Congenital malformations of the right atrium and the coronary sinus: an analysis based on 103 cases reported in the literature and two additional cases

Congenital right atrial diverticulum in a kitten

A four-month-old domestic shorthair cat with no clinical signs was referred for further examination of a heart murmur. An echocardiogram revealed marked right atrial dilation, extending into the left hemithorax. Computed tomography angiography was conducted to investigate further, which revealed a balloon-shaped, contrast-filled cavity on the cranial and left side of the chest that connected to the right atrium through a narrow passage. This was diagnosed as a congenital right atrial diverticulum. Treatment included clopidogrel to reduce the risk of thrombus formation. Two months after the initial diagnosis, castration surgery was successfully performed without complications. The cat died suddenly at home 10 months after diagnosis. To the authors' knowledge, this is the first right atrial diverticulum reported in a cat.

Markedly dilated right atrium in an infant: what is the diagnosis?

An 18-month-old boy presented with recurrent episodes of irritability and documented fast heart rate suggestive of supraventricular tachycardia. Cardiovascular examination revealed significant cardiomegaly, normal heart sounds and no murmurs. The differential diagnosis of marked right atrial dilatation and management principles of idiopathic dilatation of the right atrium are described.

A rare case of an unexpected trigger of paroxysmal atrial fibrillation in the right atrial appendage diverticulum

INTRODUCTION

We described a rare case of an adolescent girl with paroxysmal atrial fibrillation originating from the right atrial appendage diverticulum and successfully converted to sinus rhythm after surgical intervention.

METHODS

A 19-year-old girl was referred to the hospital for a catheter ablation of paroxysmal atrial fibrillation. conventional radiofrequency ablation using 3-D mapping were ineffective. Activation mapping showed the root of the free wall atrial appendage was first excited and catheter modeling (3D Carto map) showed a sac-like structure.

RESULTS

We did selective angiography and further Computed tomography angiography (CTA) and Transesophageal echocardiography (TEE) which showed diverticulum originating from the right atrial appendage. Hence the patient was referred to cardiac surgery and had no recurrent atrial fibrillation at three months postoperative follow up.

CONCLUSIONS

Right atrial appendage diverticulum was an extremely rare malformation that can coexist with atrial tachyarrhythmia. Surgical ligation or excision of the abnormal structure with local ablation can achieve excellent results.

Idiopathic Dilatation of the Right Atrium: Diagnosis and Management

Idiopathic dilatation of the right atrium is a rare condition with an unknown etiology. It is characterized by a significant enlargement of the right atrium without the presence of other valvopathies, intracardiac shunts, or pulmonary hypertension. This report presents the case of a 50-year-old woman with a significantly enlarged right atrium that was identified at birth; however, a definitive diagnosis was made later in life. The patient did not have any genetic diseases. Through the help of regular follow-up, anticoagulant therapy, previous radio-frequency ablation, and antiarrhythmic medications, she was able to carry a pregnancy to full term and live a regular life.

Idiopathic enlargement of the right atrium masking left atrial aneurysm in a neonate

An idiopathic enlargement of the right atrium is an extremely rare cardiac malformation. There are no established guidelines for the management of this disease, especially concerning medical versus surgical therapeutic approach and the timing for an operation. We report in this case about a neonate that first was treated conservatively until the age of 5 month and finally got an operative resection of the aneurysm. After surgery, unexpected complications occurred. A second aneurysm in the left atrium was demasked. Furthermore, a progressive dilatation of both atrial chambers after resection required regular follow-up and ongoing evaluation of treatment.

A Focus on the Right Atrium

We report a case of a 70-year-old woman who presented for a cavotricuspid isthmus atrial flutter ablation that was aborted prematurely. On subsequent imaging, she was discovered to have a right atrial diverticulum, which was present on prior imaging but not reported, likely due to unfamiliarity with the entity. (Level of Difficulty: Intermediate.).

Contractile pericarditis-like hemodynamics in dilated-phase hypertrophic cardiomyopathy with giant atrium

A 47-year-old man with dilated-phase hypertrophic cardiomyopathy was admitted to the hospital with worsening heart failure. As the enlarged atrium caused a constrictive pericarditis-like hemodynamic condition, atrial wall resection and tricuspid valvuloplasty were performed. Postoperatively, pulmonary artery pressure rose due to increased preload; however, the rise in pulmonary artery wedge pressure was restrained, and the cardiac output significantly improved. When the pericardium is extremely stretched due to atrial enlargement, it can lead to an elevation of intrapericardial pressure, and both atrial volume reduction and tricuspid valve plasty could lead to increased compliance and contribute to hemodynamic improvement.

