自体骨髓间充质干细胞移植对急性心肌梗死后心律失常影响的实验研究

目的 观察自体骨髓间充质干细胞(MSC)移植对小型猪心肌梗死后心律失常的影响,并研究其作用机制.方法 利用介入方法制作小型猪心肌梗死模型并进行自体MSC移植.MSC移植组12头和心肌梗死对照组10头,分别于移植2 h及4周后通过电生理程序刺激,观察室性心动过速(室速)的发生情况.于建模4周后,通过膜片钳技术研究移植后MSC在心肌环境下的离子通道表达和梗死区域心电异质性变化.结果 (1)建模后2 h MSC移植组9头(75%)、对照组9头(90%)诱发出室速,两组间差异无统计学意义(P=0.445).术后4周MSC移植组3头(25%)、对照组8头(80%)可诱发出持续性单形性室速(P=0.012).(2)MSC移植组的心外膜细胞(Epi)、心内膜细胞(Endo)和中层细胞(M)INa峰值电流密度分别为(-12.43±3.04)pA/pF、(-14.04±3.82)pA/pF和(-29.26±5.70)pA/pF,对照组梗死边缘区的Epi、Endo和M层INa峰值电流密度分别为(-8.47±3.34)pA/pF、(-9.71±3.38)pA/pF和(-18.98±4.05)pA/pF;MSC移植组在三层心肌的表达具有异质性,与对照组相比差异具有统计学意义(P<0.05).(3)MSC移植未室速组MSC的Epi、Endo和M层INa失活半数电压分别为(-93.1±13.8)mV、(-95.2 ±15.5)mV和(-103.4±8.7)mV,MSC移植室速组分别为(-126.2±10.9)mV、(-106.7±11.9)mV和(-105.4±11.0)mV,心肌梗死室速组分别为(-129.1±10.9)mV、(-112.2±9.9)mV和(-109.7±9.3)mV,MSC移植室速组和心肌梗死室速组相比各层差异无统计学意义(P>0.05),和MSC移植未室速组相比各层差异有统计学意义(P<0.05).(4)多元logistic回归分析表明INa失活半数电压(RR=1.449,95%CI1.276～2.079,P=0.029)、INa峰值密度(RR=1.092,95%CI1.008～1.917,P=0.012)是影响心肌梗死室性心律失常的独立危险因素.结论 自体MSC移植致心律失常可能性较小,且有抑制梗死后心律失常发生的作用.自体MSC在心肌内可分化成为具有心肌细胞离子通道特性的类心肌细胞,其离子通道分化程度可能是影响室性心律失常发生的主要机制.     

Low-dose aspirin in patients with stable cardiovascular disease: a meta-analysis

Objective

Many recommendations for aspirin in stable cardiovascular disease are based on analyses of all antiplatelet therapies at all dosages and in both stable and unstable patients. Our objective was to evaluate the benefit and risk of low-dose aspirin (50-325 mg/d) in patients with stable cardiovascular disease.

Methods

Secondary prevention trials of low-dose aspirin in patients with stable cardiovascular disease were identified by searches of the MEDLINE database from 1966 to 2006. Six randomized trials were identified that enrolled patients with a prior myocardial infarction (MI) (n = 1), stable angina (n = 1), or stroke/transient ischemic attack (n = 4). A random effects model was used to combine results from individual trials.

Results

Six studies randomized 9853 patients. Aspirin therapy was associated with a significant 21% reduction in the risk of cardiovascular events (nonfatal MI, nonfatal stroke, and cardiovascular death) (95% confidence interval [CI], 0.72-0.88), 26% reduction in the risk of nonfatal MI (95% CI, 0.60-0.91), 25% reduction in the risk of stroke (95% CI, 0.65-0.87), and 13% reduction in the risk of all-cause mortality (95% CI, 0.76-0.98). Patients treated with aspirin were significantly more likely to experience severe bleeding (odds ratio 2.2, 95% CI, 1.4-3.4). Treatment of 1000 patients for an average of 33 months would prevent 33 cardiovascular events, 12 nonfatal MIs, 25 nonfatal strokes, and 14 deaths, and cause 9 major bleeding events. Among those with ischemic heart disease, aspirin was most effective at reducing the risk of nonfatal MI and all-cause mortality; however, among those with cerebrovascular disease, aspirin was most effective at reducing the risk of stroke.

Conclusion

In patients with stable cardiovascular disease, low-dose aspirin therapy reduces the incidence of adverse cardiovascular events and all-cause mortality, and increases the risk of severe bleeding.     

Antiarrhythmic effects of growth hormone--in vivo evidence from small-animal models of acute myocardial infarction and invasive electrophysiology

Introduction

A growing body of evidence suggests a possible role for growth hormone (GH) in the treatment of congestive heart failure (CHF) and myocardial infarction (MI). The aim of this study was to investigate in vivo the effects of GH treatment on incidence and severity of ventricular arrhythmias normal and MI rats.

