Normal Values of Left Ventricular Size and Function on 3D Echocardiography: Results of the World Alliance of Societies of Echocardiography Study

Normal values and distribution of ventricular global longitudinal strain in 513 healthy fetuses measured by two-dimensional speckle-tracking echocardiography: a multi-institutional cohort study

This study aimed to determine the normal reference values and distribution of global longitudinal strain (GLS) in the right and left ventricles of healthy Japanese fetuses during pregnancy. This multi-institutional cohort study included healthy Japanese fetuses during normal pregnancies without maternal or fetal complications between 18 and 40 weeks of gestation. Two-dimensional fetal echocardiographic images of the four-chamber view with a high frame rate were acquired and stored as DICOM clips. Data were collected and analyzed in a central laboratory to measure the left ventricular (LV) and right ventricular (RV) GLS using two-dimensional speckle tracking. In total, 513 fetuses were enrolled. The mean LV-GLS and RV-GLS were - 24.3% ± 3.5% and - 23.5% ± 3.7%, respectively. The magnitude of the GLS, with normal limits in both ventricles, decreased with advancing gestation. LV values were r = 0.34 (95% confidence interval, 0.27-0.42) and p  < 0.0001; RV values were r = 0.33 (95% confidence interval, 0.25-0.41) and p  < 0.0001. The normal values of healthy Japanese fetuses in healthy pregnancies is the first to be established by the large-scale, multi-institutional cohort study as LV-GLS of 24.3% ± 3.5% and RV-GLS of - 23.5% ± 3.7%, respectively. This can serve as a basic reference for assessing the cardiac functions in Japanese fetuses with various heart diseases.

Clinical and plasma proteomic characterization of heart failure with supranormal left ventricular ejection fraction: An emerging entity of heart failure

AIMS

The clinical guidelines categorize heart failure (HF) based on left ventricular ejection fraction (LVEF). However, the current LVEF cutoffs, 40% and 50%, may not fully address the underlying characteristics and cardiovascular risk of HF, particularly for HF with higher LVEF. This study aimed to characterize HF with supranormal ejection fraction (HFsnEF) using different LVEF cutoffs (35%, 55%, and 70% for men, and 40%, 60%, and 75% for women).

METHODS AND RESULTS

This study divided 442 patients from the CHART-Omics study into four groups: HF with reduced ejection fraction (HFrEF) (n = 55, 65.5 years), HF with mildly reduced ejection fraction (HFmrEF) (n = 125, 69.3 years), HF with normal ejection fraction (HFnEF) (n = 215, 69.0 years) and HFsnEF (n = 47, 67.1 years). When clinical backgrounds were adjusted and HFnEF served as the reference, HFsnEF carried an increased hazard ratio (HR) for the composite of cardiovascular death and HF hospitalization of 2.71 (95% confidence interval [CI] 1.10-6.66, p = 0.030), while HFrEF had a HR of 3.14 (95% CI 1.36-7.23, p = 0.007). HFsnEF was characterized by an increase in relative left ventricular wall thickness and a decrease in left ventricular dimensions, whereas increased left ventricular mass and dimensions characterized HFrEF. Quantitative analysis of 4670 plasma proteins showed essential differences between HFsnEF and HFrEF, for example, 'protein synthesis' versus 'cell morphology', 'cellular assembly and organization' and 'nucleic acid metabolism' for underlying pathophysiology, and 'energy production' versus 'connective tissue disorders' and 'cell-to-cell signalling and interaction' for prognostication.

CONCLUSIONS

Heart failure with supranormal ejection fraction, an unnoticed but emerging entity in HF, carries a similarly increased cardiovascular risk as HFrEF but has unique structural and plasma proteomic characteristics.

Echocardiographic reference ranges of myocardial work in children and adolescents: A meta-analysis

BACKGROUND

Establishing reference values for LV myocardial work (MW) is essential before its widespread implementation in pediatrics. This study aims to provide normal LV MW ranges, encompassing global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE).

METHODS

Databases were searched through February 1st, 2024, for studies reporting MW indices in healthy children across pediatric age categories. Weighted means were obtained from random-effect models with corresponding 95 % confidence intervals (CI). Subgroup analyses were conducted to identify sex or geographic differences. Meta-regression analysis was used to identify modulating effects of demographic, clinical, and echocardiographic variables.