Learning objective

Atrial wall resection for massive atrial enlargement and tricuspid annuloplasty in patients with diastolic-phase hypertrophic cardiomyopathy effectively relieves unstable hemodynamics.

Repair of Congenital Right Atrial Aneurysm Associated With Wolff-Parkinson-White Syndrome in a 5-Year-Old Girl

This report describes our experience with a 5-year-old girl who had an extremely rare presentation of a right atrial aneurysm and associated Wolff-Parkinson-White syndrome. Before being referred to our department, she underwent an ineffective radiofrequency ablation for repeated episodes of paroxysmal supraventricular tachycardia that were causing dizziness, palpitations, and chest discomfort. We resected the aneurysm with good results; she was doing well and was in normal sinus rhythm at the time of her 1-year follow-up visit.

Surgical Repair of a Giant Right Atrium Aneurysm That was Incidentally Found in a Boy

Giant right atrial aneurysms are rare defects with different clinical presentations ranging from lack of symptoms to heart failure. They are diagnosed based on incidental findings. It is commonly found when echocardiography or chest X-ray is performed. Concurrent congenital heart disease and large atrial size are risk factors that may increase the risks of complications such as thromboembolism, fatal arrhythmias, aneurysm rupture, and sudden death. The best treatment has been controversial, with some patients managed surgically and others conservatively. We present a case of a giant right atrium aneurysm that was incidentally detected during a routine examination. The patient underwent successful surgical resection of the right atrial aneurysm.

Giant Right Atrial Aneurysm in an Infant

Right atrial aneurysm (RAA) is a rare congenital anomaly with a diverse clinical spectrum. We present a case of antenatal detection of a giant RAA. The infant had 3 episodes of staring spells presumed to be thrombo-embolic phenomena originating from the RAA. The infant underwent successful RAA resection with preservation of the right coronary artery that was displaced from its usual position due to invagination of the RAA in the subepicardial space of the right atrio-ventricular groove.

Totally Endoscopic Resection of Right Atrial Diverticulum: A Case Report

Right atrial diverticulum is a rare congenital heart defect with only about 30 cases reported. Surgery is the main method of treatment and is indicated when the patients have signs of right heart compression. In this study, we report the case of a 43-year-old male patient who was diagnosed with massive right atrial diverticulum. This patient was the first case who underwent successful repair by totally endoscopic surgery on the beating heart.

An Extremely Rare Congenital Muscle Bundle Crossing the Right Atrial Cavity

Muscle bundles in the right atrium are an extremely rare congenital anomaly. We report the case of a patient with 2 atrial septal defects and a large muscle bundle crossing the right atrium. Only 3 comparable cases have previously been published. (Level of Difficulty: Intermediate.)

Cardiac Outpouchings: Definitions, Differential Diagnosis, and Therapeutic Approach

Background and Aims

Cardiac outpouchings encounter a series of distinct congenital or acquired entities (i.e. aneurysms, pseudoaneurysms, diverticula, and herniations), whose knowledge is still poorly widespread in clinical practice. This review aims to provide a comprehensive overview focusing on definition, differential diagnosis, and prognostic outcomes of cardiac outpouchings, as well as further insights on therapeutic options, in order to assist physicians in the most appropriate decision-making.

Methods

The material reviewed was obtained by the following search engines: MEDLINE (PubMed), EMBASE, Google Scholar, and Clinical Trials databases, from January 1966 until March 2021. We searched for the following keywords (in title and/or abstract): (“cardiac” OR “heart”) AND (“outpouching” OR “outpouch” OR “aneurysm” OR “pseudoaneurysm” OR “false aneurysm” OR “diverticulum” OR “herniation”). Review articles, original articles, case series, and case reports with literature review were included in our search. Data from patients with congenital or acquired cardiac outpouchings, from prenatal to geriatric age range, were investigated.

