右冠状动脉起源于左主干5例临床分析

目的：分析右冠状动脉起源于左主干的临床特征，探讨其与心肌缺血的关系。方法：回顾分析5例右冠状动脉起源于左主干的临床资料及相关文献。结果：（1）本组5例患者中，女性1例，男性4例，年龄27～70岁。（2）临床表现主要为胸痛、胸闷等心绞痛症状，除1例老年患者外，其余4例病人都有典型的心绞痛症状和缺血心电图变化。（3）冠状动脉造影示3例合并严重冠状动脉粥样硬化，给予冠状动脉搭桥术，术后随访2月～6年无明显不适；另2例冠状动脉无明显病变，药物治疗后仍有劳累性心绞痛发作，其中1例半年后猝死。结论：右冠状动脉起源于左主干是一种罕见的冠脉畸形，对存在严重心肌缺血的患者应进行预防性冠状动脉搭桥术或介入治疗，预防不良事件的发生。     

左冠状动脉旋支异位开口于右冠状动脉窦1例

成年男性 ,心脏正常。右冠状动脉发自右冠状动脉窦中 1/3,开口处内径 5ｍｍ ,经右冠状沟分布于右心。左冠状动脉旋支直接开口于右冠状动脉窦 ,紧接右冠状动脉口的后方。此口略呈园形 ,内径 3ｍｍ(附图 )。此支发出后 ,贴绕主动脉起始部急转变向后方行走 ,管腔呈裂隙样 ,平对右主动脉窦上界行向左 ,发窦房结动脉 (外径 1ｍｍ ) ,此动脉穿房间肌束上行 ,以逆时针方向绕上腔静脉口达结区。旋支主干沿主动脉壁向左前达左冠状沟 ,分支分布于左心。左冠状动脉前室间支直接开口于左冠状动脉窦 ,开口处内径 4ｍｍ。前室间支起始段与旋支未段平行 ,两…     

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。     

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。     

具不同狭窄-吻合口位置关系的冠状动脉搭桥术的血流动力学仿真分析

目的通过有限元仿真探索带有辅助搭桥血管模式的冠状动脉搭桥术中,辅助搭桥管吻合口与冠状动脉狭窄处之间的距离对该吻合口及其下游区域的血流动力学影响,为带有辅助搭桥管的新型冠状动脉搭桥术的临床应用提供理论指导。方法利用有限元分析方法,假定血液为不可压缩牛顿流体,建立3种搭桥血管模型,其冠状动脉上吻合口和狭窄的距离分别为0.0045 m、0.006 m和0.009 m。通过仿真结果考察不同模型中的血流速度、壁面切应力等参数的变化。结果吻合口与狭窄处之间的距离不同,冠状动脉血管内的血流动力学参数也不相同。速度方面,心动周期0.09 s时刻L1.5模型中吻合口足跟处轴向截面的最大速度约为0.54 m/s,同时刻L2和L3模型中其最大速度分别为0.45 m/s和0.37 m/s。壁面切应力方面,0.09 s时刻,L1.5模型中吻合口对应面的血管壁上其流动停滞点距离吻合口足跟仅为0.0024 m,同时刻L2和L3模型中其流动停滞点距离足跟处分别为0.0039 m和0.0068 m,长度明显增加。其他时刻流动停滞点分布有相同趋势。结论在实施冠状动脉搭桥术时,吻合口与狭窄处之间保持较大的距离,有利于改善吻合口处的血流动力学环境,降低吻合口处发生再狭窄的可能性。     

右冠状动脉左房后支变异一例

在解剖一成年男尸心脏时，发现其右冠状动脉的左房后支变异，现报告如下：右冠状动脉起于主动脉右窦中部，始处直径4．32mm，沿冠状沟内走行至房室交点处分为左室后支和后室间支。左室后支起始处直径为2．20mm，起始后在冠状沟内发出四支至左心室膈面，另有一支发出后分为两支，分别布于左心     

冠状动脉移植管的血流动力学数值模拟

采用有限元数值计算的方法，模拟了冠状动脉搭桥术中移植管内的生理流动。计算模型包括了冠状动脉狭窄，并考虑了由于移植管直径大于冠状动脉直径而在两者缝合时移植管的变形。计算结果分析了缝合区附近的流场、二次流、壁面切应力在心动周期内的时空分布情况。计算结果表明，在缝合前端下游，存在一个低切应力、高切应力梯度的区域，在缝合区底部存在一个高切应力、高切应力梯度的区域。这两个区域都是内皮细胞增生并造成移植管术后再阻塞的危险部位。     