RESULTS

The search yielded 104 articles, of which, 12 articles with 1037 patients (age 10.7 ± 0.7 years, 47.5 % female) were eligible for inclusion. The reported normal overall pooled mean values of GWI and GCW were 1525.4 (95 % CI, 1328.1-1722.6) mmHg% and 1880.3 (95 % CI, 1683.6-2077.0) mmHg%, respectively. Pooled mean GWW was 57.2 (95 % CI, 51.9-62.5) mmHg%, and pooled mean GWE was 96.8 (95 % CI, 96.6-97.0) %. Subgroup analysis found no sex differences (P > 0.050), but significant regional variations: GCW and GWW differed in European or US cohorts versus East Asian cohorts (P = 0.033 and P = 0.039, respectively). Meta-regression identified age, blood pressure, and heart rate as significant modulators. Pooled inter-observer intraclass correlation coefficients (ICCs) ranged from 0.86 to 0.96, while pooled intra-observer ICCs ranged from 0.81 to 0.93, indicating excellent reproducibility.

CONCLUSIONS

We provide age-specific MW reference ranges for children, valuable for both clinical and research purposes, and confirm the reproducibility of MW.

Long-term hemodynamic responses and reverse remodeling after pharmacotherapy in HFpEF versus HFrEF: a systematic review and meta-analysis

The acute response to therapeutic afterload reduction differs between heart failure with preserved (HFpEF) versus reduced ejection fraction (HFrEF), with larger left ventricular (LV) stroke work augmentation in HFrEF compared with HFpEF. This may (partially) explain the neutral effect of HFrEF-medication in HFpEF. It is unclear whether such differences in hemodynamic response persist and/or differentially trigger reverse remodeling in the case of long-term afterload reduction. A systematic search was performed, identifying 21 clinical trials investigating renin-angiotensin-aldosterone system (RAAS) inhibitors, β-blockers, and sodium-glucose cotransport 2 inhibitors that report data on afterload reduction, stroke volume, and reverse remodeling in HFpEF and/or HFrEF. In both HFpEF and HFrEF, meta-analyses revealed limited long-term change in systolic/diastolic blood pressure (-5.6/-3.2 and -4.6/-1.4 mmHg, respectively) and LV afterload reduction (arterial elastance: -0.039 and -0.055 mmHg/mL, respectively). Long-term treatment did not result in an increase in stroke volume, with the exception of β-blockers in HFrEF. Indexed LV mass decreased slightly in both HFpEF and HFrEF (-2.8 and -2.3 g/m2, respectively). In HFrEF, treatment reduced LV end-diastolic and end-systolic volume (-8 and -6 mL, respectively), whereas in HFpEF there was no relevant change. Contrary to acute heart failure studies, long-term afterload reduction had little effect on blood pressure and stroke volume augmentation in both HFpEF and HFrEF. However, reverse remodeling was clearly present in HFrEF but was essentially absent in HFpEF.

3D echocardiography derived reference values and determinants of left ventricular twist and torsion from the population-based STAAB cohort study

Left ventricular (LV) rotational function parameters provide in-depth information about LV mechanical function as well as prognostic information. Using three-dimensional (3D) echocardiography, we identified determinants of LV "twist" and "torsion", and established reference values using a large population-based cohort. 3D echocardiography images were recorded in n = 2803 subjects within the prospective STAAB cohort study investigating a representative age- and sex-stratified sample of residents of the city of Würzburg, aged 30-79 years, without history of heart failure. Valid 3D image analysis was performed in n = 1831 (65.3%) subjects (mean age 57 ± 11 years, 49.3% women). Using general linear models, we identified determinants of LV twist and torsion: there was a positive association between LV rotational parameters and age, female sex, and blood pressure but a negative association with body weight. From a subset of 479 apparently healthy individuals exhibiting no cardiovascular (CV) risk factors or CV disease (mean age 52 ± 10 years, 56.4% women), we derived reference percentiles for twist and torsion. LV rotation is determined by a complex interplay of sub-endocardial and sub-epicardial fibers which might be affected differentially by potential risk factors. We found a differential association with respective determinants as LV rotational parameters increased with age and with higher blood pressure but decreased with higher body weight. Further research is needed to elucidate these associations in more detail and to determine the additional information contributed by twist and torsion. To facilitate respective attempts and to set an individual's results in relation to a population-based reference, we derived normal values for twist and torsion from a sub-collective of healthy individuals.

