Anomalous origin of the left coronary artery from the pulmonary trunk and its relationship with the morphology of the cardiac semilunar valves in Syrian hamsters

Summary The conditions of the aortic and pulmonary valves and the arrangement in the origin of the coronary arteries were studied in 247 Syrian hamsters belonging to a single family subjected to high endogamous pressure. Most specimens (n=216) were examined using a stereomicroscope. The remaining 31 were studied histologically. In 110 specimens both cardiac semilunar valves were normal. The aortic valve was bicuspid and the pulmonary valve was normal in 79 animals, while a normal aortic valve and a bicuspid pulmonary valve occured in 37. In the remaining 21 specimens both semilunar valves were bicuspid. In 34 cases, the left coronary artery originated from the pulmonary trunk. Statistical analyses indicate that there is no significant relationship between the bicuspid condition of the pulmonary valve and the fact that a coronary artery arises from the pulmonary trunk. On the other hand, they substantiate that the frequency of this coronary artery anomaly significantly increases when the aortic valve is bicuspid. The present findings agree with the hypothesis that abnormal migration of the neural crest cells may be responsible for the combined occurrence of bicuspid aortic valve and anomalous origin of the left coronary artery from the pulmonary trunk. In addition, they suggest that the neural crest cells involved in the formation of the pulmonary valve diverge from those migrating into the aortic valve and those imposing spatial order upon the development of the proximal coronary arteries.     

Origin of the right from the left main coronary artery (single coronary ostium in aorta)

Origin of both the right and left main (LM) coronary arteries from the aortic wall of the right sinus of Valsalva frequently is a lethal anomaly.¹ Origin of both the right and LM coronary arteries from the aortic wall of the left sinus of Valsalva, in contrast, usually is a benign anomaly.² Although many studies have described origin of both LM and right coronary arteries from the aortic wall of the same sinus of Valsalva, few^1,2 have described origin of the right coronary artery from the LM. Husaini et al³ described angiographic features of this anomaly in a 52-year-old man who underwent selective coronary angiography after probable acute myocardial infarction. Muus and McManus⁴ described this anomaly in a fullterm stillborn infant who also had a bicuspid aortic valve. Whether the coronary anomaly played a role in the stillbirth is uncertain. In both of these previously described patients, the anomalously arising right coronary artery coursed between aorta posteriorly and the pulmonary trunk anteriorly.     

Anomalous origin of the right coronary artery from the ascending aorta: case history

A patient is described with an anomalous right coronary artery arising high above the left sinus of Valsalva. This patient is unique because the other 2 cases with such an anomalous origin of a right coronary artery had bicuspid aortic with such an anomalous origin of a right coronary artery had bicuspid aortic valves; this patient had a normal tricuspid aortic valve.     

Anomalous origin and course of the coronary arteries

In the normal heart, the right and left coronary arteries arise from the aortic valvar sinuses adjacent to the pulmonary trunk. The right coronary artery then directly enters the right atrioventricular groove, whereas the main stem of the left coronary artery runs a short course before dividing to become the anterior interventricular and circumflex arteries. These arteries can have an anomalous origin from either the aorta or pulmonary trunk; their branches can have various anomalous origins relative to arterial pedicles. Other abnormal situations include myocardial bridging, abnormal communications, solitary coronary arteries, and duplicated arteries. Understanding of these variations is key to determining those anomalous patterns associated with sudden cardiac death. In the most common variant of an anomalous origin from the pulmonary trunk, the main stem of the left coronary artery arises from the sinus of the pulmonary trunk adjacent to the anticipated left coronary arterial aortic sinus. The artery can, however, arise from a pulmonary artery, or the right coronary artery can have an anomalous pulmonary origin. The key feature in the anomalous aortic origin is the potential for squeezing of the artery, produced by either the so-called intramural origin from the aorta, or the passage of the abnormal artery between the aortic root and the subpulmonary infundibulum.     

Origin of both coronary arteries from the same sinus of valsalva: Report of two cases

Origin of both coronary arteries from the same sinus of Valsalva was found in two patients. In one patient the right coronary artery opened from the left sinus of Valsalva, coursed between the pulmonary artery and aorta, disclosed a 95% obstruction in its proximal third with good runoff. The portion of the artery between the aorta and pulmonary artery showed cyclic narrowing during systole. In the second patient the left coronary opened from the right sinus of Valsalva, the left main trunk crossed anteriorily the pulmonary artery conus, and both the circumflex and the left anterior descending branches showed significant narrowing. In both patients the arteries shared a common sinus with two separate orifices, both had a bicuspid aortic valve, and in both, nonaberrant coronary vessels also had stigmata of atherosclerosis.     

