.11)ng/mL、(78.60±13.24)ng/mL,明显高于再缺血未发生组的(79.85±17.69)ng/mL、(67.42±10.38)ng/mL,CK-MB水平分别为(38.28±11.94)μg/L、(23.09±6.83)μg/L,明显高于再缺血未发生组的(34.83±10.16)μg/L、(17.69±5.12)μg/L,sCD40L水平分别为(4681.69±305.63)pg/mL、(3721.59±175.63)pg/mL,明显高于再缺血未发生组的(4369.39±227.84)pg/mL、(3129.46±132.88)pg/mL,差异均有统计学意义(P<0.05);经Logistic回归方程分析结果显示,OPT-CAD评分及术后3 d、14 d血清PAF、CK-MB、sCD40L水平均为AMI患者PCI术后再缺血发生的危险因素(P<0.05);经ROC分析结果显示,术后3 d血清PAF、CK-MB、sCD40L联合预测再缺血发生的AUC为0.877,术后14 d血清PAF、CK-MB、sCD40L联合预测再缺血发生的AUC为0.930,均大于各时间点三项血清指标单独预测。结论血清PAF、CK-MB、sCD40L水平是AMI患者PCI术后再缺血发生的危险因素,围手术期血清PAF、CK-MB、sCD40L联合预测患者PCI术后再缺血风险的效能较高,可为临床防治PCI术后再缺血提供参考。

Electroacupuncture modulates the activity of the hippocampus-nucleus tractus solitarius-vagus nerve pathway to reduce myocardial ischemic injury

The hippocampus is involved in the regulation of the autonomic nervous system,together with the hypothalamus and brainstem nuclei,such as the paraventricular nucleus and nucleus tractus solitarius.The vagus nerve-nucleus tractus solitarius pathway has an important role in cardiovascular reflex regulation.Myocardial ischemia has been shown to cause changes in the autonomic nervous system,affecting the dynamic equilibrium of the sympathetic and vagal nerves.However,it remains poorly understood how the hippocampus communicates with brainstem nuclei to regulate the autonomic nervous system and alleviate myocardial ischemic tissue damage.A rat model of acute myocardial ischemia（AMI） was made by ligating the left anterior descending branch of the coronary artery.Three days before ischemia,the hippocampal CA1 region was damaged.Then,3 days after ischemia,electroacupuncture（EA） at Shenmen（HT7）-Tongli（HT5） was performed（continuous wave,1 m A,2 Hz,duration of 30 minutes）.Cluster analysis of firing patterns showed that one type of neuron was found in rats in the sham and AMI groups.Three types of neurons were observed in the AMI ＋ EA group.Six types of neurons were found in the AMI ＋ EA ＋ Lesion group.Correlation analysis showed that the frequency of vagus nerve discharge in each group was negatively correlated with heart rate（HR）（P 〈 0.05,r =-0.424）,and positively correlated with mean arterial pressure（MAP）（P 〈 0.05,r = 0.40987） and the rate-pressure product（RPP）（P 〈 0.05,r = 0.4252）.The total frequency of the nucleus tractus solitarius discharge in each group was positively correlated with vagus nerve discharge（P 〈 0.01,r = 0.7021）,but not with hemodynamic index（HR： P 〉 0.05,r =-0.03263; MAP： P 〉 0.05,r =-0.08993; RPP： P 〉 0.05,r =-0.03263）.Some neurons（Neuron C） were negatively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA group（vagus nerve discharge： P 〈 0.05,r =-0.87749; HR： P 〈 0.01,r =-0.91902; MAP： P 〈 0.05,r =-0.85691; RPP： P 〈 0.01,r =-0.91902）.Some neurons（Neurons C,D and E） were positively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA ＋ Lesion group（vagus nerve discharge： P 〈 0.01,r = 0.8905,P 〈 0.01,r = 0.9725,P 〈 0.01,r = 0.9054; HR： P 〈 0.01,r = 0.9347,P 〈 0.01,r = 0.9089,P 〈 0.05,r = 0.8247; MAP： P 〈 0.05,r = 0.8474,P 〈 0.01,r = 0.9691,P 〈 0.01,r = 0.9027; RPP： P 〈 0.05,r = 0.8637,P 〈 0.01,r = 0.9407,P 〈 0.01,r = 0.9027）.These findings show that the hippocampus-nucleus tractus solitarius-vagus nerve pathway is involved in the cardioprotective effect of EA at the heart meridian.Some interneurons in the nucleus tractus solitarius may play a particularly important role in the cardiomodulatory process.

