Quantification of Tricuspid Regurgitation by Live Three-Dimensional Transthoracic Echocardiographic Measurements of Vena Contracta Area

Echocardiography Imaging of the Right Ventricle: Focus on Three-Dimensional Echocardiography

Right ventricular function strongly predicts cardiac death and adverse cardiac events in patients with cardiac diseases. However, the accurate right ventricular assessment by two-dimensional echocardiography is limited due to its complex anatomy, shape, and load dependence. Advances in cardiac imaging and three-dimensional echocardiography provided more reliable information on right ventricular volumes and function without geometrical assumptions. Furthermore, the pathophysiology of right ventricular dysfunction and tricuspid regurgitation is frequently connected. Three-dimensional echocardiography allows a more in-depth structural and functional evaluation of the tricuspid valve. Understanding the anatomy and pathophysiology of the right side of the heart may help in diagnosing and managing the disease by using reliable imaging tools. The present review describes the challenging echocardiographic assessment of the right ventricle and tricuspid valve apparatus in clinical practice with a focus on three-dimensional echocardiography.

Three-dimensional echocardiography of the tricuspid valve

Due to the proportionally high mortality rates associated with isolated tricuspid valve surgery, the invasive treatment of such pathology, historically, has been left largely unaddressed. Recently, there has been an appreciation for the mortality and morbidity of tricuspid valve disease, giving rise to the movement towards identifying less invasive, transcatheter approaches for treatment. Due to the technical complexity of these procedures along with the uniqueness and variability of tricuspid valve anatomy, a better appreciation of the tricuspid valve anatomy and pathology is required for pre-procedural planning. While two-dimensional echocardiography serves as the initial non-invasive modality for tricuspid valve evaluation, three-dimensional echocardiography provides a complete en face view of the tricuspid valve and surrounding structures, as well contributes further information regarding disease etiology and severity. In this review, we discuss the utility of three-dimensional echocardiography as a supplement to two-dimensional imaging to better assess tricuspid valve disease and anatomy to aide in future innovative therapies.

Three-Dimensional Echocardiography for Tricuspid Valve Assessment

PURPOSE OF REVIEW

This review article provides an overview of the various roles of 3-dimensional (3D) echocardiography in the evaluation of the tricuspid valve (TV) with specific focus on tricuspid regurgitation (TR) and its treatment.

RECENT FINDINGS

The prognostic implications of TR and the advent of new transcatheter therapies have underscored the need of accurate assessment of the TV. 3D echocardiography is key to assess the anatomy and function of TV and has provided new insights that have led to new classifications of the type of TR. Furthermore, 3D echocardiography is superior to 2-dimensional echocardiography to assess the right ventricle, an important parameter to select the patients with severe TR who may benefit from intervention. Finally, the use of 3D echocardiography during the guidance of transcatheter interventions is pivotal to ensure procedural success and minimize the complications. Three-dimensional echocardiography provides the soft tissue resolution that fluoroscopy does not provide.

The evolving role of multi-modality imaging in transcatheter tricuspid valve interventions

Tricuspid valve pathophysiology is not well-understood. Emergence of novel transcatheter tricuspid therapies has fueled the requirements for improved imaging visualization techniques and interventional imaging physician skillsets in guiding these complex transcatheter procedures. There is growing understanding on the clinical significance of tricuspid regurgitation which expanded the interest for percutaneous tricuspid valve interventions. The present review concentrates on three essential aspects of tricuspid valve pathophysiology: anatomical considerations for tricuspid interventions, optimal timing of tricuspid interventions by imaging guidance, and the role of interventional imaging physicians’ skillset and knowledge in this field.