Results

Out of the 378 papers initially retrieved, 165 duplicates and 84 records in languages other than English were removed. Among the 129 remaining articles, 76 were included in our research material, on the basis of the following inclusion criteria: (a) papers pertaining to the research topic; (b) peer-reviewed articles; (c) using standardized diagnostic criteria; and (d) reporting raw prevalence data. Location, morphologic features, wall motion abnormalities, and tissue characterization were found to have a significant impact in recognition and differential diagnosis of cardiac outpouchings as well as to play a significant role in defining their natural history and prognostic outcomes.

Conclusions

Careful recognition of cardiac outpouchings remains a diagnostic challenge in clinical practice. Due to a broad cluster of distinctive and heterogeneous entities, their knowledge and timely recognition play a pivotal role in order to provide the most appropriate clinical management and therapeutic approach.

The 'Cauliflower Heart': a case report of congenital bi-atrial aneurysms causing non-controllable arrhythmia

Background

Congenital aneurysms of the atrium are very rare malformations. Known complications are therapy-resistant arrhythmias. Different treatments such as medical therapy, electrophysiological ablation, and surgery have been proposed. However, there are no guidelines on treatment.

Case summary

We describe the case of a neonate with bi-atrial aneurysms causing atrial arrhythmia. Arrhythmia was first observed in the 28th week of gestation. Maternal digoxin treatment did not show any effect. After birth, bi-atrial aneurysms were diagnosed and determined as the probable cause of the atrial tachycardia and later of atrial flutter. Antiarrhythmic drug treatment was initiated. However, only frequency control could be achieved. At the age of 7 months, the patient underwent surgical resection. Since surgery, sinus rhythm is present.

Conclusion

Atrial aneurysms are rare malformations, known complications are atrial arrhythmia. If medical treatment fails, surgery correction appears to be indicated going along with low operative risk and a high probability of successful termination of arrhythmia.

Right Atrial Diverticulum in an Adult Woman with Left Bundle Branch Block

Right atrial diverticulum is a very rare anomaly. It is an outpouching arising from the right atrial free wall. Clinical presentations vary widely but some cases are associated with supraventricular tachycardia and atrial flutter/fibrillation. The incidence/prevalence of this anomaly is not available because only a few cases have been reported. We report a 38-year-old female patient who presented to the Heart Clinic, Tehran, Iran in 2019 with a history of dyspnea and chest pain. Electrocardiography revealed left bundle branch block. Following a magnetic resonance imaging study, the patient was diagnosed with a right atrial diverticulum. She underwent surgical resection of the diverticulum. The post-operative course was uneventful and no recurrence of the arrhythmia was detected during the six months of follow-up. To the best of the authors’ knowledge, this combination has not been described in the literature.

Left atrial diverticulum-An unexpected finding in routine transesophageal echocardiography

We report a 55-year-old male patient with lone paroxysmal atrial fibrillation who underwent routine transesophageal echocardiography (TOE) at our institution. In a mid-esophageal 125° three-chamber angulation, a distinct thinning of the left atrial (LA) wall was observed, forming a 7 × 4 mm canal with only a small membrane separating the LA from the pericardial space. Cardiac magnetic resonance imaging diagnosed a small LA diverticulum. To the best of our knowledge, this is the first manuscript describing detection of a small LA diverticulum via TOE.

Clinical Presentation, Diagnosis, and Management of Idiopathic Enlargement of the Right Atrium: An Analysis Based on Systematic Review of 153 Reported Cases

Idiopathic enlargement of the right atrium (IERA) is a rare cardiac anomaly, and only sporadic cases have been reported. Little is known about its clinical relevance, and inconsistencies in medical and surgical management remain among different settings. In this paper, we systematically reviewed the published cases of the IERA in terms of clinical presentation, diagnosis, and management. A total of 153 cases of IERA were covered. Arrhythmia, dyspnea, and palpitation were found to be the most common clinical manifestations. It tends to be associated with life-threatening complications and sudden cardiac death. Diagnosis was mostly established by using echocardiography. Presenting symptoms, abnormal ECG findings, and therapeutic modalities were significantly related to the prognosis of IERA. Symptomatic patients were significantly more likely to have poor outcomes than asymptomatic patients (p = 0.044), and conservative treatment was more associated with adverse outcomes compared to surgical resection (p = 0.016). In conclusion, IERA, although rare, tends to be associated with potential life-threatening complications and sudden cardiac death. Echocardiography is the most common diagnostic modality. Surgical resection is indicated for symptomatic patients.