基于CT成像的冠状动脉狭窄血流动力学分析

目的基于心血管患者的冠状动脉血管模型,通过计算和分析血管内血液流动的各个动力学参数,研究冠状动脉狭窄对心血管疾病的影响。方法基于心血管患者冠状动脉造影的CT图像,用Mimics软件对左冠状动脉及其主要分支进行三维重建;利用有限元方法,对冠状动脉模型进行流体力学计算。假设血管壁不发生变形,血液为不可压缩牛顿流体,在非定常速度进口的条件下计算各血流动力学参数的变化规律。结果冠状动脉狭窄(75%面积狭窄)对下游的壁面剪切力和振荡剪切指数影响较大,并且会导致涡流和二次流的产生;在模型中装上血管支架,使得血管狭窄消失之后,涡流和二次流基本消失,而且振荡剪切指数明显变小。结论冠状动脉狭窄对血流动力学参数有重大影响,可能是引起动脉粥样硬化的原因;通过CT图像重建方法,可以诊断狭窄发生的地点以及严重性,对心血管疾病的治疗有一定的辅助作用。     

支架植入动脉后的血流动力学特性的研究方法

支架植入术是当今治疗动脉粥样硬化冠心病的一个非常重要的方法,而支架内血栓和新生内膜增生所致的再狭窄是导致冠脉内支架植入术失败的主要原因。大量研究表明支架的血流动力学特性影响了血栓的形成和新生内膜的增生,从而导致了支架内的再狭窄。我们回顾了病变血管支架术的重要性及其存在的问题,通过分析支架血流动力学特性的研究方法,综述了该领域的研究成果和进展。     

右冠状动脉开口于左前降支1例报道

左、右冠状动脉分别起自左、右主动脉窦内。以主动脉瓣附着缘连线为界,可将主动脉分分为窦内和窦外,开口的绝大多数（80％～91％）处于窦内,少数开口在窦外或窦线上。右冠状动脉起自右主动脉窦。     

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.     

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.     

冠状动脉左主干病变的治疗研究

冠状动脉左主干病变（LMCA）因其高危险、高死亡率,一直受到心脏科医师的高度重视,且在不断的努力探索LMCA的有效治疗策略。单纯药物治疗预后差,冠状动脉旁路移植术（CABG）一直以来是LMCA的首选治疗策略,但随着经皮冠状动脉介入治疗（PCI）相关技术的发展,新一代药物涂层支架的问世,使LMCA患者的PCI治疗预后显著改善。本文总结了近年来CABG和PCI治疗LMCA的相关研究,以探讨LMCA的最佳治疗策略。     

冠状动脉搭桥血流动力学数值模拟

目的深入研究缝合区附近的血流动力学特性,这对于了解内膜增生的发生机制以及提高冠状动脉搭桥畅通率有重要的指导与临床意义。方法通过运用三维重建软件和逆向工程软件从CT医学图像中重建出弯曲冠状动脉模型,并考虑移植管缝合到冠状动脉上时端口的变形。采用有限体积法数值研究的方法,模拟冠状动脉搭桥术中下游缝合区附近的血液流动的流场。结果临床上常出现内膜增生的位置都存在不正常的血流动力学现象,缝合前端和缝合后端都出现了严重的回流现象。结论在冠状动脉旁路移植术中,移值管远端应缝合到曲率较小的冠状动脉上。     

羊心左冠状动脉形态学观察

目的　探讨羊心脏左冠状动脉的解剖结构 ,丰富动物实验资料。方法　局解手术学实验后处死山羊 ,取羊心 90例 ,经 10 %甲醛固定 ,手工剥制显示左冠状动脉 ,6例用过氯乙烯 乙酸乙脂填充剂注入冠状动脉中制成动脉血管铸型 ,测量左冠状动脉及其分支。结果　羊冠状动脉分左、右冠状动脉 ,左冠状动脉粗大较浅表 ,前降支行于心肌表面或深达心肌不能明视 ,上多附有心肌桥 ,旋支粗大行程长分支多 ,二者之间多有对角支出现。羊心冠状动脉为左优势性。结论　羊冠状动脉与人相比有较大差异     

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