犬左冠状动脉前室间支心肌桥的形态学特征

目的探讨犬壁冠状动脉和心肌桥的形态学特点,为比较解剖学提供资料。方法取犬心41例,10%甲醛溶液固定,解剖显示冠状动脉及其分支,观测心肌桥及壁冠状动脉的出现率。结果犬冠状动脉心肌桥多出现于前室间支、后室间支和左室前支。心肌桥出现率70.7%,前室间支79.3%,心肌桥厚度为0.56±0.61 mm。前室间支前段内径1.64±0.46 mm,厚度0.18±0.06 mm;壁冠状动脉内径1.35±0.46 mm,厚度0.13±0.04 mm。心肌桥近段距第一对角支距离为19.78±8.20 mm,距前室间支起始部距离为24.49±12.37mm,距右冠起始部距离为24.21±5.80 mm。心肌桥纤维走向与壁冠状动脉夹角为68.94±14.38。结论犬冠状动脉心肌桥出现率及位置与人相似,可作为科研动物模型。     

Myocardial bridges over coronary arteries in Cercopithecus.

The presence of myocardial bridges over the coronary arteries has been studied in 29 monkey (Cercopithecus aethiops) hearts. The great resemblance between the Cercopithecus subepicardial arterial net with the corresponding one in humans has been revealed. There is a high incidence (83%) of myocardial bridges only over the ventricular branches of both coronary arteries. Myocardial bridges are usually (90%) located over the left coronary artery branches, and the left anterior interventricular branch is the most frequently (69%) overbridged vessel. The bridges are always single over the vessel examined and their length varies from 0.5 mm to 31.6 mm. No statistically significant sexual difference in myocardial bridges distribution is reported.     

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     

Histologic and immunohistochemical analysis of the antiatherogenic effects of myocardial bridging in the adult human heart

BackgroundMyocardial bridging is a common anatomic variation of the human heart in which an epicardial coronary artery takes an intramural course within the myocardium. Studies have proposed that myocardial bridges offer a “protective effect” from atherosclerosis within the involved coronary artery.MethodsWe examined 250 formalin-fixed human hearts with gross dissection and histologic and immunohistochemical techniques. The bridged arteries were divided into premyocardial, myocardial, and postmyocardial segments. Atherogenic activity was assessed by comparing proliferative activity (Ki-67), smooth muscle α-actin, and macrophages. In addition, atherosclerotic lesions were carefully categorized according to the Stary classification.ResultsThe presence of myocardial bridges was confirmed in 92 hearts (36.8%). The most common location of a myocardial bridge was over the anterior interventricular artery in 38 (41.3%) hearts. Overall, the bridged segments demonstrated weaker Ki-67 activity, a decreased number of smooth muscle cells and macrophages, and lower modal Stary classifications for atherosclerosis severity as compared to pre- and postbridge segments of the same coronary artery.ConclusionAtherosclerotic lesions in vessel sections deep to the myocardial bridges were found to be less developed in contrast to the pre- and postbridge segments of the same coronary arteries. Although the precise mechanism of atherogenic protection is unknown, it has been proposed that compression by the contracting myocardium stimulates the release of anticoagulant and growth factors, which could have a synergistic effect in protecting the endothelium from denudation, inflammation, and resultant atherosclerosis.     

The significance of myocardial bridge upon atherosclerosis in the left anterior descending coronary artery

The relation between myocardial bridges (MB) and atherosclerosis in the left anterior descending coronary artery (LAD) was explored using morphometric methods in 642 hearts. The location of myocardial bridges in the LAD was classified according to distribution as proximal, middle and distal. Myocardial bridges were found in 48 per cent of males and 36 per cent of females. When proximal myocardial bridging was present intimal thickening and macroscopic raised lesion were increased just before the bridge as compared with the corresponding site in the other two categories. Underneath bridges eccentric plaques and raised lesions are absent although there is often concentric intimal thickening. The overall frequency of myocardial infarction was the same in patients with and without myocardial bridges. However, when infarction occurred in the patients having bridges, it was almost confined to those in the proximal group despite this being infrequent in the general distribution of myocardial bridges in the left anterior descending artery. It is postulated that hypertension may enhance infarction in the case of myocardial bridges in the very proximal left anterior descending artery. It is concluded that the location of myocardial bridges greatly alters the distribution of physical force against the arterial wall and influences the extent of atherosclerosis.     

