AMI犬TMLR术后心肌血流量变化及意义

目的 本实验观察了激光心肌血管重建术(TMLR)后心肌血流量的变化,探讨TMLR的作用机制。方法 18只犬随机等分为三组:A组-对照组;B组-缺血组;C组-激光组。采用连续型Nd:YAG激光行心肌打孔,光纤直径0.6mm,功率20～25W,脉冲时间0.3～0.5s,孔间距离8～10mm。于LAD结扎前、结扎后30min和60min收集冠状静脉窦血计算心肌血流量。统计学处理采用随机区组设计的方差分析(α=0.05)。结果 缺血组LAD结扎后心肌血流量进行性下降(P<0.05),而激光组LAD结扎前后比较无显著性差异(P>0.05),但结扎后明显高于缺血组(P<0.05)。结论 TMLR可迅速有效地改善心肌缺血。     

激光心肌血运重建术后激光孔道及心肌血管新生的研究

目的　研究并比较传统激光心肌血运重建术 (T TMLR)与非透壁激光心肌血运重建术(N TMLR)对心肌缺血面积、心肌坏死面积及血管新生的影响。方法　在家兔急性心肌缺血模型中 ,采用伊文氏蓝 氯化三苯基四唑 (TTC)双重染色法测定心肌缺血和心肌坏死面积 ,并通过HE染色观察新生血管的密度。结果　T TMLR和N TMLR术后均可明显缩小心肌缺血面积 ,明显增加新生血管密度 ,二者之间无显著差异 ;T TMLR和N TMLR术后心肌坏死面积无改变。结论　N TMLR可获得与T TMLR相同的效果。通过激光孔道诱导血管新生并缩小心肌缺血面积可能是激光心肌血运重建术的主要作用机制之一 ,而激光孔道是否通畅与其作用机制无关。     

第三届心肌血管再生和心肌再血管化国际研讨会简介

20 0 0年 6月 2 2日在美国首都华盛顿召开了血管再生 (Ａｎｇｉｏｇｅｎｅｓｉｓ)和直接心肌再血管化 (ＤｉｒｅｃｔＭｙｏｃａｒｄｉａｌＲｅｖａｓｃｕ ｌａｒｉｚａｔｉｏｎ,ＤＭＲ)国际研讨会。会议为期2天 ,来自美国、瑞士、比利时、加拿大、法国、德国的 35位心脏外科和介入治疗领域的国际知名专家 ,参加了讨论会。与会代表还包括介入血管外科专家、介入影像专家、血管生物学家、分子生物学家、胸心血管外科专家和其他保健领域的工作者。会议以专题论坛、临床试验研讨、论文壁报的形式探讨了在血运再生、心肌直接再血管化领域从基础到…     

经皮穿刺激光心肌血管建术后细胞外信号调节激酶的动脉变化

目的：探讨经皮穿刺激光心肌血管重建术（ＰＴＭＲ）后细胞外信号调节激酶的动脉变化。方法：实验组和对照组分别在猪心脏上进行ＰＴＭＲ和假手术,于ＰＴＭＲ和假手术后２、２４ｈ,３、７、１４ｄ取左室前壁心肌组织,分别以放射免疫法和Ｗｅｓｔｅｒｎ ｂｌｏｔ方法测定其细胞外信号调节激酶（ＥＲＫｓ）活性和相对蛋白含量。结果：与假手术对照组比较,ＰＴＭＲ实验组心组织内ＥＲＫｓ于２ｈ开始激活,持续至２４ｈ;其蛋白含量于术后２４ｈ开始升高并持续至术后７ｄ。结论：ＰＴＭＲ激活ＥＲＫｓ并使其蛋白合成增加。     

