Bileaflet Tethering With Preserved LV Geometry and Function: An Unusual Mechanism of Functional Mitral Regurgitation

An 81-year-old woman presented with acute pulmonary edema. Echocardiography revealed severe functional mitral regurgitation, the mechanism of which was unusual. An atypical bileaflet tethering caused by disharmonic annular remodeling, concomitant aortic dilatation, and reduced aorto-mitral angle without left ventricular dysfunction or dilatation was found. A transcatheter edge-to-edge repair was nonetheless successfully performed.

Echocardiographic Characteristics of Left and Right Ventricular Longitudinal Function in Patients With a History of Cardiac Surgery

Previous studies have indicated a reduction in right ventricular (RV) longitudinal motion after cardiac surgery. However, the long-term effect of cardiac surgery on longitudinal motion and the involvement of left ventricular (LV) motion remains unclear. Therefore, this study aimed to comprehensively investigate the longitudinal function of the right ventricle and left ventricle in patients who underwent cardiac surgery. The study included patients who underwent comprehensive transthoracic echocardiography with 3-dimensional RV data sets. By propensity score matching of the clinical and echocardiographic variables, including LV and RV ejection fraction, the echocardiographic parameters were compared between patients with and without a history of cardiac surgery (the surgery and nonsurgery groups, respectively). In this study, the surgery group had significantly lower LV global longitudinal strain values than the nonsurgery group, despite having similar LV ejection fraction. The tricuspid annular plane systolic excursion (TAPSE), tricuspid annular velocity, and RV free wall longitudinal strain were also significantly smaller in the surgery group, whereas the RV ejection fraction was comparable between the 2 groups. In addition, a subgroup analysis based on the time from previous surgery to transthoracic echocardiography (≤1 and >1 year) revealed that TAPSE was reduced in both postoperative phases. In conclusion, LV and RV longitudinal parameters were reduced after cardiac surgery, despite preserved LV and RV global functions. Moreover, TAPSE was reduced even after a long time after cardiac surgery. These findings emphasize the need for careful interpretation of biventricular longitudinal motion in patients with a history of cardiac surgery.

Assessment of Right Ventricular Systolic Function with 3-Dimensional Speckle Tracking Echocardiography in Isolated Mild Mitral Stenosis

BACKGROUND

In rheumatic severe mitral stenosis, right ventricular mechanics deteriorate with the increasing severity of mitral stenosis. Therefore, we aimed to investigate right ventricular mechanics in patients with mild mitral stenosis using 3-dimensional speckle tracking echocardiography.

METHODS

In total, 40 patients with mild mitral stenosis and 36 age- and gender-matched healthy controls were included. Conventional echocardiographic examination was performed and 3-dimensional data sets were acquired for strain analysis. Besides conventional echocardiographic parameters, right ventricular volume and function and 3-dimensional speckle tracking echocardiography-derived right ventricular free wall longitudinal strain were compared between patients with mild mitral stenosis and healthy controls.

RESULTS

Although 3-dimensional right ventricular volumes and ejection fraction were similar between the groups, 3-dimensional speckle tracking echocardiography-derived right ventricular free wall longitudinal strain was significantly lower in patients with mild mitral stenosis than in controls (25.57 ± 4.39% vs. 27.90 ± 4.71%, P =.028). Significant correlations were observed between right ventricular free wall longitudinal strain and mitral valve area and estimated systolic pulmonary artery pressure (r = 0.597, P <.001; r = -0.508, P =.003, respectively). Another significant positive correlation was observed between planimetric mitral valve area and 3-dimensional speckle tracking echocardiography-derived right ventricular free wall longitudinal strain (r = 0.597, P <.001).

CONCLUSION

The degree of severity of mild mitral stenosis in terms of mitral valve area can help in the early detection of subclinical right ventricular systolic function impairment which can be easily detected by 3-dimensional speckle tracking echocardiography. Right ventricular contractile performance could decrease even in mild mitral stenosis.

Restoring Sinus Rhythm Reverses Cardiac Remodeling and Reduces Valvular Regurgitation in Patients With Atrial Fibrillation

BACKGROUND

Cardiac chamber remodeling in atrial fibrillation (AF) reflects the progression of cardiac rhythm and may affect functional regurgitation.

OBJECTIVES

The purpose of this study was to explore the 3-dimensional echocardiographic variables of cardiac cavity remodeling and the impact on functional regurgitation in patients with AF with/without sinus rhythm restoration at 12 months.

METHODS

A total of 117 consecutive patients hospitalized for AF were examined using serial 3-dimensional transthoracic echocardiography at admission, at 6 months, and at 12 months (337 examinations).

RESULTS

During follow-up, 47 patients with active restoration of sinus rhythm (SR) (through cardioversion and/or ablation) had a decrease in all atrial indexed volumes (Vi), end-systolic (ES) right ventricular (RV) Vi, an increase in end-diastolic (ED) left ventricular Vi, and an improvement in 4-chambers function (P < 0.05). Patients with absence/failure of restoration of SR (n = 39) had an increase in ED left atrial Vi and ED/ES RV Vi without modification of 4-chambers function, except for a decrease in left atrial emptying fraction (P < 0.05). Patients with spontaneous restoration of SR (n = 31) had no changes in Vi or function. The authors found an improvement vs baseline in severity of functional regurgitation in patients with active restoration of SR (tricuspid and mitral regurgitation) and in spontaneous restoration of SR (tricuspid regurgitation) (P < 0.05). In multivariable analysis, right atrial and/or left atrial reverse remodeling exclusively correlated with intervention (cardioversion and/or ablation) during 12-month follow-up.

