Rapid progression of nonculprit coronary lesions six weeks after successful primary PCI in culprit artery： a case report

We report a case of a 49-year-old man who was admitted with a 3-hour history of sudden onset of substemal chest pain. Coronary angiography revealed that the left circumflex artery （LCX） was acutely and totally occluded at the mid-portion. In addition, the proximal and mid-portion of the right coronary artery （RCA） had a 60% occlusion. We inferred that the LCX was the culprit artery and primary PCI was successfully performed. Six weeks later, the patient had an eventful course with recurrence of chest pain. Coronary angiography showed no significant ste- nosis in the previous LCX lesion, while the proximal and middle potion of the RCA had a 90% occlusion. Our case demonstrates the systemic nature of acute coronary syndromes and highlights the inherent instability of coronary artery disease.     

基于病例研究冠状动脉扭曲对血流动力学的影响

目的探讨扭曲冠状动脉血流动力学的改变,从而阐明扭曲对冠状动脉血流灌注和壁面切应力(wall shear stress,WSS)的影响。方法选取冠状动脉左前降支(left anterior descending,LAD)扭曲和无扭曲两例个体病例,在Mimics软件中重建出LAD扭曲和无扭曲血管模型,并将模型导入ANSYS Fluent软件中进行血流动力学模拟计算,比较两种不同LAD模型的血流动力学情况。结果扭曲的冠状动脉在最大曲率大于1 mm~(-1)的弯曲处WSS下降较为明显,这种情况可能导致下游供血不足;弯曲外侧具有较低WSS(0~26 Pa),而弯曲内侧WSS相对较高(100 Pa);无扭曲和扭曲血管WSS均值分别为10.79、36.12 Pa,相比于无扭曲血管,扭曲血管整体WSS增高。结论扭曲冠状动脉整体WSS增高,从而可能延缓冠状动脉粥样硬化的进展。     

左前降支冠状动脉瘤搭桥手术血流动力学研究

目的采用计算流体力学方法,研究大隐静脉(saphenous vein graft,SVG)与左乳内动脉(left internal mammary artery,LIMA)分别作为移植管搭桥手术旷置与结扎冠脉瘤(coronary artery aneurysm,CAA)时移植管的血流动力学,并以此为根据探讨冠脉瘤搭桥手术移植管的选择与冠脉瘤的结扎与否,为临床手术提供可靠帮助。方法首先分别构建SVG和LIMA搭桥旷置冠脉瘤手术模型、SVG和LIMA搭桥结扎冠脉瘤手术三维模型(three-dimensional model,3D Model) 4个模型。然后在建立集中参数模型(lumped parameter model,LPM,zero-dimensional,0D)的基础上,采用几何多尺度方法,将0D集中参数模型与3D冠脉模型耦合计算。研究SVG和LIMA为移植管时流量、壁面切应力(wall shear stress,WSS)、振荡剪切指数(oscillatory shear index,OSI)血流动力学参数。结果不同手术术式左前降支总流量基本相同,约为82 m L/min。OSI:模型1为0. 014 044、模型2为0. 283 494、模型3为0. 0130 35、模型4为0. 023 263。一个周期内平均WSS:模型1为0. 474 5 Pa、模型2为0. 8600 Pa、模型3为0. 442 4Pa、模型4为1. 699 Pa。结论当采用SVG桥时,冠脉瘤旷置与结扎两种方式都有较好的手术效果;当采用LIMA桥时,结扎冠脉瘤有较好的手术效果。旷置冠脉瘤移植管会因高OSI与竞争流较高、桥流量不足导致较不利的血流动力学环境,从而影响手术预期效果。     

右冠状动脉畸形1例

<正>随着冠状动脉介入诊疗技术的普及,各种冠脉畸形(coronary artery anomalies CAA)检出日益增多,但右冠状动脉开口异常的畸形病例却罕有报道[1,2]。作者自19     

右冠状动脉缺如1例

随着冠状动脉介入诊疗技术的普及,各种冠脉畸形(coronary artery anomalies CAA)的检出日益增多,但右冠状动脉开口异常的畸形病例报告却很少见[1,2].作者自1991年开展冠状动脉造影以来共检查冠脉介入诊疗病人5000例,其中发现仅1例此种畸形.     