激光心肌血运重建术后心肌组织学改变的研究

激光心肌血运重建术 (ｔｒａｎｓｍｙｏｃａｒｄｉａｌｌａｓｅｒｒｅｖａｓｃｕｌａｒｉｚａ ｔｉｏｎＴＭＬＲ)是 90年代初在临床上兴起的一种治疗晚期弥漫性冠脉病变的新方法 ,它是应用激光光束在缺血心肌上造成与心室腔相通的孔道 ,来改善缺血心肌的血供。 1981年Ｍｉｒ ｈｏｓｅｉｎｉ[1 ] 首次利用ＣＯ2 激光在犬心左室壁打孔获得成功。激光照射到生物组织后可被组织吸收 ,反射 ,发散或传导 ;对心肌的生物效应受激光波长 ,能量 ,密度 ,辐射时间及组织吸收等特点的影响 ,并由此引起生物组织的不同反应。对该技术产生的心肌组织学改变研…     

超声微泡造影观测钬激光心肌激光再血管化的实验研究

目的：应用经静脉注射造影剂心肌超声微泡造影探讨激光心肌再血管化的机制及对心肌缺血的治疗效果。方法：部分钳闭犬的冠状动脉前降支形成急性心肌缺血模型，用钬激光在缺血区进行心肌激光再血管化，并在缺血前、缺血后及激光打孔后取左室短轴切面进行超声微泡造影。结果：缺血后心肌超声微泡声学密度较缺血前明显降低（Ｐ＜０．００１），心肌激光再血管化后，缺血区超声微泡声学密度较缺血时明显升高（Ｐ＜０．００１），接近正常心肌超声微泡声学密度（Ｐ＞０．０５），激光再血管化区心肌超声微泡较正常心肌提前显像。结论：心肌激光再血管化可即刻明显缓解心肌缺血，使缺血区血流灌注明显改善。经静脉注射造影剂进行心肌超声微泡造影可作为观测和评价心肌激光再血管化的可靠手段，钬激光心肌再血管化的中远期效果尚待观察。     

治疗性血管新生在心肌梗死中的应用

急性心肌梗死(AMI)修复过程及预后与心肌组织血管的功能状态密切相关,迅速有效地建立侧支循环对改善梗死区血液供应及梗死区心肌的存活均具有非常重要的意义.介入治疗如经皮冠状动脉腔内成形术(PTCA)和冠状动脉内支架是目前AMI后血运重建的常用方法,但由于介入治疗只适于直径＞2 mm的动脉,对直径＜2 mm的动脉和具体负责灌注的微小血管则无能为力,且存在术后再狭窄(25%～50%)问题,以至有相当多的急性病人(20%～37%)不能达到完全血运重建而影响预后.     

Contrast-echocardiography: confirmation of patency of laser channels after transmyocardial laser revascularization.

AIMS: Apart from casuistic autopsy results there is no long-term evidence for channel perfusion after transmyocardial laser revascularization in humans. METHODS AND RESULTS: Fifteen consecutive patients aged 63+/-17 years were investigated 71+/-15 days after coronary artery bypass surgery and/or transmyocardial revascularization with 13-37 (20+/-5) channels (CO(2) laser, 40 J/pulse). Echocardiography was performed after injection of 6 ml echo contrast medium into left ventricular cavity and after injection of 3 ml contrast medium into the left main coronary artery. In five patients with additional bypass surgery to the same region, we also injected 3 ml contrast medium into bypass graft. We could prove in 10 of 15 patients (67%) one or two laser channels in the apical left ventricular myocardium. Channels were perfused exclusively during systole. During following heart cycles myocardium was opacified up to a mean width of 1.4+/-0.4 cm, a mean depth of 0.71+/-0.1cm, and a mean area of 1.0+/-0.6 cm(2). Contrast medium was washed out via coronary venous system in 9+/-8 systoles. CONCLUSION: This is the first clinical evidence of long-term laser-channel patency in humans showing perfused myocardium via left ventricular cavity.     

