心肌桥与临床

心肌桥(myocardial bridge)并不罕见,有时它可以毫无症状,显得没有多大临床意义;但有时它竟能成为致死的原因,这就非同小可,不容轻视,目前对它的认识和研究还很不足,本文旨在提醒临床医师注意,希望对心肌桥给予足够的重视,并进行深入地研究。 1.何谓心肌桥? 正常冠状动脉主干及其主要分支行走于心外膜下脂肪组织内或心外膜的深面,有的人其冠状动脉全部或部分被浅层心肌掩盖,在心肌内行走一段距离后又浅露出心肌表面,被心肌掩盖的动脉段称壁性冠状动脉(mural artery)或隧道型冠状动脉(tun-neled artery),掩盖动脉的心肌称作心肌桥。     

心肌肌桥与心肌缺血

冠状动脉主干及其重要分支主要走行于心外膜下脂肪组织或心外膜的深面;有时可以被浅层心肌所掩盖,在心肌内行走一段距离后,又回复到心肌浅表来。埋藏在心肌的一段冠状动脉可在心室收缩期受压而发生狭窄。1960年Portsmann和Iwig首先发现冠状动脉造影中。在收缩期冠状动脉发生暂时狭窄,并称之为心肌肌桥(myocardial bridging,MB)。目前一致认为MB为一种先天性解剖学异常。近年来,心肌肌桥作为     

心肌桥研究的新进展

冠状动脉 (冠脉 )及其分支 ,一般走行于心外膜下脂肪组织中。心肌桥是指冠脉某一段或其分支的某一段走行于心肌纤维中 ,被形似桥的心肌纤维所覆盖 ,该心肌纤维束称为心肌桥 (ｍｙｏｃａｒｄｉａｌｂｒｉｄｇｅ)。早在 192 2年 ,Ｇｒａｉｎｉｃｉａｎｕ首先对此现象加以描述。 196 0年Ｐｏｒｔｍａｎｎ和Ｉｗｉｇ首先报道了心肌桥的影像学表现———收缩期狭窄 (ｓｙｓｔｏｌｉｃｎａｒｒｏｗｉｎｇ) ,即冠脉某一节段收缩期变得狭窄、模糊或显影不清 ,而舒张期冠脉显影正常。近年来 ,有关心肌桥的解剖学、临床意义所导致心肌缺血的血流动力学…     

心肌桥

心肌桥是一种先天性冠状动脉解剖异常.当心肌收缩时壁冠状动脉受到压迫,且受压持续至舒张期.壁冠状动脉近端容易发生动脉粥样硬化,壁冠状动脉存在内皮功能紊乱.心肌桥可引起心肌梗死、心绞痛、心律失常、左心室功能减低和猝死等不良心血管事件.药物治疗包括β受体阻滞剂和钙拮抗剂,硝酸酯类因可使症状恶化而应避免使用.冠状动脉内支架和外科手术治疗可用于选择性的病例.本文对心肌桥的解剖、病理生理、临床表现和治疗方法等进行综述.     

心肌桥临床诊疗分析

目的 探讨心肌桥(myocardial bridge,MB)的临床诊疗策略.方法 应用双源CT(double source CT,DSCT)对有心绞痛及类似症状的可疑冠心病患者行冠状动脉血管成像,其中部分病人同时行选择性冠脉造影(selective coronary arteriography,SCA).按年龄分3组,分析MB的检出率、MB壁冠状动脉粥样硬化斑块的发生率、壁冠状动脉粥样硬化斑块的性质及各年龄组的差别.结果 478例患者行DSCT 检查,检出MB 96例,检出率20.1%.共检出MB 107个,合并粥样硬化斑块59个,其中近段粥样硬化斑块48个(81.4%).59例患者行SCA 检查,检出MB 5例,检出率8.5%.青年组、中年组与老年组比较MB近段冠脉斑块性质明显不同,差异有统计学意义(P＜0.01).结论 DSCT对MB及其近段冠脉病变的诊断有较高敏感性.MB近段冠脉粥样斑块的发生与年龄增长相关.青年组、中年组与老年组比较MB近段冠脉粥样硬化斑块性质有所不同.     

