An unusual case of aorta-right atrial tunnel with windsock aneurysm: imaging, diagnosis and treatment.

The first successfully diagnosed and treated case of aorta-right atrial tunnel was reported by Coto et al. in 1980. The most common cause of aorta-right atrial tunnel is a ruptured aneurysm of the sinus of Valsalva. Sinus of Valsalva aneurysms had been reported as early as 1840 by Thurnam; these were diagnosed at autopsy. With the advances in radiology, many cases of aorta-right atrial tunnel have been reported since then, each with its own subtle variations. We report on a unique case of aorta-right atrial tunnel with a windsock aneurysm in the right atrium. A 55-year-old male presented with abdominal pain and the chest X-ray revealed cardiomegaly. On further investigation with echocardiography and computed tomography angiography, there was an incidental aorta-right atrial tunnel with a windsock aneurysm in the right atrium. He was treated successfully with surgery. A similar case has been reported only once before by Iyisoy et al. in 2014.

Coronary arterial development: a review of normal and congenitally anomalous patterns.

Coronary artery development is a delicate, complex, and finely tuned process that includes multiple interactions among many pathways, especially in the pericardium and the developing myocardium. There still exists some controversy on the exact origin of certain cellular components. Nevertheless, an understanding of this extremely important developmental process is paramount in identifying some of the causes of anomalous coronary development. There are different patterns of anomalous coronary arteries, with variable risk of myocardial ischemia, malignant arrhythmias, and sudden cardiac death. These anomalies can be broadly categorized into 2 basic anatomic subsets: those with origin of the anomalous coronary artery from the opposite aortic sinus, and those with origin of the anomalous coronary artery from the pulmonary artery. Diagnosis and management of such patterns continues to be challenging. A good knowledge of the normal and abnormal coronary artery development could potentially help us explore new avenues in the treatment of ischemic heart disease as well as anomalous coronary arteries.

Coronary artery anomalies Part II: recent insights from clinical investigations.

Congenital anomalies of the coronary arteries occur in 0.2-1.2% of the general population; they cause 12% of sports-related sudden cardiac deaths and 1.2% of non-sports-related deaths. We review some of the substantial advances that have been made both, in the understanding of the embryonic development of the coronary arteries and in the clinical diagnosis and management of their anomalies. In this second part of our review we elucidate recent approaches to defining coronary anomalies and provide information on their incidence and prognosis. In addition, we discuss the options for screening large populations for potentially lethal coronary malformations and elucidate the role of invasive diagnostic modalities such as intravascular ultrasound, flow wire and pressure wire. The clinical relevance of coronary anomalies is discussed particularly for the ill-defined group of anomalies that only occasionally cause severe clinical events comprising anomalous origination of a coronary artery from the opposite sinus (ACAOS), coronary artery fistulae and myocardial bridging. Finally, we provide an update on current diagnostic and therapeutic recommendations.

Development of proximal coronary arteries in quail embryonic heart: multiple capillaries penetrating the aortic sinus fuse to form main coronary trunk.

Studies have shown that the proximal coronary artery (PCA) develops via endothelial ingrowth from the peritruncal ring (PR) of the coronary vasculature. However, the details of PCA formation remain unclear. We examined the development of PCAs in quail embryonic hearts from 5 to 9 days of incubation (embryonic day [ED]) using double-immunostaining for QH1 (quail endothelial marker) and smooth muscle alpha-actin. At 6 to 7 ED, several QH1-positive endothelial strands from the PR penetrated the facing sinuses, and in some embryos, several endothelial strands penetrated the posterior (noncoronary) sinus. At 7 to 8 ED, the endothelial strands penetrating the facing sinuses seemed to fuse, forming a proximal coronary stem that was demarcated from the aortic wall by the nascent smooth muscle layer of the coronary artery. By 9 ED, two coronary stems were completely formed, and the endothelial strands previously penetrating the noncoronary sinus had disappeared. Confocal microscopy at 6 ED revealed discontinuous QH1-positive endothelial progenitors in the aortic wall at sites where the endothelial strands would later develop. Observations demonstrate that during the formation of the PCA, endothelial strands from the PR penetrate the facing sinuses and then fuse, whereas those strands penetrating the noncoronary sinus disappear. Thereafter, the coronary artery tunica media demarcates the definitive PCA from the aortic media.