Echocardiographic Assessment of Right Ventricular Function in Paediatric Heart Disease: A Practical Clinical Approach

As the right ventricle (RV) plays an integral role in different paediatric heart diseases, the accurate assessment of RV size and function is essential in the diagnosis, management, and prognostication of congenital and acquired cardiac lesions. Yet, echocardiographic evaluation of the RV is challenging because of its complex and variable morphology, its different physiology compared with the left ventricle, and its capability to adapt to different loading conditions associated with congenital and acquired heart diseases within certain ranges. Reliable echocardiographic detection of RV systolic and diastolic dysfunction remains challenging while important for patient management. This review provides an updated, practical approach to assessing RV function in structurally normal hearts and in children with common congenital heart defects and in those with pulmonary hypertension. We also review the impact of tricuspid valve function on RV functional parameters. There is no single functional RV parameter that uniquely describes RV function; instead a combination of different parameters is recommended in clinical practice. Qualitative and quantitative analysis of RV function will be reviewed including more recent techniques such as speckle tracking and 3D echocardiography.

Developing Insights Regarding Tricuspid Valve Regurgitation: Morphology, Assessment of Severity, and the Need for a Novel Grading Scheme

Current understanding that progressive tricuspid regurgitation (TR) is associated with worse outcomes has highlighted the clinical need for a more accurate assessment of TR morphology and severity. This need has been further emphasized owing to the development of a myriad of percutaneous right-sided interventions, which may offer successful treatment of TR in selected patients. Understanding the etiology and quantification of the severity of TR has important implications in the selection of novel therapeutic strategies, i.e., medical vs. percutaneous vs. surgical approaches. Newer grading schemas that better reflect the TR lesion severity have been recently proposed and may facilitate monitoring of the evolution of TR following percutaneous and/or surgical treatment. In this review, we summarize contemporary concepts regarding tricuspid valve morphology, TR etiology, and associated mechanisms and echocardiographic approaches to grade TR severity.

Transcatheter Tricuspid Valve Therapy: From Anatomy to Intervention

Nowadays, severe symptomatic tricuspid regurgitation (TR) affects millions of persons worldwide. However, the benefit of surgical correction of isolated secondary TR remains controversial because of the increased risk of periprocedural mortality and morbidity. In recent years, novel transcatheter tricuspid valve interventions (TTVI) were developed to treat TR, so that TTVI is currently considered in symptomatic, inoperable, anatomically eligible patients. TTVI can be divided into these five domains: edge-to-edge leaflet repair, tricuspid annuloplasty, caval implants, spacer, and total valve replacement. Each transcatheter intervention needs specific imaging protocols for assessing the anatomical feasibility and consequentially predicting the procedural success. This review summarizes the available multimodality imaging tools for screening patients with TR, and identifies anatomical characteristics to choose the best option for the patient.

Echocardiographic Advances in Dilated Cardiomyopathy

Although the overall survival of patients with dilated cardiomyopathy (DCM) has improved significantly in the last decades, a non-negligible proportion of DCM patients still shows an unfavorable prognosis. DCM patients not only need imaging techniques that are effective in diagnosis, but also suitable for long-term follow-up with frequent re-evaluations. The exponential growth of echocardiography’s technology and performance in recent years has resulted in improved diagnostic accuracy, stratification, management and follow-up of patients with DCM. This review summarizes some new developments in echocardiography and their promising applications in DCM. Although nowadays cardiac magnetic resonance (CMR) remains the gold standard technique in DCM, the echocardiographic advances and novelties proposed in the manuscript, if properly integrated into clinical practice, could bring echocardiography closer to CMR in terms of accuracy and may certify ultrasound as the technique of choice in the follow-up of DCM patients. The application in DCM patients of novel echocardiographic techniques represents an interesting emergent research area for scholars in the near future.

Multimodality cardiac imaging and new display options to broaden our understanding of the tricuspid valve

PURPOSE OF REVIEW

The prognostic impact of tricuspid regurgitation (TR) and the subsequent development of percutaneous procedures targeting the tricuspid valve (TV), has brought to the forefront the role of imaging for the assessment of the forgotten valve. As illustrated in several studies and summarized in this review, currently a multimodality imaging approach is required to understand the pathophysiology of TR, due to the complex TV anatomy and the close relationship between the severity of TR and the extent of the remodeling of the right heart chambers.

RECENT FINDINGS

Recently, the advance in the tranhscatheter treatment of the TV has led to a growing interest in the development of dedicated software packages and new display modalities to increase our understanding of the TV. As a consequence, a transversal knowledge of the different imaging modalities is required for contemporary cardiac-imaging physicians.