The anatomy of the coronary sinus and its tributaries

The coronary sinus and its tributaries were studied by anatomical dissection in 37 adult human cadaveric hearts, which had been fixed in formalin solution. An anastomosis of approximately 1.0mm in calibre was observed between the anterior and posterior interventricular veins in 19% of specimens. Myocardial bridges were detected above the anterior interventricular vein or its tributaries in 8% of specimens. The great cardiac vein formed the base of the arteriovenous trigone of Brocq and Mouchet with the bifurcating branches of the left coronary artery in 89% of specimens and formed an angle accompanying these arterial branches in 11%. In the trigone the anterior interventricular and great cardiac veins were superficial to the arteries in 73% of specimens. The left marginal vein was present in 97% of specimens, emptying into the great cardiac vein in 81% of cases and into the coronary sinus in the remaining 19%. The small cardiac vein was present in 54% of specimens. In the coronary sulcus the great cardiac vein was adjacent to the circumflex branch of the left coronary artery in 76% of specimens and to the right coronary artery in 5% in 19% there was no relationship with either artery. The coronary sinus maintained a relationship with the right coronary artery in 46% of specimens and with the left coronary artery in 32% in 22% it had no relationship with these vessels.     

Pathomorphology and Pathogenic Role of Myocardial Bridges in Sudden Cardiac Death

Pathognomonic incidence of myocardial bridges during obstructive hypertrophic cardiomyopathy, hypertension, and ischemic heart disease was established. Myocardial bridges were predominantly found in the median segments of major coronary arteries with prevailence of bridge-like obstructions in the anterior interventricular branch of the left coronary artery. Typical changes in cardiac angioarchitectonics indicating pronounced inadequacy of coronary blood flow were determined depending on the segmentary directionality of bridge obstruction. The data attest to pronounced pathogenetic role of myocardial bridges in sudden cardiac death.     

Posterior right diagonal artery

Background: There is general confusion about a branch of the posterior segment of the right coronary artery that has been referred to as 1) the lower trunk of a divided right coronary artery; 2) a posterior reflection of the right marginal artery; 3) the ramus lateralis; and 4) a posterolateral branch or a posterior descending artery. Materials: Three hundred human hearts were studied by direct observation, X-ray films, and corrosion casting. Results: This branch of the right coronary artery arises either after the right marginal artery (in 84% of hearts) or it constitutes the continuation of this artery in the remaining 16%. We named it the posterior right diagonal artery (PRDA). It was found in 14% of 266 hearts of right dominant type. It was present in 39% when the length of the posterior descending artery (PDA) was shorter than half of the length of the posterior interventricular sulcus (PIS) and in 6% when it was longer. When the PRDA originated directly from the RCA, the RMA appeared underdeveloped; the PRDA always occupied the inferior part of the PIS and appears either as continuation of a short PDA or as a replacement for a long PDA from the point where this artery leaves the PIS to enter the posterior wall of the left ventricle. The PDRA when present serves as a bridge between the RCA and the left anterior descending artery. Conclusions: These findings are of practical importance for the correct interpretation of coronary arteriographies and in the field of coronary artery surgery. © 1994 Wiley-Liss, Inc.     

The Third Branch of the Main Trunk of the Left Coronary Artery in Cercopithecus aethiops sabaeus. Is the Nonhuman Primate Model Appropriate?

