Spontaneous dissection in the left main coronary artery

We present two cases of spontaneous left main stem coronary artery dissection. One was underdiagnosed with suboptimal percutaneous coronary artery intervention followed by acute vessel occlusion again during the hospitalization. The other one was identified and confirmed by intravascular ultrasound, followed by conservative medical treatment, with completed healing of SCAD during two-month follow up.     

Significance of intravascular ultrasound and exercise stress echocardiography in diagnosis of exercise-induced vasospastic angina at the site of moderate stenosis

Recently, exercise-induced spastic coronary artery occlusion at the site of moderate stenosis, which Prinzmetal’s angina or cardiac syndrome X does not cover, was reported. Multi-modality imaging is important for the diagnosis of coronary artery disease with a complex ischemic mechanism. However, the previous report did not include findings from intracoronary imaging at the site of moderate coronary stenosis. We report a case of exercise-induced vasospastic angina at the site of moderate stenosis, where multi-modality imaging, including exercise stress echocardiography and intravascular ultrasound, was utilized to make a definitive diagnosis and investigate underlying causes.     

Large atherosclerotic plaque related severe right coronary artery dissection during coronary angiography

Catheter-induced coronary artery dissection and occlusion is a rare but serious complication of diagnostic cardiac angiography. A 50 year-old man presented with unstable angina. ECG, exceptional of bradycardia, was normal (57 beat/min). Selective coronary angiography demonstrated 98% narrowing in the mid-portion of the left anterior descending coronary artery (LAD). During the right coronary angiography, following catheter manipulation in the vicinity of the aortic valve, the patient complained of severe chest discomfort, and he had electrocardiographic evidence of acute inferior wall myocardial infarction. Right coronary artery (RCA) was free of the significant obstruction, and it was observed to be having a dominant artery with a spiral dissection (NHLBI Grade IV) located between ostium and the proximal portion of the posterior descending and posterolateral artery bifurcation. The patient was immediately operated with off-pump coronary artery bypass surgery. Consequently, iatrogenic right coronary dissection that is a very rare condition as a cause of myocardial infarction, is discussed in this case report.     

Survival with acute primary coronary artery dissection: A case report and review of the literature

Primary coronary artery dissection its a rare etiology of acute myocardial Infarction (AMI) that often has divestating consequences. We present the case of a 46-year-old side survivor of primary coronary artery dissection who was diagnosed angiographiically. He suffered a non-Q-wave MI but had no electrocardiographic (ECG) charges during his coarse. A review of the literature of primary coronary artery dissection, particularly those diagnosed antemortem, is provided.     

Clinical Outcome of Coronary Stenting in Patients with Variant Angina Refractory to Medical Treatment: A Consecutive Single-Center Analysis

Objective

To investigate the efficacy of coronary stenting in patients with variant angina refractory to medical treatment.

Subjects and Methods

Variant angina was diagnosed in 81 patients admitted to the Department of Cardiology between January 2003 and June 2011. However, coronary stenting was performed in 21 patients refractory to medical treatment, but coronary angiography and intravascular ultrasound were performed in all patients, and acetylcholine provocative test was performed in 11 of the 21 patients refractory to medical treatment. Coronary angiography was repeated after 9–12 months in the 21 patients with coronary stents. Clinical follow-up time was 2.5 ± 3.1 years (range 1–8).

Results

Of the 81 patients, coronary angiography and intravascular ultrasound did not reveal significant stenosis in 13 (16.0%), but revealed 20–75% fixed stenosis in the remaining 68 (84.0%) patients. The acetylcholine provocative test was positive in the 11 patients. Of the 21 patients with coronary stents, the spasm site was located in the right coronary artery in 16 (76.2%) and in the left anterior descending artery in the remaining 5 (23.8%) patients. During the 1- to 8-year follow-up period, 1 of the 21 patients with stents developed recurrent episodes of variant angina, 5 patients had occasional chest pain, and the other 15 were asymptomatic. Coronary angiography at 9–12 months after initial evaluation demonstrated no stenosis in 3 patients, 20–40% in-stent mild intimal hyperplasia in 15 patients, and 50–80% in-stent restenosis in 3 patients. Coronary stenting was performed again in 2 patients.