SUMMARY

This review highlights the main features, and the pros and cons of echocardiography, cardiac computed tomography, cardiac magnetic resonance and emerging technologies, as 3D printing and virtual reality, in the assessment of patients with TR.

Dynamic Systolic Changes in Tricuspid Regurgitation Vena Contracta Size and Proximal Isovelocity Surface Area in Hypoplastic Left Heart Syndrome: A Three-Dimensional Color Doppler Echocardiographic Study

BACKGROUND

The aims of this study were to investigate the dynamic changes in the vena contracta (VC) and proximal isovelocity surface area (PISA) through systole in patients with hypoplastic left heart syndrome and tricuspid regurgitation and to identify the stage of systole (early, mid, or late) in which VC and PISA radius are optimal.

METHODS

Twenty-eight patients with hypoplastic left heart syndrome were prospectively studied using continuous two-dimensional (2D) and three-dimensional (3D) echocardiography. Two-dimensional VC width, 3D VC area, and PISA radii (2D and 3D) were measured frame by frame throughout systole. The maximal 2D VC width, 3D VC area, and PISA radii in the first, middle, and last thirds of systole were compared, and correlations were explored with 3D tricuspid annular areas, right atrial volumes, and right ventricular volumes.

RESULTS

In all, 35 data sets that met inclusion criteria were analyzed. On frame-by-frame analysis, maximal 2D VC width and 3D VC area were found in the first third of systole in 17% and 20% of studies, in the second third in 34% and 31%, and in the final third in 49% and 49%. Similarly, the maximal 2D and 3D PISA radii were found in the first third of systole in 26% and 17% of studies, in the second third in 28% and 34%, and in the final third in 46% and 49%.

CONCLUSIONS

In hypoplastic left heart syndrome, detailed temporal analysis of tricuspid regurgitation-associated VC and PISA by 2D and 3D echocardiography reveals no reliable pattern predicting when in systole these parameters peak. Frame-by-frame measurement is necessary for identification of maximal VC and PISA radius on 2D and 3D color Doppler echocardiography because the severity of tricuspid regurgitation could be underestimated because of temporal variability in VC and PISA.

Echocardiographic assessment of the tricuspid and pulmonary valves: a practical guideline from the British Society of Echocardiography

Transthoracic echocardiography is the first-line imaging modality in the assessment of right-sided valve disease. The principle objectives of the echocardiographic study are to determine the aetiology, mechanism and severity of valvular dysfunction, as well as consequences on right heart remodelling and estimations of pulmonary artery pressure. Echocardiographic data must be integrated with symptoms, to inform optimal timing and technique of interventions. The most common tricuspid valve abnormality is regurgitation secondary to annular dilatation in the context of atrial fibrillation or left-sided heart disease. Significant pulmonary valve disease is most commonly seen in congenital heart abnormalities. The aetiology and mechanism of tricuspid and pulmonary valve disease can usually be identified by 2D assessment of leaflet morphology and motion. Colour flow and spectral Doppler are required for assessment of severity, which must integrate data from multiple imaging planes and modalities. Transoesophageal echo is used when transthoracic data is incomplete, although the anterior position of the right heart means that transthoracic imaging is often superior. Three-dimensional echocardiography is a pivotal tool for accurate quantification of right ventricular volumes and regurgitant lesion severity, anatomical characterisation of valve morphology and remodelling pattern, and procedural guidance for catheter-based interventions. Exercise echocardiography may be used to elucidate symptom status and demonstrate functional reserve. Cardiac magnetic resonance and CT should be considered for complimentary data including right ventricular volume quantification, and precise cardiac and extracardiac anatomy. This British Society of Echocardiography guideline aims to give practical advice on the standardised acquisition and interpretation of echocardiographic data relating to the pulmonary and tricuspid valves.

Sources of Variability in Vena Contracta Area Measurement for Tricuspid Regurgitation Severity Grading: Comparison of Technical Settings and Vendors

BACKGROUND

Previous studies found different cutoffs of vena contracta area (VCA) to define severe tricuspid regurgitation (TR). The aim of this study was to investigate the factors associated with such variability by comparing technical variables and vendors.

