Multimodal imaging of the tricuspid valve: normal appearance and pathological entities

Prenatal sonographic findings of prominent fetal tricuspid annulus: A case report

The tricuspid valve positioned between the right atrium and right ventricle is composed of 3 leaflets (anterior, posterior, and septal) anchored by a collagenous fibrous annulus, a saddle-shaped, oval structure, providing a firm yet dynamic structural support for the tricuspid valve. The annulus is considered to separate between the right atrium and right ventricle. Structural anomalies of the fetal tricuspid valve are rare and include Ebstein's anomaly, tricuspid atresia, partial absence, unguarded tricuspid orifice (absent leaflets) cleft, double orifice, bicuspid valve and Uhl anomaly (absence of the right ventricular myocardium with an apposing endocardium and epicardium). We present an unusual case in which a prominent peripheral circular structure was noted above the periphery of the fetal tricuspid valve at 31 weeks' gestation. Inflow across the tricuspid valve was unimpaired, with no tricuspid regurgitation. The right atrium appeared normal with a normal functioning foramen ovale, and the entire fetal cardiac anatomy and function were normal with no signs of congestive cardiac failure or fetal hydrops. The prominent non-obstructing circular structure in immediate proximity to the tricuspid valve leaflets was considered to represent a prominent tricuspid annulus. An appropriate for gestational age fetus was delivered at term and neonatal echocardiography was normal. This case emphasizes that normal variations in fetal anatomical structures should always be considered and specifically that unimpaired inflow across the tricuspid valve in diastole is key upon encountering an unusually prominent fetal tricuspid annulus, which may be noted at a considerable distance above the tricuspid leaflets within the right atrium.

Multimodality imaging for transcatheter tricuspid valve repair and replacement

Transcatheter tricuspid intervention is a rapidly evolving field with multiple classes of therapeutic devices currently in development. Procedural success in tricuspid intervention is predicated on appropriate device selection for patient specific anatomy and satisfactory imaging for intra-procedural guidance. This review will outline protocols and methodology for multi-modality imaging assessment of the tricuspid valve and associated structures, with emphasis on anatomic and functional characteristics that determine suitability for each class of tricuspid intervention. Intra-procedural imaging requirements for each class of device, with design and procedural imaging guidance of specific devices, will also be addressed.

Utility of CT and MRI in Tricuspid Valve Interventions

Transcatheter tricuspid valve interventions (TTVIs) comprise a variety of catheter-based interventional techniques for treatment of tricuspid regurgitation (TR) in patients at high surgical risk and those with failed previous surgeries. Several TTVI devices with different mechanisms of action are either currently used or in preclinical evaluation. Echocardiography is the first-line modality for evaluation of tricuspid valve disease that provides information on tricuspid valve morphology, mechanism of TR, and hemodynamics. Cardiac CT and MRI have several advantages for a comprehensive preprocedure evaluation. CT and MRI provide complementary information to that of echocardiography on the mechanism and cause of TR. MRI can quantify the severity of TR using indirect or direct techniques that involve two-dimensional or four-dimensional flow sequences. MRI and CT can also accurately quantify right ventricular volumes and function, which is crucial for timing of intervention. CT provides comprehensive three-dimensional information on the morphology of the valve, annulus, subvalvular apparatus, and adjacent structures. CT is the procedure of choice for evaluation of several device-specific measurements, including tricuspid annulus dimensions, annulus-to-right coronary artery distance, leaflet morphology, coaptation gaps, caval dimensions, and cavoatrial-to-hepatic vein distance. CT allows evaluation of the vascular access as well as optimal procedure fluoroscopic angles and catheter trajectory. Postprocedure CT and MRI are useful in detection of complications such as paravalvular leak, pseudoaneurysm, thrombus, pannus, infective endocarditis, and device migration. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Cellular and Molecular Mechanisms Underlying Tricuspid Valve Development and Disease

Tricuspid valve (TV) disease is highly prevalent in the general population. For ages considered "the forgotten valve" because of the predominant interest in left-side valve disease, the TV has now received significant attention in recent years, with significant improvement both in diagnosis and in management of tricuspid disease. TV is characterized by complex anatomy, physiology, and pathophysiology, in which the right ventricle plays a fundamental role. Comprehensive knowledge of molecular and cellular mechanisms underlying TV development, TV disease, and tricuspid regurgitation-related right-ventricle cardiomyopathy is necessary to enhance TV disease understanding to improve the ability to risk stratify TR patients, while also predicting valve dysfunction and/or response to tricuspid regurgitation treatment. Scientific efforts are still needed to eventually decipher the complete picture describing the etiopathogenesis of TV and TV-associated cardiomyopathy, and future advances to this aim may be achieved by combining emerging diagnostic imaging modalities with molecular and cellular studies. Overall, basic science studies could help to streamline a new coherent hypothesis underlying both the development of TV during embryogenesis and TV-associated disease and its complications in adult life, providing the conceptual basis for the ultimate and innovative field of valve repair and regeneration using tissue-engineered heart valves.

Role of computed tomography in transcatheter replacement of 'other valves': a comprehensive review of preprocedural imaging

Transcatheter procedures for heart valve repair or replacement represent a valid alternative for treating patients who are inoperable or at a high risk for open-heart surgery. The transcatheter approach has become predominant over surgical intervention for aortic valve disease, but it is also increasingly utilized for diseases of the 'other valves', that is the mitral and, to a lesser extent, tricuspid and pulmonary valve. Preprocedural imaging is essential for planning the transcatheter intervention and computed tomography has become the main imaging modality by providing information that can guide the type of treatment and choice of device as well as predict outcome and prevent complications. In particular, preprocedural computed tomography is useful for providing anatomic details and simulating the effects of device implantation using 3D models. Transcatheter mitral valve replacement is indicated for the treatment of mitral regurgitation, either primary or secondary, and computed tomography is crucial for the success of the procedure. It allows evaluating the mitral valve apparatus, the surrounding structures and the left heart chambers, identifying the best access route and the landing zone and myocardial shelf, and predicting obstruction of the left ventricular outflow tract, which is the most frequent postprocedural complication. Tricuspid valve regurgitation with or without stenosis and pulmonary valve stenosis and regurgitation can also be treated using a transcatheter approach. Computer tomography provides information on the tricuspid and pulmonary valve apparatus, the structures that are spatially related to it and may be affected by the procedure, the right heart chambers and the right ventricular outflow tract.