CONCLUSIONS

Management of AF should focus on restoration of SR to induce anatomical (all atrial Vi, ES RV Vi) and/or functional (4 chambers) cardiac cavity reverse remodeling and reduce severity of functional regurgitation. (Thromboembolic and Bleeding Risk Stratification in Patients With Non-valvular Atrial Fibrillation [FASTRHAC]; NCT02741349).

Anthracycline Treatment and Left Atrial Function in Children: A Real-Time 3-Dimensional Echocardiographic Study

Anthracycline (AC) therapy is associated with left ventricular (LV) dysfunction. Left atrial (LA) size and function are used to assess LV diastolic function in heart failure in adults. Data on LA size and function following AC therapy in children is limited. We hypothesized that LA size and function will be abnormal in children following AC chemotherapy. This retrospective review included patients who received AC for pediatric cancers. Controls had normal echocardiograms performed for evaluation of chest pain, murmur, or syncope. Real-time three-dimensional echocardiography was performed to evaluate LA reservoir, conduit, and booster pump function parameters. In addition to LA volume data, LV shortening fraction, spectral and tissue Doppler variables assessing diastolic function as well as myocardial performance index was obtained. Groups with and without AC therapy were compared by student t-test and chi-square test. We evaluated 136 patients, 55 (40.4%) had received AC. There was no significant difference between the groups in LV shortening fraction, diastolic as well as global function indices. LA reservoir and conduit function parameters were significantly lower in AC group compared to controls. The booster function parameters showed variable results. It is intriguing that AC-treated children have smaller LA reservoir and abnormal booster function. We speculate that these findings may reflect early changes in LA compliance associated with AC exposure. Assessment of LA volumes and function as prognostic markers of AC-induced cardiotoxicity in children is warranted.

Mitral valve perforation, a hole-in-one for 3-dimensional echocardiography

Mitral valve perforation is an uncommon aetiology of mitral regurgitation in the paediatric population. We present a case where 3-dimensional echocardiography assisted in the diagnosis of the source of mitral regurgitation and the surgical correlation.

Prediction of procedural success of transcatheter mitral valve repair with normal and extended clip arms

TMVR using different clip sizes is a treatment option for selected patients with mitral regurgitation (MR). This study sought to identify predictors of successful transcatheter mitral valve repair (TMVR) by 3-dimensional (3D) echocardiography and to compare different effects of the larger XTR and the smaller NT/NTR devices. 3D transesophageal echocardiography was performed on 54 patients with secondary MR undergoing TMVR with one clip (55.6% NT/NTR, 44.4% XTR). All NT/NTR and 96% of XTR patients had MR reduction ≤ 2+. Despite more severe baseline MR (3D vena contracta area (VCA): 0.67 ± 0.34 cm2 vs. 0.43 ± 0.19 cm2, p = 0.004) and greater mitral valve area (MVA) (6.8 ± 2.1 cm2 vs. 5.1 ± 1.6 cm2, p = 0.001) in the XTR group, MR severity after TMVR was not different between XTR and NT/NTR patients (3D VCA: 0.19 ± 0.14 vs. 0.17 ± 0.10, p = 0.51). Baseline 3D VCA > 0.45 cm2 in NT/NTR (AUC = 0.802, 95% CI 0.602 to 1.000) and 3D VCA > 0.54 cm2 in XTR devices (AUC = 0.868, 95% CI 0.719 to 1.000) were associated with ineffective MR reduction defined as residual VCA ≤ 0.2 cm2. Baseline MVA ≤ 4.2 cm2 in NT/NTR (AUC = 0.920, 95% CI 0.809 to 1.000) and MVA ≤ 6.0 cm2 in XTR devices (AUC = 0.865, 95% CI 0.664 to 1.000) were associated with postprocedural transmitral pressure gradient (TMPG) ≥ 5 mmHg. TMVR using the XTR device resulted in an equally effective reduction of MR despite of a greater baseline MR. Distinct cut-off values of baseline 3D VCA and MVA for prediction of successful MR reduction and postprocedural increase of TMPG were identified for the different devices.

Right ventricular area strain from 3-dimensional echocardiography: Mechanistic insight of right ventricular dysfunction in pediatric pulmonary hypertension

BACKGROUND

Right ventricular (RV) function is a major contributor to the outcome of pulmonary arterial hypertension (PAH). Adult studies demonstrated that regional and global changes in RV deformation are prognostic in PAH using 3-dimensional echocardiography (3DE). However, regional and global dynamic changes in RV mechanics have not been described in pediatric PAH. We compared 3DE RV regional and global deformation between pediatric patients who had associated PAH with congenital heart disease (APAH-CHD), pediatric patients who had idiopathic PAH (IPAH), and normal controls, and evaluated the clinical outcomes.

METHODS

A total of 48 controls, 47 patients with APAH-CHD, and 45 patients with IPAH were evaluated. 3DE RV sequences were analyzed and post-processed to extract global and regional deformation (circumferential, longitudinal, and area strain). Statistical analyses compared the sub-groups on the basis of global and regional deformation, and outcome analysis was performed.

RESULTS

Patients with PAH had significantl8y different global and regional deformation (p < 0.001) compared with controls. Patients with APAH-CHD and and those with IPAH significantly differed in global circumferential strain (p < 0.010), area strain (inlet septum, p = 0.041), and circumferential strain at the inlet septum (p < 0.019), apex free wall (p < 0.004), and inlet free wall (p < 0.004). Circumferential strain at the inlet free wall and circumferential, longitudinal, and area strain at the apex free wall were predictors of adverse events.