METHODS

Sixty-nine patients with scheduled tricuspid surgery were included in this prospective study. For each patient, TR data sets were obtained on three-dimensional color Doppler transthoracic echocardiography on at least two of three systems: GE Vivid E95 (n = 39), Siemens SC2000 Prime (n = 64), and Philips EPIQ 7C (n = 60). VCA was measured using default settings or with color baseline shifted on all three platforms and with minimal color gain (10%-20%) on the GE platform.

RESULTS

Color gain reduction and baseline shift caused significant change sin VCA measurement (-46% and 10%, respectively). Intervendor comparison exhibited wide limits of agreement (narrowest range, -74% to 167%), with either default or optimized settings. Different technical settings, platforms, and reference methods all produced different VCA cutoffs for severe TR.

CONCLUSIONS

VCA measurement in TR is sensitive to technical factors and demonstrates intervendor variability. Technical variables in VCA measurement should be reported in detail to allow comparison among research studies. The same vendor and settings should be used for longitudinal analysis of TR VCA in the same patient in multivendor echocardiography laboratories.

Quantification of tricuspid regurgitation area by 3-dimensional color Doppler echocardiography considering different clinical settings

PURPOSE

The precise assessment of tricuspid regurgitation (TR) using 2D imaging techniques may be associated with significant difficulties due to the nonround regurgitation area. Direct analysis of the regurgitation area by 3D color Doppler echocardiography at the vena contracta (3D VCA) has the potential to adequately quantify even complex TR. This study compared 3D VCA for quantification of the TR with the regurgitant area determined by proximal isovolumetric convergence method (PISA-EROA) considering different clinical settings.

METHODS

In 95 patients with TR of different severity, the regurgitant orifice area was determined by 3D color Doppler echocardiography and by PISA-EROA. Using 3D color Doppler echocardiography, the regurgitant orifice area was determined three times in each patient considering 3 datasets.

RESULTS

Mean 3D VCA was 0.27 ± 0.14, 0.27 ± 0.13, and 0.29 ± 0.14 cm² , respectively, as determined by three separate measurements in each of the 95 patients. There was a mean relative deviation between the three measurements in each patient of 12.4 ± 14.9%. The regurgitant orifice area using the PISA method was 0.28 ± 0.14 cm² . There was a mean difference of 0.07 cm² (95% CI -0.124 to 0.138 cm² ) between 3D VCA and PISA-EROA. The correlation between 3D VCA and PISA-EROA was r = .88 (P < .001). Considering a grading of TR severity in grade I (regurgitant area < 0.2 cm² ), grade II (area 0.2-0.4 cm² ), and grade III (area > 0.4 cm² ), there was a good agreement between severity grade determined by 3D VCA and severity grade determined by PISA-EROA (kappa 0.71).

CONCLUSION

The analysis of the VCA of a TR using 3D color Doppler echocardiography is an alternative method to determine the regurgitant severity with good agreement to the PISA method.

The tricuspid valve in review: anatomy, pathophysiology and echocardiographic assessment with focus on functional tricuspid regurgitation

The tricuspid valve (TV) is a complex anatomical structure that incorporates a saddle-shaped annulus, asymmetric leaflets, the subvalvular apparatus and the right ventricle and its loading conditions. In this paper, an appreciation of the normal anatomy and physiology of the TV is reviewed before discussing functional tricuspid regurgitation (TR), a disease that has garnered renewed interest due to increased awareness of adverse outcomes and novel transcatheter therapeutic options. Two and three-dimensional echocardiographic imaging of the TV using transthoracic and transesophageal windows are subsequently discussed. The future of cardiovascular medicine will have more to offer the “forgotten” right-sided chambers and valves, and this review aims to refresh knowledge and enthusiasm around the forgotten but crucially important TV.