Baroreceptor and prostanoid control of fetal renal cortical blood flow and plasma renin activity.

Renal function in the fetus is important for maintenance of fetal fluid and electrolyte balance. This study was performed to test the role of prostaglandins and their interaction with arterial baroreceptors and chemoreceptors in the control of renal cortical blood flow during hypotension produced by vena caval obstruction in late-gestation fetal sheep. We studied 18 time-dated, chronically catheterized, fetal sheep (124-136 days gestation). Fetuses were either studied intact (n = 11) or sinoaortic denervated (n = 7), and each fetus was studied twice, with and without pretreatment with indomethacin (0.2 mg kg(-1), i.v.). Each fetus was subjected to hypotension caused by vena caval obstruction for 10 min. Before hypotension, renal cortical blood flow was higher in the vehicle-treated sinoaortic denervated fetuses than in vehicle-treated intact fetuses. The increased renal cortical blood flow observed in the sinoaortic denervated fetuses was counteracted by indomethacin, so that the difference between sinoaortic denervated and intact fetuses was eliminated after indomethacin treatment. Hypotension decreased renal blood flow equally in all groups. Plasma renin activity was increased in response to hypotension in the intact fetuses, but not in the sinoaortic denervated fetuses. Indomethacin treatment, by itself, did not alter plasma renin activity. It is concluded that both arterial baroreceptors and prostanoids influence renal blood flow. Further, renin secretion is influenced by arterial baroreceptors and chemoreceptors and there is no apparent modulatory effect of prostanoids on the baroreflex control of renin secretion.

Association of the cardiac neural crest with development of the coronary arteries in the chick embryo.

BACKGROUND: Chick coronary arteries originate as penetrating channels from a subepithelial peritruncal ring into the wall of all three aortic coronary sinuses. Two of these capillaries develop a muscular wall and become the definitive coronary arteries. Since cardiac neural crest (CNC) contributes ectomesenchyme to the tunica media (TM) of the aortic arch vessels, we wished to learn if the CNC also contributes to the media of the coronary arteries and if CNC plays an inductive role in determining the site of aortic penetrations and influences which channels persist to hatching. METHODS: Quail-to-chick chimeras were made by bilaterally removing the chick CNC and replacing it with quail CNC. The chimeras and unoperated controls were collected on embryonic days (ED) 7-18, fixed in Carnoy's fixative, serially sectioned, stained with Feulgen-Rossenbeck stain, and analyzed. Several ED 18 controls and chimeras were also stained with Gomori's trichrome stain, or labeled with antineurofilament or antivascular smooth muscle alpha actin. RESULTS: The TM of the coronary arteries and the aortic coronary sinuses did not consist of CNC cells. The media of the surviving coronary arteries was disrupted by clusters of CNC cells scattered in the wall of the base of the coronary artery on ED 14 and 18. Persisting coronary arteries were always associated with large neural crest-derived parasympathetic ganglia near their origin. Branches from parasympathetic nerves entered the base of the coronary arteries where the clusters of neural crest cells were located. Quail cells were also associated with tiny vessels exiting the ostia of the coronary arteries and traveling in the outer aortic wall. Labeling with antibodies confirmed a disruption of the TM at the base of the coronary arteries, and showed innervated clusters of quail cells in the disrupted part of the TM. CONCLUSION: Although the TM of the coronary arteries and the aortic coronary sinuses contained no CNC cells, clusters of innervated quail cells disrupted the TM at the base of the coronary arteries. CNC does not appear to induce capillary penetration directly; however, the exclusive association of CNC-derived parasympathetic ganglia and nerves with persisting coronary arteries suggests that the presence of parasympathetic ganglia is essential to the survival of the definitive coronary arteries. CNC cells may also be associated with the development of the aortic vasa vasorum.

Development of the coronary arteries in staged human embryos (the Paris Embryological Collection revisited).