CONCLUSIONS

RV regional and global strain differ between controls and pediatric patients with PAH. RV apical free-wall area strain provides insight into the mechanism of RV dysfunction in pediatric patients with PAH, with regional strain emerging as outcome predictors, suggesting that this novel measure may be considered as a future measure of RV function.

Features of Lead-Induced Tricuspid Regurgitation in Patients With Heart Failure Events After Cardiac Implantation of Electronic Devices - A Three-Dimensional Echocardiographic Study

BACKGROUND

Lead-induced tricuspid regurgitation (TR) after cardiac implantable electronic device (CIED) implantation is not fully understood. This study aimed to reveal the features of lead-induced TR by 3-dimensional echocardiography (3DE) in patients with heart failure (HF) events after CIED implantation.Methods and Results:In 143 patients, 3DE assessments for the tricuspid valve (TV) and right ventricular morphologies were sequentially performed within 3 days after CIED implantations, during TR exacerbations, and at ≥6 months after TR exacerbations. TR exacerbations were observed in 29 patients (median 10 months after CIED implantation, range 1-28 months), 15 of whom had lead-induced TR. In the 29 patients, the tenting height of the TV, tricuspid annular (TA) height, and TA area at baseline were independent predictors for worsening TR. In patients with lead-induced TR, tenting height of the TV and TA area were identified as the risk factors. In addition, all patients with a lead positioned on a leaflet immediately after CIED implantations developed lead-induced TR. At follow up, TR exacerbation of lead-induced TR persisted with TA remodeling, but it was improved in the lead non-related-TR group.

CONCLUSIONS

TA remodeling at baseline and a lead location on a leaflet immediately after CIED implantation were associated with lead-induced TR in patients with HF events after CIED implantation. Persistent TA remodeling may make lead-induced TR refractory against HF treatments.

Insufficient Mitral Leaflet Remodeling in Relation to Annular Dilation and Risk of Residual Mitral Regurgitation After MitraClip Implantation

OBJECTIVES

The purpose of this study was to determine whether the mitral valve (MV) total leaflet area (TLA)-to-mitral annular area (MAA) (TLA/MAA) ratio measured using 3-dimensional (3D) transesophageal echocardiography (TEE) was associated with residual mitral regurgitation (MR) after MitraClip implantation in patients with secondary MR.

BACKGROUND

The factors influencing the results of MitraClip implantation for secondary MR are controversial. This study hypothesized that insufficient remodeling of the mitral leaflets relative to the annular dilation may be associated with significant MR after MitraClip implantation.

METHODS

This study included patients with secondary MR treated with MitraClips. Using 3D TEE dataset, the TLA in diastole and MAA in systole were measured with dedicated software.

RESULTS

In a total cohort of 119 patients (mean age 74 ± 9 years; 61% male), significant residual MR (≥2+) was present in 43 patients (36%). In patients with significant residual MR, MAA was greater than in patients without residual MR (10.7 ± 2.4 cm² vs. 9.0 ± 2.1 cm²; p < 0.001) whereas no significant difference was observed in TLA (12.2 ± 2.6 cm² vs. 12.0 ± 2.9 cm²; p = 0.836). TLA/MAA ratio was lower in patients with significant residual MR as compared to their counterparts (1.14 ± 0.15 vs. 1.34 ± 0.16; p < 0.001), suggesting insufficient leaflet remodeling relative to annular dilation. On receiver-operating characteristic curve analysis, the TLA/MAA ratio had better discriminative power to identify patients who will have significant residual MR compared to MAA alone (area under the curve [AUC]: 0.830 vs. 0.723; p = 0.049).

CONCLUSIONS

In patients with secondary MR, insufficient mitral leaflet remodeling relative to the annulus dilation, as reflected by a lower TLA/MAA ratio, is associated with significant residual MR after MitraClip implantation.

Early Detection and Prediction of Anthracycline-Induced Right Ventricular Cardiotoxicity by 3-Dimensional Echocardiography

Objectives

The purpose of this study was to assess the associations between 3-dimensional echocardiography (3DE)-derived changes in right ventricular (RV) volumes and strains with subsequent RV cardiotoxicity in patients treated with anthracyclines.

Background

Although early detection and prediction of left ventricular (LV) dysfunction has been widely studied in patients receiving anthracyclines, little is known about the early changes in RV size and function in this population.

Methods

A total of 74 patients with diffuse large B-cell lymphoma who received 6 cycles of anthracycline-based treatment were enrolled. Echocardiography was performed at baseline or before chemotherapy (pre-chemotherapy) (T0); after 2 cycles (T1); after 4 cycles (T2); and at the end of 6 cycles of chemotherapy (T3). Right ventricular end-diastolic volume (RVEDV), end-systolic volume (RVESV), ejection fraction (RVEF), longitudinal free wall strain (RVLFS), and longitudinal septal strain (RVLSS) were quantified by 3DE. RV cardiotoxicity was defined as a relative reduction of >10% in 3D RVEF or a relative reduction of >5% to a value of <45%. Volume status was assessed by inferior vena cava diameter (IVCD) and the estimated right atrial pressure (RAP).