Conclusions

The present study showed that coronary stenting for severe refractory coronary vasospasm was effective and without serious complications. It can be an alternative and viable option for some patients who are refractory to medical therapy and at a high risk of acute coronary syndrome recurrence.Key Words: Variant angina, Coronary artery disease, Coronary angiography, Electrocardiography, Stenting, Ultrasonography, Angioplasty, Acetylcholine, Ischemia, Acute coronary syndrome     

冠状动脉造影和血管内超声在诊断变异型心绞痛中的临床价值

目的 探讨冠状动脉造影、血管内超声在诊断变异型心绞痛患者中的临床价值.方法 选择我院2007年12月至2009年3月临床诊断为冠心病患者23例,其中变异型心绞痛患者10例,稳定型心绞痛患者13例.对每位患者行冠状动脉造影及血管内超声检查,对病变斑块的性质、形态、部位、血管管腔面积狭窄程度、血管重构指数等指标进行分析.结果 变异型心绞痛组与稳定型心绞痛组两组斑块偏心指数分别为0.90±0.06 vs 0.70±0.25,局部面积狭窄率分别为(53.56±3.88)%vs(68.66±14.52)%,管腔面积狭窄率分别为(41.23±23.91)%vs(63.10±14.64)%,以上指标两组差异有统计学意义(均P<0.05).血管内超声检测病变血管重构指数,正性重构、负性重构在两组差异有统计学意义(P<0.05).对于变异型心绞痛患者,以血管内超声为参照,以节段为基础,冠状动脉造影和血管内超声检测血管管腔平均狭窄程度差异有统计学意义(P<0.05).冠状动脉造影和血管内超声检测轻中度管腔面积狭窄差异有统计学意义,重度管腔面积狭窄两者差异无统计学意义.结论 变异型心绞痛患者冠状动脉目标斑块以偏心性斑块为主,血管管腔面积狭窄程度以轻中度狭窄为主,血管重构以正性重构为主.冠状动脉造影低估病变管腔面积狭窄程度.     

CT, MRI for diagnosis of acute coronary syndrome

Recent pathological and clinical observations support the notion that coronary artery plaque disruption and subsequent thrombosis is the primary cause of acute coronary syndrome (ACS) including acute myocardial infarction and unstable angina. Therefore, detection and characterization of coronary artery plaques are of utmost importance in the management of patients with suspected coronary artery disease. Histologic and clinical observations using intravascular ultrasound have suggested that vulnerable, rupture-prone plaques are characterized by the presence of large lipid cores, thin fibrous caps and positive coronary artery remodeling. In this review, we describe the efficacy of multislice computed tomography (MSCT) to characterize vulnerable plaques, especially in patients with suspected ACS. In addition, the efficacy of coronary magnetic resonance imaging is discussed.     

Spontaneous coronary dissection should not be ignored in patients with chest pain in autosomal dominant polycystic kidney disease: A case report

BACKGROUNDWhen autosomal dominant polycystic kidney disease (ADPKD) presents with acute coronary syndrome (ACS), the possibility of spontaneous coronary artery dissection (SCAD) should be highly considered. In some cases, SCAD is considered an extrarenal manifestation of ADPKD depending on the pathological characteristics of the unstable arterial wall in ADPKD. CASE SUMMARYHere, we report a 46-year-old female patient with ADPKD who presented with ACS. Coronary angiography revealed no definite signs of dissection, while intravascular ultrasound revealed a proximal to distal dissection of the left circumflex. After a careful conservative medication treatment, the patient exhibited favorable prognosis. CONCLUSIONIn cases of ADPKD co-existing with ACS, differential diagnosis of SCAD should be considered. Moreover, when no clear dissection is found on coronary angiography, IVUS should be performed to prevent missed diagnosis.     

Application of intravascular ultrasound for detection and quantitation of coronary atherosclerosis