基于CT血管成像的斑块定量分析在冠状动脉血流动力学异常诊断中的应用价值

目的 探讨基于冠状动脉CT血管成像(CCTA)分析斑块定量指标在冠状动脉血流动力学异常诊断中的应用价值。方法 回顾性病例对照研究。纳入2020年7—10月天津医科大学总医院行CCTA检查的冠状动脉单支或多支局限性狭窄患者104例(共检出病变血管200支)的临床及影像学资料,其中男63例、女41例,年龄45~83岁。依据靶血管病变部位的CT血流储备分数(CT-FFR)值将200支血管分为两组:CT-FFR≤0.80为血流动力学异常组、CT-FFR＞0.80为血流动力学正常组。用半自动斑块分析软件测量靶血管病变长度、管腔体积、斑块总体积、钙化体积、脂质体积、纤维体积、最小管腔面积(MLA)、狭窄程度(SG)、重构指数(RI)、偏心指数(EI)、周围脂肪密度(FAI)等斑块定量指标。采用单因素分析及多因素logistic回归分析冠状动脉血流动力学异常的影响因素,采用Pearson相关法分析法分析CT-FFR与斑块定量分析指标之间的相关性。基于以上统计分析,设计两种模型:模型一(使用SG判断心肌血流动力学异常)、模型二(SG+有统计学意义的斑块定量指标);采用受试者操作特征曲线(ROC曲线)比较两种模型预测血流动力学异常的效能。结果 单因素分析显示,两组的病变长度、斑块总体积、钙化体积、MLA、SG差异均有统计学意义(Z=-2.613、-2.356、-2.435、-7.499、-5.516, P值均＜0.05);多因素logistic回归分析显示,MLA是冠状动脉血流动力学异常的独立预测因子(OR=0.653, 95%CI 0.509~0.838, P＜0.01);Pearson相关分析,病变长度、MLA、SG与CT-FFR呈相关关系(r=-0.41、0.49、-0.49, P值均＜0.05)。模型一和模型二在判断血流动力学异常的ROC曲线下面积分别为0.730(95% CI 0.659~0.800)和0.804(95% CI 0.757~0.875),模型二显示出了更高的诊断效能(重分类改善指标为0.181, P＜0.05)。结论 基于CCTA的冠状动脉斑块定量分析表明,病变长度、MLA、SG是血流动力学异常的影响因素,MLA是血流动力学异常的独立预测因子,且SG联合病变长度、斑块总体积、钙化体积、MLA等斑块定量指标诊断血流动力学异常的准确性更高。     

冠状动脉旁路移植术后竞争血流对桥血管血流动力学的影响

目的 研究冠状动脉旁路移植术后,不同程度竞争血流对左侧胸廓内动脉管壁壁面切应力(wall shear stress, WSS)的影响。方法 基于阈值分割方法,通过采用SimVascular软件从CT图像提取并重建左侧胸廓内动脉(left internal mammary artery, LIMA) 左前降支（left anterior descending, LAD）吻合口模型。根据LAD的狭窄程度将竞争血流分为无竞争（100%狭窄）、轻度竞争（50%、75%狭窄）和高度竞争血流（0%、30%狭窄）3组。通过数值模拟方法观察上述情况下吻合口模型的血流动力学表现。结果 随着竞争血流的增加,LIMA桥血管管壁WSS逐渐降低,但是震荡程度逐渐增加。高度竞争血流组LIMA管壁平均WSS（0%狭窄：2.73 Pa,30%狭窄：2.85 Pa）明显低于轻度竞争血流组（50%狭窄：4.77 Pa,75%狭窄：6.01 Pa）和无竞争血流组(100%狭窄：8.64 Pa);而其震荡剪切指数(oscillatory shear index, OSI)（0%狭窄：0.206,30%狭窄：0.085）却明显高于轻度竞争血流组（50%狭窄：0.014,75%狭窄：0.013）和无竞争血流组(100%狭窄：0.006)。结论 当LAD狭窄程度小于50%时,大量的竞争血流会使LIMA管壁WSS明显降低,并且呈剧烈震荡的状态,这种不利的WSS表现会影响LIMA的远期通畅率,并造成手术远期疗效的下降。     