Right atrial appendage aneurysm in a fetus-Does precise prenatal diagnosis matter?

Introduction

Congenital malformations of the right atrium-aneurysms and diverticula-are rare heart defects with only a few cases having been described prenatally. Early diagnosis of these anomalies is extremely important due to the possibility of such serious complications such as supraventricular arrhythmia, thromboembolic events and sudden death.

Topic Description

Although each of these anomalies is well known, there are still significant discrepancies in diagnosis. At the same time, there is no essential difference in the postnatal management of patients with right atrial aneurysms or diverticula. Treatment mode varies between centers and is selected individually depending on the presence of symptoms.

Discussion

We discuss the problems of terminology, ultrasound criteria and prenatal differential diagnosis, anatomic and histological features and current limitations for the accurate diagnosis of right atrial aneurysms and diverticula in utero. As a clinical example, we describe a case of right atrial appendage aneurysm diagnosed in a fetus.

Conclusions

Considering the prenatal diagnostic difficulties and similar management of such patients after birth, we suggest avoiding the use of exact terms in the fetus, leaving the precise diagnosis for the postnatal period.

Idiopathic dilatation of the right atrium: a not so benign entity

Idiopathic dilatation of the right atrium is an isolated enlargement of the right atrium in the absence of other cardiac lesions. This rare anomaly has a clinical spectrum ranging from asymptomatic to heart failure or even sudden death. It can be associated with atrial arrhythmias and thrombus formation. Antiplatelet therapy is prescribed in most cases reported in the literature, and reduction plasty is indicated when there is rapid growth of the right atrium, compression of adjacent structures, or refractory arrhythmias. We report four cases of idiopathic dilatation of the right atrium diagnosed during prenatal screening. We describe the intrauterine course and management in postnatal life until early childhood.

Left atrial diverticula: Innocent bystanders or wolves in sheep's clothing?

INTRODUCTION

The finding of left atria diverticula (LAD) on cardiac computed tomography images obtained from patients with atrial fibrillation (AF) referred for pulmonary vein isolation is not uncommon. Prior studies reporting on LAD do not always provide definitions of LAD resulting in confusion with other anatomical structures such as left atrial accessory appendages (LAAA) and atrial aneurysms. The aim of this review is to identify an accurate definition of LAD and to describe distinctive properties between LAD and other left atrial structures, such as LAAA and aneurysms. Also, the relation between LAD and development of atrial tachyarrhythmias is discussed.

METHODS

PubMed was searched for studies reporting on atrial aneurysms, left atrial diverticula, left atrial accessory appendages and atrial congenital aneurysms, resulting in 36 papers.

RESULTS

LAD can be distinguished from LAAA by taking into account embryologic origins of the left atrium and their locations, resulting in the following definitions: (a) LAAA are contractile, trabeculated structures with circumscriptive ostia and narrow necks, originating from the primitive atria, (b) LAD are contractile, sac like structures with either smooth or trabeculated inner surfaces, circumscriptive ostia, narrow necks, and variable morphologies, originating from the embryologic common pulmonary vein, that incorporates into the LA, and (c) atrial aneurysms are non-contractile structures with wide necks and sac like bodies. There are no differences in prevalences of LAD between patients with sinus rhythm and AF.

CONCLUSION

The pathophysiology of LAD is not yet fully understood. It is unlikely, that LAD are related to the development of atrial tachycardia's and AF by either being a source of ectopic activity or being part of an arrhythmogenic substrate. No differences in LAD prevalences between patients with sinus rhythm and AF have been found. Thus, it is unlikely that LAD could potentially be wolves in sheep's clothing.

Surgical Management of Congenital Bilateral Multiple Atrial Aneurysms

Congenital atrial aneurysms are a rare malformation, often associated with supraventricular arrhythmias. Here, we present the case of a child with biatrial aneurysms and a type 2 atrioseptal defect. Directly after birth the girl became symptomatic with incessant ectopic atrial tachyarrhythmia. On echocardiography, multiple biatrial aneurysms and septations were observed. The diagnosis was confirmed with computed tomography. After 7 months of antiarrhythmic therapy, the child underwent surgical intervention by aneurysm resection, atrioseptal defect closure, and ablation. Since then the patient has been in stable sinus rhythm.