The aim of this study was to investigate the morphometry of branching patterns of the main trunk of the left coronary artery (MT of LCA) in nonhuman primates, and comment on the current nomenclature. The biometric study was performed using stereomicroscopic dissection of hearts of healthy and fertile nonhuman primates (Cercopithecus aethiops sabaeus) of both sexes. Our results reveal that the MT of LCA terminates in a bifurcation into the anterior interventricular branch (AIB) and the circumflex branch (CB) (74.6%), trifurcation into the AIB, CB, and diagonal branch (DB) (23.6%), or occasionally quadrifurcation into the AIB, CB, and two DBs (1.8%). This is similar to the case in humans. Furthermore, two morphological aspects of the DB spatial distribution, in addition to its branching pattern, resemble the DB in humans. Myocardial bridges observed over the DB in the Cercopithecus aethiops heart further contribute to the similarity with humans. The resemblance of the DB and its branches to their human counterparts make them a suitable model for experimental study on coronary circulation. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

Changes in the angioarchitectonics of the heart in sudden coronary death

Changes in cardiac angioarchitectonics were studied in 60 cases of sudden coronary death and in 20 controls by means of multiprojection, quantitative coronarography and WHO standard anatomic method. A significant rate (60%) of stenotic atherosclerotic and dilatational (40%) changes was revealed in 3 major coronary arteries. Rearrangement of collateral circulation with the development of myocardial hypervascularization signs was found in 53.3% of cases, with the formation of "new" coronary path ways in 26.7%, and complete bypass blood flow in 20% of cases. Frequent stenoses of the anterior branch of the interventricular septum and sinus node artery were revealed, as well as intramural localization of the anterior interventricular artery due to myocardial muscular bridges, decrease of vascularization density in the left ventricular posterior wall myocardium and septum.     

Anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters (Mesocricetus auratus)

This study describes the coronary artery distribution patterns associated with the anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters. The hearts of 15 affected animals were examined by means of a corrosion-cast technique, histology and scanning electron microscopy. The hamsters belonged to a laboratory inbred colony with a high incidence of coronary artery anomalies and bicuspid aortic valves. The aortic valve was tricuspid in eight hamsters and bicuspid in the other seven. In all cases, the right coronary artery was normal, whereas the left main coronary artery trunk arose from the right aortic sinus or from the right side of the ventral aortic sinus when the aortic valve was bicuspid. In 12 specimens, the left main trunk crossed the infundibular septum and then divided into the left circumflex branch and the obtuse marginal branch. In another specimen, the course of the left main trunk was ventral to the right ventricular outflow tract; in the remaining two, it surrounded the aorta dorsally. In man, some of these distribution patterns may cause myocardial ischaemia and sudden death. The present findings prove that the origin of the left coronary artery from the right aortic sinus occurs in primitive mammals such as the Syrian hamster, suggesting that the defect may occur in other mammalian species. Its possible occurrence should be borne in mind in domestic animals, especially in those with signs of myocardial ischaemia after strenuous activity.     

Terminal branching pattern of the right coronary artery in left-dominant hearts: a cadaveric study

BackgroundLeft coronary dominance has been reported to be associated with increased mortality and severity in case of myocardial ischemia involving left coronary artery. The present cadaveric study was proposed to objectively study and document the termination and branching pattern of the right coronary artery in left-coronary-dominant hearts in relation to the blood supply to the posterior surface of the right ventricle.MethodsSeventy-five cadaveric hearts were studied. The coronary vessels were injected with colored cellulose acetate butyrate and dissected. The coronary dominance was determined. In left-dominant hearts, branches and termination of the right coronary artery were studied.ResultsLeft coronary dominance was found in 13% of the specimens. The number of ventricular branches was found to be present as 0, 1, 2, and 4 in two, four, two, and two of the cases, respectively. The average length of the ventricular branch was 12.7 mm with a range of 5–35 mm. The atrial branch was found in 50% of hearts, varying from 2 to 3 mm in length. In three hearts, the acute marginal artery did not give any posterior ventricular branch, while two, three, and five posterior ventricular branches were seen in four, two, and one heart(s), respectively. The length of the posterior ventricular arteries was between 5 and 15 mm.ConclusionThe RCA is an inconstant and unreliable source of posterior right ventricular perfusion in a significant percentage of population with left-coronary-dominant hearts. This might be the reason for the increased morbidity and mortality seen in the event of left coronary ischemia.     

