Anatomic, histologic, and mechanical features of the right atrium: implications for leadless atrial pacemaker implantation.

Background: Leadless pacemakers (LPs) may mitigate the risk of lead failure and pocket infection related to conventional transvenous pacemakers. Atrial LPs are currently being investigated. However, the optimal and safest implant site is not known.

Spatially resolved multiomics of human cardiac niches.

The function of a cell is defined by its intrinsic characteristics and its niche: the tissue microenvironment in which it dwells. Here we combine single-cell and spatial transcriptomics data to discover cellular niches within eight regions of the human heart. We map cells to microanatomical locations and integrate knowledge-based and unsupervised structural annotations.

Familial Recurrence Patterns in Congenitally Corrected Transposition of the Great Arteries: An International Study.

Background: Congenitally corrected transposition of the great arteries (ccTGA) is a rare disease of unknown cause. We aimed to better understand familial recurrence patterns.

Methods: An international, multicentre, retrospective cohort study was conducted in 29 tertiary hospitals in 6 countries between 1990 and 2018, entailing investigation of 1043 unrelated ccTGA probands.

Predicting Survival in Repaired Tetralogy of Fallot: A Lesion-Specific and Personalized Approach.

Objectives: This study sought to identify patients with repaired tetralogy of Fallot (rTOF) at high risk of death and malignant ventricular arrhythmia (VA).

Background: To date there is no robust risk stratification scheme to predict outcomes in adults with rTOF.

Methods: Consecutive patients were prospectively recruited for late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) to define right and left ventricular (RV, LV) fibrosis in addition to proven risk markers.

Multimodality Imaging of the Anatomy of Tricuspid Valve.

Even though the tricuspid valve is no longer "forgotten", it still remains poorly understood. In this review, we focus on some controversial and still unclear aspects of tricuspid anatomy as illustrated by noninvasive imaging techniques. In particular, we discuss the anatomical architecture of the so-called tricuspid annulus with its two components (i.

Morphology of Mitral Annular Disjunction in Mitral Valve Prolapse.

Mitral annular disjunction (MAD) is an abnormal insertion of the hinge line of the posterior mitral leaflet on the atrial wall: the mitral annulus shows a separation or "disjunction" between the leaflet-atrial wall junction and the crest of the left ventricle myocardium. This anomaly is often observed in patients with myxomatous mitral valve prolapse. The anatomical substrate of MAD remains unclear for the following reasons: (1) most studies are focused on the association between MAD and arrhythmias, rather than on pathomorphological aspects of MAD; and (2) the complex anatomic architecture of the posterior mitral annulus is often simply described as the posterior segment of a fibrous ring.

The Predicament of Surgical Correction of Tetralogy of Fallot.

Surgery for tetralogy of Fallot has a long history, which may be described as both a success story and a failure story. It is a success story because prognosis without surgery is very poor, but surgery makes it possible for affected babies to reach adulthood and lead productive lives. It is a failure story, however, since we still cannot cure this condition; we can only palliate it as illustrated in the sobering long-term outcome of affected patients.

State-of-the-Art Review: Anatomical and Imaging Considerations During Transcatheter Tricuspid Valve Repair Using an Annuloplasty Approach.

Transcatheter techniques for the treatment of tricuspid regurgitation (TR) are being more frequently used and several new devices are in development. Since 90% of patients with TR have secondary TR, catheter based systems which reduce the dilated tricuspid annulus area are of particular interest. In order to perform an annuloplasty procedure effectively and safely, knowledge about the anatomy of the tricuspid valve apparatus and especially of the annulus in relation to the important neighboring structures such as the aortic root, the RCA, the electrical pathways and the CS is fundamental.

Systematic Evaluation of High-Resolution Activation Mapping to Identify Residual Endocardial and Epicardial Conduction Across the Mitral Isthmus.

Objectives: This study sought to systematically evaluate the ability of a high-resolution mapping system (Rhythmia, Boston Scientific, Marlborough, Massachusetts) to rapidly and accurately localize residual endocardial and epicardial conduction after mitral isthmus (MI) ablation, facilitating MI block.

Background: Achieving conduction block across the mitral isthmus (MI) is challenging.

Methods: Fifty consecutive patients undergoing MI ablation after pulmonary vein isolation were enrolled.

Myxomatous Mitral Valve Disease with Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical and Functional Significance of the Coincidence.

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death.

Multimodality imaging anatomy of interatrial septum and mitral annulus.