Results

Twenty-seven patients developed cardiotoxicity after 6 cycles of chemotherapy (T3). Compared to baseline, increases in 3D RVEDV (58.5 ± 7.7 ml vs. 64.2 ± 7.0 ml; p < 0.001) and RVESV (27.8 ± 4.2 ml vs. 31.3 ± 4.2 ml; p < 0.001) were observed by the end of the fourth cycle of chemotherapy (T2). 3D RVLFS (−27.3 ± 3.1% vs. −24.2 ± 2.6%; p < 0.001) was also decreased at T2 compared to baseline. Statistically significant declines in 3D RVLSS (−26.1 ± 2.5% vs. −22.9 ± 2.7%; p < 0.001) and RVEF (54.0 ± 2.8% vs. 49.8 ± 2.4%; p < 0.001) were only observed at T3. A relative decrease in RVLFS of >12.4% (sensitivity, 78.6%; specificity, 82.6%; area under the curve (AUC), 0.80; p ＜ 0.001); and a relative increase in RVESV of >13.2% (sensitivity, 71.4%; specificity, 71.7%; AUC, 0.76; p ＜0.001) from baseline to T2 predicted subsequent RV cardiotoxicity at T3. IVCD and RAP did not change significantly over time.

Conclusions

3DE-derived measurements of RV strain and volume were associated with subsequent changes in RVEF. With further study, RVLFS and RVESV could potentially be used to predict subsequent declines in RVEF with anthracyclines.

A Thrombus in Transit Complicating Acute Pulmonary Embolism

A 51-year-old man presented with acute pulmonary embolism. He was found to have a large intracardiac thrombus in transit across a patent foramen ovale. He underwent anticoagulation and urgent surgical thrombectomy with good outcome. (Level of Difficulty: Beginner.)

Left Atrial Structure and Function, and Left Ventricular Diastolic Dysfunction: JACC State-of-the-Art Review

Defining left atrial (LA) function has recently emerged as a powerful parameter, particularly in evaluation of left ventricular (LV) diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction. Echocardiographic assessment of LVDD by echocardiography remains a challenging task; recent recommendations provide a simpler approach than previous. However, the shortcomings of the proposed approach (including transmitral flow, tissue velocity, maximum left atrial volume [LAV], and estimated pulmonary artery systolic pressure), lead to the presence and severity of LVDD remaining undetermined in a significant proportion of patients. Maximum LAV is a surrogate measure of the chronicity and severity of LVDD, but LAV alone is an insensitive biomarker of early phases of LVDD, because the LA may take time to remodel. Because the primary function of the LA is to modulate LV filling, it is not surprising that functional LA changes become evident at the earliest stages of LVDD. Moreover, LA function may provide additive value, not only in diagnosing LVDD, but also in grading its severity and in monitoring the effects of treatment. The current review provides a critical appraisal on the existing evidence for the role of LA metrics in evaluation of LVDD and consequent heart failure with preserved ejection fraction.

Mitral Valve Adaptation to Isolated Annular Dilation: Insights Into the Mechanism of Atrial Functional Mitral Regurgitation

OBJECTIVES

This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement.

BACKGROUND

Functional MR occurs in patients with AF and isolated annular dilation, but the relationship of MLA adaptation with annular area (AA) is unknown.

METHODS

Three-dimensional echocardiographic images were acquired from 86 patients with quantified MR: 53 with nonvalvular persistent AF (23 MR+ with moderate or greater MR, 30 MR-) without LV dysfunction or dilation and 33 normal controls. Comprehensive 3-dimensional analysis included total diastolic MLA, adaptation ratios of MLA to annular area and MLA to leaflet closure area, and annular and tenting geometry.

RESULTS

Total MLA was 22% larger in patients with AF than in controls, thus paralleling the increased AA. However, as AA increased, adaptive indices (MLA/AA ratio and ratio of MLA to closure area) plateaued, becoming lowest in MR+ patients (ratio of MLA to closure area = 1.63 ± 0.17 controls, 1.60 ± 0.11 MR-, 1.32 ± 0.10 MR+; p < 0.001). MR increased as the ratio of MLA to closure area decreased (R2 = 0.68; p < 0.001). The posterior-to-anterior MLA ratio remained constant, whereas the posterior-to-anterior mitral annulus perimeter increased (1.21 ± 0.16 controls, 1.32 ± 0.20 MR-, 1.46 ± 0.19 MR+; p < 0.001). Multivariate MR determinants were annular area, total MLA to closure area, and posterior-to-anterior perimeter ratios.

CONCLUSIONS

MLA adaptively increases in AF with isolated annular dilation and normal LV function. This compensatory enlargement becomes insufficient with greater annular dilation, and the leaflets fail to match asymmetrical annular remodeling, thereby increasing MR. These findings can potentially help optimize therapeutic options and motivate basic studies of adaptive growth processes.

Comparison of Left Atrial Measurements Using 2- and 3-Dimensional Transesophageal Echocardiography

OBJECTIVES

To assess the correlation between left atrial measurements using 2- and 3-dimensional transesophageal echocardiography.

DESIGN

Prospective, observational study.

SETTING

Single, tertiary care, academic medical center.

PARTICIPANTS

The study comprised 63 consecutive patients undergoing cardiac surgery with cardiopulmonary bypass and intraoperative transesophageal echocardiography.

INTERVENTIONS

In addition to the standard comprehensive intraoperative transesophageal examination, study images were obtained by designated anesthesiologists from the study team.

MEASUREMENTS AND MAIN RESULTS

The 2-dimensional transesophageal echocardiography views included 4-chamber, 2-chamber, aortic valve short axis, and aortic valve long axis. For the 3-dimensional images, full-volume (90 × 90) data sets were acquired from 4-chamber and aortic valve short-axis views over 4 beats with apnea. Left atrial height, mediolateral length, anteroposterior length, and area were measured in 2- and 3-dimensional images. Left atrial length in the short- and long-axis views of the aortic valve also were measured in 2- and 3-dimensional images. Results indicate that for all patients in this study, the 2- and 3-dimensional measurements correlate well and the 2 observers were in agreement with each other.