Comprehensive Evaluation of Tricuspid Regurgitation Location and Severity Using Vena Contracta Analysis: A Color Doppler Three-Dimensional Transesophageal Echocardiographic Study

BACKGROUND

The clinical significance of three-dimensional (3D) vena contracta area (VCA) in tricuspid regurgitation (TR) is not fully elucidated. The aim of this study was to investigate the diagnostic accuracy of 3D VCA using 3D echocardiography-derived regurgitation volume as a reference standard.

METHODS

One hundred sixteen patients with at least moderate TR underwent two-dimensional transthoracic and color Doppler 3D transesophageal echocardiography. The 3D vena contracta, which was located at the narrowest neck of the TR jet just above and toward the right atrial side of the flow convergence zone, was assessed for TR location and severity.

RESULTS

As for TR location, patients with severe functional TR had the highest prevalence of central jet location among TR subgroups, whereas patients with severe primary TR showed a greater spatial extent of TR jet location involved compared with the moderate TR group (P < .05 for both). As for TR severity, a 3D VCA cutoff value of 0.61 cm² discriminated severe TR with sensitivity of 78% and specificity of 97% in the total patient population (area under the curve = 0.93, P < .001). Multivariate analysis revealed that 3D VCA, a dilated right ventricle, and hepatic vein systolic reversal were independently associated with regurgitant volume (P < .001 for all). The χ² value for the model that incorporated clinical and two-dimensional integrative parameters and 3D VCA > 0.61 cm² to evaluate severe TR was significantly higher than that for the model that incorporated only clinical and two-dimensional integrative parameters (P = .001).

CONCLUSIONS

Three-dimensional VCA has independent and incremental diagnostic value for evaluating severe TR. Comprehensive evaluation of TR location and severity using 3D vena contracta analysis may help in treatment selection for TR.

Application of three-dimensional proximal isovelocity surface area method in tricuspid regurgitation quantification

OBJECTIVES

Recently, three-dimensional proximal isovelocity surface area (3D PISA) method has already been widely used in tricuspid regurgitation assessment. This study attempts to demonstrate the feasibility and accuracy of 3D PISA quantifying tricuspid regurgitation and explore the clinical value of 3D PISA in quantifying tricuspid regurgitation.

METHODS

Fifty-four patients with more than mild tricuspid regurgitation (TR) were enrolled. Effective regurgitant orifice area (EROA) and regurgitant volume (Rvol) were assessed by transthoracic 3D PISA method and three-dimensional vena contracta area (3D VCA) method. The 3D VCA was used as reference method. We analyzed the correlation and differences of EROA between 3D PISA method and the reference method.

RESULTS

Both EROA and Rvol assessed by the 3D PISA had good correlations with the reference method, particularly in the assessment of eccentric jets, with the correlation coefficients of r (EROA) = 0.83, P < 0.001, r (Rvol) = 0.90, P < 0.001, respectively. 3D PISA method had good agreement with 3D VCA method in grading TR. Intra-observer and inter-observer agreement were also good.

CONCLUSIONS

Three-dimensional proximal isovelocity surface area method can accurately quantify the degree of tricuspid regurgitation with good repeatability and shorter time-consuming, which is worthy of further study. 3D PISA method is expected to be a new method for evaluating tricuspid regurgitation in clinic practice.

Tricuspid regurgitation and the right ventricle in risk stratification and timing of intervention

Tricuspid regurgitation natural history and treatment remains poorly understood. Right ventricular function is a key factor in determining prognosis, timing for intervention and longer-term outcome. The right ventricle is a thin walled chamber with a predominance of longitudinal fibres and a shared ventricular septum. In health, the low-pressure pulmonary circulation results in a highly compliant RV well equipped to respond to changes in preload but sensitive to even small alterations in afterload. In Part 1 of this article, discussion focuses on key principles of ventricular function assessment and the importance of right ventricular chamber size, volumes and ejection fraction, particularly in risk stratification in tricuspid regurgitation. Part 2 of this article provides an understanding of the causes of tricuspid regurgitation in the contemporary era, with emphasis on key patient groups and their management.