The detailed anatomy of the interatrial septum (IAS) and mitral annulus (MA) as observed on cardiac magnetic resonance, computed tomography and two-dimensional/three-dimensional transthoracic and transesophageal echocardiography is reviewed. The IAS comprises of two components: the septum primum that is membrane-like forming the floor of the fossa ovalis (FO) and the septum secundum that is a muscular rim that surrounds the FO. The latter is an enfolding of atrial wall forming an interatrial groove.

Anatomy of the Atrioventricular Junction, Atrioventricular Grooves, and Accessory Pathways.

Accessory pathways that bypass all or part of the normal atrioventricular conduction system traverse the atrioventricular junction. The atrioventricular junction comprises of a limited septal component and much more extensive right and left parietal components. Its composition forms a plane of insulation between atrial and ventricular myocardium, preventing direct continuity between them.

Three-Dimensional Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Predicts Inducibility of Ventricular Tachycardia in Adults With Repaired Tetralogy of Fallot.

Background: Adults with repaired tetralogy of Fallot die prematurely from ventricular tachycardia (VT) and sudden cardiac death. Inducible VT predicts mortality. Ventricular scar, the key substrate for VT, can be noninvasively defined with late gadolinium enhancement (LGE) cardiovascular magnetic resonance but whether this relates to inducible VT is unknown.

[Anatomic pitfalls and challenges of His bundle pacing].

Long-term right ventricular apical pacing is known to be deleterious for left ventricular function leading to the clinical picture of heart failure with all the possibly associated complications, ranging up to death of the affected patient. This led to the ambition to find alternative pacing sites such as pacing at the right ventricular outflow tract or septal pacing. An attractive alternative is selective His bundle pacing with the goal to use the physiologic His-Purkinje system in order to enable intrinsic conduction and physiologic myocardial contraction.

Autopsy in adults with congenital heart disease (ACHD).

The adult congenital heart diseases (ACHD) population is exceeding the pediatric congenital heart diseases (CHD) population and is progressively expanding each year, representing more than 90% of patients with CHD. Of these, about 75% have undergone surgical and/or percutaneous intervention for palliation or correction. Autopsy can be a very challenging procedure in ACHD patients.

Isomerism of the atrial appendages: morphology and terminology.

Background: Our aim is to identify the pathognomonic anatomical markers and the best terminology to describe the cardiac malformations associated with absent or multiple spleens, which are known as asplenia or polysplenia syndromes or isomerism.

Materials And Methods: We have reviewed 65 hearts with isomerism of atrial appendages of the Anatomical Collections of Congenital Heart Disease, Institute of Pathological Anatomy of the University of Padua consisting of 1800 specimens. All the hearts were classified according to sequential segmental classification.

The left atrial appendage in humans: structure, physiology, and pathogenesis.

For many years, the left atrial appendage (LAA) was considered a dormant embryological remnant; however, it is a structurally complex and functional organ that contributes to cardiac haemodynamic changes and volume homeostasis through both its contractile properties and neurohormonal peptide secretion. When dysfunctional, the LAA contributes to thrombogenesis and subsequent increased predisposition to cardioembolic events. Consequently, the LAA has gained much attention as a therapeutic target to lower this risk.

Uncertainties and challenges in surgical and transcatheter tricuspid valve therapy: a state-of-the-art expert review.

Tricuspid regurgitation (TR) is a frequent and complex problem, commonly combined with left-sided heart disease, such as mitral regurgitation. Significant TR is associated with increased mortality if left untreated or recurrent after therapy. Tricuspid regurgitation was historically often disregarded and remained undertreated.

The Intrusive Nature of Epicardial Adipose Tissue as Revealed by Cardiac Magnetic Resonance.

The epicardial adipose tissue (EAT) refers to the deposition of adipose tissue fully enclosed by the pericardial sac. EAT has a complex mixture of adipocytes, nervous tissue, as well as inflammatory, stromal and immune cells secreting bioactive molecules. This heterogeneous composition reveals that it is not a simply fat storage depot, but rather a biologically active organ that appears playing a "dichotomous" role, either protective or proinflammatory and proatherogenic.

Anatomy of mitral annulus insights from non-invasive imaging techniques.

The mitral annulus (MA) is not a continuous ring of connective tissue from which are suspended mitral leaflets. Instead, it is a much more complex structure made up of a mix of fibrous, muscular, and adipose tissues. MA is a key structure in any type of mitral valve repair and recently it has been targeted for transcutaneous devices.

Inadvertent transseptal puncture into the aortic root: the narrow edge between luck and catastrophe in interventional cardiology.

Aims: Inadvertent puncture of the aortic root (AR) is a well-known complication of transseptal puncture (TSP). Strategies for handling of this potentially lethal complication have not been identified yet. In this study, we present typical anatomical locations and clinical management of aortic root puncture (ARP) due to TSP.