Catheter Ablation of Atrial Tachycardia in a Giant Right Atrium

A 25-year-old male patient with a giant right atrium presented with atrial tachycardia. Electroanatomic mapping revealed micro–re-entry from a low-voltage zone in the region of the right atrial appendage. Linear ablations across the low-voltage zone terminated the tachycardia. The remaining right atrial tissue was electrically normal. (Level of Difficulty: Intermediate.)

Giant right atrial aneurysm

Only a handful of congenital aneurysms of the right atrium have been reported in the literature. They are most commonly found in the third decade of life, and the differential diagnosis depends on the patient's age profile. They are associated with 5% risk of sudden cardiac death. Once diagnosed, they should be surgically removed even in the absence of symptoms.

Giant right atrial aneurysm with atrial fibrillation

Congenital right atrial aneurysm is a rare condition. Here we reported a 16-year-old male with giant right atrial aneurysm, atrial fibrillation, and atrial septal defect. Surgical resection of extensive right atrium, ASD repair, and maze procedure were performed. In the present case, we found extensive enlargement of right atrium protruding to the apex on the surface of the right ventricle. With the exist of atrial fibrillation, thrombus formation was always a lethal threat. Surgical treatment can provide excellent clinical results and further avoided life-threatening complications.

Cardiac Outpouchings: A Multimodality Imaging Review

Cardiac outpouchings pose a diagnostic challenge when encountered in practice, as the signs, symptoms, and initial investigations, such as radiographs and electrocardiogram, are nonspecific. They may remain asymptomatic and be incidentally detected. However, a few may present with progressive shortness of breath, thromboembolic complications, arrhythmias, pressure effects, rupture, or even death. Imaging is of paramount importance in establishing an accurate diagnosis, delineating morphology and extent of the lesion along with its hemodynamic significance, planning management, and in the follow-up.

Congenital Aneurysm of the Right Atrium: Two Cases Report

Congenital aneurysm or enlargement of the right atrium is a rare condition. Two children operated on at the age of 14 months and 11 years old for congenital aneurysm of the right atrium are reported. Both presented cardiomegaly and symptoms of paroxysmal supraventricular tachycardia. Diagnosis was established by echocardiography. Surgical resection was successful. Both patients are free of symptoms and their chest X-ray and echocardiogram are normal. The first patient is now in her 17^th postoperative year. The patients' evolution suggests that the surgery is a curative procedure.

Surgical Treatment of Idiopathic Enlargement of the Right Atrium

Idiopathic enlargement of the right atrium (IERA) is a very rare abnormality. Approximately one-half (48%) of the patients with a congenital enlargement of the right atrium have no symptoms. When they occur, symptoms include shortness of breath (28% of cases), palpitations (17%), arrhythmias (12%), and in rare cases, right heart failure and extreme tiredness. We report one such case of a young man with a disproportionally enlarged right atrium. The basal transthoracic echocardiogram demonstrated a huge right atrium with a thick smoke pattern and mild tricuspid regurgitation in the absence of congenital heart disease. Magnetic resonance imaging confirmed the right atriomegaly, with initial compression of the right ventricle, and excluded congenital heart defects or absence of pericardium. The patient underwent surgical resection of the right atrial wall and the atriotomy was closed, leaving an atrial chamber of normal consistency and size. The resected atrium had normal and homogeneous wall thickness without significant fibrosis which confirmed the diagnosis of an idiopathic enlargement of the right atrium.

Surgical repair of massive dilatation of the right atrium with tricuspid regurgitation

Background

Massive dilatation of the right atrium with tricuspid regurgitation is frequently diagnosed by accidental recognition of an enlarged cardiac silhouette during routine chest radiography. Although some patients are asymptomatic, enlargement of the right atrium can cause secondary tricuspid regurgitation due to dilatation of the tricuspid annulus, associated with arrhythmias and thrombus formation leading to pulmonary embolism, stroke, and, rarely, sudden death due to left ventricular compression.

