Common Atrioventricular Junction Research Articles

Diagnosis and surgical treatment for complete atrioventricular septal defect with intact atrial septum.

A six-month-old boy with Down syndrome, complete atrioventricular septal defect with intact atrial septum, and moderate left-sided atrioventricular valve regurgitation underwent surgery. The presence of a common atrioventricular junction could not be diagnosed preoperatively. Postoperative left-sided atrioventricular valve regurgitation remained mild by complete cleft closure, direct closure of incised atrial septum, and patch augmentation of the underside of septum primum.

Defining the Spectrum of Hypoplastic Left Heart Syndrome (HLHS).

The 2021 International Paediatric and Congenital Cardiac Code and the Eleventh Revision of the International Classification of Diseases provide the following definition for hypoplastic left heart syndrome (HLHS): "Hypoplastic left heart syndrome (HLHS) is defined as a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch." Although HLHS with intact ventricular septum (HLHS + IVS) and HLHS with ventricular septal defect (HLHS + VSD) are different cardiac phenotypes, both of these lesions are part of the spectrum of HLHS.

Hypoplastic Left Ventricle: Hypoplastic Left Heart Complex.

Hypoplastic left heart syndrome (HLHS) without intrinsic valvar stenosis or atresia is synonymous with the term hypoplastic left heart complex (HLHC) and is defined as a cardiac malformation at the milder end of the spectrum of HLHS with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle and hypoplasia of the aortic or mitral valve, or both valves, in the absence of intrinsic valvar stenosis or atresia, and with hypoplasia of the ascending aorta and aortic arch. This article describes the definitions, nomenclature, and classification of HLHC; the indications and contraindications for biventricular repair of HLHC; the surgical treatment of HLHC; and the associated outcomes.

Hypoplastic Left Heart Syndrome: Definition, Morphology, and Classification.

This manuscript will provide information about hypoplastic left heart syndrome (HLHS) and related malformations, including definitions, morphology, and classification, based on the 2021 International Paediatric and Congenital Cardiac Code (IPCCC) and the Eleventh Revision of the International Classification of Diseases (ICD-11). HLHS is defined as "a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch." Functionally univentricular heart is defined as "a spectrum of congenital cardiac malformations in which the ventricular mass may not readily lend itself to partitioning that commits one ventricular pump to the systemic circulation, and another to the pulmonary circulation." The Norwood operation is synonymous with the term "Norwood (Stage 1)" and is defined as (1) creation of an aortopulmonary connection and neoaortic arch construction resulting in univentricular physiology and (2) creation of a controlled source of pulmonary blood flow with a calibrated systemic-to-pulmonary artery shunt, a right ventricle to pulmonary artery conduit, or rarely, a cavopulmonary connection. The goals of the Norwood (Stage 1) Operation are creation of (1) unobstructed systemic blood flow via aortopulmonary connection and neoaortic arch construction, (2) unobstructed coronary blood flow, (3) unobstructed flow across the atrial septum, and (4) controlled pulmonary blood flow.

Prenatal ultrasound diagnostics of atrioventricular communication in combination with the tetralogy of Fallot in a fetus with Down's syndrome phenotype

This article presents a description of our own case of ultrasound prenatal diagnostics of complex combined heart disease (complete atrioventricular communication in combination with tetralogy of Fallot) at 19–20 weeks of gestation with ultrasound markers of Down's syndrome in fetus. Pregnancy termination was performed at 21 weeks. Prenatal diagnosis was fully confirmed at the fetus autopsy. This publication discusses the frequency, mechanism of occurrence of such a combination of congenital heart defects, prenatal management, methods, timing and efficiency of surgical correction after birth. Complete atrioventricular communication occurs in approximately 1.7–2% patients with tetralogy of Fallot, and tetralogy of Fallot occurs in 5–10% of patients with atrioventricular communication, most often in patients with Down's syndrome. It is believed that tetralogy of Fallot and a complete defect of the atrioventricular septum develop as a result of different mechanisms, but their joint occurrence is recognized as an association. The prevalence of such a combination in Down syndrome indicates the general foundations of its development.Sonographic diagnosis of atrioventricular communication and tetralogy of Fallot is usually not difficult for prenatal screening. Main diagnostic criteria for complete atrioventricular communication at routine ultrasound screening and targeted fetal echocardiography are an abnormal 4-chamber image of the heart in the form of a common atrioventricular junction and a common five-leafed atrioventricular valve. Typical prenatal sonographic signs of the tetralogy of Fallot are a high defect of the interventricular septum, expansion of the aortic root, displacement of the aorta forward and to the right, narrowing of the pulmonary artery at the level of the valve ring from minor to complete atresia, it is also possible reduction the size of the right ventricle and increasing the size of the left ventricle.The combination of atrioventricular communication with the tetralogy of Fallot refers to severe congenital heart defects requiring surgical correction.