Echocardiographic assessment of left ventricular volumes: a comparison of different methods in athletes

BACKGROUND

Cardiac magnetic resonance imaging (cMRI) is considered the gold standard for the assessment of left ventricular (LV) systolic function. However, discrepancies have been reported in the literature between LV volumes assessed by transthoracic echocardiography (TTE) and cMRI. The objective of this study was to analyze the differences in LV volumes between different echocardiographic techniques and cMRI.

METHODS AND RESULTS

In 64 male athletes (21.1 ± 4.9 years), LV volumes were measured by TTE using the following methods: Doppler echocardiography, anatomical M-Mode, biplane/triplane planimetry and 3D volumetry. In addition, LV end-diastolic (LVEDV), end-systolic (LVESV), and stroke volumes (LVSV) were assessed in 11 athletes by both TTE and cMRI. There was no significant difference between LVEDV and LVESV determined by biplane/triplane planimetry and 3D volumetry. LVEDV and LVESV measured by M-Mode were significantly lower compared to 3D volumetry. LVSV determined by Doppler with 3D planimetry of LV outflow tract was significantly higher than 2D planimetry and 3D volumetry, whereas none of the planimetric or volumetric methods for determining LVSV differed significantly. There were no significant differences for LVEDV, LVESV, LVSV and LVEF between cMRI and TTE determined by biplane planimetry in the subgroup of 11 athletes.

CONCLUSION

The choice of echocardiographic method used has an impact on LVSV in athletes, so the LVSV should always be checked for plausibility. The same echocardiographic method should be used to assess LVSV at follow-ups to ensure good comparability. The data suggest that biplane LV planimetry by TTE is not inferior to cMRI.

Echocardiographic Measurements in Normal Chinese Adults (EMINCA) II focusing on left ventricular and left atrial size and function by three-dimensional echocardiography

Current guidelines encourage large studies in a diverse population to establish normal reference ranges for three-dimensional (3D) echocardiography for different ethnic groups. This study was designed to establish the normal values of 3D-left ventricular (LV) and left atrial (LA) volume and function in a nationwide, population-based cohort of healthy Han Chinese adults. A total of 1117 healthy volunteers aged 18-89 years were enrolled from 28 collaborating laboratories in China. Two sets of 3D echocardiographic instruments were used, and full-volume echocardiographic images were recorded and transmitted to a core laboratory for image analysis with a vendor-independent off-line workstation. Finally, 866 volunteers (mean age of 48.4 years, 402 men) were qualified for final analysis. Most parameters exhibited substantial differences between different sex and age groups, even after indexation by body surface area. The normal ranges of 3D-LV and 3D-LA volume and function differed from those recommended by the American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines, presented by the World Alliance Societies of Echocardiography (WASE) study, and from the 2D values in the EMINCA study. The normal reference values of 3D echocardiography-derived LV and LA volume and function were established for the first time in healthy Han Chinese adults. Normal ranges of 3D-LV and 3D-LA echocardiographic measurements stratified with sex, age, and race should be recommended for clinical applications.

Right ventricular stroke work index from echocardiography in patients with pulmonary arterial hypertension-the role in short-term follow-up assessment

Aims

Right ventricular (RV) failure causes high mortality in patients with pulmonary arterial hypertension (PAH). RV stroke work index (RVSWi) poses as a potential predictor of outcome. We evaluated how RVSWi by echocardiography (ECHO) or right heart catheterization (RHC) is altered following PAH treatment and if RVSWi is an indicator of outcome in PAH.

Methods and results

Fifty-four patients with PAH performed ECHO and RHC (median, 0 days between examinations) at baseline and treatment follow-up. RVSWiRHC was computed as (mPAP-mRAP)×SViRHC, (mPAP, mean pulmonary arterial pressure; mRAP, mean right atrial pressure; SVi, stroke volume indexed to body surface area). ECHO-derived RVSWi was calculated as RVSWiECHO-Mean = TRmeanPG × SViECHO and RVSWiECHO-Max = TRmaxPG × SViECHO (TRmeanPG and TRmaxPG: tricuspid regurgitant mean and maximum pressure gradient). Invasive sPAP, mPAP, and pulmonary vascular resistance decreased and SVi increased from baseline to follow-up (P < 0.01 for all). RVSWiRHC and RVSWiECHO (Mean and Max) did not differ from baseline to follow-up (P > 0.05). Forty patients died during 109 ± 24 months. In univariate Cox proportional hazard analysis, age > 65 years, 6-minute-walk test < 160 m, WHO class III-IV and indexed right atrial volume were associated with long-term mortality, but none of the RVSWi methods. In multivariate analysis with clinical parameters, both RVSWiECHO methods were independently associated with mortality.