从心肌组织无复流现象谈中医治疗急性心肌梗死的可能优势

急性心肌梗死(AMI)相关动脉的血运重建,开创了AMI现代治疗的新纪元,减少了AMI患者住院并发症和死亡率,改善了预后,但AMI仍是冠心病主要的死亡原因,相关冠状动脉血运重建后一年内心血管病事件的发生率仍在18%左右。相关冠状动脉局部病变的介入治疗为目前成熟并普遍推广应用的技术,但对介入治疗后的心肌组织无复流现象,尽管近年来进行机械、药物干预的许多尝试,仍无理想的干预对策,原因在于AMI作为一种应激损伤引起的机体病变的复杂性,包括内皮功能障碍、高凝状态、氧化应激、微血栓形成等,使心肌组织无法得到理想灌注,心肌细胞不能恢复正常的代谢状态。传统中医药包括益气、活血、解毒等的单味或复方中药,可作用于AMI后应激损伤的多个病理环节,如抑制氧化应激损伤、抗血小板聚集、改善微循环和内皮细胞功能等。应用现代科学技术,从复杂成分和效应关系,复杂效应和患者预后关系等方面进行系统研究,对提高现代中医药防治AMI的疗效将有十分重要的意义。     

激光心肌血运重建术后QT离散度的测定及其临床意义

目的 :测量激光心肌血运重建术 （TMR）后的 QT离散度 （QTd）和心率校正 QT离散度 （QTcd） ,并探讨其临床意义。方法 :随访记录单纯行 TMR的 14例患者术前 1d、术后 1周 ,1,3,6月及 1年的心电图 ,同时观察症状缓解和心功能改善状况。结果 :患者术后 QTd、QTcd明显下降 ,3月时基本恢复正常水平 （44 .4± 2 0 .5 ms;47.0± 19.1m s） ,6月后 QTd,QTcd似有轻度升高 ,但统计学检测尚无明显差异。心绞痛症状明显缓解 ,心功能明显改善。结论 :TMR术后 QTd,QTcd明显减少与症状缓解和心功能改善相一致 ,可将 QTd,QTcd作为 TMR术后疗效观察的一项指标     

Myocardial Viability Detected by Myocardial Contrast Echocardiography—Prognostic Value in Patients after Myocardial Infarction

Objective: This study aimed to assess the role of myocardial contrast echocardiography (MCE) as a predictor of cardiac events and death in patients with acute myocardial infarction (AMI). Methods: Eighty‐six patients underwent primary percutaneous coronary angioplasty for AMI. Segmental perfusion was estimated by MCE in real time at mean 5 days after PCI using low MI (0.3) after 0.3–0.5 ml bolus injection of intravenous Optison. MCE was scored semiquantitatively as: (1) normal perfusion (homogenous contrast effect), (2) partial perfusion (patchy myocardial contrast enhancement), (3) lack of perfusion (no visible contrast effect). A contrast score index (CSI) was calculated as the sum of MCE scores in each segment divided by the total number of segments. The patients were followed up for cardiac events and death. Results: A CSI of >1.68 was taken to be a predictor of cardiac events and death. Death occurred only in patients with CSI >1.68. Patients with CSI >1.68 had a significantly (P = 0.03) higher incidence of cardiac death or cardiac events (75%) compared to those with CSI <1.68 (27%). The absence of residual perfusion within the infarct zone was an independent predictor of death and cardiac events (P = 0.02). Conclusions: The absence of residual myocardial viability in the infarct zone supplied by an infarct‐related artery is a powerful predictor of cardiac events in patients after AMI. (Echocardiography 2010;27:430‐434)     

经皮激光心肌打孔对老年终末期冠心病心绞痛的影响

目的 观察经皮激光心肌打孔血运重建术治疗老年终末期冠心病心绞痛的临床疗效和对运动缺血阈值的影响.方法 应用经皮激光(HOYAG laser)心内膜心肌打孔治疗16例老年终末期冠心病心绞痛患者.结果 每例打孔数5～15个,平均(9±4)个.按加拿大心绞痛标准分级,打孔前为(3.3±0.6)级,打孔后1个月为(2.0±0.9)级,打孔后3个月为(2.1±1.0)级.将Naughton运动试验ST段下移至1 mm所需时间作为运动缺血阈值指标,打孔前为(320±136)s,打孔后1个月为(397±170)s,打孔后3个月为(430±307)s.结论 经皮激光心肌打孔后可降低心绞痛的严重程度,对临床有严重心绞痛发生而不宜施行经皮冠状动脉腔内成形术(PTCA)或冠状动脉搭桥术(CABG)等干预治疗的老年终末期冠心病心绞痛患者,经皮激光心肌打孔术是一种新颖而有效的治疗方法.     