64排螺旋CT冠脉成像效果与影响因素研究

目的 探讨64排螺旋CT冠脉成像中影响图像质量的各种因素及其影响程度以及评估冠脉狭窄的效果.方法 通过838例临床疑似冠心病患者的6_4排螺旋CT冠脉成像,并以其中218例在1周内进行的常规冠状动脉造影为标准,分析64排螺旋CT冠脉成像在评估冠脉狭窄的灵敏度、准确率、阳性预测值和阴性预测值.结果 心率、心率变化幅度、延迟时间设定、β受体阻滞剂、呼吸频率、屏气合作与否、造影剂注射总量与速度、图像重建时相、冠状动脉钙化、扫描参数、患者年龄性别、机器软硬件性能等是影响64排螺旋CT成像质量的因素.64排螺旋CT冠脉成像评估冠脉狭窄的准确率为95.9%,阳性与阴性预测值分别为92.3%、90.0%.结论 得到了影响64排螺旋CT冠脉成像的各种因素,分析了减少和消除这些因素影响的方法.在评估冠脉狭窄方面,64排螺旋CT冠脉成像基本能满足临床要求. Abstract： Objective To study the various factors that influence image quality of 64-slice spiral CT coronary artery imaging, their impact extent and the assessment effect of coronary artery stonnsis. Methods Through examination of 838 clinical coronary heart disease suspect patients, by 64-slice spiral CT coronary artery imaging, in which, 218 patients were also examined by conventional coronary angiagraphy in a week, we took the conventional coronary angiography as the standard, analyzed the 64-slice spiral CT coronary artery imaging in the assessment of coronary artery stenosis by sensitivity, accuracy, positive predictive value and negative predictive value. Results The factors which affect the image quality of 64-slice spiral CT coronary artery imaging include heart rate, heart rate change range, delay time setting, β-blocker, respiratory rate, breath-holding or not, total amount of contrast medium and the speed of injection, image reconstruction phase, coronary artery calcification, the scan parameters, age and sex of patients, machine     

基于主动脉流-固双向耦合数值模拟的微循环负载影响研究

目的研究微循环负载和其他生理结构的耦合关系,以构建合理的血流动力学模型。方法在双向流-固耦合管道模型的基础上,进一步考虑微循环负载的影响,构建具有弹性管壁的长直管和多孔介质渗流负载的模型。根据负载条件和血管壁弹性的不同计算4个算例,入口条件为瞬态单脉冲速度入口,出口条件为自由出口。结果管道内部压力处处保持在80~120 mm Hg(1 mm Hg=0.133 k Pa)。从静止状态开始,流场通过增加储存血液总量的方式提高舒张压,最终稳定在生理指标。血管壁弹性模量增加时,血压为65~140 mm Hg;而微循环阻力增加时,血压为128~166 mm Hg,微循环负载在循环系统中起到了阻碍流动并重新分配血管内压力的作用。结论在构建血流动力学模型时,必须考虑微循环负载及其耦合效应,特别对分析高血压等循环系统疾病的致病机制有重要的临床意义。     

双支右冠状动脉畸形1例

<正>在制作心肺联合标本时发现双支右冠状动脉畸形,冠状动脉畸形(coronary artery anomalies,CAA)[1],包括冠状动脉起源、分支以及支数异常等。本例标本在其主动脉右窦发出两支右冠状动脉,主动脉左窦发出一支左冠状动脉。CAA已有较多的报道,但此种畸形少见文献报道,现将其报道如下。     