CONCLUSIONS

Two- and 3-dimensional measurements of the left atrium correlated well. Measurements made using 3-dimensional transesophageal echocardiography were subject to similar limitations as those made using 2-dimensional echocardiography. The benefits of 3-dimensional transesophageal echocardiography and multiplanar reconstruction could be expanded by improvements in ultrasound technology and software.

Differences in Two- and Three-Dimensional Assessment of the Mitral Valve by Novices and Experts, Illustrated Using Anterior Mitral Valve Leaflet Length

OBJECTIVES

In this measurement validation study, the authors evaluated agreement between 2-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE), measuring anterior mitral valve leaflet length by both novice and experienced echocardiographers.

DESIGN

This was a retrospective, observational study.

SETTING

Single university hospital.

PARTICIPANTS

Analyses on datasets from 44 patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Fifty datasets from 44 patients with mitral regurgitation were analyzed by 4 observers (2 novices, 2 experts). All observers measured the anterior mitral valve leaflet length from end-systolic 2D TEE images from the midesophageal longitudinal axis view and 3D software-augmented TEE images. The overall mean anterior mitral valve leaflet length was significantly shorter with 3D versus 2D TEE measurements (24.6 ± 4.5 mm v 26.2 ± 5.3 mm; p < 0.001), with novices measuring shorter leaflets than experts for both techniques (p < 0.001 and p = 0.005, respectively). Bland-Altman plots of 3D and 2D TEE measurements showed mean biases (95% limits of agreement) of -1.6 mm (-9.0 to 5.9 mm), -1.8 mm (-9.6 to 6.0 mm), and -1.3 mm (-8.4 to 5.7 mm) for all observers, novices, and experts, respectively. For 2D measurements, interobserver reliability was very strong among experts and strong among novices (Pearson's r = 0.83 v 0.66; p = 0.055). For 3D measurements, interobserver reliability was strong in experts and moderate in novices (Pearson's r = 0.69 v 0.51; p = 0.168).

CONCLUSION

For both novices and experts, 3D TEE measurements of the anterior mitral valve leaflet were significantly shorter than 2D measurements. Interobserver reliability was lowest for novices making 3D TEE measurements, indicating that reliable, quantitative evaluation of 3D TEE may require a greater amount of practice.

Noteworthy Literature published in 2017 for Perioperative Echocardiography

In this inaugural review, we present noteworthy advances in perioperative echocardiography relevant to the cardiac anesthesiologist. These studies come from different clinical realms including advances in mitral valve imaging, perioperative echocardiographic evaluation, and critical care echocardiography. The importance of perioperative echocardiography continues to grow with cardiac anesthesiologists positioned in a critical role throughout the perioperative care continuum.

Surgical Echocardiography of the MV: Focus on 3D

The mitral valve remains a complex structure where multiple forms of pathology can be seen. Mitral regurgitation continues to be one of the most common valvular diseases in the industrialized world. While intraoperative 2-dimensional transesophageal echocardiography has been commonplace for some time, 3-dimensional technology has emerged and has shown great benefit for diagnosis and guidance during mitral valve surgery. In the hands of a trained sonographer, high-quality real-time images can easily be obtained and correlate well with gross anatomical findings. The use of multiple angled views and color Doppler within 3-dimensional transesophageal echocardiography has become a valuable asset in the understanding and interpretation of the mitral valve for surgical interventions.

3D and 4D Ultrasound: Current Progress and Future Perspectives

PURPOSE OF REVIEW

Three-dimensional (3D) echocardiography (3DE) and 4-dimensional echocardiography (4DE), also known as real-time (RT) 3DE (RT3DE), are rapidly emerging technologies which have made significant impact in the clinical arena over the years. This review will discuss the recent applications of 3DE in diagnosing and treating different types of cardiovascular disease.

RECENT FINDINGS

Recent studies using 3DE expanded on prior findings and introduced additional applications to different cardiac conditions. Some studies have used 3D parameters to prognosticate long-term outcomes. Numerous innovative software designs including fully automated algorithms have been introduced to better evaluate valvular heart disease and cardiac function.

SUMMARY

With further evolution of 3DE technologies, this imaging modality will emerge as a powerful tool and likely become the imaging modality of choice in the diagnosis and management of various cardiac disorders.

[Evaluation of the clinical suitability of automated left ventricle's fraction and volume measurements in 3-dimensional echocardiography compared to values obtained in magnetic resonance imaging (pilot study)]

Recently a lot of authors have been trying to determine the usefulness of 3-dimensional echocardiography (TTE 3D) in evaluation of ejection fraction and left ventricular volume, but few attempt to compare it to the current gold standard of cardiac magnetic resonance (CMR). 3D imaging technics allows to avoid errors caused by geometry of the heart chambers and foreshortened views. American Echocardiographic Guidelines recommend the use of 3-dimensional echocardiography in daily clinical practice.

AIM

The aim of the study was to establish clinical usefulness of automated 3D TTE software to calculate left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV) and left ventricle end systolic volume (LVESV), and to compare those measurements calculated in CMR and in 3D TTE.

MATERIALS AND METHODS

The aim of the study was to establish clinical usefulness of automated 3D TTE software to calculate left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV) and left ventricle end systolic volume (LVESV), and to compare those measurements calculated in CMR and in 3D TTE.