Conclusion

The RVSWi methods did not differ from baseline to short-term follow-up and were not associated with long-term outcomes in univariate analysis. However, baseline RVSWiECHO was associated with mortality when adjusting for clinical parameters.

Significant Disagreement Between Conventional Parameters and 3D Echocardiography-Derived Ejection Fraction in the Detection of Right Ventricular Systolic Dysfunction and Its Association With Outcomes

AIMS

Conventional echocardiographic parameters such as tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and free-wall longitudinal strain (FWLS) offer limited insights into the complexity of right ventricular (RV) systolic function, while 3D echocardiography-derived RV ejection fraction (RVEF) enables a comprehensive assessment. We investigated the discordance between TAPSE, FAC, FWLS, and RVEF in RV systolic function grading and associated outcomes.

METHODS

We analyzed two- and three-dimensional echocardiography data from 2 centers including 750 patients followed up for all-cause mortality. Right ventricular dysfunction was defined as RVEF <45%, with guideline-recommended thresholds (TAPSE <17 mm, FAC <35%, FWLS >-20%) considered.

RESULTS

Among patients with normal RVEF, significant proportions exhibited impaired TAPSE (21%), FAC (33%), or FWLS (8%). Conversely, numerous patients with reduced RVEF had normal TAPSE (46%), FAC (26%), or FWLS (41%). Using receiver-operating characteristic analysis, FWLS exhibited the highest area under the curve of discrimination for RV dysfunction (RVEF <45%) with 59% sensitivity and 92% specificity. Over a median 3.7-year follow-up, 15% of patients died. Univariable Cox regression identified TAPSE, FAC, FWLS, and RVEF as significant mortality predictors. Combining impaired conventional parameters showed that outcomes are the worst if at least 2 parameters are impaired and gradually better if only one or none of them are impaired (log-rank P < .005).

CONCLUSION

Guideline-recommended cutoff values of conventional echocardiographic parameters of RV systolic function are only modestly associated with RVEF-based assessment. Impaired values of FWLS showed the closest association with the RVEF cutoff. Our results emphasize a multiparametric approach in the assessment of RV function, especially if 3D echocardiography is not available.

Effect of cross-platform variations on transthoracic echocardiography measurements and clinical diagnosis

Aims

Accurate cardiac chamber quantification is essential for clinical decisions and ideally should be consistent across different echocardiography systems. This study evaluates variations between the Philips EPIQ CVx (version 9.0.3) and Canon Aplio i900 (version 7.0) in measuring cardiac volumes, ventricular function, and valve structures.

Methods and results

In this gender-balanced, single-centre study, 40 healthy volunteers (20 females and 20 males) aged 40 years and older (mean age 56.75 ± 11.57 years) were scanned alternately with both systems by the same sonographer using identical settings for both 2D and 4D acquisitions. We compared left ventricular (LV) and right ventricular (RV) volumes using paired t-tests, with significance set at P < 0.05. Correlation and Bland-Altman plots were used for quantities showing significant differences. Two board-certified cardiologists evaluated valve anatomy for each platform. The results showed no significant differences in LV end-systolic volume and LV ejection fraction between platforms. However, LV end-diastolic volume (LVEDV) differed significantly (biplane: P = 0.018; 4D: P = 0.028). Right ventricular (RV) measurements in 4D showed no significant differences, but there were notable disparities in 2D and 4D volumes within each platform (P < 0.01). Significant differences were also found in the LV systolic dyssynchrony index (P = 0.03), LV longitudinal strain (P = 0.04), LV twist (P = 0.004), and LV torsion (P = 0.005). Valve structure assessments varied, with more abnormalities noted on the Philips platform.

Conclusion

Although LV and RV volumetric measurements are generally comparable, significant differences in LVEDV, LV strain metrics, and 2D vs. 4D measurements exist. These variations should be considered when using different platforms for patient follow-ups.