冠脉心肌桥临床研究新进展

冠脉心肌桥的定义1922年Crainicianu首先报导冠脉心肌桥(My-ocardial bridge,MB)的存在。1960年Portmann alwig在冠脉造影时证实心肌桥在心室收缩期压迫冠状动脉使其狭窄,而在舒张期时恢复正常。     

心肌桥对冠状动脉粥样硬化的作用

目的:探讨心肌桥与冠状动脉粥样硬化病变之间的关系。方法:回顾性分析冠脉造影术中检出的心肌桥患者92例的冠脉病变与临床资料。结果:1500例冠脉造影患者检出心肌桥92例,检出率6.1%;心肌桥近段冠状动脉粥样硬化病变发生率71.7%,远段冠状动脉粥样硬化病变发生率10.9%,两者差异有显著性（P<0.01）。结论:心肌桥可能导致冠状动脉心肌桥近段冠脉粥样硬化病变。     

心肌桥

心肌桥是一种特殊类型的冠状动脉畸形,本文综述了心肌桥的病理生理,临床表现,治疗及预后。     

壁冠状动脉心肌桥近端动脉粥样硬化的危险因素分析

目的探讨壁冠状动脉的心肌桥近端发生动脉粥样硬化相关的危险因素。方法回顾性分析于我院行冠状动脉造影并确诊心肌桥的941例患者,根据纳入及排除标准最终共纳入541例,其中动脉粥样硬化组(心肌桥合并单纯壁冠状动脉的肌桥近端动脉粥样硬化) 262例,对照组(孤立心肌桥) 279例。收集两组患者的一般资料、心肌桥相关的临床特征以及入院时的实验室指标,比较两组间各指标的差异,并采用Logistic回归模型分析与心肌桥近端动脉粥样硬化独立相关的危险因素。结果动脉粥样硬化组的年龄、男性比例、糖尿病发生率、使用调脂药比例、C反应蛋白和血同型半胱氨酸水平均高于对照组(P 0. 05)。多因素Logistic回归分析结果显示,年龄(OR=1. 07,95%CI:1. 05～1. 09)、男性(OR=1. 59,95%CI:1. 04～2. 41)、糖尿病(OR=2. 52,95%CI:1. 36～4. 69)和高C反应蛋白水平(OR=1. 04,95%CI:1. 01～1. 08)与动脉粥样硬化独立相关。结论高龄、男性、糖尿病和高C反应蛋白水平是心肌桥患者发生近端动脉粥样硬化的独立危险因素。     

心肌桥的诊治现状

心肌桥(MBs)是一种先天性冠状动脉发育畸形,与心绞痛、心肌梗死、心律失常和猝死等心脏事件有关。其造影检出率较低,从而为相关心脏事件的预防带来了困难。以往心肌桥以内科治疗为主,近年来冠脉介入和支架越来越多的被应用于内科治疗效果不佳的病例,外科治疗亦取得了不错的效果。本文就心肌桥的诊断及治疗方面的现状作一综述。     

Coronary Artery Shape and Flow Changes Induced by Myocardial Bridging

Changes in coronary shape and blood flow induced by myocardial bridging were analyzed in a 56-year-old patient with symptoms of unstable angina after the exclusion of other heart disease. Coronary angiography demonstrated a 1.8-cm long myocardial bridge in the middle part of the left anterior descending coronary artery. In systole, an eccentric compression of the artery occurred, resulting in a stenosis that occupied 86% of the diameter and 96% of the area. Intraluminal ultrasound was performed with a 20-MHz transducer in a 4.8-Fr catheter sheath (Boston Scientific Corp.) connected to an ultrasound console (Diasonics Inc.). A side saddle catheter was introduced into the left anterior descending coronary artery via a giant guiding catheter. A circular shape with typical systolic pulsation was seen in the proximal part of the artery (maximal and minimal diameters 3.6 mm and 3.5 mm, respectively). Distally an eccentric compression of the coronary artery was visualized, decreasing one diameter from 3.0 to 2.6 mm, whereas the orthogonal diameter remained constant at 3.3 mm. The myocardial bridge compressed 160°–180° of the circumference of the artery, leading to a change from a circular to an elliptical arterial shape. A delayed relaxation of the bridging was demonstrated. Only the proximal part of the vessel in the muscle bridge could be passed. Coronary flow was measured using a Doppler 3-Fr 20-MHz catheter (Millar Instruments Inc.) using a pulse repetition rate of 62.5 kHz. Coronary flow velocity was calculated in the proximal part of the left anterior descending coronary artery before and after intracoronary injection of 10 mg papaverine. Phasic coronary flow velocity increased from 14 to 21 cm/sec and mean flow from 6 to 13.5 cm/sec, yielding an estimated flow reserve of 1.5 and 2.2, respectively (normal > 3.0). Thus, intravascular and Doppler ultrasound are useful techniques for analyzing the effect of myocardial bridging on changes in coronary shape and blood flow. An eccentric compression of the coronary artery was visualized with delayed relaxation. Coronary flow reserve was reduced. Further studies in larger patient populations are necessary to demonstrate whether reduction of coronary flow reserve is, in general, related to delayed relaxation in diastole.     