RESULTS

The mean LVEF in 3D TTE was 65% +/- 12%; LVEDV 123 ml +/- 67 ml, LVESV 42 ml +/- 29 ml. The CMR LVEF in the study group was 61% +/- 9%, LVEDV 134 ml +/- 51ml, LVESV 54 ml +/- 33 ml. Wilcoxon rank test showed no difference between medians of the measurements, the correlation coefficient between LVEF in 3D TTE and CMR was R = 0.84 (p = 0.036). LVEF calculated in 3D TTE shows good correlation with LVEF computed in CMR. However good visualization of the endocardium, especially in the apex, is essential. The volume of left ventricle is underestimated in 3D TTE. In previous studies underestimation of LVEDV and LVESV was explained by exclusion of endocardial trabeculae from the left ventricle cavity in automated measurement.

CONCLUSIONS

The automated 3D TTE software allows simple, fast and precise evaluation of parameters of the left ventricle - especially LVEF. Automated 3D TTE software gives hope for the inclusion of 3D TTE in routine clinical practice due to its repeatability and easy use of the Heart Model software.

3D Morphological Changes in LV and RV During LVAD Ramp Studies

OBJECTIVES

The purpose of this study was to investigate the differential impact of the 2 most commonly available left ventricular assist device (LVAD) types on the right ventricle (RV) and left ventricle (LV) using 3-dimensional (3D) echocardiography-based analysis of ventricular morphology.

BACKGROUND

LVADs have emerged as common therapy for advanced heart failure. Recent data suggest that the heart responds differently to speed settings in the 2 main devices available (HeartMate II [HMII], St Jude Medical, Pleasanton, California, and HVAD, HeartWare International, Framingham, Massachusetts). The authors hypothesized that 3D echocardiographic assessment of LV and RV volumes and shape would help describe the differential impact of the 2 LVAD types on the heart.

METHODS

Simultaneous 3D echocardiography, ramp test, and right heart catheterization were performed in 31 patients with LVADs (19 with HMII and 12 with HVAD). Device speed was increased stepwise (8,000 to 12,000 for HMII and 2,300 to 3,200 revolutions per minute for HVAD). 3D echocardiographic full-volume LV and RV datasets were acquired, and endocardial surfaces were analyzed using custom software to calculate LV sphericity, conicity (perfect sphere/cone = 1) and RV septal and free-wall curvature (0 = flat; <0 = concave; >0 = convex).

RESULTS

For both devices, cardiac output increased and wedge pressure decreased with increasing speed. In HMII, LV volumes progressively decreased (meanΔ = 127 ml) as the LV became less spherical and more conical, whereas the RV volume initially remained stable, but subsequently increased at higher speeds (meanΔ = 60 ml). Findings for the HVAD were similar, but less pronounced (LV:meanΔ = 51 ml, RV:meanΔ = 22 ml), and the LV remained significantly more spherical even at high speeds. On average, in HMII patients, the RV septum became more convex (bulging into the LV) at the highest speeds whereas in HVAD patients, there was no discernable change in the RV septum.

CONCLUSIONS

The heart responds differently to pump speed changes with the 2 types of LVAD, as reflected by the volume and shape changes of both the LV and RV. Our study suggests that adding RV assessment to the clinical echo-ramp study may better optimize LVAD speed. Further study is needed to determine whether this would have an impact on patient outcomes.

LA Phasic Volumes and Reservoir Function in the Elderly by Real-Time 3D Echocardiography: Normal Values, Prognostic Significance, and Clinical Correlates

OBJECTIVES

This study sought to assess the prevalence and prognostic value of abnormalities in left atrial (LA) phasic volumes and reservoir function in a community cohort.

BACKGROUND

LA enlargement is associated with adverse cardiovascular outcomes. Real-time 3-dimensional (RT3D) echocardiography allows assessment of LA phasic volumes and reservoir function. However, there is a paucity of data regarding normal values, clinical correlates, and prognostic value of RT3D echocardiography-derived LA phasic volumes and reservoir function, especially in the elderly, a subgroup at high risk for cardiovascular events.

METHODS

Left atrial maximum volume (LAVi_max), minimum volume (LAVi_min), and reservoir function assessed as emptying volume (LAEV), emptying fraction (LAEF), and expansion index (LAEI), were measured by RT3D echocardiography in participants from a community-based cohort study. Cut-off values for LA phasic volumes were derived from a healthy subgroup of participants free of cardiovascular disease and risk factors (n = 142; 66 ± 9 years of age; 55% women). Annual follow-up examinations were performed for cardiovascular outcomes (myocardial infarction, ischemic stroke, and vascular death).

RESULTS

The cohort included 706 participants (71 ± 9 years of age; 59% women). LAVi_max and LAVi_min were not associated with age in the healthy subgroup but progressively increased with age in the entire cohort (p < 0.001). During a median follow-up of 7 years (minimum 0.06, maximum 9.5 years), 78 cardiovascular events occurred. In univariate analysis, LAVi_max, LAVi_min, and reservoir function parameters were significantly associated with outcome. In multivariate analysis, LAVi_min ≥20.5 ml/m² (adjusted hazard ratio [aHR]: 1.79; 95% confidence interval [CI]:1.02 to 3.16) and LAEV ≤5.7 ml/m² (aHR: 1.98; 95% CI: 1.02 to 3.85) remained significantly associated with events. LAVi_min and LA reservoir function showed incremental prognostic value over that of LAVi_max.

CONCLUSIONS

LA phasic volumes and reservoir functions assessed by RT3D echocardiography were strong independent predictors of cardiovascular events in a community-based elderly cohort. LAVi_min and reservoir function assessment may improve cardiovascular outcome prediction over LAVi_max.

Atrial chamber remodelling in healthy pre-adolescent athletes engaged in endurance sports: A study with a longitudinal design. The CHILD study

AIMS

Previous studies investigated the exercise-induced adaptation of left (LA) and right atrium (RA) in adults, but little is known about respective changes in the growing heart of children. We aimed to longitudinally investigate the effects of endurance training on biatrial remodelling in preadolescent athletes.