Twenty seven human embryos from stages 15 to 23 (postsomitic period), belonging to the collection of the "UFR Biomédicale des Saints-Pères, Université René Descartes Paris V", were studied. Details of the aorticopulmonary cleavage were analysed specially aortic valve development and origin of the coronary artery. At stage 18 the aortic valve was clearly distinguished (cup-shaped) presenting semilunar valves and aortic sinus (Valsalvae); at this stage the left coronary artery was detected in 66.7 per cent of the cases as an endothelial epicardial invagination. At stage 19, the left and right coronary arteries were detected simultaneously in 100 per cent of the cases. At stage 20, the coronary arteries showed greater structural complexity with a coat of mesenchymal cells. These results agree with previous data from different embryological collections. These findings suggest that the left coronary artery has a tendency to develop earlier than the right. We found no evidence of the coronary origin from the aortic lumen. This work provides additional information about the embryological development of the heart, obtained from the analyses of a French collection of human embryos.

Development of the coronary arteries in staged human embryos: the Paris embryological collection revisited

Twenty seven human embryos from stages 15 to 23 (postsomitic period), belonging to the collection of the "UFR Biomédicale des Saints-Peres, Université René Descartes Paris V", were studied. Details of the aorticopulmonary cleavage were analysed specially aortic valve development and origin of the coronary artery. At stage 18 the aortic valve was clearly distinguished (cup-shaped) presenting semilunar valves and aortic sinus (Valsalvae); at this stage the left coronary artery was detected in 66.7 per cent of the cases as an endothelial epicardial invagination. At stage 19, the left and right coronary arteries were detected simultaneously in 100 per cent of the cases. At stage 20, the coronary arteries showed greater structural complexity with a coat of mesenchymal cells. These results agree with previous data from different embryological collections. These findings suggest that the left coronary artery has a tendency to develop earlier than the right. We found no evidence of the coronary origin from the aortic umen. This work provides additional information about the embryological development of the heart, obtained from the analyses of a French collection of human embryos

Development of the coronary arteries in the embryonic human heart.

It is not known why the coronary arteries almost always originate only from the right and left aortic sinuses of Valsalva, since the structure and conditions appear to be the same for all six sinuses of the embryonic great arteries. We sought a possible mechanical explanation for the phenomenon by studying the development of the coronary vasculature in 351 staged, serially sectioned human embryos of Carnegie stages 9 through 23 from the Carnegie Embryological Collection. A plexus of blind epicardial capillaries appears on the heart in Carnegie stage 14 or 15 and acquires a coronary sinus connection in stage 15, 16, or 17. The connection of the proximal coronary arteries to the aorta does not appear until stage 18. We found no histologic features of the cardiac nerves or any other component of the tissues to account for the consistent origin of coronary arteries from the right and left aortic sinuses of Valsalva. However, serial section reconstructions showed that the two sinuses where coronary arteries develop acquire a positive transverse curvature and a negative longitudinal curvature, i.e., a catenoidal or saddle-shaped configuration, before the appearance of the coronary arteries. The four noncoronary sinuses also have a positive transverse curvature, but longitudinally, in contrast, they have a positive curvature or are straight. The results suggest that the coronary arteries originate from those sinuses of Valsalva where wall tension is increased by a catenoidal configuration.

Formation of coronary arteries sprouting from the primitive aortic sinus wall of the chick embryo.

The formation of coronary arteries in chick embryos was observed by scanning electron microscopy on injected casts as well as by transmission electron microscopy. Usually, 2-4 primitive coronary arteries appear from the right aortic sinus below the level of the cusp margin, and 1-3 from the left one. As development proceeds, the arteries are generally reduced in number to form a single definitive coronary artery on each side. Canalization of the arteries seems to take place by partially degenerative changes of the primordia.

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.

The effect of blood flow on the surface morphology of the human endothelium.

The endothelial lining from the aortae of three 17 week human fetuses was examined by scanning electron microscopy. Orientation of the endothelial cells, particularly in the region above the aortic valve, was related to known flow patterns. Endothelial morphology showed regional variation noticeably at the mouths of arteries and at the aortic bifurcation. The possibility that this morphological change may be a hitherto unrecognised risk factor related to the site of atheromatous deposition is discussed.