Directional Doppler in Cardiology: A 50-Year Journey

In 1968, while cardiologists were focused on cardiac structures imaged by ultrasound, Daniel Kalmanson in Paris, France, devised a new ultrasonic modality, directional continuous-wave Doppler, enabling him to record instantaneous cardiovascular blood flow velocities with recognition of their direction (relative to the transducer) in vessels. An innovative presentation of Doppler data also made velocity traces physiologically understandable. Following the noninvasive study of the arterial and venous beds, flow velocity in the right (1969) and left (1970) cardiac chambers was studied by means of a directional Doppler catheter. The curtain was then raised for the renewal of our pathophysiologic understanding of cardiac dynamics and the adoption of a new methodology. Technological evolution paved the way for clever researchers to pioneer important advances, diversifying the technique. Guided by the early principles, which are still valid in 2018, directional Doppler finally gained acceptance from the entire scientific community.

Functional Tricuspid Regurgitation in Mitral Valve Disease

Functional tricuspid regurgitation is a common finding in patients with left-sided heart disease. If left untreated, it may reduce survival, limit functional capacity and cause end-organ dysfunction. Annulus dilation and leaflet tethering due to right ventricle remodeling are 2 major pathophysiologic mechanisms in functional tricuspid regurgitation. Even if surgical treatment remains the gold standard, indication and timing of surgical interventions remain the object of debate in the medical community. More recently, numerous transcatheter therapies have been developed in order to offer less invasive options to patients who otherwise would have a high risk of mortality and morbidity with surgical interventions.

Assessment of tricuspid valve by two- and three-dimensional echocardiography with special reference to percutaneous repair and prosthetic valve implantation procedures

Moderate-to-severe tricuspid regurgitation affects approximately 1.6 million people in the United States. An estimated 8000 patients will undergo tricuspid surgery annually, leaving a large number of patients with this condition untreated. Many of these individuals who are not referred for surgery engender a large unmet clinical need; this may be primarily due to the surgical risk involved. In persons who are categorized as high-risk surgical candidates, percutaneous procedures present a viable alternative. The majority of developmental attention as regards percutaneous approaches has been focused on the aortic and mitral valves recently, but few data are available about the feasibility and efficacy of minimally invasive tricuspid valve treatment. We review the usefulness of two- and three-dimensional echocardiography in the assessment of the tricuspid valve with special reference to recent interest in percutaneous repair and prosthetic valve implantation procedures for severe functional tricuspid regurgitation.

Current transcatheter devices to treat functional tricuspid regurgitation with discussion of issues relevant to clinical trial design

Functional or secondary tricuspid regurgitation (TR) has seen increased attention in recent times as relationships with clinically-relevant outcomes have come to light. Despite the association of increased mortality with significant TR, the disease remains under-recognized and thus relatively untreated. In addition, the disease itself has not been extensively studied and the interactions between annular dilatation, right heart disease and pulmonary hypertension are poorly understood. However, the high mortality and recurrence rate with current surgical replacement or repair techniques is well recognised, opening the door to transcatheter therapies for functional TR. The current perspective reviews the rationale for transcatheter solutions, describes some of the current approaches and discusses the ongoing questions of a poorly-studied condition which may limit the design of clinical trials for this disease.

Real-Time 3-Dimensional Echocardiographic Assessment of Effective Regurgitant Orifice Area in Dogs With Myxomatous Mitral Valve Disease

BACKGROUND

Effective regurgitant orifice area (EROA), calculated from the vena contracta width (VCW) as the narrowest portion of the proximal regurgitant jet, might be used to estimate severity of mitral regurgitation. However, this simplified assumption only holds when the EROA is circular, which might not be true in dogs with myxomatous mitral valve disease (MMVD).

HYPOTHESIS

Effective regurgitant orifice area in dogs with MMVD is noncircular, and using color Doppler real-time 3-dimensional (RT3D) echocardiography, measured EROA in the en face view will be significantly different from calculated EROA.

ANIMALS

Hundred and fifty-eight privately owned dogs with naturally occurring MMVD.

MATERIALS AND METHODS

Prospective observational study comparing en face view of EROA with calculated EROA using VCW in 4-chamber (4Ch) and 2-chamber (2Ch) view only or combined 4Ch and 2Ch views using RT3D echocardiography.