Fetal heterotaxy: Should we still categorize?

Heterotaxy (HTX) is usually stratified in right (RI) and left isomerism (LI). We analyzed 61 fetal specimens with HTX divided in 5 groups: classic LI [CLI: bronchopulmonary LI, bilaterally absent pectinate muscles (PM), polysplenia, n = 22], non-classic LI (NCLI: one discordant feature, n = 13), classic RI (CRI: bronchopulmonary RI, bilateral extent of PM to the crux, asplenia, n = 12), non-classic RI (NCRI: one discordant feature, n = 6, totally discordant features, n = 8). Non-classic patterns were found in 44% (33% RI, 37% LI). Among those, the status of the spleen was highly variable (NCLI with asplenia 38%, NCRI with single spleen 66%), while the bronchial status was almost always concordant. Intestinal malrotation was present in 83% CRI, 64% CLI, 50% NCLI, 50% NCRI. Extent of PM was highly variable in NCLI (bilaterally left 46%, normal 46%, bilaterally right 8%), and bilaterally right in 83% of NCRI only. Interrupted inferior caval vein was seen in LI only; total extracardiac anomalous pulmonary venous connection (APVC) was seen only in RI, ipsilateral APVC only in LI. A common atrioventricular (AV) junction was constant in RI vs. 66% in LI, with a complete AV canal in 100% RI, 75% LI. Functionally univentricular hearts were found in 67% RI, 46% LI, right in 62.5%. Ventriculo-arterial (VA) connections were abnormal in 100% RI, 59% LI, double outlet right ventricle (DORV) being the most frequent type in all categories. Pulmonary atresia and stenosis were frequent in RI (77%), rare in LI. Aortic arch hypoplasia and coarctation were found almost exclusively in LI (57%). Right-sided aortic arch was found in 67% RI, 6% LI. HTX and isomerism are not synonymous. Extent of PM is not always symmetrical (15%) and cannot therefore be considered the hallmark of HTX. Because HTX includes both abnormal symmetry and random organization of organs, each anatomic feature should be analysed individually rather than trying to categorize.

"Repair of common atrioventricular junction in isolation and when associated with other congenital heart defects".

Management of atrioventricular septal defects has grown leaps and bounds since the first correction of this malformation. Main reasons considered for the improvement are good understanding of lesion anatomy, precise preoperative diagnosis including imaging, progress in surgical technique, myocardial protection, and post-operative care. In this article we review the anatomy, pathophysiology, clinical features, associations, diagnosis, surgical therapy, complications, and results of atrioventricular septal defects.

Assessment of Atrioventricular Septal Defect on Echocardiography

Atrioventricular septal defect comprise of 1.4-2.9% of congenital cardiac defect and is most common congenital cardiac defect in Trisomy 21. This anomaly is characterized by a common atrioventricular junction coexisting with atrial and/or ventricular septal defect, cleft of left atrioventriocular valve along with left ventricular outflow tract abnormality. Due to cleft of left atrioventricular valve, valve regurgitation is almost invariably present leading to early onset of congestive cardiac failure in these patients. Other associated structural heart defects are pulmonary stenosis, ductal arteriosus, aortic arch anomalies, pulmonary and systemic venous anomalies and unbalaned atrioventricular valve connection leading to univentricular physiology. Echocardiography plays very crucial role in defning the anomaly and planning management In this article, I am going to focus on role of echocardiography in atrioventricular septal defect.