Right ventricular volume and function by three-dimensional echocardiography: results of the echocardiographic measurements in normal Chinese adults (EMINCA) II

Three-dimensional (3D) echocardiography is an emerging technique for assessing right ventricular (RV) volume and function, but 3D-RV normal values from a large Chinese population are still lacking. The aim of the present study was to establish normal values of 3D-RV volume and function in healthy Chinese volunteers. A total of 1117 Han Chinese volunteers from 28 laboratories in 20 provinces of China were enrolled, and 3D-RV images of 747 volunteers with optimal image quality were ultimately analyzed by a core laboratory. Both vendor-dependent and vendor-independent software platforms were used to analyze the 3D-RV images. We found that men had larger RV volumes than women did in the whole population, even after indexing to body surface area, and older individuals had smaller RV volumes. The normal RV volume was significantly smaller than that recommended by the American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines in both sexes. There were significant differences in 3D-RV measurements between the two vendor ultrasound systems and the different software platforms. The echocardiographic measurements in normal Chinese adults II study revealed normal 3D-RV volume and function in a large Chinese population, and there were significant differences between the sexes, ages, races, and vendor groups. Thus, normal 3D-RV values should be stratified by sex, age, race, and vendor.

Design and Analysis of a Polymeric Left Ventricular Simulator via Computational Modelling

Preclinical testing of medical devices is an essential step in the product life cycle, whereas testing of cardiovascular implants requires specialised testbeds or numerical simulations using computer software Ansys 2016. Existing test setups used to evaluate physiological scenarios and test cardiac implants such as mock circulatory systems or isolated beating heart platforms are driven by sophisticated hardware which comes at a high cost or raises ethical concerns. On the other hand, computational methods used to simulate blood flow in the cardiovascular system may be simplified or computationally expensive. Therefore, there is a need for low-cost, relatively simple and efficient test beds that can provide realistic conditions to simulate physiological scenarios and evaluate cardiovascular devices. In this study, the concept design of a novel left ventricular simulator made of latex rubber and actuated by pneumatic artificial muscles is presented. The designed left ventricular simulator is geometrically similar to a native left ventricle, whereas the basal diameter and long axis length are within an anatomical range. Finite element simulations evaluating left ventricular twisting and shortening predicted that the designed left ventricular simulator rotates approximately 17 degrees at the apex and the long axis shortens around 11 mm. Experimental results showed that the twist angle is 18 degrees and the left ventricular simulator shortens 5 mm. Twist angles and long axis shortening as in a native left ventricle show it is capable of functioning like a native left ventricle and simulating a variety of scenarios, and therefore has the potential to be used as a test platform.

Role and application of three-dimensional transthoracic echocardiography in the assessment of left and right ventricular volumes and ejection fraction: a UK nationwide survey

Three-dimensional echocardiography (3DE) imaging has permitted advancements in the quantification of left ventricular (LV) and right ventricular (RV) volumes and ejection fraction. We evaluated the availability of 3DE equipment / analysis software, the integration of 3DE assessment of the LV and RV in routine clinical practice, current training provisions in 3DE, and aimed to ascertain barriers preventing the routine use of 3DE for volumetric analysis. Through the British Society of Echocardiography (BSE) regional representatives' network, echocardiographers were invited to participate in an open online survey. A total of 181 participants from echocardiography departments in the United Kingdom (UK), the majority from tertiary centres (61%), completed the 28-question survey. For 3DE quantification, 3DE-LV was adopted more frequently than 3DE-RV (48% vs 11%, respectively). Imaging feasibility was a recognised factor in 3DE RV and LV adoption. Many respondents had access to 3D probes (93%). The largest observed barriers to 3DE routine use were training deficiencies, with 83% reporting they would benefit from additional training opportunities and the duration of time permitted for the scan, with 68% of responders reporting allowances of less than the BSE standard of 45-60 min per patient (8% < 30-min). Furthermore, of those respondents who had undertaken professional accreditation, competence in 3DE was not formally assessed in 89%. This UK survey also reported good accessibility to magnetic resonance imaging (72%), which was related to overall 3DE adoption. In summary, although 3DE is now readily available, it remains underutilised. Further training opportunities, integrated formal assessment, improved adoption of BSE minimum recommended scanning times, alongside industry and societal support, may increase 3DE utilisation in routine practice.

Three-dimensional echocardiographic evaluation of longitudinal and non-longitudinal components of right ventricular contraction: results from the World Alliance of Societies of Echocardiography study

AIMS

Right ventricular (RV) functional assessment is mainly limited to its longitudinal contraction. Dedicated three-dimensional echocardiography (3DE) software enabled the separate assessment of the non-longitudinal components of RV ejection fraction (EF). The aims of this study were (i) to establish normal values for RV 3D-derived longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their relative contributions to global RVEF, (ii) to calculate 3D RV strain normal values, and (iii) to determine sex-, age-, and race-related differences in these parameters in a large group of normal subjects (WASE study).