RESULTS

The calculated EROA using the 2Ch view showed a systematic underestimation of 17% compared with the measured en face EROA corrected for body surface area. The calculated EROA using 4Ch and 4Ch + 2Ch views showed less agreement with the en face EROA, and the difference between methods increased with increasing EROA. The difference between calculated and measured EROA showed a systematic underestimation of the calculated EROA by 36% (4Ch) and 33% (4Ch + 2Ch), respectively, compared to measured en face EROA.

CONCLUSION AND CLINICAL IMPORTANCE

When replacing measured EROA with calculated EROA using VCW measurements, the 2Ch view is preferred in dogs with MMVD.

State-of-the-Art Review of Echocardiographic Imaging in the Evaluation and Treatment of Functional Tricuspid Regurgitation

Functional or secondary tricuspid regurgitation (TR) is the most common cause of severe TR in the Western world. The presence of functional TR, either isolated or in combination with left heart disease, is associated with unfavorable natural history. Surgical mortality for isolated tricuspid valve interventions remains higher than for any other single valve surgery, and surgical options for repair do not have consistent long-term durability. In addition, as more patients undergo transcatheter left valve interventions, developing transcatheter solutions for functional TR has gained greater momentum. Numerous transcatheter devices are currently in early clinical trials. All patients require an assessment of valve morphology and function, and transcatheter devices typically require intraprocedural guidance by echocardiography. The following review will describe tricuspid anatomy, define echocardiographic views for evaluating tricuspid valve morphology and function, and discuss imaging requirements for the current transcatheter devices under development for the treatment of functional TR.

Two- and Three-dimensional Transthoracic Echocardiographic Assessment of Tricuspid Valve Prolapse with Mid-to-Late Systolic Tricuspid Regurgitation

We present the two-dimensional echocardiographic findings of tricuspid valve prolapse with mid-to-late systolic tricuspid regurgitation and describe the incremental value provided by live/real time three-dimensional transthoracic echocardiography. We also discuss a potential pitfall when assessing the severity of regurgitation in this setting.

Echocardiographic assessment of Ebstein's anomaly

Ebstein's anomaly is a complex congenital lesion which primarily involves the tricuspid valve. The tricuspid leaflets are tethered to varying degrees to the right ventricular free wall and the ventricular septum often resulting in significant tricuspid regurgitation and a small functioning right ventricular chamber. Although the septal leaflet originates normally at the right atrioventricular junction, the proximal portion is often completely tethered to the ventricular septum resulting in a misconception and erroneous statements in many publications that its attachment is apically displaced. Although two-dimensional echocardiography represents the primary modality for the diagnosis of this anomaly, three-dimensional echocardiography provides incremental value in characterizing the extent and severity of tethering of individual tricuspid valve leaflets. This information is useful in surgical decision making whether to repair or replace the tricuspid valve.

Usefulness of the multiplanar reformatting mode of three-dimensional echocardiography in evaluating valvular and structural heart disease: An experience from Saudi Arabia

OBJECTIVE

The aim of this study is to compare the feasibility and capacity of multiplanar reformatting (MPR) mode of three-dimensional echocardiography (3DE-MPR technique) with two-dimensional echocardiography (2DE) for visualizing morphological details during evaluation of congenital heart disease (CHD). The study also seeks to validate the accuracy of 3DE MPR in determining cardiac valvular lesions and the application of the 3DE-MPR technique in daily clinical practice.

METHODS

A cross-sectional study was carried out at Madinah Cardiac Centre, Saudi Arabia from May to December 2012. Various forms of CHD were diagnosed in 43 patients by conventional 2DE, and the patients were then examined with the 3DE-MPR technique using dedicated software and a standard protocol.