Case presentation

A 76-year-old woman was followed up due to atrial fibrillation and tricuspid regurgitation for 8 years. A follow-up echocardiogram showed progressive dilatation of the right atrium. Because of the development of shortness of breath, right atrial plication and tricuspid valve repair were performed. Tricuspid annuloplasty was performed on the beating heart with the use of a 28-mm Carpentier-Edwards Physio tricuspid annuloplasty ring. Plication of the enlarged right atrium was performed at the interatrial septum, the free right atrium wall including the appendage, and the space between the inferior vena cava and the tricuspid ring. Closure of the left atrial appendage was performed from outside to prevent left atrial thrombus formation. Postoperative X-ray and computed tomography showed reduced cardiac silhouette and right atrial volume. The patient was discharged uneventfully and returned for follow-up visits with improved symptoms.

Conclusions

An adult case of massive dilatation of the right atrium of unknown etiology is reported. The patient’s symptoms were relieved by our operative procedure.

Giant Right Atrial Aneurysm Accompanying Intrahepatic Cholestasis

Right atrial aneurysms were first described in 1955, and subsequently, only a few cases have been reported. The etiology of this condition is unknown. Its comorbidity with cholestasis has not previously been reported in the literature. An 11-month-old baby female, who was an offspring from a first-cousin marriage, was referred to our hospital for investigation of jaundice. She underwent echocardiography because of a heart murmur, and this revealed a giant right atrial aneurysm. In addition, her liver biopsy confirmed the diagnosis of progressive familial intrahepatic cholestasis (PFIC) type 3. Although both conditions are rare, we found their comorbidity interesting and are thus reporting the case.

Echocardiographic Features of Giant Right Atrial Diverticulum in a Dog

A 12‐year‐old spayed female miniature Poodle presented for coughing, respiratory distress, and anorexia. After thoracentesis for pleural effusion, radiography revealed an enlarged cardiac silhouette with a bulge in the area of the body of the right atrium. Echocardiography revealed an anechoic chamber‐like cavity lateral to the right atrium that communicated with the right atrium through a 13 mm defect in the right atrial free wall. Contrast echocardiography and color flow Doppler were used to prove that the cavity communicated with the right atrium. The cavity was diagnosed as a giant right atrial diverticulum.

Isolated Congenital Right Atrial Aneurysm: Monitoring Parameters for Asymptomatic Patients

Isolated congenital right atrial aneurysm is rare. Indications for surgery in asymptomatic patients with moderate-size right atria remain controversial. Evidence in support of medical management and timing of prophylactic surgery is reviewed. We propose the use of three echocardiographic indices to help identify inappropriate atrial growth and facilitate surgical decision-making.

Contrast Transesophageal Echocardiography in Diagnosing Congenital Enlargement of the Right Atrium

Congenital malformation of the right atrium or the coronary sinus is rare, and cases are clas sified into 1 of the following 4 categories: (1) congenital enlargement of right atrium, (2) single diverticulum, (3) multiple diverticula of the right atrium, and (4) diverticulum of the coronary sinus. This report presents a 63-year-old man with cardiomegaly and no chest symptoms. A chest radiograph revealed an enlarged cardiac silhouette with a prominent right heart border. Although a transesophageal echocardiography revealed marked enlargement of the right atrium, neither further anomaly nor massive regurgitation was observed. The systolic pulmonary artery pressure derived from the peak velocity of mild tricuspid regurgitation was 38 mm Hg. Secondary enlargement of the right atrium due to atrial septal defect or pulmonary venous connection anomaly was deemed negligible by use of transesophageal contrast echocardiography, and primary enlargement of the right atrium was confirmed. Trans esophageal echocardiography using ultrasound contrast was determined to be feasible for diagnosing congenital malformation of the right atrium.

Right atrial aneurysm with downward displacement of the anterior leaflet that resembled Ebstein's anomaly

A 13-year-old boy presented with right atrial aneurysm and downward displacement of the anterior leaflet in the tricuspid valve into the right ventricle, without tricuspid valve regurgitation. Paroxysmal atrial flutter was caused by an abnormal electrical re-entry circuit, which could not be treated using catheter radiofrequency ablation. Therefore, the patient underwent surgical ablation and resection of the enlarged right atrial wall. The anterior leaflet of the tricuspid valve was plastered and displaced downward into the right ventricle, which resembled Ebstein's anomaly. Pathological evaluation revealed a thin wall that contained fibrous tissue with lipomatous degeneration and few muscular elements. No postoperative arrhythmia was observed.

