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Concept: Right atrium

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OPINION STATEMENT: Ebstein anomaly (EA) is a rare congenital heart defect that may not be detected until late in adolescence or adulthood. Since the original description in a 19-year-old laborer with severe tricuspid valve (TV) regurgitation in 1866, our understanding of this rare condition has increased to the recognition that it is an abnormality not only of the TV, but also of the right ventricle (RV). EA is the result of failure of delamination of the TV leaflets from the interventricular septum, resulting in adherence of the leaflets to the underlying myocardium. This results in a wide variety of abnormalities, including apical and posterior displacement of the dilated TV annulus; dilation of the “atrialized” portion of the RV; and fenestrations, redundancy, and tethering of the anterior leaflet of the TV. The malformed TV is usually regurgitant, but may rarely be stenotic. The clinical manifestations of EA in the adult depend on several factors, including the extent of TV leaflet distortion, degree of tricuspid regurgitation (TR), right atrial pressure, and presence of a right-to-left atrial level shunt. Over the past several decades, advances in diagnostic imaging and surgical techniques have contributed to our current management of this challenging congenital heart defect.

Concepts: Heart, Right ventricle, Ventricle, Right atrium, Tricuspid valve, Congenital heart defect, Congenital heart disease, Ebstein's anomaly

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Due to the increased life expectancy and continual improvements in cardiological treatment options, diseases of the tricuspid valve, in particular tricuspid valve insufficiency will become increasingly more recognized as an interventional target. While tricuspid stenosis is rare and can be effectively treated with balloon valvuloplasty, no effective transcatheter approach to tricuspid regurgitation (TR) has yet been established. As the tricuspid annulus is a complex and highly dynamic structure that offers little resistance, orthotopic long-term fixation of transcatheter valves with the current techniques is challenging and has not yet been performed in human patients. Alternative treatment concepts include transcatheter caval valve implantation (CAVI) to address the regurgitation of blood into the caval veins, which has resulted in hemodynamic improvement and is currently undergoing further clinical investigation. Other interventional treatment concepts are aimed at tricuspid valve repair, e.g. by annular plication with the Mitralign™ device or the TriCinch™ system. In the medium-term it can be assumed that percutaneous systems and therapy options will become available for these indications whereby the functional and prognostic effects of these treatment procedures will be corroborated in the appropriate patient groups by corresponding studies.

Concepts: Heart, Right atrium, Tricuspid valve, Annulus, Abstraction, Tricuspid insufficiency, Regurgitation, Valvular heart disease

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The acknowledgment of tricuspid regurgitation (TR) as a stand-alone and progressive entity, worsening the prognosis of patients whatever its aetiology, has led to renewed interest in the tricuspid-right ventricular complex. The tricuspid valve (TV) is a complex, dynamic and changing structure. As the TV is not easy to analyse, three-dimensional imaging, cardiac magnetic resonance imaging and computed tomography scans may add to two-dimensional transthoracic and transoesophageal echocardiographic data in the analysis of TR. Not only the severity of TR, but also its mechanisms, the mode of leaflet coaptation, the degree of tricuspid annulus enlargement and tenting, and the haemodynamic consequences for right atrial and right ventricular morphology and function have to be taken into account. TR is functional and is a satellite of left-sided heart disease and/or elevated pulmonary artery pressure most of the time; a particular form is characterized by TR worsening after left-sided valve surgery, which has been shown to impair patient prognosis. A better description of TV anatomy and function by multimodality imaging should help with the appropriate selection of patients who will benefit from either surgical TV repair/replacement or a percutaneous procedure for TR, especially among patients who are to undergo or have undergone primary left-sided valvular surgery.

Concepts: Blood, Heart, Medical imaging, Magnetic resonance imaging, Pulmonary artery, Right ventricle, Right atrium, Tricuspid valve

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Nowadays some percutaneous options for tricuspid valve (TV) repair are available: Tricinch (4Tech Cardio, Galway, Ireland) mimicking the Kay procedure, Trialign (Mitralign, Boston, MA, USA) aiming to bicuspidise TV, MitraClip (Abbott Vascular, Abbott Park, Illinois, USA) mimicking Alfieri’s stitch, direct transcatheter annuloplasty with Cardioband (Valtech Cardio, Or Yehuda, Israel) and transcatheter Forma Repair (Edwards Lifesciences, Irvine, California, USA) providing a surface for leaflet coaptation. A multimodality imaging approach is fundamental for defining the pathophysiology of tricuspid regurgitation (TR), preprocedural planning and intraprocedural monitoring. Both 2-dimensional and 3-dimensional (3D) transthoracic echocardiography and transoesophageal echocardiography (TOE) are essential for grading and anatomical characterisation of TR, and evaluation of dimensions and function of right ventricle (RV) and estimation of pulmonary pressure. In particular, 3D echocardiography provides a better anatomical definition of TV apparatus and tricuspid annulus (TA) and additional information about the anatomical relationships of TV and surrounding structures. CT offers complementary information during the preprocedural planning especially for procedures targeting TA such as annular structure and dimensions, quality and amount of annular tissue and its relationship with the right coronary artery, and the sizing of the inferior vena cava. Moreover, appropriate patient selection is crucial. The best candidate seems to be a patient with functional TR due to predominant annular dilatation with modest apical tethering, at least partial preservation of leaflets coaptation, not severe pulmonary hypertension and not advanced RV dilation and dysfunction. An example of intraprocedural multimodality imaging approach with TOE, fluoroscopy, angiography and intracardiac echocardiography is also reported.