METHODS AND RESULTS

3DE RV wide-angle datasets from 1043 prospectively enrolled healthy adult subjects were analysed to generate a 3D mesh model of the RV cavity (TomTec). Dedicated software (ReVISION) was used to analyse RV motion along the three main anatomical planes. The EF values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS, and GAS, respectively). Results were categorized by sex, age (18-40, 41-65, and >65 years), and race. Absolute REF, AEF, LEF, and global RVEF were higher in women than in men (P < 0.001). With aging, both sexes exhibited a decline in all components of longitudinal shortening (P < 0.001), which was partially compensated in elderly women by an increase in radial contraction. Black subjects showed lower RVEF and GAS values compared with white and Asian subjects of the same sex (P < 0.001), and black men showed significantly higher RV radial but lower longitudinal contributions to global RVEF compared with Asian and white men.

CONCLUSION

3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex-, age-, and race-related differences in RV contraction patterns that may prove useful in disease states involving the right ventricle.

Left atrial strain in adults after the arterial switch operation for transposition of the great arteries

BACKGROUND

No study has focused on left atrial (LA) function assessed by echocardiography in adult patients with simple D-TGA after arterial switch operation (ASO). We aimed to describe LA strain parameters in these patients.

METHODS

A prospective cohort study including 42 adult patients with simple D-TGA after ASO and 33 aged-matched controls. Phasic LA and LV global longitudinal strain (GLS) were obtained by transthoracic 2D-speckle tracking echocardiography (STE). Volumetric and functional analysis of LA and LV were also evaluated by 2D and 3D analysis. A multivariable model was performed to investigate the variables that best differentiate patients with D-TGA from healthy controls.

RESULTS

LA strain parameters in D-TGA patients were within the normal range described for healthy subjects. However, the three LA strain parameters (Reservoir, Conduit, and Contraction) were lower in patients (LASr: 31.13 ± 7.67 vs. 49.71 ± 8.38; LAS cd: -22.91 ± 5.69 vs. -34.55 ± 6.54; LASct: -8.14 ± 4.93 vs. -15.15 ± 6.07, p < .001 for all three comparisons). LA volumes were similar between patients and controls. LV-GLS remained significantly lower in the D-TGA group than in controls (-17.29 ± 2.68 vs. -21.98 ± 1.84, p < .001). D-TGA patients had evidence of worse LV ejection fraction measured by the Teichholz method (63.38 ± 8.23 vs. 69.28 ± 5.92, p = .001) and 3D analysis (57.97% ± 4.16 vs. 60.67 ± 3.39, p = .011) and diastolic dysfunction as compared to healthy controls. LV-GLS and conduit LAS were the variables best differentiating patients with D-TGA from healthy controls.

CONCLUSIONS

LA strain is impaired in young adults with simple D-TGA late after the ASO, probably in agreement with some degree of LV dysfunction previously described.

Topology-sensitive weighting model for myocardial segmentation

Accurate myocardial segmentation is crucial for the diagnosis of various heart diseases. However, segmentation results often suffer from topology structural errors, such as broken connections and holes, especially in cases of poor image quality. These errors are unacceptable in clinical diagnosis. We proposed a Topology-Sensitive Weight (TSW) model to keep both pixel-wise accuracy and topological correctness. Specifically, the Position Weighting Update (PWU) strategy with the Boundary-Sensitive Topology (BST) module can guide the model to focus on positions where topological features are sensitive to pixel values. The Myocardial Integrity Topology (MIT) module can serve as a guide for maintaining myocardial integrity. We evaluate the TSW model on the CAMUS dataset and a private echocardiography myocardial segmentation dataset. The qualitative and quantitative experimental results show that the TSW model significantly enhances topological accuracy while maintaining pixel-wise precision.

Normal reference values for mitral annular plane systolic excursion by motion-mode and speckle tracking echocardiography: a prospective, multicentre, population-based study

AIMS

Mitral annular plane systolic excursion (MAPSE) is a simple and reliable index for evaluating left ventricular (LV) systolic function, particularly in patients with poor image quality; however, the lack of reference values limits its widespread use. This study aimed to establish the normal ranges for MAPSE measured using motion-mode (M-mode) and two-dimensional speckle tracking echocardiography (2D-STE) and to explore its principal determinants.