Cardiac troponin T is necessary for normal development in the embryonic chick heart

The heart is the first functioning organ to develop during embryogenesis. The formation of the heart is a tightly regulated and complex process, and alterations to its development can result in congenital heart defects. Mutations in sarcomeric proteins, such as alpha myosin heavy chain and cardiac alpha actin, have now been associated with congenital heart defects in humans, often with atrial septal defects. However, cardiac troponin T (cTNT encoded by gene TNNT2) has not. Using gene‐specific antisense oligonucleotides, we have investigated the role of cTNT in chick cardiogenesis. TNNT2 is expressed throughout heart development and in the postnatal heart. TNNT2‐morpholino treatment resulted in abnormal atrial septal growth and a reduction in the number of trabeculae in the developing primitive ventricular chamber. External analysis revealed the development of diverticula from the ventricular myocardial wall which showed no evidence of fibrosis and still retained a myocardial phenotype. Sarcomeric assembly appeared normal in these treated hearts. In humans, congenital ventricular diverticulum is a rare condition, which has not yet been genetically associated. However, abnormal haemodynamics is known to cause structural defects in the heart. Further, structural defects, including atrial septal defects and congenital diverticula, have previously been associated with conduction anomalies. Therefore, to provide mechanistic insights into the effect that cTNT knockdown has on the developing heart, quantitative PCR was performed to determine the expression of the shear stress responsive gene NOS3 and the conduction gene TBX3. Both genes were differentially expressed compared to controls. Therefore, a reduction in cTNT in the developing heart results in abnormal atrial septal formation and aberrant ventricular morphogenesis. We hypothesize that alterations to the haemodynamics, indicated by differential NOS3 expression, causes these abnormalities in growth in cTNT knockdown hearts. In addition, the muscular diverticula reported here suggest a novel role for mutations of structural sarcomeric proteins in the pathogenesis of congenital cardiac diverticula. From these studies, we suggest TNNT2 is a gene worthy of screening for those with a congenital heart defect, particularly atrial septal defects and ventricular diverticula.

Giant Right Atrial Aneurysm: Antenatal Diagnosis and Surgical Treatment

Giant congenital right atrial aneurysms are rare, with their natural history complicated by death, heart failure, arrhythmias, and thrombosis. Prenatal diagnosis of the defect is feasible and allows an early preparation of a plan for management. We present details of a patient diagnosed prenatally with a giant right atrial aneurysm, which was successfully treated surgically as soon as the patient became symptomatic.

Fetal Diagnosis of Right Atrial Aneurysms

Right atrial aneurysm is a rare condition of unknown etiology, characterized by marked dilatation of the right atrial free wall. We report 2 symptomatic cases following a fetal diagnosis.

A Case of Giant Right Atrial Aneurysm in a Child

Giant right atrial aneurysm is a rare entity in infants and children. It needs to be distinguished from an atrial diverticulum, which can have similar presentation. Generally, an incidental finding in children, it can present with varied symptoms. We report a case of a giant right atrial aneurysm in an asymptomatic child with a large clot in the dilated right atrium, who underwent successful resection of the atrial aneurysm.

Surgical repair of a giant congenital right atrial aneurysm: a case report

Giant congenital right atrial aneurysms are rare defects of the heart. Though usually asymptomatic, they can be potentially life-threatening. Major risks include heart failure, supraventricular arrhythmias, rupture of the wall of the aneurysm. This defect is usually diagnosed incidentally. It is commonly found when transthoracic echocardiography or chest X-ray is performed. In some cases computed tomography or cardiac magnetic resonance imaging is needed to establish the diagnosis. Potential therapeutic options include surgery, catheter ablation and conservative follow-up. Currently preferred method for correcting this defect is surgical excision of the aneurysm, when surgical indications are met. In this article we describe a successful aneurysmectomy performed on a 16-month old female infant, who at the time of hospitalization presented with severe heart failure and symptoms of cardiac tamponade.

Giant aneurysm of the atrial appendages in infants

This case series describe two patients with giant aneurysms of the atrial appendages. This report discusses the clinical symptoms, imaging modalities, indications for surgical intervention, and histology of atrial appendage aneurysms.

Giant right atrial diverticulum with thrombus formation

A 28-year-old man was referred to our hospital with a giant right atrial diverticulum. The mass of the right atrial diverticulum compressed the right atrium and right ventricle, and thrombus formation was suspected. The diverticulum was surgically excised and the patient remained asymptomatic a year later.