Although angiography is widely utilized to assess the extent and severity of coronary artery disease (CAD), arteriography yields only a silhouette of the vessel lumen. Coronary intravascular ultrasound supplements angiography by providing a tomographic perspective of lumen geometry and vessel wall structure. Intracoronary ultrasound can now be performedin vivo utilizing small, flexible probes capable of negotiating tortuous vessles. We have performed coronary ultrasound in more than 100 patients, including a group of normal subjects, with no serious complications. Measurements of coronary lumen dimensions by angiography and ultrasound correlated closely for normal vessels (r=0.92) and for concentrically narrowed atherosclerotic vessels (r=0.90). However, the correlation between angiography and ultrasound was only fair for eccentrically narrowed arteries (r=0.79) and was poor following angioplasty (r=0.30). Coronary artery wall motion was measured by intravascular ultrasound and demonstrated significant differences between normal arteries (18% lumen area change) and atherosclerotic vessels (11% change). Coronary ultrasound demonstrated important differences in the structure of normal and altherosclerotic vessel walls. Arteries in normal subjects exhibited a thin intimal leading-edge echo (mean 0.20 mm) and subadjacent sonolucent zone (mean 0.12 mm). Atherosclerotic vessels typically demonstrated increased thickness of both structures and often exhibited dense fibrocalcific plaques that shadowed underlying anatomy. These ultrasound abnormalities were often present at angiographically normal sites. Several limitations of coronary intravascular ultrasound were apparent, including echo ‘dropout’, distortions produced by non-coaxial imaging, and inability to image small or severely narrowed vessels. Coronary intravascular ultrasound holds great promise for the detection and quantification of CAD in the clinical setting.     

血管内超声评价冠心病患者的冠状动脉

目的报告应用血管内超声(IVUS)评估冠心病患者冠状动脉重构及斑块稳定性诊疗的体会。方法使用血管内超声观察236例冠心病患者(经冠状动脉造影确诊),其中不稳定型心绞痛(UA)78例,稳定型心绞痛(SA)61例,急性心肌梗死(AMI)97例。结果SA组以稳定的纤维斑块为主,UA和AMI组以不稳定的软斑为主;UA和AMI组的偏心指数明显高于SA组(P<0.05)。UA组和AMI组以正性重构为主。结论IVUS能更准确观察冠状动脉内粥样斑块的特点,观察冠状动脉管腔的形态及狭窄的严重程度,对冠心病诊断具有独特的临床价值。     

血管内超声对冠状动脉粥样斑块和介入性治疗的评价研究

本研究通过对８７例患者包括９７支病变血管在ＰＴＣＡ和ＤＣＡ前后的形态特征的观察，结果显示ＩＶＵＳ对斑块钙化和冠状动脉夹层的检出率高于ＣＡＧ检查，是一项可以对粥样斑块形态特征做出准确评价的敏感的影像技术，并能对各种介入性冠状动脉治疗后血管壁及斑块的形态改变做出定性和定量的评价。ＰＴＣＡ后导致被扩张的血管内腔面积增大是由血管壁扩张和夹层共同作用的结果，而在ＤＣＡ之后管腔面积增加的主要机理是斑块的减少。     

血管内超声显像在冠状动脉粥样硬化性心脏病支架置入中的应用

背景:支架扩张不充分以及与操作相关的异常病变形态是支架内再狭窄以及急性、亚急性和慢性支架内血栓形成的重要原因.目的:观察应用血管内超声指导支架置入能否获得更大的支架内管腔面积,能否发现更多与操作相关的并发症.设计、时间及地点:回顾性病例分析,于2004-01/2005-02在首都医科大学附属北京朝阳医院心脏中心进行.对象:选择50 例患者的52 处在血管内超声指导下行支架置入的病变进行分析.入选患者均为自体冠状动脉非弥漫性病变,血管直径≥ 2.5 mm,严重的左主干病变除外.方法:50 例患者的52 处病变在支架置入前后分别用血管造影和血管内超声进行定量和定性分析,并根据血管内超声标准决定支架的直径以及置入的终点.主要观察指标:分析血管造影和血管内超声对支架置入终点判断的差异和最终获得的管腔面积大小的差别.结果:①血管内超声判断的平均支架直径大于血管造影(P=0.011),支架囊的最终峰值压力明显增大(P < 0.001),定量冠状动脉造影测得的支架面积狭窄百分比减小(P =0.044).②首次高压扩张后支架满意率血管造影达96.2%,而血管内超声只有37.7%.③血管内超声指导后最终的球囊压力更高(P < 0.001),获得的管腔直径更大(P < 0.001),管腔面积也更大(P < 0.001),面积狭窄百分比更小(P < 0.001).④所有患者支架的近段和远段血管造影均未发现明显的狭窄.而血管内超声却发现支架近段血管有39 例(75.0%),远段血管有23 例(44.2%)存在动脉粥样硬化斑块.⑤支架置入后非脂质斑块较脂质斑块获得的管腔面积更大(P < 0.001),其中脂质斑块血管面积增大较非脂质斑块小1.30 mm2,斑块压缩程度却增加0.48 mm2.结论:血管内超声能更好地指导支架选择,获得更大的管腔面积,也能更精确地发现操作相关的并发症.     