RESULTS

Of the 43 patients, 23 (53.5%) were males and 20 (46.5%) females. Their age varied from 30 days to 146 months (mean age, 70.2 months and SD = 42.5 months) and their weight from 4 to 42 kg (mean weight, 20.2 kg and SD = 9.7 kg). The 2DE showed left heart lesions in nine patients (20.9%), right heart lesions in 23 (53.5%), atrial septal defects in five (11.6%) and complex CHD in six patients (14%). The 3DE MPR technique application and analysis was possible in all patients. The study demonstrated the fields where 3DE MPR was of additive value to conventional 2DE for the vena contracta area in valvular regurgitation severity and the planimetry for the valvular stenosis precise estimation, enface views of atrial septal defects with direct visualisation of shape and size of the defect, and segmental analysis of complex CHD using one window. The clinician and surgeon were then able to determine the mechanism and severity of the lesions and thus decide on appropriate treatment and management.

CONCLUSION

The study demonstrated the usefulness of 3DE-MPR as a complement to conventional 2DE. The technique is a significant technological breakthrough that allows instant visualization of morphological details and precise determination of cardiac valvular lesions, which were less clearly delineated by 2DE alone.

Feasibility and effectiveness of three-dimensional echocardiography in diagnosing congenital heart diseases

Three-dimensional echocardiography (3DE), a novel approach employed in detecting congenital heart disease (CHD), has gained popularity since it was made commercially available in 2002. This modality is now accepted as an important diagnostic tool for diagnosing CHD. Advancement in transducer technologies and digital data processing allows the use of 3DE in daily clinical practice. In this review, modes of 3DE data acquisition and storage methods in the echocardiogram's machine's hard disk (data processing) are examined. Analysis of the acquired data (cropping or slicing the data set) and methods of illustrating the cropped data set for cardiologists and pediatric cardiovascular surgeons are also discussed. Published literature was searched in PubMed using the keywords "three-dimensional echocardiography", "congenital heart disease", "cropping", and "echoangiogram". This search produced 100 articles, which were further short-listed to 30 articles. Based on this algorithm, the final selected 30 articles were extensively examined in the current review. The clinical applications of real-time transthoracic 3DE, as well as novel transesophageal 3DE and color flow 3DE data set analyses (echoangiogram) in the routine practice of CHD assessment, are also reviewed. Finally, the limitations 3DE, together with the potential future developments required to improve various techniques of 3DE to make it more readily applicable, are examined.

Proximal isovelocity surface area by single-beat three-dimensional color Doppler echocardiography applied for tricuspid regurgitation quantification

BACKGROUND

The two-dimensional (2D) proximal isovelocity surface area (PISA) method has known technical limitations, mainly the geometric assumptions of PISA shape required to calculate effective regurgitant orifice area (EROA). Recently developed single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions and has already been validated for mitral regurgitation assessment. The aim of this study was to apply this novel method in patients with chronic tricuspid regurgitation (TR).

METHODS

Ninety patients with chronic TR were enrolled. EROA and regurgitant volume (Rvol) were assessed using transthoracic 2D and 3D PISA methods. Quantitative Doppler and 3D transthoracic planimetry of EROA were used as reference methods.

RESULTS

Both EROA and Rvol assessed using the 3D PISA method had better correlations with the reference methods than using conventional 2D PISA, particularly in the assessment of eccentric jets. On the basis of 3D planimetry-derived EROA, 35 patients had severe TR (EROA ≥ 0.4 cm(2)). Among these 35 patients, 25.7% (n = 9) were underestimated as having nonsevere TR (EROA ≤ 0.4 cm(2)) using the 2D PISA method. In contrast, the 3D PISA method had 94.3% agreement (33 of 35) with 3D planimetry in classifying severe TR. Good intraobserver and interobserver agreement for 3D PISA measurements was observed, with intraclass correlation coefficients of 0.92 and 0.88 respectively.

CONCLUSIONS

TR quantification using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.

Recommendations for the echocardiographic assessment of native valvular regurgitation: an executive summary from the European Association of Cardiovascular Imaging

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Echocardiography has become the primary non-invasive imaging method for the evaluation of valvular regurgitation. The echocardiographic assessment of valvular regurgitation should integrate the quantification of the regurgitation, assessment of the valve anatomy and function, as well as the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation thus largely integrates the results of echocardiography. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing regurgitation.