Concepts: Cardiology, Heart, Echocardiography, Right ventricle, Right atrium, Tricuspid valve, Inferior vena cava, Tricuspid insufficiency

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Cone reconstruction (CR) is a novel technique for surgically treating the tricuspid valve and right ventricle (RV) in patients with Ebstein’s anomaly. However, precise changes in the RV function after CR remain unclear. This study aimed to evaluate the RV size and New York Heart Association (NYHA) functional class by conducting a meta-analysis of reported data.

Concepts: Heart, Right ventricle, Ventricle, Right atrium, Tricuspid valve, Left ventricle, Pulmonary valve, Ebstein's anomaly

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Injuries to the superior vena cava (SVC) during transvenous lead extraction (TLE) procedures are a rare but life-threatening complication. The Bridge Occlusion Balloon (BOB) is specifically designed for temporary SVC occlusion in TLE procedures. We report the first case of a 27-year-old man using the BOB as a safety net in a high-risk TLE procedure. This patient, with a congenitally corrected transposition of the great arteries and a third-degree atrioventricular block, presented with 4 dysfunctional pacemaker leads, venous stenosis and the necessity for a new pacemaker system. The leads were implanted for 10 and 19 years. The BOB was placed with a radiopaque marker at the cavoatrial junction and was inflated with 46 ml of an 80/20 saline/contrast agent mixture. An angiography was performed to confirm SVC occlusion. With the deflated balloon in place, the TLE procedure with laser and mechanical sheaths was performed. Successful extraction of 2 dysfunctional leads, as well as venous recanalization, for the new right atrial and right ventricular lead implantation was achieved. We have shown the feasibility of using powered extraction sheaths with a deflated BOB in place. This allows for immediate balloon inflation, in case of an SVC perforation.

Concepts: Blood, Heart, Vein, Right atrium, Inferior vena cava, Superior vena cava, Transposition of the great vessels, New Right

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Atrial fibrosis is the hallmark of atrial fibrillation (AF) dependent structure remodeling. Besides, sprouty 1 (Spry1) plays a key role in the process of fibrosis. In this study, we investigated whether Spry1 could regulate TGF-β1 in atrial fibrosis. Ten dogs or patients were assigned to control (n=4) and AF group (n=6). The left atrium of dogs or right atrial appendage of patients was taken. After that, cardiac fibroblasts were treated with or without angiotensin II (Ang II). Furthermore, cardiac fibroblasts were transfected with lentivirus of Spry1 over-expression vector, Spry1 shRNA or negative control (NC). And the protein expression of Spry1 and TGF-β1 was analyzed by western blot and immunohistochemistry. The results showed that TGF-β1 was highly expressed while Spry1 was lowly expressed in the models of human and canine with AF. Besides, the protein expression of TGF-β1 was up-regulated and Spry1 was down-regulated in Ang II stimulated cardiac fibroblasts. Furthermore, when Spry1 was knockdown in Ang II-induced cardiac fibroblasts, the cell proliferation and the TGF-β1 protein expression increased significantly, while Spry1 over-expression showed inverse results. Our results demonstrated that Spry1 may target TGF-β1 in regulating fibrosis. These findings may provide possible therapeutic targets in atrial fibrosis.

Concepts: Molecular biology, Blood, Heart, Atrial fibrillation, Circulatory system, Atrium, Angiotensin, Right atrium

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This study examines the incidence of iatrogenic atrial septal defect (iASD) after the MitraClip procedure and its influence on echocardiographic and clinical outcomes. We examined 96 patients who underwent a successful MitraClip procedure and who also had baseline and 1-year postprocedure transthoracic echocardiograms. At 1-year follow-up, iASD were observed in 24% of cases. Compared with the patients without iASD, the patients with iASD had a larger right atrium and greater severity of tricuspid regurgitation (TR) at baseline. After the MitraClip procedure, mitral regurgitation lessened significantly in both groups. Although right atrial area and right ventricular diameters increased significantly in patients with iASD (25.3 ± 8.0 to 28.3 ± 9.5 cm2, 39.7 ± 7.1 to 42.2 ± 8.1 mm, p <0.05 for both comparisons), these variables did not change in patients without iASD. In addition, patients with iASD had worse TR at follow-up. The incidence of stroke was comparable between the 2 groups during 1-year follow-up (4.3% vs 4.1%). However, patients with iASD had a markedly higher re-hospitalization rate for heart failure (26% vs 2.7%, p <0.05). In conclusion, iASD occurred in 24% of patients who underwent the MitraClip therapy and the presence of iASD was associated with right-sided heart enlargement, worse TR, and a higher re-hospitalization rate for heart failure.

Concepts: Blood, Cardiology, Heart, Right atrium, Tricuspid valve, Mitral valve, Mitral regurgitation, Mitral valve repair

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Persistent right valve of the systemic venous sinus is a rare anomaly with anatomical variations. This anomaly may present as an obstructive structure that can inhibit the antegrade flow through the tricuspid valve. We report on a 4-day-old neonate who presented with pronounced peripheral and central cyanosis. Echocardiographic examination showed a giant Eustachian valve moving towards the tricuspid valve during late systole and leading to complete obstruction of the inflow. Blood flow was redirected through the persistent foramen ovale, producing a right-to-left shunt.

Concepts: Heart failure, Heart, Vein, Cardiovascular system, Right atrium, Tetralogy of Fallot

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Right ventricular (RV) volume overload increases morbidity and mortality after tetralogy of Fallot (TOF) repair. Surgical strategies like pulmonary leaflets sparing and tricuspid valve repair at time of primary repair may decrease RV overload. Our objective is to evaluate early and midterm results of pulmonary leaflets sparing with infundibular preservation and tricuspid valve repair in selected TOF patients with moderate pulmonary annular hypoplasia.

Concepts: Mortality rate, Heart, Right ventricle, Right atrium, Tricuspid valve, Tetralogy of Fallot, Preservation, Pulmonary valve