基于体外实验和数值仿真的冠脉介入手术中球囊去充盈瞬间的血流动力学研究

目的研究冠脉介入手术中血流参数在球囊去充盈瞬间发生的动态变化,探讨球囊去充盈对术后无复流发生风险的潜在影响。方法搭建体外实验装置,利用高速摄像机拍摄球囊变形过程和由染色剂标记的流场(流体介质为水),使用图像分析技术提取球囊变形参数,并估测球囊下游的流体流动速度;构建计算机仿真模型,导入实测的球囊变形数据,在多种灌注压和流体介质条件下模拟球囊去充盈过程。结果球囊在去充盈过程中呈现显著的非线性变形特征。球囊下游流速的数值计算结果与实测数据吻合良好,两者均显示流速随去充盈后的时间增长和灌注压升高而增大。数值计算进一步揭示,球囊下游流速在接近冠脉血流速度生理值时,球囊-管壁间隙流速和壁面剪应力分别达到其生理值的8~10倍和60~70倍。结论球囊去充盈引起球囊-管壁间隙流体急剧加速和壁面剪应力异常升高,从而增大斑块、血栓碎屑剥离的风险。鉴于壁面剪应力的升高程度随灌注压升高而增大,在冠脉介入手术中采取术前降压或选择舒张期去充盈等措施可能有助于降低无复流的发生风险。     

直接支架术对急性冠脉综合征无复流的影响

目的 评价直接支架术对急性冠脉综合征(ACS)患者无复流现象的影响。方法 203例急性冠脉综合征患者分为直接支架术79例与常规支架术124例,分析其罪犯病变血管术中无复流现象的发生率,并随访观察其对急性期心脏事件的影响。结果直接支架术中发生无复流现象4例(5.1％),常规支架术中发生无复流现象18例(14.5％)(P<0.05)。22例发生无复流的患者,件院期间心脏负性事件的发生率与未发生无复流现象者比较明显增高(27％vs 7％,P<0.01)。结论 直接支架术有助于降低ACS患者无复流现象的发生率;发生无复流现象预示着较高的负性预后事件。     

EFFECT OF A THROMBOXANE SYNTHETASE INHIBITOR UK-38, 485 ON THE TOLERANCE OF SKIN FLAPS OF PRIMARY ISCHAEMIA

The harmful effects of ischaemia or skin flaps were modified using the thromboxane synthetase inhibitor UK - 38,485. The epigastric island flaps of Sprague-Dawley rats (n= 288) were subjected to 10, 12 or 14 h of total pedicle occlusion, or 3, 5 or 7 h of venous occlusion of the sole vascular pedicle. Within each time period, rats received intravenous deoses of either physiological saline (controls) or UK - 38,485 at the beginning or end of the ischaemic episode. Flaps treated with UK - 38, 485 overall had a higher survival rate than control ischaemic flaps (P < 0.001). this applied both to total (arterial) ischaemia (P < 0.001) and partial (venous) ischaemia (P < 0.01). There was no significant difference between treatment given at the beginning or at the end of the ischaemic episode. These results may be explained by reduced platelet aggregation and thrombosis in the microvasculature due to the lower thromboxane/prostacyclin ratios for treated flaps. The possible inter-relationship of the prostanoids with free radical mechanisms in the no-reflow phenomenon is also discussed.     