MR Image-Based Geometric and Hemodynamic Investigation of the Right Coronary Artery with Dynamic Vessel Motion

The aim of this study was to develop a fully subject-specific model of the right coronary artery (RCA), including dynamic vessel motion, for computational analysis to assess the effects of cardiac-induced motion on hemodynamics and resulting wall shear stress (WSS). Vascular geometries were acquired in the right coronary artery (RCA) of a healthy volunteer using a navigator-gated interleaved spiral sequence at 14 time points during the cardiac cycle. A high temporal resolution velocity waveform was also acquired in the proximal region. Cardiac-induced dynamic vessel motion was calculated by interpolating the geometries with an active contour model and a computational fluid dynamic (CFD) simulation with fully subject-specific information was carried out using this model. The results showed the expected variation of vessel radius and curvature throughout the cardiac cycle, and also revealed that dynamic motion of the right coronary artery consequent to cardiac motion had significant effects on instantaneous WSS and oscillatory shear index. Subject-specific MRI-based CFD is feasible and, if scan duration could be shortened, this method may have potential as a non-invasive tool to investigate the physiological and pathological role of hemodynamics in human coronary arteries.     

Hemodynamic Computation Using Multiphase Flow Dynamics in a Right Coronary Artery

Hemodynamic data on the roles of physiologically critical blood particulates are needed to better understand cardiovascular diseases. The blood flow patterns and particulate buildup were numerically simulated using the multiphase non-Newtonian theory of dense suspension hemodynamics in a realistic right coronary artery (RCA) having various cross sections. The local hemodynamic factors, such as wall shear stress (WSS), red blood cell (RBC) buildup, viscosity, and velocity, varied with the spatially nonuniform vessel structures and temporal cardiac cycles. The model generally predicted higher RBC buildup on the inside radius of curvature. A low WSS region was found in the high RBC buildup region, in particular, on the area of maximum curvature of a realistic human RCA. The complex recirculation patterns, the oscillatory flow with flow reversal, and vessel geometry resulted in RBC buildup due to the prolonged particulate residence time, specifically, at the end of the diastole cycle. The increase of the initial plasma viscosity caused the lower WSS. These predictions have significant implications for understanding the local hemodynamic phenomena that may contribute to the earliest stage of atherosclerosis, as clinically observed on the inside curvatures and torsion of coronary arteries.     

Effects of Cardiac Motion on Right Coronary Artery Hemodynamics

The purpose of this work was to investigate the effects of physiologically realistic cardiac-induced motion on hemodynamics in human right coronary arteries. The blood flow patterns were numerically simulated in a modeled right coronary artery (RCA) having a uniform circular cross section of 2.48 mm diam. Arterial motion was specified based on biplane cineangiograms, and incorporated physiologically realistic bending and torsion. Simulations were carried out with steady and pulsatile inflow conditions (mean Re_D=233, =1.82) in both fixed and moving RCA models, to evaluate the relative importance of RCA motion, flow pulsation, and the interaction between motion and flow pulsation. RCA motion with a steady inlet flow rate caused variations in wall shear stress (WSS) magnitude up to 150% of the inlet Poiseuille value. There was significant spatial variability in the magnitude of this motion-induced WSS variation. However, the time-averaged WSS distribution was similar to that predicted in a static model representing the time-averaged geometry. Furthermore, the effects of flow pulsatility dominated RCA motion-induced effects; specifically, there were only modest differences in the WSS history between simulations conducted in fixed and moving RCA models with pulsatile inflow. RCA motion has little effect on time-averaged WSS patterns. It has a larger effect on the temporal variation of WSS, but even this effect is overshadowed by the variations in WSS due to flow pulsation. The hemodynamic effects of RCA motion can, therefore, be ignored as a first approximation in modeling studies. © 2003 Biomedical Engineering Society. PAC2003: 8719Uv, 8719Hh, 8719St, 8719Rr     