Methods

Male Sprague-Dawley rats weighing approximately 350 g were randomized into 3 groups. Growth hormone-treated rats (n = 6) received 6 mg/kg of human GH. The placebo group (n = 10) received 1 mL of saline. Amiodarone-treated rats (n = 10) were injected with 25 mg/kg and served as positive controls. All animals received a single intraperitoneal injection 6 hours before induction of MI. Myocardial infarction was induced by ligation of the left coronary artery, resulting in a large (approximately 40%) anterolateral MI. A computerized electrocardiographic tracing was obtained continuously before induction of MI and up to 1 hour postinfarction. Invasive hemodynamics including intraventricular and arterial pressure were registered for 60 minutes post-MI. Qualitative as well as quantitative variables of ventricular arrhythmias were analyzed. Invasive electrophysiology with pacing in right atrium and ventricle was performed in normal rats (control, n = 13; GH, n = 6; amiodarone, n = 6) to asses inducibility of supraventricular and ventricular arrhythmias.

Results

Growth hormone- and amiodarone-treated rats had lower resting heart rate at baseline before induction of MI. The arrhythmia scores in the GH- (3.8 ± 1) and amiodarone-treated (3.9 ± 0.5) animals were significant lower than in the placebo group (5.9 ± 0.5, P < .05). There was no significant difference in arrhythmia score between the GH and amiodarone groups. The incident of inducible ventricular arrhythmias was lower in the GH (2/6, 33%) and amiodarone (2/6, 33%) groups compared with controls (13/16, 81%; P = .05). There was no difference in inducibility of atrial fibrillation between the GH (5/6, 83%) and control (13/14, 93%) groups, whereas the inducibility of atrial fibrillation was significantly lower in the amiodarone group (2/6, 33%; P < .05).

Conclusions

Pretreatment with GH reduces the burden of ventricular arrhythmias in rats with postinfarction CHF due to acute MI. Growth hormone may be useful in the treatment of CHF and acute MI.     

A survey of primary percutaneous coronary intervention for patients with ST segment elevation myocardial infarction in Canadian hospitals

BACKGROUND:

Historically, access to primary percutaneous coronary intervention (PCI) for the treatment of patients with ST segment elevation myocardial infarction (STEMI) has been limited in Canada. Recent studies have identified innovative strategies to improve timely access and reduce reperfusion time. Accordingly, the contemporary use of primary PCI treatment in Canada was ascertained.

METHODS:

A cross-sectional survey of all 38 Canadian hospitals that were capable of performing PCI procedures was conducted from June 2007 to November 2007. The survey focused on the practice of primary PCI for patients with STEMI and whether the hospitals had implemented internal strategies to reduce ‘door-to-balloon’ times. Analyses were performed at the level of geographical regions.

RESULTS:

Overall, 71% of PCI hospitals (27 of 38) provided around-the-clock primary PCI for patients with STEMI, but the proportion of PCI hospitals offering this service varied widely, from 33% to 100% across regions. All Canadian PCI hospitals provided around-the-clock rescue PCI treatment to STEMI patients who had failed fibrinolytic therapy. In terms of strategies that are associated with reduced reperfusion time, it was observed that only 42% of PCI hospitals (16 of 38) provided feedback on door-to-balloon time to the emergency department and to the cardiac catheterization laboratories within one week of the primary PCI procedure. Overall, 24% of the hospitals had not adopted any of the four identified strategies to improve door-to-balloon time.

CONCLUSION:

Although the majority of Canadian hospitals with PCI capability provide around-the-clock primary PCI for patients with STEMI, significant variations in this practice exist across the country. Canadian PCI hospitals have not consistently adopted strategies that are associated with improved door-to-balloon time.     

16导联心电图ST段改变对急性心肌梗死的临床价值

目的探讨16导联心电图中ST段改变对急性心肌梗死的临床诊断价值。方法对332例急性心肌梗死患者,在原有标准12导联的基础上,增加后壁导联（V7和V8）和右胸导联（V4R和V5R）,观察附加导联中ST段改变,是否可提高心电图诊断急性心肌梗死的价值。结果12导联心电图诊断急性心肌梗死的敏感性为71.4%,特异性为86.0%;12导联＋后壁导联诊断急性心肌梗死的敏感性为79.2%,特异性为85.0%;12导联＋右胸导联诊断急性心肌梗死的敏感性为75.3%,特异性为84.5%;12导联＋后壁＋右胸导联诊断急性心肌梗死的敏感性为81.9%,特异性为83.7%。结论增加后壁和右胸导联可提高诊断急性心肌梗死的敏感性,而特异性并无显著降低。     