Coronary arterial anatomy in bicuspid aortic valve. Necropsy study of 100 hearts.

In a necropsy study, the conjoined cusps of 50 congenitally and 50 acquired bicuspid aortic valves most commonly involved the right and left aortic cusps. In hearts with congenitally bicuspid aortic valves, the left coronary ostium arose at or above the aortic sinotubular junction in 44 per cent, whereas the incidence for the left coronary ostium in the acquired group was 20 per cent and that for the right coronary ostium in both groups was less than 20 per cent. In hearts with congenitally bicuspid aortic valves, the incidence of left coronary dominance (26%) was higher than in normal hearts. In hearts with apparently acquired bicuspid aortic valves, this incidence was also higher than normal, possibly because of acquired fusion of atypical congenitally bicuspid valves in some cases. In both types of aortic valve disease, the length of the left main coronary artery was similar; this length, however, was significantly shorter in hearts with left coronary dominance than in those with right or shared dominance.     

Bicuspid aortic and pulmonary valves in the Syrian hamster.

We studied the conditions of the aortic and pulmonary valves of 153 Syrian hamsters belonging to a single family subjected to high endogamous pressure. Semilunar valves of 143 specimens were examined using a stereomicroscope, and in 5 of these cases a histologic study was also performed. The remaining 10 specimens were studied by means of scanning electron microscopy. In 77 specimens both semilunar valves were normal. The aortic valve was bicuspid and the pulmonary valve was normal in 46 animals, while a normal aortic valve and a bicuspid pulmonary valve occurred in 24. In the remaining 6 specimens both semilunar valves were bicuspid. All bicuspid semilunar valves detected herein showed the same morphotype, namely with the leaflets oriented ventrodorsally. The incidence of these anomalous valves did not significantly differ between sexes. Results of a chi 2-test substantiate that conditions of both outflow tract semilunar valves are independent traits. Thus, concurrence of a bicuspid aortic valve and a bicuspid pulmonary valve in an individual is a random event. The present findings support the assumption that bicuspid aortic and pulmonary valves have different morphogenetic origin, although factors producing a bicuspid aortic valve and those leading to a bicuspid pulmonary valve are not mutually exclusive.     

Left coronary artery anatomy in patients with bicuspid aortic valves

The anatomy of the proximal left coronary artery in 33 adult patients with bicuspid aortic valves was compared with that in 33 adult patients with aortic valve disease of other aetiologies and with that in 50 adult control patients with no valve or congenital heart disease. Patients with bicuspid aortic valves had a higher incidence of immediate bifurcation of the left main coronary artery, of left main coronary length less than 10 mm, and of left coronary artery dominance. The mean length of the left main coronary artery was significantly less in the patients with bicuspid aortic valves. These variations from the usual coronary artery anatomy may be part of the developmental abnormalities responsible for bicuspid aortic valves, and require evaluation and consideration when considering angiography and valve replacement in patients with aortic stenosis.     

Left coronary artery anatomy in patients with bicuspid aortic valves.

The anatomy of the proximal left coronary artery in 33 adult patients with bicuspid aortic valves was compared with that in 33 adult patients with aortic valve disease of other aetiologies and with that in 50 adult control patients with no valve or congenital heart disease. Patients with bicuspid aortic valves had a higher incidence of immediate bifurcation of the left main coronary artery, of left main coronary length less than 10 mm, and of left coronary artery dominance. The mean length of the left main coronary artery was significantly less in the patients with bicuspid aortic valves. These variations from the usual coronary artery anatomy may be part of the developmental abnormalities responsible for bicuspid aortic valves, and require evaluation and consideration when considering angiography and valve replacement in patients with aortic stenosis.     

Persistent truncus arteriosus: A study of 66 autopsy cases with special reference to definition and morphogenesis

Sixty-six hearts were examined in which a single arterial trunk, leaving the base of the heart through a single semilunar valve, supplied the aorta, pulmonary artery and coronary arteries. Careful attention was paid to the infundibular morphologic features in these hearts, and these were compared with findings in 24 hearts with single aortic trunk, pulmonary atresia and ventricular septal defect. It was concluded that the two anomalies represented morphologically discrete conditions. This was particularly true with regard to the disposition of the infundibular septum, the ventriculo-infundibular fold and the relation of the coronary arteries to the semilunar sinuses. Although it is theoretically possible for a heart with true persistent truncus arteriosus to have absence of the pulmonary trunk and right and left pulmonary arteries, it is argued that such hearts (“truncus type IV”) are best classified as pulmonary atresia with ventricular septal defect. It is also argued that hearts with a common arterial trunk supplied through discrete ventricular outflow tracts and two semilunar valves are best considered examples of aorticopulmonary window. It is suggested that persistent truncus arteriosus is best defined as that condition in which a single arterial trunk leaves the heart through a single semilunar valve and supplies the aorta, one or both pulmonary arteries and the coronary arteries.     