METHODS AND RESULTS

Ninety-four children (57 endurance athletes, 37 sedentary controls; mean age 10.8±0.2 and 10.2±0.2years, respectively) were evaluated at baseline and after 5months by ECG and by two-dimensional, three-dimensional (3D) and speckle-tracking echocardiography. Athletes were trained at least 10h/week. The resting heart rate was lower in athletes (p=0.046) and decreased further after training (p<0.0001). Neither athletes nor controls had ECG evidence for LA or RA enlargement. At baseline, indexed LA volumes did not differ between groups (p=0.14) but indexed RA dimensions were larger in athletes (p=0.007). After 5months, indexed LA volumes increased in athletes but not in controls (p<0.0001, p=0.29; respectively) while indexed RA volumes increased in both groups (p<0.0001, p=0.018; respectively). At the same time, slight differences in biatrial reservoir and contractile function were found either in athletes, as demonstrated by speckle-tracking echocardiography, but 3D-derived LA and RA ejection fraction remained stable in both groups.

CONCLUSION

Endurance training influences the growing heart of preadolescent athletes with an additive increase in biatrial size, suggesting that morphological adaptations can occur also in the early phases of the sports career. Training-induced remodelling was associated with a preserved biatrial function, supporting the hypothesis of a physiological remodelling.

How Does Subclinical Hyperthyroidism Affect Right Heart Function and Mechanics?

OBJECTIVES

Right heart function and mechanics have not been investigated in patients with subclinical hyperthyroidism. Our aim was to investigate right ventricular (RV) and right atrial (RA) function and deformation as evaluated by 3-dimensional echocardiography (3DE) and speckle-tracking 2-dimensional echocardiography (2DE) in these individuals.

METHODS

We included 39 untreated women with endogenous subclinical hyperthyroidism and 39 healthy women matched by age. All participants underwent laboratory analyses that included thyroid hormone levels and comprehensive 2DE and 3DE examinations.

RESULTS

Three-dimensional echocardiographic RV volumes were significantly elevated in the patients with subclinical hyperthyroidism (P < .05), whereas the 3DE RV ejection fraction was reduced in this group, but with borderline significance. Two-dimensional echocardiographic longitudinal RV and RA strain were significantly reduced in the patients with subclinical hyperthyroidism. Two-dimensional echocardiographic RV systolic and early diastolic strain rates were reduced, whereas late diastolic strain rates were increased in the patients with subclinical hyperthyroidism. The same changes were detected in RA mechanics among the patients with subclinical hyperthyroidism. The thyrotropin (TSH) level correlated with the left ventricular mass index, transmitral early diastolic peak flow velocity (E)/late diastolic flow velocity (A) ratio, tricuspid E/A ratio, 2DE RV global strain, 2DE RA, strain, and 3DE RV end-diastolic volume. A multivariate regression analysis showed that the mitral E/A ratio, 2DE RV global strain, and 3DE RV end-diastolic volume were independently associated with the TSH level.

CONCLUSIONS

Right ventricular and RA function as evaluated by 3DE and speckle-tracking 2DE is significantly impaired in patients with subclinical hyperthyroidism. The TSH level correlated with parameters for RV function and mechanics in the whole study population.

Important advances in technology: echocardiography

Echocardiography has evolved over the past 45 years from a simple M-mode tracing to an array of technologies that include two-dimensional imaging, pulsed and continuous wave spectral Doppler, color flow and tissue Doppler, and transesophageal echocardiography. Together, these modalities provide a comprehensive anatomic and functional evaluation of cardiac chambers and valves, pericardium, and ascending and descending aorta. The switch from analog to digital signal processing revolutionized the field of ultrasound, resulting in improved image resolution, smaller instrumentation that allows bedside evaluation and diagnosis of patients, and digital image storage for more accurate quantification and comparison with previous studies. It also opened the door for new advances such as harmonic imaging, automated border detection and quantification, 3-dimensional imaging, and speckle tracking. This article offers an overview of some newer developments in echocardiography and their promising applications.

Prognostic value of LA volumes assessed by transthoracic 3D echocardiography: comparison with 2D echocardiography

OBJECTIVES

The hypothesis of this study was that minimal left atrial volume index (LAVImin) by 3-dimensional echocardiography (3DE) is the best predictor of future cardiovascular events.

BACKGROUND

Although maximal left atrial volume index (LAVImax) by 2-dimensional echocardiography (2DE) is a robust index for predicting prognosis, the prognostic value of LAVImin and the superiority of measurements by 3DE over 2DE have not been determined in a large group of patients.

METHODS

In protocol 1, we assessed age and sex dependency of LAVIs using 2DE and 3DE in 124 normal subjects and determined their cutoff values (mean + 2 SD). In protocol 2, 2-dimensional (2D) and 3-dimensional (3D) LAVImax/LAVImin were measured in 556 patients with high prevalence of cardiovascular disease. After excluding patients with atrial fibrillation, mitral valve disease, and age <18 years, 439 subjects were followed to record major adverse cardiovascular events (MACE). Patients were divided into 2 groups by the cutoff criteria of LAVI in each method.

RESULTS

In protocol 1, there was no significant age and sex dependency for each 2D and 3D LAVI. In protocol 2, during a mean of 2.5 years of follow-up, MACE developed in 88 patients, including 32 cardiac deaths. Kaplan-Meier survival analyses showed that all 4 LAVI cutoff criteria had significant predictive power of MACE. After variables were adjusted for clinical variables and left ventricular ejection fraction, all 4 methods were still independently and significantly associated with MACE, but 3D-derived LAVImin had the highest risk ratio. 3D LAVImin also had an incremental prognostic value over 3D LAVImax.

