Heightened interest in tricuspid regurgitation (TR) stems from the consistent association of mortality with greater severity of TR, and a low use of surgical solutions in the setting of high in-hospital mortality attributed to the late presentation of the disease. The delay in intervention is likely related to a limited understanding of the valvular/ventricular anatomy and disease pathophysiology, along with an underestimation of TR severity by standard imaging modalities. With the rapid development of transcatheter solutions which have shown early safety and efficacy, there is a growing need to understand and accurately diagnose the valvular disease process in order to determine appropriate management solutions. The current review will describe both normal and pathologic tricuspid valvular anatomy, the classification of these anatomic substrates of TR, the strengths and limitations of the current guidelines-recommended multi-parametric echocardiographic approach and the role of multi-modality imaging, as well as the role of transcatheter device therapy in the management of the disease.

Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is an advanced imaging technique designed for left ventricular (LV) myocardial deformation analysis based on 3D data sets. 3DSTE has the potential to overcome some of the intrinsic limitations of two-dimensional STE (2DSTE) in the assessment of complex LV myocardial mechanics, offering additional deformation parameters (such as area strain) and a comprehensive quantitation of LV geometry and function from a single 3D acquisition. Albeit being a relatively young technique still undergoing technological developments, several experimental studies and clinical investigations have already demonstrated the reliability and feasibility of 3DSTE, as well as several advantages of 3DSTE over 2DSTE. This technique has provided new insights into LV mechanics in several clinical fields, such as the objective assessment of global and regional LV function in ischemic and non-ischemic heart diseases, the evaluation of LV mechanical dyssynchrony, as well as the detection of subclinical cardiac dysfunction in cardiovascular conditions at risk of progression to overt heart failure. However, 3DSTE generally requires patient’s breathhold and regular rhythm for enabling an ECG-gated multi-beat 3D acquisition. In addition, the measurements, normal limits and cut-off values pertaining to 3D strain parameters are currently vendor-specific and highly dependent on the 3D ultrasound equipment used. Technological advances with improvement in spatial and temporal resolution and a standardized methodology for obtaining vendor-independent 3D strain measurements are expected in the future for a widespread application of 3DSTE in both clinical and research arenas. The purpose of this review is to summarize currently available data on 3DSTE methodology (feasibility, accuracy and reproducibility), strengths and weaknesses with respect to 2DSTE, as well as the main clinical applications and future research priorities of this emerging technology.

Background—: Despite the fact that assessment of right ventricular longitudinal strain (RVLS) carries important implications for patient diagnosis, prognosis, and treatment, its implementation in clinical settings has been hampered by the limited reference values and the lack of uniformity in software, method, and definition used for measuring RVLS. Accordingly, this study was designed to establish (1) the reference values for RVLS by 2-dimensional speckle-tracking echocardiography; and (2) their relationship with demographic, hemodynamic, and cardiac factors. Methods and Results—: In 276 healthy volunteers (55% women; age, 18–76 years), free wall and septum RVLS (6 segments) and free wall RVLS (3 segments) using both 6- and 3-segment regions of interest were obtained. Feasibility of 6-segment RVLS was 92%. Free wall RVLS from 3- versus 6-segment regions of interest had similar values, yet 6-segment region of interest was more feasible (86% versus 73%; P <0.001) and reproducible. Reference values (lower limits of normality) were as follows: 6-segment RVLS, −24.7±2.6% (−20.0%) for men and −26.7±3.1% (−20.3%) for women; 3-segment RVLS, −29.3±3.4% (−22.5%) for men and −31.6±4.0% (−23.3%) for women ( P <0.001). Free wall RVLS was 5±2 strain units (%) larger in magnitude than 6-segment RVLS, 10±4% larger than septal RVLS, and 2±4% larger in women than in men ( P <0.001). At multivariable analysis, age, sex, pulmonary systolic pressure, right atrial minimal volume, as well as right atrial and left ventricular longitudinal strain resulted as correlates of RVLS values. Conclusions—: This is the largest study providing sex- and method-specific reference values for RVLS. Our data may foster the implementation of 2-dimensional speckle-tracking echocardiography–derived RV analysis in clinical practice.