Surgical treatment of atrioventricular septal defect

Atrioventricular septal defect is a congenital heart disease caused by abnormal development of endocardial cushion.The main characteristic feature of the disease include the common atrioventricular junction, the five-leaflet valve and the abnormality of the conduction system.Surgical treatment mainly includes single patch technique, two-patch technique and modified single patch technique.With the continuous understanding of this disease, the surgical treatment of atrioventricular septal defect has made a great progress. Key words: Congenital heart disease; Atrioventricular septal defect; Surgical treatment; Anatomy

Sequential segmental analysis of the crocodilian heart.

Differences between hearts of crocodilians and those of mammals and birds are only partly understood because there is no standardised approach and terminology for describing cardiac structure. Whereas most reptiles have an undivided ventricle, crocodilians have a fully septated ventricle. Their hearts, therefore, are more readily comparable with the hearts of mammals and birds. Here, we describe the heart of a crocodile (Crocodylus noliticus). We use the versatile sequential segmental approach to analysis, juxtaposing several key views of the crocodilian heart to the comparable views of human hearts. In crocodiles, the atrial and ventricular septums are complete but, unlike in placental mammals, the atrial septum is without an oval fossa. The myocardial component of the crocodilian ventricular septum dominates, but the membranous septum likely makes up a greater proportion than in any mammal. In the crocodile, the aortic trunk takes its origin from the left ventricle and is not wedged between the atrioventricular junctions. Consequently, there is a common atrioventricular junction, albeit with separate right and left atrioventricular valvar orifices. As in mammals, nonetheless, the crocodilian left atrioventricular valvar orifice is cranial to the right atrioventricular valvar orifice. By applying a method of analysis and terminology usually restricted to the human heart, we build from the considerable existing literature to show neglected and overlooked shared features, such as the offset between the left and right atrioventricular valvar orifices. Such commonalities are surprising given the substantial evolutionary divergence of the archosaur and synapsid lineages, and likely reflect evolutionarily shared morphogenetic programmes.

The angulation of the septal structures impacts ventricular imbalance in atrioventricular septal defects with a common atrioventricular junction.

Multiplanar re-formatting of full-volume three-dimensional echocardiography data sets offers new insights into the morphology of atrioventricular septal defects. We hypothesised that distortion of the alignment between the atrial and ventricular septums results in imbalanced venous return to the ventricles, with consequent proportional ventricular hypoplasia. A single observer evaluated 31 patients, with a mean age of 52.09 months, standard deviation of 55, and with a range from 2 to 264 months, with atrioventricular septal defects, of whom 17 were boys. Ventricular imbalance, observed in nine patients, was determined by two-dimensional assessment, and confirmed at surgical inspection in selected cases when a univentricular strategy was undertaken. Offline analysis using multiplanar re-formatting was performed. A line was drawn though the length of the ventricular septum and a second line along the plane of the atrial septum, taking the angle between these two lines as the atrioventricular septal angle. We compared the angle between 22 patients with adequately sized ventricles, and those with ventricular imbalance undergoing univentricular repair. In the 22 patients undergoing biventricular repair, the septal angle was 0 in 14 patients; the other eight patients having angles ranging from 1 to 36, with a mean angle of 7.4°, and standard deviation of 11.1°.The mean angle in the nine patients with ventricle imbalance was 28.6°, with a standard deviation of 3.04°, and with a range from 26 to 35°. Of those undergoing univentricular repair, two patients died, with angles of 26 and 30°, respectively. The atrioventricular septal angle derived via multiplanar formatting gives important information regarding the degree of ventricular hypoplasia and imbalance. When this angle is above 25°, patients are likely to have ventricular imbalance requiring univentricular repair.

Clarifying the morphology of the ostium primum defect.