CONCLUSIONS

LAVIs by both 2DE and 3DE are powerful predictors of future cardiac events. 3D LAVImin tended to have a stronger and additive prognostic value than 3D LAVImax.

Assessment of age-related changes in left ventricular twist by 3-dimensional speckle-tracking echocardiography

OBJECTIVES

The purpose of this study was to determine the normal value of left ventricular (LV) twist in 3-dimensional (3D) geometry and to study the effects of aging on 3D LV twist by sophisticated newly developed 3D speckle-tracking echocardiographic techniques.

METHODS

Recent developments in miniaturized ultrasound arrays have provided us with high-quality 3D echocardiographic data. Speckle tracking based on 3D images is robust to out-of-plane motion error, whereas 2-dimensional speckle tracking is inherently unable to analyze 3D cardiac motion and may lead to measurement inaccuracies. Three-dimensional LV volumetric images were acquired from 124 healthy volunteers (aged 21-82 years) and were analyzed by a recent speckle-tracking method. Left ventricular twist was analyzed as apical rotation relative to the base in the 3D coordinates. The measured parameters in this study were peak apical rotation, peak basal rotation, peak LV twist, normalized peak LV twist, and peak untwist velocity.

RESULTS

As seen from the apex, the normal LV maintains a wringing systolic displacement with an initial counterclockwise rotation followed by a clockwise rotation in the LV basal plane and a counterclockwise rotation in the LV apical plane. In general, the apical and basal twist increases during the aging process, leading to an increased LV twist value. The mean peak twist ± SD in young participants (21-35 years) was 11.73° ± 2.67°, whereas the value for older participants (>65 years) was 18.57° ± 3.08° (P < .001).

CONCLUSIONS

Three-dimensional speckle-tracking echocardiography can be an effective noninvasive method for assessing 3D LV twist. Age-related differences in the 3D LV twist may be the result of the age-related changes in the endocardial myofibers.

Assessment of mitral valve adaptation with gated cardiac computed tomography: validation with three-dimensional echocardiography and mechanistic insight to functional mitral regurgitation

BACKGROUND

Mitral valve (MV) enlargement is a compensatory mechanism capable of preventing functional mitral regurgitation (FMR) in dilated ventricles. Total leaflet area and its relation with closure area measured by 3-dimensional (3D) echocardiography have been related to FMR. Whether these parameters can be assessed with other imaging modalities is not known. Our objectives are to compare cardiac computed tomography (CT)-based measurements of MV leaflets with 3D echocardiography and determine the relationship of these metrics to the presence of FMR.

METHODS AND RESULTS

We used 2 cohorts of patients who had cardiac CT to measure MV total leaflet, closure, and annulus areas. In cohort 1 (26 patients), we validated these CT metrics to 3D echocardiography. In cohort 2 (66 patients), we assessed the relation of MV size with the presence of FMR in 3 populations: heart failure with FMR, heart failure without FMR, and normal controls. Cardiac CT and 3D echocardiography produced similar results for total leaflet (R(2)=0.97), closure (R(2)=0.89), and annulus areas (R(2)=0.84). MV size was the largest in heart failure without FMR compared with controls and patients with FMR (9.1 ± 1.7 versus 7.5 ± 1.0 versus 8.1 ± 0.9 cm(2)/m(2); P<0.01). Patients with FMR had reduced ratios of total leaflet to closure areas and total leaflet to annulus areas when compared with patients without FMR (P<0.01).

CONCLUSIONS

MV size measured by CT is comparable with 3D echocardiography. MV enlargement in cardiomyopathy suggests leaflet adaptation. Patients with FMR have inadequate adaptation as reflected by decreased ratios of leaflet area and areas determined by ventricle size (annulus and closure areas). These measurements provide additional insight into the mechanism of FMR.

Right ventricular remodeling determines tricuspid valve geometry and the severity of functional tricuspid regurgitation: a real-time 3-dimensional echocardiography study

Background and Objectives

Right ventricle (RV) remodeling can determine tricuspid valve (TV) geometry and the severity of functional tricuspid regurgitation (TR).

Subjects and Methods

In 53 patients with various degrees of functional TR and in sinus rhythm, RV and TV geometries were analyzed using real-time 3-dimensional echocardiography, including tenting angles of 3 leaflets, septal-lateral and antero-posterior tricuspid annulus diameters and inlet RV dimensions, mid-RV septal-lateral dimension, and the distance between annulus and apex. A mid-systole frame when the TV tenting is smallest was selected for the analysis. RV end-diastolic and end-systolic volumes were measured. The severity of functional TR was determined by distal jet area.

Results

TR distal jet area was mainly determined by septal-lateral annulus diameter (p<0.001) RV inlet dimension (p=0.015), RV end-systolic volume (p=0.010), septal (p=0.019), and anterior leaflet tenting angles (p=0.045) by multiple stepwise linear regression analysis. Leaflet tenting angles were mainly determined by septal-lateral RV inlet dimension. Septal-lateral annulus diameter was determined by septal-lateral RV inlet dimension (p<0.001) and mid RV dimension (p=0.033), whereas antero-posterior annulus diameter was determined by antero-posterior RV inlet dimension (p<0.001).

Conclusion

Functional TR severity is determined by septal-lateral annulus and RV dilation, and tenting of septal and anterior leaflets. TV leaflet tenting is mainly determined by septal-lateral RV inlet dilation, and tricuspid annulus dilation is closely linked with inlet RV dilation.