Effects of antiarrhythmic peptide 10 on acute ventricular arrhythmia

Objective:To observe the effects antiarrhythmic peptide 10(AAPIO) aon acute ventricular arrhythmia and the phosphorylation state of ischemic myocardium conncxin.Methods:Acute total ischemia and partial ischemia models were established by ceasing perfusion and ligating the left anterior descending coronary artery in SD rats.The effects of AAP10(1 mg/L) on the incidence rate of ischemia-induced ventricular arrhythmia were observed.The ischemic myocardium was sampled to detect total-Cx43 and NP-Cx43 by immunofluorcsecnt staining and western blotting,the total-Cx43 expression was detected through image analysis system by semi-quantitative analysis.Results:AAP10 could significantly decrease the incidence of ischemia-induced ventricular tachycardia and ventricular fibrillation.During ischemic stage,total ischemia(TI) and AAP10 total ischemia(ATI) groups were compared with partial ischemia(Pi) and AAP10 partial ischemia(API) groups.The rates of incidence for arrhythmia in the ATI and API groups(10%and 0%) were lower than those in the TI and PI groups(60%and 45%).The difference between the two groups was statistically significant(P=0.019,P=0.020).The semi-quantitative analysis results of the ischemic myocardium showed that the total-Cx43 protein expression distribution areas for TI.ATI,PI and API groups were significantly decreased compared with the control group.On the other hand,the NP-Cx43 distribution areas of TI,ATI,PI and API groups were significantly increased compared with the control group(P>0.05).AAP10 could increase the total-Cx43 expression in the ischemic area and decrease the NP-Cx43 expression.Western blot results were consistent with the results of immunofluorescence staining.Conclusions:AAP10 can significantly decrease the rate of incidence of acute ischemia-induced ventricular tachycardia and ventricular fibrillation.Acute ischemic ventricular arrhythmias may have a relationship with the decreased phosphorylation of Cx43 induced by ischemia.AAP10 may stimulate the phosphorylation of Cx43 by increasing the totai-Cx43 expression and decreasing the NP-Cx43 expression in the ischemic area,so as to decrease ventricular arrhythmia.

Elevated Platelet Activating Factor Level in Ischemia-Related Arrhythmia and Its Electrophysiological Effect on Myocardium

Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction （AMI） and the underlying mechanism. Methods （1） Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram （ECG） was recorded continuously. （2） Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. （3） PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization （APD 90 ）under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

Atypical presentation of acute and chronic coronary artery disease in diabetics

In patients with diabetes mellitus, cardiovascular disease is the principal cause of mortality and chest pain is the most frequent symptom in patients with stable and acute coronary artery disease. However, there is little knowledge concerning the pervasiveness of uncommon presentations in diabetics. The symptomatology of acute coronary syndrome, which comprises both pain and non-pain symptoms, may be affected by traditional risk factors such as age, gender, smoking, hypertension, diabetes, and dyslipidemia. Such atypical symptoms may range from silent myocardial ischemia to a wide spectrum of non-chest pain symptoms. Worldwide, few studies have highlighted this under-investigated subject, and this aspect of ischemic heart disease has also been under-evaluated in the major clinical trials. The results of these studies are highly diverse which makes definitive conclusions regarding the spectrum of atypical presentation of acute and even stable chronic coronay artery disease difficult to confirm. This may have a significant impact on the morbidity and mortality of coronary artery disease in diabetics. In this up-to-date review we will try to analyze the most recent studies on the atypical presentations in both acute and chronic ischemic heart disease which may give some emphasis to this under-investigated topic.