The 'ostium primum' defect is still frequently considered to be the consequence of deficient atrial septation, although the key feature is a common atrioventricular junction. The bridging leaflets of the common atrioventricular valve, which are joined to each other, are depressed distal to the atrioventricular junction, and fused to the crest of the muscular ventricular septum, which is bowed in the concave direction towards the ventricular apex. As a result, shunting across the defect occurs between the atrial chambers. These observations suggest that the basic deficiency in the 'ostium primum' defect is best understood as a product of defective atrioventricular septation, rather than an atrial septal defect. We have now encountered four examples of 'ostium primum' defects in mouse embryos that support this view. These were identified from a large number of mouse embryo hearts collected from a normal, outbred mouse colony and analysed by episcopic microscopy as part of an ongoing study of normal mouse cardiac development. The abnormal hearts were identified from embryos collected at embryonic days 15.5, 16.5 and 18.5 (two cases). We have analysed the features of the abnormal hearts, and compared the findings with those obtained in the large number of normally developed embryos. Our data show that the key feature of normal atrioventricular septation is the ventral growth through the right pulmonary ridge of a protrusion from the dorsal pharyngeal mesenchyme, confirming previous findings. This protrusion, known as the vestibular spine, or the dorsal mesenchymal protrusion, reinforces the closure of the primary atrial foramen, and muscularises along with the mesenchymal cap of the primary atrial septum to form the ventro-caudal buttress of the oval foramen, identified by some as the 'canal septum'. Detailed analysis of the four abnormal hearts suggests that in each case there has been failure of growth of the vestibular spine, with the result that the common atrioventricular junction found earlier during normal development now persists during cardiac development. Failure of separation of the common junction also accounts for the trifoliate arrangement of the left atrioventricular valve in the abnormal hearts. Analysis of the episcopic datasets also permits recognition of the location of the atrioventricular conduction axis. Comparison of the location of this tract in the normal and abnormal hearts shows that there is no separate formation of a ventricular component of the 'canal septum' as part of normal development. We conclude that it is abnormal formation of the primary atrial septum that is the cause of so-called 'secundum' atrial septal defects, whereas it is the failure to produce a second contribution to atrial septation (via growth of the vestibular spine) that results in the 'ostium primum' defect.

Atrioventricular septal defect with an imperforate right-sided component of the common atrioventricular valve: anatomic and embryologic considerations

We describe an atypical case of an atrioventricular septal defect with a common atrioventricular junction in which the right-sided component of the common atrioventricular valve was imperforate, producing tricuspid atresia with a severely hypoplastic right ventricle and an ostium primum defect. We discuss the implications of the anatomic findings with regard to concepts of cardiac development, drawing a comparison with similar cases previously reported.

How Best Can We Define Double Outlet Right Ventricle When Describing Congenitally Malformed Hearts?

How Best Can We Define Double Outlet Right Ventricle When Describing Congenitally Malformed Hearts?

Atrioventricular Septal Defect with Common Atrioventricular Junction Guarded by a Common Valve Consisting of Left Atrioventricular Trifoliate Valve

Introduction:Atrioventricular septal defect with common atrioventricular junction is a rare adult congenital cardiac syndrome. This occurrence with prolonged survival is exceptionally rare.Case report:We present the case of a patient who presented with this defect with common atrioventricular junction who survived to the age of 32. We describe a 32-year-old man with atrioventricular septal defect with common atrioventricular junction guarded by a common valve. His history, clinical course, and anatomic findings are discussed along with the factors which may have contributed to his longevity, which is unique in the medical literature. His management reflected the state of medical knowledge at the time when he presented, and although alternate approaches may have been utilized if the patient presented today. We discuss the findings, frequency, classifi cation, and management of congenital defects. Development of embryonic structure is altered by interaction between genetics and environmental factors toward a rare associated of congenital cardiac defects-complex congenital heart disease.Conclusion:This case demonstrates that patients with very complex congenital cardiac disease may survive to adulthood, presenting challenges in both medical and surgical treatment.