Factors Influencing Blood Flow Patterns in the Human Right Coronary Artery

Evidence suggests that atherogenesis is linked to local hemodynamic factors such as wall shear stress. We investigated the velocity and wall shear stress patterns within a human right coronary artery (RCA), an important site of atherosclerotic lesion development. Emphasis was placed on evaluating the effect of flow waveform and inlet flow velocity profile on the hemodynamics in the proximal, medial, and distal arterial regions. Using the finite-element method, velocity and wall shear stress patterns in a rigid, anatomically realistic model of a human RCA were computed. Steady flow simulations (Re_D=500) were performed with three different inlet velocity profiles; pulsatile flow simulations utilized two different flow waveforms (both with Womersley parameter=1.82, mean Re_D=233),1 as well as two of the three inlet profiles. Velocity profiles showed Dean-like secondary flow features that were remarkably sensitive to the local curvature of the RCA model. Particularly noteworthy was the rotation of these Dean-like profiles, which produced large local variations in wall shear stress along the sidewalls of the RCA model. Changes in the inlet velocity profiles did not produce significant changes in the arterial velocity and wall shear stress patterns. Pulsatile flow simulations exhibited remarkably similar cycle-average wall shear stress distributions regardless of waveform and inlet velocity profile. The oscillatory shear index was very small and was attributed to flow reversal in the waveform, rather than separation. Cumulatively, these results illustrate that geometric effects (particularly local three-dimensional curvature) dominate RCA hemodynamics, implying that studies attempting to link hemodynamics with atherogenesis should replicate the patient-specific RCA geometry. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 0270Dh, 8719Xx, 8710+e     

FFR值与冠动脉狭窄度的数值模拟

目的：利用有限体积法对冠状动脉进行数值模拟,探讨不同狭窄程度的冠状动脉简化模型在舒张期血液的压力分布,并以此计算出（Fractional Flow Reserve,FFR）FFR值,阐明冠状动脉不同狭窄程度与肿值之间的关系,为冠状动脉狭窄的诊断提供参考。方法：以血流动力学基本原理建立不同狭窄度冠脉的物理模型,利用有限体积法,计算不同狭窄几何模型的速度、压力和壁面剪切力等血液流体动力学特征。利用开源软件OpenFOAM对人的冠状动脉不同狭窄程度的简化模型进行血流三维数值模拟。结果：计算获得了人的左冠状动脉不同狭窄程度的血流在舒张期压力分布图。当狭窄程度小于70％,FFR值下降缓慢;当狭窄程度在70％和90％之间内,彤R值下降速度明显加快,当狭窄程度大于90％时,FFR值急速下降,另外,当狭窄程度在大于80％之后,冠脉血管内血流流场的速度压力变化加大。结论：通过对不同狭窄度下冠脉血管血液流体动力学特性的计算,进一步说明有限体积法对冠脉狭窄的模拟问题的计算,人左冠状血管狭窄的百分数与冠脉的FFR值并不是呈线性关系,而是呈曲线样改变。     

Mass Transport in an Anatomically Realistic Human Right Coronary Artery

The coronary arteries are a common site of atherosclerotic plaque formation, which has been putatively linked to hemodynamic and mass transport patterns. The purpose of this paper was to study mass transport patterns in a human right coronary artery (RCA) model, focusing on the effects of local geometric features on mass transfer from blood to artery walls. Using a previously developed characteristic/finite element scheme for solving advection-dominated transport problems, mass transfer calculations were performed in a rigid, anatomically realistic model of a human RCA. A qualitative and quantitative examination of the RCA geometry was also carried out. The concentration field within the RCA was seen to closely follow primary and secondary flow features. Local variations in mass transfer patterns due to geometric features were significant and much larger in magnitude than local variations in wall shear stress. We conclude that the complex secondary flows in a realistic arterial model can produce very substantial local variations in blood-wall mass transfer rates, and may be important in atherogenesis. Further, RCA mass transfer patterns are more sensitive to local geometric features than are wall shear stress patterns. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 8719Hh, 0270Dh, 8710+e     