心肌缺血-再灌注损伤治疗新进展

急性心肌梗死是目前严重威胁人类健康的疾病之一,再灌注治疗是目前最有效的治疗手段,但会引起致命的缺血-再灌注损伤。如何有效地减轻缺血-再灌注损伤已成为近年来研究的热点,现就心肌缺血-再灌注损伤的治疗方法做一综述,并对新兴的治疗靶点进行展望。     

心肌桥的冠状动脉造影特点及临床意义

目的 :探讨心肌桥的冠状动脉 (冠脉 )造影特点及其临床意义。方法 :对 747例接受选择性冠脉造影的病例进行回顾性分析 ,共检出心肌桥 3 8例 ,采用计算机辅助定量冠脉造影系统软件对心肌桥进行定量分析。结果 :3 8例均为前降支肌桥 ,在冠脉投照位中以左肩位及右肩位收缩期狭窄最严重 ,肌桥长度平均 18 8± 5 1mm ,肌桥近端距第一对角支距离平均 2 0 1± 7 6mm ,距前降支起始部距离平均 3 1 3± 9 7mm ,距左冠脉起始部距离平均45 1± 10 4mm。肌桥前有动脉硬化或狭窄表现者 11例 ( 2 9% ) ,合并冠脉瘘 3例 ( 8% ) ,合并肥厚性心肌病 2例 ( 5 % )。结论 :在冠脉造影中心肌桥现象并非罕见 ,左肩位造影发现率高 ,严重心肌桥可以造成心肌缺血。     

肥厚型心肌病冠状动脉肌桥造影特点分析

目的 :分析在肥厚型心肌病患者冠状动脉 (冠脉 )肌桥的临床及造影特点。　　方法 :肥厚型心肌病患者 90例 ,所有患者通过采用Judkins法接受选择性冠脉造影及左心室造影检查 ,每支冠脉均经多体位投照 ,以收缩期冠脉管腔直径压缩至少 5 0 %或出现吸吮效应作为确定肌桥存在的证据 ,同时以至少一支冠脉管腔狭窄≥ 5 0 %作为有意义狭窄。　　结果 :90例患者中发现肌桥 19例 (2 1 1% ) ,其造影特点显示　①按压缩部位分类 :前降支中段 14例 (74% ) ,前降支中远段 1例 (5 % ) ,前降支弥漫性压缩 1例 (5 % ) ,间隔支 2例 (11% ) ,前降支中远段加对角支 1例 (5 % ) ;②按压缩程度分类 :收缩期管腔直径压缩 <5 0 %者 4例 (2 1% ) ,≥ 5 0 %～≤ 80 %者 11例 (5 8% ) ,>80 %～≤ 90 %者 2例(11% ) ,>90 %～ 10 0 %者 2例 (11% ) ;③左心室造影显示异常者 13例 (68% ) ,正常者 6例 (3 2 % )。此外经造影证实合并冠心病者 2例 (11% )。　　结论 :在肥厚型心肌病中肌桥为常见征象 ,明显高于其他患者 ,故临床应予以重视。     

冠状动脉心肌桥的研究进展

冠状动脉心肌桥是由于先天性冠状动脉解剖异常,可导致心肌缺血、心肌梗死、甚至猝死,了解心肌桥的解剖学、影像学特征、病理生理改变、临床意义对指导心肌桥的治疗及预后具有重要意义,现就近几年进展作一综述。     

Myocardial infarction associated with myocardial bridging: Case history and review of the literature

A 38-year-old male presented with an acute anterior myocardial infarction. Immediate cardiac catheterization revealed no evidence of angiographically significant atherosclerotic coronary artery disease, but there was a subtotal occlusion of the mid-left anterior descending coronary artery from myocardial muscle bridging. The patient did well with medical management. This review details myocardial bridging and its treatment. Cathet. Cardiovasc. Diagn. 40:364–367, 1997. © 1997 Wiley-Liss, Inc.     

Silent myocardial ischemia: concepts and controversies

Silent myocardial ischemia is a relatively common, but poorly understood, clinical entity. The most accurate means of detecting silent myocardial ischemia and the precise treatment endpoints remain unclear. However, the amount of ischemic myocardium appears to correlate with the likelihood of future adverse cardiac events. Evidence suggests that patients at highest risk of severe myocardial ischemia, even in the absence of symptoms, derive the greatest benefit from an aggressive diagnostic and therapeutic approach. This paper reviews the diagnosis and treatment of silent myocardial ischemia, and its clinical implication in select patient groups: those without coronary artery disease, those with coronary artery disease, diabetic patients, postrevascularization patients, and women.     

Myocardial bridging in a young patient with sudden death

Systolic compression of a coronary artery is considered to be a benign phenomenon, although numerous case reports have suggested an association between bridging and sudden death or ischemia in certain patients without other abnormalities on cardiovascular evaluation. We present the case of a young patient with two episodes of spontaneous ventricular fibrillation and electrocardiographic evidence of ischemia, whose only primary abnormality on extensive workup was a long segment of left anterior descending systolic compression. This case adds to the growing body of anecdotal evidence that myocardial bridging may be associated with significant cardiac events.