METHODS AND RESULTS

This multicentre, prospective, cross-sectional study included 1952 healthy participants [840 men (43%); age range, 18-80 years] from 55 centres. MAPSE was measured using M-mode echocardiography and 2D-STE. The results showed that women had a higher MAPSE than men and MAPSE decreased with age. The age- and sex-specific reference values for MAPSE were established for these two methods. Multiple linear regression analyses revealed that MAPSE on M-mode echocardiography correlated with age and MAPSE on 2D-STE with age, blood pressure (BP), heart rate, and LV volume. Moreover, MAPSE measured by 2D-STE correlated more strongly with global longitudinal strain compared with that measured using M-mode echocardiography.

CONCLUSION

Normal MAPSE reference values were established based on age and sex. BP, heart rate, and LV volume are potential factors that influence MAPSE and should be considered in clinical practice. Normal values are useful for evaluating LV longitudinal systolic function, especially in patients with poor image quality, and may further facilitate the use of MAPSE in routine assessments.

Quantification of Myocardial Contraction Fraction with Three-Dimensional Automated, Machine-Learning-Based Left-Heart-Chamber Metrics: Diagnostic Utility in Hypertrophic Phenotypes and Normal Ejection Fraction

Aims: The differentiation of left ventricular (LV) hypertrophic phenotypes is challenging in patients with normal ejection fraction (EF). The myocardial contraction fraction (MCF) is a simple dimensionless index useful for specifically identifying cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) when calculated by cardiac magnetic resonance. The purpose of this study was to evaluate the value of MCF measured by three-dimensional automated, machine-learning-based LV chamber metrics (dynamic heart model [DHM]) for the discrimination of different forms of hypertrophic phenotypes. Methods and Results: We analyzed the DHM LV metrics of patients with CA (n = 10), hypertrophic cardiomyopathy (HCM, n = 36), isolated hypertension (IH, n = 87), and 54 healthy controls. MCF was calculated by dividing LV stroke volume by LV myocardial volume. Compared with controls (median 61.95%, interquartile range 55.43-67.79%), mean values for MCF were significantly reduced in HCM-48.55% (43.46-54.86% p < 0.001)-and CA-40.92% (36.68-46.84% p < 0.002)-but not in IH-59.35% (53.22-64.93% p < 0.7). MCF showed a weak correlation with EF in the overall cohort (R2 = 0.136) and the four study subgroups (healthy adults, R2 = 0.039 IH, R2 = 0.089; HCM, R2 = 0.225; CA, R2 = 0.102). ROC analyses showed that MCF could differentiate between healthy adults and HCM (sensitivity 75.9%, specificity 77.8%, AUC 0.814) and between healthy adults and CA (sensitivity 87.0%, specificity 100%, AUC 0.959). The best cut-off values were 55.3% and 52.8%. Conclusions: The easily derived quantification of MCF by DHM can refine our echocardiographic discrimination capacity in patients with hypertrophic phenotype and normal EF. It should be added to the diagnostic workup of these patients.

Application of Allometric Methods for Indexation of Left Ventricular End-Diastolic Volume to Normal Echocardiographic Data and Assessing Gender and Racial Differences

BACKGROUND

Gender and racial differences in cardiac chamber size are vital to establish normal ranges of cardiac chamber size in healthy subjects. Many studies report either nonindexed raw measurements or measurements indexed to isometric body surface area (BSA) when establishing normal reference values. Other studies advocate allometric indexation for standardization of heart size. We compared several allometric methods on gender and racial differences in left ventricular end-diastolic volume (LVEDV) measured on three-dimensional echocardiography.

METHODS

Three-dimensional echocardiographic LVEDV data from the World Alliance Societies of Echocardiography normal values study were indexed to isometric BSA, BSA^1.5, BSA^1.8, isometric height, height^2.3, height^2.9, and estimated lean body mass. Gender, racial, national, and regional differences in indexed and nonindexed LVEDV were assessed using Cohen's d statistic or Cohen's f statistic, according to the number of groups being compared. Cohen's d < 0.20 and Cohen's f < 0.10 were regarded as very small relative magnitudes of difference.

RESULTS

Differences in LVEDV among White, Black, and Asian races were smallest when BSA^1.5 or BSA^1.8 was used for indexation, followed by estimated lean body mass. LVEDV/BSA^1.5 was nearly identical for men and women (very small, d = 0.05). However, both LVEDV/BSA^1.5 and LVEDV/BSA^1.8 still provided moderate relative magnitudes of difference (f = 0.22-0.37) among geographic regions. Specifically, among Asians, Indians had the smallest LVEDV/BSA^{1.5 (1.8)}. Brazilians had the smallest LVEDV/BSA^{1.5 (1.8)} among Whites.