出口边界条件和壁厚对冠状动脉壁面剪切力和冯米塞斯应力的影响

探讨基于个体化患者计算机断层血管造影(CTA)影像的冠状动脉流固耦合(FSI)数值分析中,不同出口边界条件和血管壁模型对时间平均壁面剪切力(TAWSS)和冯米塞斯应力(VMS)的影响。根据患者CTA影像重建右冠状动脉(RCA)管腔流域三维几何;将管腔流域表面向外扩张0.5 mm,形成均匀厚度血管壁;运用类似虚拟去除斑块的方法建立不均匀厚度血管壁模型。FSI分析时,分别给予zero和impedance两种出口边界条件;获得从舒张末期开始心动周期主要时间点TAWSS和VMS的分布,比较不同模型结果的差异。结果表明, 两种出口边界条件下,TAWSS空间分布基本一致,且血管狭窄段均高于其他部位;zero条件下峰值VMS出现在压强最大时刻点0.42 s,而impedance条件下峰值VMS出现在入口血流速度最大时刻点0.64 s,并且达到前者的20倍。同是impedance出口边界条件时,TAWSS分布基本一致,没有显著性差异;两种血管壁模型中,VMS的分布一致,血管狭窄段比其他部位低,但是不均匀厚度血管壁模型中局部位置VMS绝对值高于均匀壁厚血管壁模型。医学影像技术的发展可以提供更高精度的冠脉结构以及出入口速度和压强边界条件,不但对研究血流动力学以及结构力学因素与心血管疾病的关系具有重要意义,也可以更好的服务于患者个体化诊断与治疗。     

冠状动脉中氧输运的数值模拟研究

利用正常人的CT数据,通过图像分割和重建建立右侧冠状动脉的真实三维几何模型;利用专业的网格划分软件ICEM CFD 12.0对几何模型进行计算网格的划分;利用商用CFD软件Fluent12.0对模型中的血液流动和氧输运进行数值模拟,获得了在入口的平均速度为0.2m/s的定常流情况下,冠状动脉内的流线图、壁面切应力分布图、重要截面上的速度分布和氧浓度分布图。数值模拟结果发现,在血管曲率较大的区域和血管分叉区域的血液流动较为复杂,存在二次流、回流和死水区;在弯曲血管附近靠近内侧的区域的氧浓度显著降低、浓度梯度也降低。这些结果与临床上观察到的这些区域易形成冠状动脉粥样硬化斑块的结论相吻合。     

Morphology of coronary vessels in coronary heart disease. An analysis of 930 coronary angiograms

Coronary anatomy was analyzed in 930 patients who underwent coronary arteriography because of coronary artery disease. There was a slight predominance of single vessel disease, whereas double and triple vessel disease were equally distributed. A left main (LM) lesion was found in 5.2%, with an additional right coronary artery lesion in 3.3%. The left anterior descending (LAD) artery was involved most frequently, followed by the right coronary artery (RCA) and left circumflex (Cx). The LAD demonstrated more often a proximal stenosis than the RCA and Cx. If the LM is associated with a RCA-stenosis then the LAD and Cx are involved more commonly, suggesting a more advanced disease in all major vessels. The analysis of ventricular function revealed a significant deterioration according to the number of diseased vessels. If the LM is associated with a RCA lesion, then the hemodynamics are similar to a 3-vessel disease, whereas isolated LM lesions are associated with good ventricular function according to the lesser degree of coronary sclerosis. The deterioration of the hemodynamics in correlation with coronary vessel involvement is significant, however due to the large standard deviations conclusions for the individual patient can not be drawn.