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OBJECTIVE: To assess the effects of intracoronary diltiazem on no-reflow phenomenon of infarct-related artery (IRA) after emergent percutaneous transluminal coronary angioplasty or/and intracoronary stenting (PTCA/Stenting) in the patients with acute myocardial infarction (AMI). METHODS: We studied 34 AMI patients with no-reflow phenomenon of IRA after emergent PTCA/Stenting between January 1999 and August 2005. Urokinase-treated group (n=16) was given intracoronary urokinase 30,0000 - 50,0000 units within 15 - 30 minutes between January 1999 and April 2002 while diltiazem-treated group (n=18) was given intracoronary diltiazem 0.5 - 2 mg within 10 - 30 minutes between May 2002 and August 2005. Fifteen minutes later, coronary arteriography (CAG) was performed and the thrombolysis in myocardial infarction (TIMI) flow grade was measured. RESULTS: No apparent change of TIMI flow grade was found between pre-administration and post-administration of intracoronary urokinase, but TIMI flow grade was significantly improved after intracoronary diltiazem (P<0.01). TIMI flow grade of diltiazem-treated group was significantly higher than that of urokinase-treated group after the administration (P<0.05). The percentage of the patients who reached TIMI flow grade 3 after the intracoronary administration was higher in the diltiazem-treated group than that in the urokinase-treated group (P<0.01). CONCLUSION: The intracoronary administration of diltiazem 0.5~2mg can effectively improve the no-reflow phenomenon after emergent PTCA/Stenting in patients with AMI.     

Management of the no-reflow phenomenon

The lack of reperfusion of myocardium after prolonged ischaemia that may occur despite opening of the infarct-related artery is termed “no reflow”. No reflow or slow flow occurs in 3-4% of all percutaneous coronary interventions, and is most common after emergency revascularization for acute myocardial infarction. In this setting no reflow is reported to occur in 30% to 40% of interventions when defined by myocardial perfusion techniques such as myocardial contrast echocardiography. No reflow is clinically important as it is independently associated with increased occurrence of malignant arrhythmias, cardiac failure, as well as in-hospital and long-term mortality. Previously the no-reflow phenomenon has been difficult to treat effectively, but recent advances in the understanding of the pathophysiology of no reflow have led to several novel treatment strategies. These include prophylactic use of vasodilator therapies, mechanical devices, ischaemic postconditioning and potent platelet inhibitors. As no reflow is a multifactorial process, a combination of these treatments is more likely to be effective than any of these alone. In this review we discuss the pathophysiology of no reflow and present the numerous recent advances in therapy for this important clinical problem.     

通心络预给药2h对猪急性心肌梗死再灌注后心肌无再流和细胞因子变化的影响

目的 评价急性心肌梗死（AMI）猪缺血再灌注前2 h给予通心络对血清细胞因子水平和心肌无再流变化的干预效果。     

脑钠肽、高敏C反应蛋白对ACS患者PCI术中冠状动脉无复流的影响

目的 探讨血浆脑钠肽(NBP)、高敏C反应蛋白(hs-CRP)水平对急性冠脉综合征(ACS)患者冠状动脉介入术(PCI)发生术中冠状动脉无复流的影响.方法 选择2014年6月至2016年12月在广元市第一人民医院接受PCI手术治疗的113例ACS患者,按照PCI手术是否发生术中冠状动脉无复流分为血流正常组78例与无复流组35例,比较两组患者术前、术后血浆NBP、hs-CRP水平,分析血浆NBP、hs-CRP水平与冠状动脉无复流的相关性.结果 术前血流正常组患者的BNP、hs-CRP水平分别为(91.82±30.21)pg/mL、(2.57±0.75)mg/L,术后分别为(91.31±28.05)pg/mL、(2.76±0.56)mg/L;无复流组患者术前分别为(122.36±30.83)pg/mL、(3.08±0.72)mg/L,术后分别为(155.72±47.64)pg/mL、(3.83±1.26)mg/L,手术前和手术后,血流正常组患者的BNP和hs-CRP水平均低于无复流组,差异均具有统计学意义(P<0.05);且无复流组患者手术后的BNP水平和hs-CRP水平均高于手术前,差异均具有统计学意义(P<0.05);经Pearson相关分析结果显示,血浆BNP及hs-CRP水平与PCI术后无复流之间呈高度正相关(r=0.752、0.805,P<0.05).结论 较高水平BNP、hs-CR能够诱导急性冠脉综合征患者PCI手术发生术中冠状动脉无复流,对于高水平的BNP、hs-CR急性冠脉综合征患者,应早期干预,以降低BNP、hs-CR水平,减少PCI术中冠状动脉无复流的发生.     