重组人生长激素对心肌梗死大鼠心功能及心肌炎性因子表达的影响

目的 观察重组人生长激素(rhGH)对大鼠急性心肌梗死后心功能及心肌炎性因子表达的影响. 方法 结扎大鼠左冠状动脉前降支建立心肌梗死模型,将术后24 h存活的大鼠随机分为对照组和rhGH组,另设假手术组.rhGH组给予rhGH 2 mg.kg-1.d-1皮下注射,对照组和假手术组给予等体积的生理盐水皮下注射,4周后观察rhGH对大鼠心功能及心肌细胞肿瘤坏死因子-α(TNF-α)、白介素-1p(IL-1p)、白介素-6(IL-6)、白介素-10(IL-10)mRNA表达的影响. 结果 与假手术组比较,对照组心肌组织中促炎性细胞因子TNF-α、IL-1β、IL-β和IL-10 mRNA表达(假手术组分别为0.10±0.02、0.08±0.01、0.18±0.01和0.14±0.05;梗死区分别为0.77±0.15、0.93±0.17、1.10±0.14和0.73±0.11;非梗死区分别为0.88±0.14、0.95±0.17、1.18±0.11和0.83±0.16)明显升高.与对照组比较,rhGH组心肌组织中TNF-α、IL-1β、IL-6 mRNA表达(梗死区分别为0.35±0.10、0.36±0.10、0.43±0.11;非梗死区分别为0.51±0.10、0.42±0.11、0.51±0.12)明显下降,IL-10 mRNA表达(梗死区为1.18±0.18;非梗死区为1.21±0.22)升高,P＜0.05.心脏超声显示rhGH组左室功能明显改善. 结论 早期rhGH治疗改善了心肌梗死大鼠心肌炎性因子表达和心脏功能.rhGH有效改善心功能与其降低心肌细胞促炎细胞因子和升高抗炎因子的作用有关.     

177例脑囊虫病误诊原因分析

目的了解脑囊虫病的误诊原因,减少误诊率,提高诊断率及治疗效果。方法通过回顾性病例分析,从鉴别诊断学方面对脑囊虫病的误诊原因进行了分析。结果177例误诊病例中脑囊虫病误诊为其他疾病者132例(74.58%),其他脑部疾病误诊为脑囊虫病者45例(25.42%),其中脑肿瘤与脑囊虫病相互误诊病例达43例(24.29%);小脓肿型脑囊虫病误诊率最高,误诊病例为63例(35.59%)。结论对脑囊虫病缺乏足够的认识,忽视了对流行病学资料的分析;对脑部症状未作详细的鉴别诊断;缺乏特殊的检查条件是误诊的主要原因。     

自制水囊改善主动脉内球囊反搏治疗患者术肢局部舒适度的探讨

目的分析自制水囊对主动脉内球囊反搏治疗（IABP）患者术侧肢体舒适度的影响。方法人选急性心肌梗死伴心源性休克的患者42例。采用7号橡胶手套充水3／4容积制成水囊,将水囊置于患者术侧膝关节和足跟下方。采用自行设计的量表评估应用水囊患者的舒适度和满意度,比较患者应用水囊前后的舒适度。结果应用水囊前患者术侧肢体有不适感和麻木感,应用水囊后舒适度显著提高（P〈0．05）,无一例压疮发生。结论IABP治疗患者术侧肢体应用自制水囊可提高其舒适度和满意度。     

急性心肌梗死合并左心室附壁血栓患者经皮冠状动脉介入术后的抗栓治疗

目的分析急性心肌梗死（AMI）并发左心室附壁血栓（LvT）行经皮冠脉介入治疗（PCI）患者的临床特征及抗栓治疗。方法收集煤炭总医院2005年8月至2012年2月确诊为急性心肌梗死并发左室附壁血栓并行PCI治疗的12例患者的临床资料,对其进行回顾性分析。结果广泛前壁心肌梗死、前壁心肌梗死9例（75％）,左室射血分数低于40％共7例（58％）,冠脉造影检查三支及以上血管病变7例（58％）。6例给予华法林、阿司匹林、氯吡格雷三联抗栓,2例给予西洛他唑、阿司匹林及氯吡格雷三联抗血小板治疗,随访期间血栓均消失。4例双联抗血小板治疗者l例发生脑梗死后加用华法林,3例患者血栓消失,1例血栓机化。12例患者均未出现严重出血现象。结论急性心肌梗死并发左心室附壁血栓并接受PCI治疗患者,充分衡量获益及出血风险,按照个体化原则给予抗栓治疗安全有效。     

院内“一键启动”流程在急性ST段抬高心肌梗死患者救治中的应用

目的 探讨院内“一键启动”流程实施对救治急性ST段抬高型心肌梗死(STEMI)患者的效果.方法 以急诊绿色通道为基础,胸痛中心为平台,建立院内“一键启动”流程,并对“一键启动”流程实施前后的临床数据进行统计分析.结果 “一键启动”流程实施后的16个月内共收治了126例STEMI患者,与流程实施前16个月相比,入门-球囊扩张时间(D2B)缩短了42.9 min(38.1％),平均住院天数缩短了2d(20.2％),人均住院费用减少了2893元(5.11％),并有效降低了STEMI患者的院内死亡率.结论 采用院内“一键启动”流程,能有效缩短STEMI患者的救治时间,明显降低病死率,是控制医疗费用和提高服务质量的有效方法.