CONCLUSIONS

Gender and racial differences in LVEDV became smaller when LVEDV was indexed to BSA^1.5 or BSA^1.8. However, differences in LVEDV among nations remain even after applying allometric scaling. This finding suggests that differences in body composition and/or hemodynamics are potentially more important determinants of heart size than race or gender.

MITEA: A dataset for machine learning segmentation of the left ventricle in 3D echocardiography using subject-specific labels from cardiac magnetic resonance imaging

Segmentation of the left ventricle (LV) in echocardiography is an important task for the quantification of volume and mass in heart disease. Continuing advances in echocardiography have extended imaging capabilities into the 3D domain, subsequently overcoming the geometric assumptions associated with conventional 2D acquisitions. Nevertheless, the analysis of 3D echocardiography (3DE) poses several challenges associated with limited spatial resolution, poor contrast-to-noise ratio, complex noise characteristics, and image anisotropy. To develop automated methods for 3DE analysis, a sufficiently large, labeled dataset is typically required. However, ground truth segmentations have historically been difficult to obtain due to the high inter-observer variability associated with manual analysis. We address this lack of expert consensus by registering labels derived from higher-resolution subject-specific cardiac magnetic resonance (CMR) images, producing 536 annotated 3DE images from 143 human subjects (10 of which were excluded). This heterogeneous population consists of healthy controls and patients with cardiac disease, across a range of demographics. To demonstrate the utility of such a dataset, a state-of-the-art, self-configuring deep learning network for semantic segmentation was employed for automated 3DE analysis. Using the proposed dataset for training, the network produced measurement biases of -9 ± 16 ml, -1 ± 10 ml, -2 ± 5 %, and 5 ± 23 g, for end-diastolic volume, end-systolic volume, ejection fraction, and mass, respectively, outperforming an expert human observer in terms of accuracy as well as scan-rescan reproducibility. As part of the Cardiac Atlas Project, we present here a large, publicly available 3DE dataset with ground truth labels that leverage the higher resolution and contrast of CMR, to provide a new benchmark for automated 3DE analysis. Such an approach not only reduces the effect of observer-specific bias present in manual 3DE annotations, but also enables the development of analysis techniques which exhibit better agreement with CMR compared to conventional methods. This represents an important step for enabling more efficient and accurate diagnostic and prognostic information to be obtained from echocardiography.

Three-Dimensional Automated, Machine-Learning-Based Left Heart Chamber Metrics: Associations with Prevalent Vascular Risk Factors and Cardiovascular Diseases

Background. Three-dimensional transthoracic echocardiography (3DE) powered by artificial intelligence provides accurate left chamber quantification in good accordance with cardiac magnetic resonance and has the potential to revolutionize our clinical practice. Aims. To evaluate the association and the independent value of dynamic heart model (DHM)-derived left atrial (LA) and left ventricular (LV) metrics with prevalent vascular risk factors (VRFs) and cardiovascular diseases (CVDs) in a large, unselected population. Materials and Methods. We estimated the association of DHM metrics with VRFs (hypertension, diabetes) and CVDs (atrial fibrillation, stroke, ischemic heart disease, cardiomyopathies, >moderate valvular heart disease/prosthesis), stratified by prevalent disease status: participants without VRFs or CVDs (healthy), with at least one VRFs but without CVDs, and with at least one CVDs. Results. We retrospectively included 1069 subjects (median age 62 [IQR 49−74]; 50.6% women). When comparing VRFs with the healthy, significant difference in maximum and minimum indexed atrial volume (LAVi max and LAVi min), left atrial ejection fraction (LAEF), left ventricular mass/left ventricular end-diastolic volume ratio, and left ventricular global function index (LVGFI) were recorded (p < 0.05). In the adjusted logistic regression, LAVi min, LAEF, LV ejection fraction, and LVGFI showed the most robust association (OR 3.03 [95% CI 2.48−3.70], 0.45 [95% CI 0.39−0.51], 0.28 [95% CI 0.22−0.35], and 0.22 [95% CI 0.16−0.28], respectively, with CVDs. Conclusions. The present data suggested that novel 3DE left heart chamber metrics by DHM such as LAEF, LAVi min, and LVGFI can refine our echocardiographic disease discrimination capacity.