Posttraumatic myocardial infarction with severe coronary intimal dissection documented by intravascular ultrasound

We present a case of posttraumatic myocardial infarction after blunt chest trauma in a previously healthy man. Coronary angiography showed an eccentric occlusion in the midportion of the left anterior descending artery. Subsequent intracoronary ultrasound imaging revealed a severe intimal dissection. The outcome after intracoronary stent placement was excellent. This rare but potentially harmful complication of blunt chest trauma should be kept in mind and coronary angiography performed immediately when coronary occlusion is suspected. Intravascular ultrasound imaging is a helpful tool in the assessment of coronary artery occlusion caused by intimal dissection.     

血管内超声评估老年不稳定型心绞痛患者冠脉病变

目的 使用血管内超声探讨老年冠心病患者冠脉病变特点.方法 选择39例老年不稳定型心绞痛患者（UA）为研究对象, 28例稳定型心绞痛患者（SA）为对照组,使用血管内超声分别测定两组患者＂罪犯＂病变血管的外弹力膜面积（EEM）、管腔横截面积（LA）、斑块面积（PA）、斑块负荷（PB）、重构指数（RI）及偏心指数（EI）等指标,并利用虚拟组织学技术对斑块成分进行比较分析.结果 UA组和SA组患者的＂罪犯＂病变血管的LA、PA、PB比较差异均无统计学意义（P＞0.05）;两组EEM、RI、EI比较差异有统计学意义（P＜0.05）;UA组斑块中脂质、坏死组织所占比例较SA组显著增高,而SA组斑块以纤维组织多见（P＜0.01）.结论 老年冠心病患者临床表现与冠脉病变斑块结构、成分关系密切.     

Assessment of the mechanical properties of coronary arteries using intravascular ultrasound: an in vivo study

The pressure-area relation of coronary arteries provides important information about the mechanical properties of these vessels. In human subjects methodological limitations have precluded measurement of instantaneous compliance and coronary stress in vivo. The purpose of this study was to assess a new method for measuring instantaneous values of coronary artery compliance and wall stress utilizing simultaneously acquired pressure and intravascular ultrasound measurements of vessel area. Ten subjects with coronary artery disease had intravascular ultrasound studies of the proximal left anterior descending or circumflex coronary arteries. Coronary luminal area was measured with a 30-MHz (3F or 3.5F) intravascular ultrasound catheter and simultaneous coronary pressure measured with a 2F micromanometer-tipped catheter. Using this technique the nonlinear pressure-area relation and mean circumferential wall stress were determined over the physiological pressure range. Coronary artery compliance at 100?mmHg ranged from 0.010 to 0.052 mm²/mmHg (mean ± SD, 0.020 ± 0.012 mm²/mmHg). Peak systolic circumferential stress ranged from 0.52 to 2.03 × 10⁶ dyn/cm² (1.09 ± 0.42×10⁶ dyn/cm²). This study describes a new method of determining coronary artery mechanical properties over the physiological pressure range. This technique may be useful in further studies of coronary artery mechanics.     

Anatomy, histology, and pathology of the major epicardial coronary arteries relevant to echocardiographic imaging techniques

We are at the threshold of a new era of coronary artery imaging with the use of transthoracic, transesophageal, and intravascular ultrasound. Echocardiographic imaging has the capability of assessing changes of the lumen and walls of major epicardial coronary arteries. This article reviews certain anatomic, histologic, and pathologic observations of the major epicardial coronary arteries relevant to these various echocardiographic imaging techniques.     

The vulnerable coronary plaque

Vulnerable coronary plaques are asymptomatic atherosclerotic lesions with the tendency to rupture. Plaque rupture is the initiating event in most acute coronary syndromes including sudden cardiac death, acute myocardial infarction, and unstable angina. Vulnerable plaques are commonly found in coronary arteries at autopsy but are virtually undetectable by standard diagnostic techniques such as stress testing and coronary angiography. Using new imaging techniques, in particular intravascular ultrasound and magnetic resonance imaging (MRI), scientists are now able to identify these plaques in vivo. A better understanding of the pathophysiology of plaque vulnerability and rupture will eventually lead to the therapeutic goal of plaque stabilization in the prevention of acute coronary syndromes. This article reviews the role of plaque vulnerability in coronary artery disease. The anatomy and pathophysiology of vulnerable plaques as well as diagnostic and therapeutic implication will be described.     