Alternative therapeutic strategies for patients with severe end-stage coronary artery disease not amenable to conventional revascularization.

Although there have been remarkable advances in medical therapy, percutaneous coronary interventions, and coronary artery bypass graft surgery, complete revascularization remains a challenge given the more complex coronary artery disease prevalent in contemporary practice. The lack of donors for cardiac transplantation will fuel the search for effective alternative strategies for dealing with patients with severe ischemic heart disease not amenable to conventional revascularization techniques. Percutaneous laser revascularization clearly diminishes anginal symptoms; however, the blinded trials have provided conflicting results, with one study showing a definite decrease in angina and another suggesting that the placebo effect may play a major role in this modality. Similarly, surgical transmyocardial laser revascularization is limited by the lack of consistent improvement in objective measurements of ischemia and the potential confounding mechanisms of denervation and the placebo effect, and thus should be reserved for only the most highly selected patients. Although enhanced external counterpulsation is associated with an improvement in anginal symptoms and exercise tolerance, this modality is limited by its availability, tolerability, and rigid exclusion criteria. Of the alternative strategies available, therapeutic angiogenesis holds the most promise. However, the long-term results of ongoing randomized clinical trials require further scrutiny. Novel methods for vascular reconstruction are evolving techniques, but should be viewed currently as mainly experimental methods. The common goals of these new treatment options would be to reduce symptoms, decrease morbidity, and potentially improve mortality by reducing ischemia through favorably impacting myocardial oxygen supply and demand. The optimal management of patients with severe end-stage coronary artery disease not amenable to conventional revascularization techniques will continue to remain a challenge for the clinician and will be the main focus of basic cardiovascular research and clinical trials in the new millennium.     

Ventricular conduction defects and atrial fibrillation after coronary artery bypass grafting. Multivariate analysis of preoperative, intraoperative and postoperative variables.

Preoperative, intraoperative and postoperative variables, which might play a role in the development of ventricular conduction defects (VCD) and atrial fibrillation (AF) following coronary artery bypass grafting (CABG), were evaluated in 236 consecutive patients. VCD and AF developed postoperatively in 15.5% of patients: 4.5% had VCD (subgroup A), 11.0% had AF (subgroup B). In 84.5% of patients VCD and AF did not occur (subgroup C). Univariate analysis showed statistically significant differences between subgroups A and C with respect to: left main significant stenoses and number of diseased vessels. Bypass pump time and aortic cross-clamp time were significantly longer in subgroup B. Multivariate analysis showed a significantly greater incidence of left main disease and of right coronary artery occlusion associated with significant stenosis of the proximal left anterior descending artery in subgroup A. In subgroup B, the duration of aortic cross-clamp time was significantly higher. Ischaemic injury, with increasing duration of cardioplegic arrest, seems to play a key role in the development of AF. Nonhomogeneous cardioplegic delivery to critical areas of myocardium, and particularly to the specialized conducting system, may cause VCD after CABG.     

不同方式激光心肌血运重建术的实验研究

目的　通过观察比较传统激光心肌血运重建术 (T TMLR)与非透壁激光心肌血运重建术 (N TMLR)后cTnI血浓度及心肌梗死 (心梗 )面积的变化 ,探讨激光心肌血运重建术对缺血心肌血流灌注的影响。方法　制备家兔急性心肌缺血模型 ,术后早期监测cTnI的变化 ;术后 2周采用伊文氏蓝 -氯化三苯基四唑 (TTC)双重染色法测定心肌缺血、心肌坏死面积。结果　T TMLR及N TMLR术后均使cTnI血浓度升高且峰值提前 ;心肌缺血面积缩小 ,而心肌坏死面积无改变 ,二者之间差异无显著性。结论　 (1)N TMLR可获得与T TMLR相同的效果 ;(2 )二者均可改善缺血心肌的血流灌注 ,从而使cTnI峰值提前并致心肌缺血面积缩小。