急诊经皮腔内冠状动脉成型术（PTCA）无复流现象对预后的影响

目的:无复流现象被定义为经皮腔内冠状动脉成型术(PTCA)或支架植入后TIM I血流≤2级,但冠脉内无机械性阻塞。本研究探讨急诊PTCA中无复流现象的临床意义。方法:我们回顾性分析了2001年1月至2002年1月就诊于同仁医院的53例[男37例,女16例,年龄(54±12.35)岁]初发急性心肌梗死(AM I)行急诊PTCA的患者。病例被分为无复流组(18例,TIM I≤2级)和PC I后冠脉血流正常组(35例,TIM I3级),随访6个月,观察有无心脏病性猝死和非致命性心脏事件。组间差别采用t检验或x2检验。结果:无复流组发生充血性心衰(P<0.05)、恶≤2级性心律失常(P<0.05)、再发心绞痛(P<0.05)、心脏性猝死(P<0.05)高于冠脉血流正常组。无复流组6个月后左室射血分数显著低于冠脉血流正常组。结论:无复流现象强烈提示AM I预后不良。但需进一步的大规模临床试验验证。     

应用Albunex评估无复流时肌酸磷酸激酶同工酶和肌钙蛋白I释放动力学变化的实验研究

目的 :通过检测肌酸磷酸激酶同工酶MB(CK MB)和肌钙蛋白I(cTnI) ,了解无复流时CK MB和cTnI的变化与心肌微血管损害之间的关系 ,分析微血管损伤对CK MB和cTnI释放的影响。方法 :19只犬通过制作急性心肌缺血 再灌注动物模型 ,采用弹丸式注射声学造影剂Albunex进行心肌声学造影研究 ;测定外周循环中CK MB和cTnI在基础状态、6 0min心肌缺血 (T0 )、再灌注 6 0min时的浓度(T60 ) ,计算再灌注 6 0min时其上升斜率 (T60 -T0 6 0 )和相对增加值 (T60 -T0 T0 )。结果 :CK MB和cT nI在心肌缺血 6 0min时外周血液浓度明显高于基础状态 (P <0 .0 1) ,复流组明显高于无复流组 (P <0 .0 1) ;6 0min再灌注时CK MB和cTnI的浓度、上升斜率和相对增加值复流组仍显著高于无复流组 (P<0 .0 1和P <0 .0 0 1)。结论 :心肌微血管床的损害影响缺血再灌注心肌酶和结构蛋白的释放。     

Short-term intestinal ischemia-reperfusion alters intestinal motility that can be preserved by xanthine oxidase inhibition

While the effects of transient intestinal ischemia on mucosa have been well investigated, less is known about its effect on motor function. An experimental study was designed to investigate the effects of ischemia–reperfusion (I/R) on intestinal motility and intestinal muscular microcirculation. Wistar albino rats were divided into four groups: (1) baseline, (2) sham operation, (3) I/R, and (4) I/R with allopurinol pretreatment. Ischemia was induced by clamping the superior mesenteric artery (SMA) for 10 min. Gastroanal transit time (GATT) was measured with serial x-rays after instillation of barium sulfate to the stomach. Intestinal muscular microcirculation was evaluated by determining the number of carbon-perfused intestinal muscular microvessels (CPIMM). I/R prolonged GATT and decreased CPIMM significantly (P < 0.01). Pretreatment with allopurinol prevented prolongation of GATT and returned the number of CPIMM to the level of sham treatment (P < 0.01). In conclusion, reperfusion after 10 min of SMA ischemia alters intestinal motility. The no-reflow phenomenon plays an important role in this alteration of motility. Administration of allopurinol before reperfusion preserves intestinal motility by preventing the occurrence of no-reflow phenomenon.