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Tricuspid valve in congenital heart disease: multimodality imaging and electrophysiological considerations

The tricuspid valve (TV) has been neglected for many years. Only recently, new studies demonstrated the prognostic role of the tricuspid valve lesions. In addition to that, new interventional approaches offer the possibility to non-invasively treat tricuspid valve disease. In this review, our aim is to summarize the role of different imaging techniques in the assessment of tricuspid valve with particular regards to congenital heart diseases. Finally, we analyze the importance of the TV and its adjacent regions from an electrophysiological point of view, both in structurally normal hearts and in congenital heart diseases. The most relevant transthoracic echocardiography (TTE) views to visualize the TV are the "modified" parasternal long axis, the apical views and subcostal projections, such as right oblique or left oblique views. However, simultaneous visualization of the three leaflets is possible only with three-dimensional TTE, or, sometimes, in parasternal short axis and subcostal short axis views in children. 3D echocardiography (3DE) is promising in this field. Indeed, its unique projections, such as en face views from the right ventricular and atrial perspectives, are able to define the spatial relationship of the tricuspid leaflets with the surrounding structures. Moreover, multimodality imaging assessment has been recently proposed for the diagnostic assessment of the TV, especially before percutaneous intervention. Cardiac Computed Tomography (CCT) provides valuable anatomic spatial information of the TV apparatus. Cardiac Magnetic Resonance (CMR) is able to provide, non-invasively, detailed morphological and functional information of the valve.

Mitral Ebstein's Anomaly Modified with a Scarred Rhabdomyoma in Tuberous Sclerosis: An Extremely Rare Cause of Mitral Insufficiency

We present an extremely rare case of mitral Ebstein's anomaly that resulted in severe mitral regurgitation (MR). A 41-year-old woman with a history of tuberous sclerosis underwent surgery. Preoperatively, it was assumed that MR had occurred due to leaflet tethering related to left ventricular posterior wall motion asynergy due to a scarred rhabdomyoma. However, surgical inspection revealed a dysplastic posterior leaflet adhering to the ventricular wall, which was completely covered by the endocardium. Both congenital mitral Ebstein's anomaly and acquired wall motion abnormality due to a scarred rhabdomyoma may have contributed to the development of severe MR in this case.

Atrioventricular Valve Regurgitation in Single Ventricle Heart Disease: A Common Problem Associated With Progressive Deterioration and Mortality

The Fontan procedure has provided patients with single ventricle physiology extended survival into adulthood and in many cases has improved their quality of life. Atrioventricular valve regurgitation (AVVR) is common in single ventricle patients and is associated with increased risk of mortality. AVVR is more common in patients with a systemic tricuspid or common atrioventricular valve but is generally progressive irrespective of underlying valve morphology. AVVR can be attributable to diverse structural and functional abnormalities at multiple levels of the valvar apparatus, as well as ventricular dysfunction and dilation. Multiple imaging modalities including recent advances in 3‐dimensional echocardiography and cross‐sectional imaging have been used to further understand AVVR. Surgery to address AVVR must be tailored to the underlying mechanism and the timing of surgical repair should be chosen carefully. In this review, we discuss the etiologies, treatment options, surgical timing, and outcomes of valve repair or replacement for AVVR in patients with single ventricle congenital heart disease, with a focus on those with a Fontan circulation as AVVR is associated with increased risk for Fontan failure and mortality. In‐depth understanding of the current literature will help guide clinicians in their approach and management of AVVR in this population.

Computed Tomography of Cardiac Valves: Review

Valvular heart disease is a common clinical problem. Although echocardiography is the standard technique for the noninvasive evaluation of the valves, cardiac CT has evolved to become a useful tool in the evaluation of the cardiac structures as well. Importantly, CT allows for improved quantification of valvular calcification due to its superior spatial resolution. It may improve the detection of small valvular or perivalvular pathology or the characterization of valvular masses and vegetations. This review describes the assessment of normal and diseased heart valves by cardiac CT and discusses its strengths and weaknesses.

Multi-Modality Imaging in the Evaluation and Treatment of Tricuspid Regurgitation

PURPOSE OF REVIEW

The goal of this review is to cover the epidemiology of tricuspid regurgitation (TR), anatomy of the tricuspid valve (TV), and the mechanisms and modern treatment of TR. The focus will be on the role of echocardiography, cardiac CT, and MRI to determine the mechanism, severity, and management strategies of TR.

RECENT FINDINGS

The evaluation and management of TR is a rapidly growing field with significant advances in both imaging and interventions. Important advances have been made to understand TV anatomy and physiology in 3D echo, CT, and MRI. Additional understanding of the abnormal outcomes in both primary TR and secondary TR have been appreciated. Multiple transcatheter devices have reached the stage of early trials in high surgical risk cohorts with favorable initial findings. TR is a significant cardiovascular problem and vastly undertreated in the present era. There has been tremendous growth in knowledge of mechanisms of TR, its prognostic implications, timing of intervention, and development of novel treatment strategies. Multimodality imaging plays a key role in evaluation and treatment of this condition.