Successful Wallstent implantation for extensive iatrogenic renal artery dissection in a patient with fibromuscular dysplasia.

PURPOSE: To describe a case of renal artery stenosis with fibromuscular dysplasia (FMD) and extensive iatrogenic dissection treated with Wallstent implantation. METHODS AND RESULTS: An 83-year-old woman with a history of coronary artery disease and hypertension presented at another facility with exertional angina and poorly controlled hypertension. Renal arteriography uncovered a critical right renal artery stenosis with severe FMD. However, angioplasty resulted in extensive dissection of the renal artery, for which the patient was referred to our institution. The renal artery was recanalized via the left brachial approach with restoration of flow using a Wallstent and a Palmaz stent. The patient's blood pressure was controllable after this procedure, and follow-up duplex imaging with flow velocities at 6 months showed patent right renal artery stents. CONCLUSIONS: Owing to its length and flexibility, the Wallstent endoprosthesis was a useful treatment modality in this case of extensive renal artery dissection.     

急性冠状动脉综合征与稳定型心绞痛患者冠状动脉病变的血管内超声比较研究

目的　探讨急性冠状动脉综合征与稳定型心绞痛患者的冠状动脉 (冠脉 )病变血管内超声特征。方法　 5 2例急性冠脉综合征患者与 79例稳定型心绞痛患者进行冠脉造影及血管内超声检查 ,根据超声检查结果 ,冠脉病变分为钙化斑块、硬斑块及软斑块。钙化斑块为斑块的回声比血管壁外膜回声强并伴有声影 ,其范围大于 90° ;硬斑块为斑块的回声与血管壁外膜回声大致相同 ,但后方无声影 ;软斑块为斑块的回声比血管壁外膜回声弱。不稳定斑块为纤维帽较薄、有脂质池的斑块或并有斑块破裂。稳定型斑块为钙化斑块及硬斑块。结果　稳定型心绞痛的冠脉病变特点以稳定型斑块为主 ,急性冠脉综合征冠脉病变特点以不稳定型斑块为主。 61.5 %急性冠脉综合征及 3 8.0 %稳定型心绞痛患者为软斑块 ( P <0 .0 1) ,2 8.9%急性冠脉综合征及 6.3 %稳定型心绞痛患者有脂质池 (P <0 .0 1) ,并且急性冠脉综合征患者冠脉斑块多伴有斑块破裂。结论　急性冠脉综合征及稳定型心绞痛的冠脉病变各有自己的特征 ,血管内超声对其有一定的诊断价值。     

Acute coronary artery stent thrombosis caused by a spasm: A case report

BACKGROUNDAcute stent thrombosis (AST) is a serious complication of percutaneous coronary intervention (PCI). The causes of AST include the use of stents of inappropriate diameters, multiple overlapping stents, or excessively long stents; incomplete stent expansion; poor stent adhesion; incomplete coverage of dissection; formation of thrombosis or intramural hematomas; vascular injury secondary to intraoperative mechanical manipulation; insufficient dose administration of postoperative antiplatelet medications; and resistance to antiplatelet drugs. Cases of AST secondary to coronary artery spasms are rare, with only a few reports in the literature.CASE SUMMARYA 55-year-old man was admitted to the hospital with a chief complaint of back pain for 2 d. He was diagnosed with coronary heart disease and acute myocardial infarction (AMI) based on electrocardiography results and creatinine kinase myocardial band, troponin I, and troponin T levels. A 2.5 mm × 33.0 mm drug-eluting stent was inserted into the occluded portion of the right coronary artery. Aspirin, clopidogrel, and atorvastatin were started. Six days later, the patient developed AST after taking a bath in the morning. Repeat coronary angiography showed occlusion of the proximal stent, and intravascular ultrasound showed severe coronary artery spasms. The patient’s AST was thought to be caused by coronary artery spasms and treated with percutaneous transluminal coronary angioplasty. Postoperatively, he was administered diltiazem to inhibit coronary artery spasms and prevent future episodes of AST. He survived and reported no discomfort at the 2-mo follow-up after the operation and initiation of drug treatment. CONCLUSIONCoronary spasms can cause both AMI and AST. For patients who exhibit coronary spasms during PCI, diltiazem administration could reduce spasms and prevent future AST.