Anatomical study of a left single coronary artery with special reference to the various distribution patterns of bilateral coronary arteries

A left single coronary artery of heart was observed during anatomy practice at Kumamoto University School of Medicine in a 73-year-old female cadaver who died from a thalamic hemorrhage. The left single coronary artery, having a single orifice in the left aortic sinus, bifurcated into the anterior interventricular (IVa) and circumflex (CIR) arteries. No orifice of the right coronary artery was found on the aortic wall. Giving off a branch which traversed the upper part of the infundibulum to supply the anterior upper region of the right ventricle, the IVa descended in the anterior interventricular sulcus to supply the apex of the heart. The CIR curved leftwards in the atrioventricular sulcus to reach the posterior surface, after which it continued to emerge again into the anterior surface. The atrial arteries showed no anomalous distribution pattern and histological observation revealed no pathological abnormality other than a slightly thickened tunica intima. Furthermore, we observed the distribution patterns of bilateral coronary arteries in 377 hearts dissected during anatomical practice over 13 years at Kanazawa University (1980–1986) and Kumamoto University (1993–1998). Although the reason why only the right coronary artery was absent is left unexplained, it was concluded that the left single coronary artery in this study, having the developed left conal and circumflex branches, was an extreme case of the left dominant series of coronary arteries. The formation of single coronary arteries can be explained embryologically by the change of flow in the capillary plexus established on the ventricle wall.     

心第3冠状动脉的解剖学

目的:研究心第3冠状动脉的大体解剖学数据,为临床诊治相关疾病提供依据。方法:共收集了118个福尔马林固定的心,观测心第3冠状动脉数量、来源、分布范围、营养区域和长度及管径等解剖学数据。结果:第3冠状动脉出现率为28.8%,其中单支出现率为26.3%,双支出现率为2.5%。它通常分布于动脉圆锥、右心室前壁、室间隔及心尖中的1个或多个位置,也有些少见情况:第3冠状动脉比右冠状动脉大并结束于心尖;第3冠状动脉比右冠状动脉小且结束于心尖;心肌桥覆盖较大的第3冠状动脉。结论:心存在第3冠状动脉情况较多,它与左冠状动脉前降支吻合且分布于心尖和室间隔。因此第3冠状动脉是在疾病诊疗期间需要着重考虑的一个因素。     

Anatomy of the coronary arteries in fetal pigs: comparison with human anatomy

In this study, 94 fetal pigs were used to comprehensively investigate the origins, number, location, and distribution of the coronary arteries to enrich knowledge on the coronary circulation in fetal pigs, and allow comparison with adult pigs and humans. In fetal pigs, the posterior interventricular sulcus branch always arose from the right coronary artery and the circumflex artery was rarely extended to the posterior interventricular sulcus, while it is variable in humans. In fetal pigs, there was sometimes anastomosis (8.5%) between the left and right conus branches as nutrient arteries of the pulmonary cone. Other branches were not significantly different between fetal pigs and humans, including the acute marginal branch, obtuse marginal branch, and sinoatrial nodal artery. Coronary dominance was also similar. In conclusion, compared with adult pigs, dissection of the coronary arteries in fetal pigs provided a more faithful overview of the porcine coronary circulation. The coronary arteries in fetal pigs were also more suitable for comparison with humans when pigs are used as experimental animals for studying the coronary vessels, which could be an important reference for investigation of clinical treatment of the coronary arteries. In summary, our data provide reliable information about the distribution and ramifications of the coronary arteries, and could be useful for clinicians and surgeons who wish to comprehensively understand coronary anatomy.     

Observation of root variations in human coronary arteries

In dissection courses conducted from 1999 through to 2003, five specimens were found to have coronary arteries with variant roots and branches, as follows: in specimens 1-4, roots of the right coronary artery (RCA) and right conus branch arose independently from the right aortic sinus (RAS); in specimen 5, the RCA and left coronary artery (LCA) originated from the RAS. The LCA pierced the upper part of the muscular interventricular septum and appeared on the surface, then dividing into the anterior interventricular and the circumflex branches. In the present study, we considered that the right conus arteries in specimens 1-4 were the remnant blood capillaries around the aorta towards the RAS in the embryonic stage. In specimen 5, the vessel near the left aortic sinus was poorly developed as a small thin artery. Instead, the LCA was developed from the anterior and posterior interventricular septal branches.     