(i) To validate a new software for right ventricular (RV) analysis by 3D echocardiography (3DE) against cardiac magnetic resonance (CMR); (ii) to assess the accuracy of different measurement approaches; and (iii) to explore any benefits vs. the previous software. We prospectively studied with 3DE and CMR 47 patients (14–82 years, 28 men) having a wide range of RV end-diastolic volumes (EDV 82–354 mL at CMR) and ejection fractions (EF 34–81%). Multi-beat RV 3DE data sets were independently analysed with the new software using both automated and manual editing options, as well as with the previous software. RV volume reproducibility was tested in 15 random patients. RV volumes and EF measurements by the new software had an excellent accuracy (bias ± SD: −15 ± 24 mL for EDV; 1.4 ± 4.9% for EF) and reproducibility compared with CMR, provided that the RV borders automatically tracked by software were systematically edited by operator. The automated analysis option underestimated the EDV, overestimated the ESV, and largely underestimated the EF (bias ± SD: −17 ± 10%). RV volumes measured with the new software using manual editing showed similar accuracy, but lower inter-observer variability and shorter analysis time (3–5′) in comparison with the previous software. Novel vendor-independent 3DE software enables an accurate, reproducible and faster quantitation of RV volumes and ejection fraction. Rather than optional, systematic verification of border tracking quality and manual editing are mandatory to ensure accurate 3DE measurements. These findings are relevant for echocardiography laboratories aiming to implement 3DE for RV analysis for both research and clinical purposes.

Background—: Our study sought to (1) identify reference values for left atrial (LA) volumes and phasic function indices by 3-dimensional echocardiography (3DE) and compare them with those measured by 2-dimensional echocardiography (2DE) and (2) analyze their relationship with age, sex, body size, and left ventricular function. Accuracy and reproducibility of 3DE and 2DE have been also tested to evaluate the robustness of our data. Methods and Results—: We obtained maximal, minimal, and preA LA volumes by 3DE and 2DE in 276 healthy volunteers (18–79 years; 57% women). Limits of normality for LA volumes and total LA emptying fraction were larger with 3DE than with 2DE (maximal LA volume: 43 versus 35 mL/m ² ; preA LA volume: 31 versus 25 mL/m ² ; minimal LA volume: 18 versus 14 mL/m ² ; 53 versus 48%, respectively; P <0.001). 3DE LA volumes indexed by body surface area were similar in men and women and increased with age. On multivariable analysis, age, weight, and left ventricular systolic and diastolic function indices resulted as correlates of LA 3DE indices. LA volumes were tightly correlated with cardiac magnetic resonance measurements, yet more underestimated by 2DE versus 3DE (bias±SD: −17±16 versus −7±15 mL, respectively). Among all LA parameters, maximal LA volume and total emptying fraction were the most reproducible, including at test-retest and at expert versus trainee comparisons. Conclusions—: This study provides reference values for LA 3DE volumes and function from a relatively large cohort of healthy subjects with a wide age range. Our data may help clinicians to identify LA remodeling and dysfunction.

Atrial secondary tricuspid regurgitation (A-STR) is a distinct phenotype of secondary tricuspid regurgitation with predominant dilation of the right atrium and normal right and left ventricular function. Atrial secondary tricuspid regurgitation occurs most commonly in elderly women with atrial fibrillation and in heart failure with preserved ejection fraction in sinus rhythm. In A-STR, the main mechanism of leaflet malcoaptation is related to the presence of a significant dilation of the tricuspid annulus secondary to right atrial enlargement. In addition, there is an insufficient adaptive growth of tricuspid valve leaflets that become unable to cover the enlarged annular area. As opposed to the ventricular phenotype, in A-STR, the tricuspid valve leaflet tethering is typically trivial. The A-STR phenotype accounts for 10%–15% of clinically relevant tricuspid regurgitation and has better outcomes compared with the more prevalent ventricular phenotype. Recent data suggest that patients with A-STR may benefit from more aggressive rhythm control and timely valve interventions. However, little is mentioned in current guidelines on how to identify, evaluate, and manage these patients due to the lack of consistent evidence and variable definitions of this entity in recent investigations. This interdisciplinary expert opinion document focusing on A-STR is intended to help physicians understand this complex and rapidly evolving topic by reviewing its distinct pathophysiology, diagnosis, and multi-modality imaging characteristics. It first defines A-STR by proposing specific quantitative criteria for defining the atrial phenotype and for discriminating it from the ventricular phenotype, in order to facilitate standardization and consistency in research.