Coronary arteries in truncus arteriosus

The origin and distribution of the coronary arteries was described in 39 autopsy specimens of truncus arteriosus (TA). The specimens were classified according to the number and the patterns of the truncal cusps. The position of the truncal cusps was defined in relation to intracardiac structures, namely, the atrioventricular orifices. Bicuspid truncal valves were observed in 8 cases (21%), tricuspid in 22 cases (56%) and quadricuspid in 9 cases (23%). All tricuspid valves had 2 anterior and 1 posterior cusp. Great variability in the origin of the coronary arteries was observed, with a tendency for the right coronary artery to arise from the anterior right quadrant and for the left coronary artery to arise from the anterior and left quadrant. Such a tendency was observed in 50% of the bicuspid, in 59% of the tricuspid and in 66% of the quadricuspid valves. The anatomic right ventricle was always observed to be vascularized by a right coronary artery, and the anatomic left ventricle by a left coronary artery, even in cases in which there was a single coronary trunk. The anterior surface of the right ventricle was crossed by a right coronary artery in 5 cases. A single coronary artery was observed in 7 cases (18%). Embryologic considerations are offered, especially regarding the relation between the observed variability in coronary artery patterns in TA and the absence of the truncal septation.     

Anomalous origin of the left coronary artery at the pulmonary trunk and its relationship with other primary coronary anomalies: experimental study

The origin and course of the coronary arteries were studied in 1,436 Syrian hamsters belonging to 10 breeding colonies subjected to high endogamous pressure by mating either animals of the same litter or first cousins. The study was carried out using a corrosion casting technique. A left coronary artery originating from the pulmonary trunk was found in 48 specimens of the series. In all cases anastomoses had developed between the right and left coronary systems. Moreover, five types of minor primary anomalies of the coronary arteries occurred in 144 hamsters. These findings agree with the morphogenetic hypothesis that each of the aortic and pulmonary sinuses has the potential to develop coronary arteries. Familial recurrence risks for coronary arterial anomalies were estimated taking into account the sex and the inbreeding coefficient of the probands carrying a left coronary artery from the pulmonary trunk. The recurrence risks increase as the inbreeding level increases, this suggesting that the whole primary coronary anomalies are a phenotypic set subordinated to a complex mode of inheritance. Therefore, an echocardiographic study of the first degree relatives of patients with coronary arterial anomalies is advisable to diagnose clinically silent coronary malformations.     

Persistent common trunk. Anatamopathological study of 25 specimen]

In order to inform the pathologic features and their associated anomalies twenty five hearts with common trunk were studied with the segmental sequential system. An anatomico-embryological correlation was made to understand the pathological complex of this malformation. The results were: type I truncus (96%), infundibular ventricular septal defect (96%), displastic truncal valve (28%), ventriculo infundibular fold (92%), left coronary artery arising from the posterior wall of the truncus (75%), right coronary artery arising from their anterior wall (96%), coronary arteries arising from opposite Valsalva sinuses in the tetracuspid valves; the biventricular conection of the truncus was balanced in 60%, prevailing on the right (16%) or on the left (16%) ventricles. Among the associated anomalies there were right aortic arch, interruption of the aortic arch, anomalous origin of the left subclavian artery, vascular ring, aneurysm of the sinus of Valsalva, and absence of the left branch of the pulmonary artery. Developmentally common trunk is explained as a failure of truncoconal septation in the embryonic heart; a migration arrest of neural crest cells is implicated in the Di George syndrome. Knowledge of the anatomic features of common trunk and their associated anomalies, provides the morphological basis to interpret correctly the clinical diagnostic imagenology.     

Anomalous origin of the left anterior descending artery from the pulmonary artery associated with bicuspid aortic valve and aortic coarctation

A 15-year-old boy presented with exertional palpitations and chest pain. Investigation revealed anomalous origin of his left anterior descending coronary artery from his pulmonary trunk causing myocardial ischaemia. He previously had aortic coarctation repair with known aortic root dilation and a bicuspid aortic valve. His left anterior descending artery was implanted into the aortic root using a Gortex interposition conduit. This represents an interesting combination of cardiac abnormalities for which repair required consideration of the requirement of further surgery in the future.     