Intersection patterns of human coronary veins and arteries

Intersections between the coronary veins (CV) and arteries (CA) of 103 adult human hearts were mapped on the heart surface. Then the correlations of these intersection patterns to their localization were studied. Eight spots were selected where one of four major CV (anterior cardiac vein, middle cardiac vein, left posterior ventricular vein, and great cardiac vein) intersected with one of CA and their branches (right coronary artery, posterior interventricular branch, left posterior ventricular branch, circumflex branch, diagonal branch, and anterior interventricular branch). The great cardiac vein (GCV) ran beneath the anterior interventricular branch in 56 specimens out of 103, beneath the diagonal branch in 75 specimens out of 103, and beneath the circumflex branch in 36 specimens out of 103, while the other CV mostly ran over CA. The present observations suggest that the CV on the right side may be formed prior to CA, while the CV on the left side may be formed simultaneously with CA.     

A Study of Coronary Dominance in the Population of Assam

With the ever increasing load of coronary heart disease, an in-depth study of the coronary arteries has been felt by the medical fraternity. Coronary arteries show wide variations among different populations. These region based variations have not been dealt with enough in the standard books. The knowledge of these variations are of paramount importance when considering various surgical interventions. This study therefore aims to focus on the pattern of coronary dominance in Assam which is ethnically unique from the rest of India. Seventy cadaveric hearts were studied. The population under study included the population of Assam. The coronary arteries were examined by gross dissection and analyzed statistically. The modes of termination of the right coronary artery and the circumflex artery were described with the help of five points: at the right border, between the right border and the crux, at the crux, between the crux and the left border and at the left border. Origin of the posterior interventricular artery was taken as the basis of dominance. Right dominance was found in 70%, left dominance was found in 18.57% while balanced pattern was observed in 11.43% hearts. The results of the study were compared with other authors and variations were noted.     

Functional dominance of the right coronary artery: Incidence in the human heart

After injection of radiopaque medium, 200 human hearts were studied by direct observation and x-ray analysis. The right coronary artery (RC) was dominant in 178 of these hearts as characterized by giving off the typical posterior interventricular artery (PIV), the posterior descending artery. Within this group, 19 specimens had right coronary arteries that gave off both a large posterior interventricular artery (LPIV) and a branch that continued beyond the crux termed a large extension of the right coronary (LERC). The subgroup of hearts supplied thusly was termed real right dominant (RRD). The RC in these hearts supplied the right ventricle and almost half of the left ventricle. These findings explain why proximal lesions of the RC in RRD hearts can be associated with extensive posterolateral ischemia and mitral dysfunction and should be of practical importance when considering angioplasty or by-pass surgery. The diameters and lengths of the arteries of the RC in RRD hearts were measured and compared with the same parameters in typical right dominant hearts. © 1996 Wiley-Liss, Inc.     

Investigation of coronary arteries in the porcupine (Hystrix cristata) by latex injection and angiography

Coronary arteries were investigated in the porcupine by means of angiography performed on each of 5 adult porcupines (3 male, 2 female) which was followed by injection of a colored latex mixture from the aortic arch for the demonstration of these arteries. The results showed that the aorta branched out at the level of the cardiac outlet to form the left and right coronary arteries and right ramus coni arteriosi. Coronary arteries coursed and ramified in the myocardium. The left coronary artery divided to form the paraconal interventricular artery and left circumflex artery when it reached the coronary sulcus. The interventricular septum was vascularized by the septal branch of the paraconal interventricular artery and by the small septal branches. The left and right coronary arteries gave off all the branches reported in the literature for other species. When the ramus coni arteriosi originates from the right coronary artery, it is designated a third coronary artery. In conclusion, it was found that the coronary arteries of the porcupine had an "intramyocardial course" as in other rodents. The coronary supply of the heart represented a "left coronary type" which was similar to those of carnivores and ruminants. The results of this study may contribute to the data in this area of science.