Anatomic Biventricular Repair in Right Isomerism With Noncommitted Ventricular Septal Defect

Biventricular repair in right atrial isomerism is rarely feasible due to associated anomalies of venous connection, ventricular imbalance, nonroutabilty of the interventricular communication, a common atrioventricular junction, and inadequate pulmonary arterial branches. These patients are also often not ideal for univentricular repair due to some of the above associations. We describe a novel surgical technique that was utilized in such a patient for biventricular repair of a child with right atrial isomerism with total anomalous pulmonary venous connection, regurgitant common atrioventricular valve, hypoplastic left ventricle, nonroutable ventricular septal defect, and pulmonary stenosis.

The spectrum of double-outlet right atrium including hearts with three atrioventricular valves

Double-outlet right atrium (DORA) is characterized by simultaneous right atrial emptying into both ventricles. Ventriculoatrial septal malalignment is the cardinal morphological feature. Three cases are presented to depict two major types of DORA-DORA with a malaligned atrial septum and DORA with a malaligned ventricular septum. We describe two subtypes of each form of DORA: DORA with a malaligned atrial septum presents with either a common atrioventricular (AV) junction (guarded by a common AV valve) or with a single AV junction (due to the absence of the left AV junction). DORA with a malaligned ventricular septum may be associated with a right ventricle (RV) that is adequate for biventricular repair or a severely hypoplastic RV not compatible with biventricular repair. DORA with a malaligned ventricular septum is closely related to typical straddling of the tricuspid valve. Peculiarly, DORA with a malaligned ventricular septum presents three AV valves at the AV junction and is associated with an abnormal disposition of the AV conduction axis. Clear understanding of the morphology of these lesions is important in preventing a surgical misadventure at the crux of the heart.

Real-Time 3-Dimensional Transesophageal Echocardiography of the Atrioventricular Septal Defect

Being able to view the morphological details of the heart malformation in any patient with the diagnosis of atrioventricular septal defect (AVSD) is invaluable in surgical planning, especially in the current era of modified 1-patch versus 2-patch techniques. Real-time 3-dimensional transesophageal echocardiography (RT 3D TEE) is a recently developed technique that allows real-time high-quality images akin to viewing the heart specimen. We present the principal pathomorphological features of AVSD as visualized by RT 3D TEE. The hallmark of AVSD is a common atrioventricular junction guarded by a common atrioventricular valve.1 In the normal heart, when seen from atrial perspective, the aortic valve is wedged between the mitral and tricuspid valve. In AVSD, because of the common AV junction, the aortic valve is in an “unwedged” position (Figure 1). The valve consists of 5 leaflets: the superior and inferior bridging leaflets, each of which overrides the ventricular septum, a left mural leaflet, a right anterior, and a right inferior leaflet (Figure 2). Whether the bridging leaflets are joined together distinguishes the complete form from the partial form. In partial AVSD (also termed “ostium primum ASD”), a tongue of leaflet tissue connects the bridging leaflets and the undersides of these leaflets …

Atrioventricular septal defect with coexisting tricuspid atresia

We describe two infants having an atrioventricular septal defect in the setting of a double inlet atrioventricular connection, but with patency of the left-sided valvar orifice and an imperforate right-sided valvar component, and a further case with atrioventricular septal defect and an imperforate Ebstein's malformation, all producing the haemodynamic effect of tricuspid atresia. We make comparisons with the arrangement in trisomy 16 mice, in whom deficient atrioventricular septation is seen at times with the common atrioventricular junction exclusively connected to the left ventricle, a situation similar to that seen in two of our infants. We also review previous reports emphasising the important theoretical implication of the findings despite their rarity.

The current surgical perspective to repair of atrioventricular septal defect with common atrioventricular junction

Atrioventricular septal defect with common atrioventricular junction is a relatively common congenital cardiac malformation. It sometimes presents challenging surgical problems, especially when seen in combination with tetralogy of Fallot. We describe herein our current concepts regarding surgical repair of atrioventricular septal defect with and without tetralogy, discussing indications for surgery, timing, technical aspects, and outcomes.