Anomalous aortic origin of a coronary artery: a universally applicable surgical strategy

The most commonly reported coronary arterial malformation, in accounts of sudden deaths, is anomalous aortic origin of a coronary artery. Anomalous coronary arteries may arise from the left, right, or non-coronary sinuses of Valsalva. Importantly, although the left coronary artery from the right sinus has the worst prognosis, sudden death has been reported in all variants of origin from the various sinuses of Valsalva. This paper describes a technique that addresses all of the problems relating to anomalous aortic origin of a coronary artery from the wrong sinus of Valsalva. This technique includes the transection of the ascending aorta and pulmonary trunk, coronary arterial enlargement with a pericardial patch, and lateral translocation of the pulmonary trunk to the left pulmonary artery. Anomalous aortic origin of a coronary artery from the wrong sinus of Valsalva is a potentially lethal cardiac anomaly that can be corrected in all cases using this simplified surgical technique that addresses the major anatomic and physiological problems.     

Anomalous origin of the right coronary artery from the ascending aorta above the left coronary sinus

Ectopic origin of the right coronary artery is an infrequent anomaly. We report a case in which the right coronary artery arose from the ascending aorta above the left sinus. This anomaly was associated with a bicuspid aortic valve. Techniques for delineation of the ectopic origin of the right coronary artery are discussed.     

Identification, imaging, functional assessment and management of congenital coronary arterial abnormalities in children

The coronary arteries, the vessels through which both substrate and oxygen are provided to the cardiac muscle, normally arise from paired stems, right and left, each arising from a separate and distinct sinus of the aortic valve. The right coronary artery runs through the right atrioventricular groove, terminating in the majority of instances in the inferior interventricular groove. The main stem of the left coronary artery bifurcates into the anterior descending, or interventricular, and the circumflex branches. Origin of the anterior descending and circumflex arteries from separate orifices from the left sinus of Valsalva occurs in about 1% of the population, while it is also frequent to find the infundibular artery arising as a separate branch from the right sinus of Valsalva. Anomalies of the coronary arteries can result from rudimentary persistence of an embryologic coronary arterial structure, failure of normal development or normal atrophy as part of development, or misplacement of connection of a an otherwise normal coronary artery. Anomalies, therefore, can be summarized in terms of abnormal origin or course, abnormal number of coronary arteries, lack of patency of the orifice of coronary artery, or abnormal connections of the arteries. Anomalous origin of the left coronary artery from the pulmonary trunk occurs with an incidence of approximately 1 in 300,000 children. The degree of left ventricular dysfunction produced likely relates to the development of collateral vessels that arise from the right coronary artery, and provide flow into the left system. Anomalous origin of either the right or the left coronary artery from the opposite sinus of Valsalva can be relatively innocuous, but if the anomalous artery takes an interarterial course between the pulmonary trunk and the aorta, this can underlie sudden death, almost invariably during or immediately following strenuous exercise or competitive sporting events. Distal anomalies of the coronary arteries most commonly involve abnormal connections, or fistulas, between the right or left coronary arterial systems and a chamber or vessel. We discuss the current techniques available for imaging these various lesions, along with their functional assessment, concluding with a summary of current strategies for management.     

Impact of Bicuspid Aortic Valve on Complications and Death in Infective Endocarditis of Native Aortic Valves

We retrospectively investigated the impact of bicuspid aortic valve on the prognosis of patients who had definite infective endocarditis of the native aortic valve.Of 51 patients, a bicuspid aortic valve was present in 22 (43%); the other 29 had tricuspid aortic valves. On average, the patients who had bicuspid valves were younger than those who had tricuspid valves. Patients with a tricuspid valve had larger left atrial diameters and were more likely to have severe mitral regurgitation.Periannular complications, which we detected in 19 patients (37%), were much more common in the patients who had a bicuspid valve (64% vs 17%, P = 0.001). The presence of a bicuspid valve was the only significant independent predictor of periannular complications. The in-hospital mortality rate in the bicuspid group was lower than that in the tricuspid group; however, this figure did not reach statistical significance (9% vs 24%, P = 0.15). In multivariate analysis, left atrial diameter was the only independent predictor associated with an increased risk of death (hazard ratio, 2.19; 95% confidence interval, 1.1–4.5; P = 0.031).In our study, patients with infective endocarditis in a bicuspid aortic valve were younger and had a higher incidence of periannular complications. Although a worse prognosis has been reported previously, we found that infective endocarditis in a native bicuspid aortic valve is not likely to increase the risk of death in comparison with infective endocarditis in native tricuspid aortic valves.Key words: Aortic valve/abnormalities/pathology/ultrasonography, aortic valve insufficiency/classification/diagnosis, echocardiography/methods, endocarditis, bacterial/complications/mortality/pathology/ultrasonography, heart defects/congenital, heart diseases/complications, heart valve diseases/classification/complications/congenital/pathology, hospital mortality, retrospective studies, risk factorsBicuspid aortic valve is the most common congenital cardiac malformation, affecting 1% to 2% of the population.¹ The incidence of infective endocarditis (IE) in the bicuspid aortic valve population ranges from 10% to 30%. Twenty-five percent of IE cases occur in a bicuspid aortic valve.^2,3Few data exist about IE in persons who have a bicuspid aortic valve, in contrast with the large amount of data involving other IE populations. Risk stratification is an important objective in the evaluation of patients who have IE, especially IE of the aortic valve. In patients with IE of the native valve, acute heart failure occurs more frequently in association with aortic valve infection (29%) than mitral valve infection (20%).⁴ In view of these factors, we sought to evaluate the impact of bicuspid aortic valve on complications and death related to IE that occurs in a native aortic valve.     

Effect of dopamine on regional myocardial function and oxygen consumption in experimental left ventricular hypertrophy

Summary We investigated the hypothesis that the capacity of left ventricular myocardium to respond to an inotropic challenge by dopamine would be diminished in left ventricular hypertrophy induced by plication of the aortic valve. Seven mongrel dogs (LVH group) aged 6–8 weeks and weighing 4–6 kg, were subjected to preliminary surgery in which the noncoronary sinus of Valsalva was plicated. Six months later these animals, as well as a control group of dogs, were subjected to acute experiments in which the effect of dopamine (7.5 and 15 g/kg/min) on regional and global myocardial function and oxygen consumption was studied. Myocardial segment length was measured with ultrasonic dimension transducers, and left ventricular and aortic blood pressures were recorded from catheter-tip transducers. Regional coronary blood flow was determined with radioactive microspheres, and regional oxygen saturation in small arteries and veins was measured using microspectrophotometry. Regional myocardial O₂ consumption was calculated from these parameters. Heart weights were significantly elevated in the LVH group, and a pressure gradient of about 25 mm Hg was observed across the aortic valve. In both groups, dopamine infusion produced a dose-dependent increase in heart rate, left ventricular pressure, and LV dP/dt_max. Prior to dopamine infusion, percent shortening per beat was greater in the LVH group (13.97 ± 1.2 %) than in the control group (9.49 ± 1.07 %). Although the maximum speed of segment shortening was elevated by dopamine in both groups, percent shortening was not elevated in the LVH group. Stimulation by the high dose of dopamine produced a threefold elevation in regional coronary blood flow in both groups. Oxygen extraction was unchanged; the proportion of small veins with low O₂ saturation was not elevated in LVH hearts, even during dopamine stimulation. Regional myocardial O₂ consumption was elevated by dopamine (15 g/kg/min) to about the same extent in both the control and LVH groups (19.1 ± 2.3 and 17.5 ± 2.3 ml O₂/min/100 g) respectively. It is concluded that, in dogs with six months of aortic stenosis, dopamine does not exhaust functional reserve and the relationship between O₂ supply and consumption is not significantly impaired.This study was supported in part by PHS research grant HL40320     

Transcatheter Aortic Valve Implantation through a Left Aortoiliac Graft

The indications for transcatheter aortic valve implantation have been increasing with the development of new-generation valves and delivery systems. Our patient, an 81-year-old man with aortic stenosis, had an existing coronary artery bypass graft and bilateral aortoiliac bypass grafts. We used the transfemoral approach through the left femoral artery and the left aortoiliac graft to successfully deploy a new-generation Edwards SAPIEN valve.Key words: Aortic stenosis, arterial disease, peripheral, heart valve prosthesis implantation/methods, transcatheter aortic valve implantationTranscatheter aortic valve implantation (TAVI) has emerged as a promising alternative to conventional aortic valve replacement for patients whose severe, symptomatic aortic stenosis is otherwise left untreated due to comorbidities and to the high operative mortality rates associated with open-heart surgery under those circumstances.¹ The first application of this method in human beings was performed in 2002 by Cribier and colleagues.² Today, there are 2 widely used valve types. These are the balloon-expandable Edwards SAPIEN transcatheter valves (Edwards Lifesciences LLC; Irvine, Calif) and the self-expanding CoreValve® valves (Medtronic CV Luxembourg S.a.r.l.; Luxembourg). The first-generation Edwards SAPIEN valve is approved for use in the United States, but the latest generations of both valves are awaiting approval.