Lower Limit of Normality of Segmental Multilayer Longitudinal Strain in Healthy Adult Subjects

Speckle tracking echocardiography is an advanced imaging technique that allows for a more detailed assessment of cardiac global and regional function. Reference values for segmental longitudinal layered strain (subendocardial, mid-myocardial, and subepicardial) are scarce, limiting the clinical use of these measurements in clinical practice. Two hundred consecutive Caucasian healthy subjects (mean age = 37 ± 11 years) were enrolled in the study. The mean values of global longitudinal strain (GLS) for endocardial (Endo), mid-myocardial (Myo) and epicardial (Epi) layers were -22.9 ± 2.7, -20.0 ± 2.4 and -17.5 ± 2.1, respectively. The GLSEndo/GLSMyo ratio was 1.1 ± 0.05, while the GLSEndo/GLSEpi ratio was 1.3 ± 0.05. The apical strain-sparing ratio was >1 in 10% of the subjects (endocardium) and 7% (mid-myocardium). The lower limits for segmental LS were as follows: for endocardial LS, -10% (basal), -12% (mid), -14% (apical); for mid-myocardial LS, -10% -10% (basal), -10% (mid), -10% (apical); and for epicardial LS, -7% (basal), -8% (mid), -8% (apical). The findings of this study provide data regarding the lower limit of normality of LS for each LV segment and suggest, for practical considerations, that an LS value below 10% should be considered abnormal in any segment. Further larger studies are warranted to confirm these findings.

Tricuspid valve agenesis: a case report of a rare cause of tricuspid regurgitation in an adult

Background

Tricuspid valve agenesis is an exceptionally rare congenital cardiac disease characterized by the incomplete formation or complete absence of one or more tricuspid leaflets. It is commonly diagnosed during childhood due to the development of heart failure symptoms.

Case summary

We report the case of a 62-year-old woman admitted for a worsening of heart failure symptoms (New York Heart Association functional Class IV at admission). A standard transthoracic echocardiogram was performed, which showed severe right heart dilatation and severe tricuspid regurgitation. A three-dimensional echocardiogram revealed the absence of the posterior tricuspid leaflet. The patient underwent an uncomplicated surgical bioprosthetic valve replacement with a favourable outcome and partial recovery of right ventricular function. In our patient, valve repair was not favoured due to the additional mild hypoplasia of the anterior leaflet. The 3-month post-operative evolution of the patient was favourable, with significant symptom relief.

Discussion

The diagnosis of tricuspid agenesis during adulthood is uniquely uncommon. A three-dimensional echocardiography can provide accurate pre-procedural insight into the valve anatomy, allowing surgeons to plan for either valve repair when the anatomy is suitable or valve replacement.

Mechanical Dyssynchrony Combined with Septal Scarring Reliably Identifies Responders to Cardiac Resynchronization Therapy

Background and aim: The presence of mechanical dyssynchrony on echocardiography is associated with reverse remodelling and decreased mortality after cardiac resynchronization therapy (CRT). Contrarily, myocardial scar reduces the effect of CRT. This study investigated how well a combined assessment of different markers of mechanical dyssynchrony and scarring identifies CRT responders. Methods: In a prospective multicentre study of 170 CRT recipients, septal flash (SF), apical rocking (ApRock), systolic stretch index (SSI), and lateral-to-septal (LW-S) work differences were assessed using echocardiography. Myocardial scarring was quantified using cardiac magnetic resonance imaging (CMR) or excluded based on a coronary angiogram and clinical history. The primary endpoint was a CRT response, defined as a ≥15% reduction in LV end-systolic volume 12 months after implantation. The secondary endpoint was time-to-death. Results: The combined assessment of mechanical dyssynchrony and septal scarring showed AUCs ranging between 0.81 (95%CI: 0.74-0.88) and 0.86 (95%CI: 0.79-0.91) for predicting a CRT response, without significant differences between the markers, but significantly higher than mechanical dyssynchrony alone. QRS morphology, QRS duration, and LV ejection fraction were not superior in their prediction. Predictive power was similar in the subgroups of patients with ischemic cardiomyopathy. The combined assessments significantly predicted all-cause mortality at 44 ± 13 months after CRT with a hazard ratio ranging from 0.28 (95%CI: 0.12-0.67) to 0.20 (95%CI: 0.08-0.49). Conclusions: The combined assessment of mechanical dyssynchrony and septal scarring identified CRT responders with high predictive power. Both visual and quantitative markers were highly feasible and demonstrated similar results. This work demonstrates the value of imaging LV mechanics and scarring in CRT candidates, which can already be achieved in a clinical routine.

Can echocardiography facilitate decision-making to CRT?

Introduction

Cardiac resynchronization therapy (CRT) remains underused despite its well-established therapeutic effect and clear guidelines. Among various reasons are the lack of referral, the fear of complications and the high therapy cost. The assessment of mechanical dyssynchrony (MD) on echocardiography has been suggested to aid patient selection. In the past, however, several studies have used old markers of MD producing disappointing results and the use of echocardiography for patient selection became discredited. Promising new markers have been developed since and could aid clinical decision-making for CRT. These should, however, first be thoroughly tested and compared to the old markers.

Purpose

(I) To confirm the relevance of the new markers of MD for survival free of cardiac death and (II) to compare old and new markers of MD for predicting cardiac death within 5 years post-CRT in patients eligible for CRT according the 2021 ESC guidelines.

Methods

222 CRT-patients were analysed retrospectively in a multicentre setting. MD was assessed using three old markers: septal-to-posterior wall-motion-delay (SPWMD), left-ventricular-filling-time/cardiac-cycle ratio (LVFT/RR), and intraventricular mechanical delay (IVMD); and three new markers: systolic stretch index (SSI), myocardial work index (MWI), and visual presence of septal flash or apical rocking (SFoAR). For each marker, patients were categorized using previously published cut-offs as “MD present” (Yes) or “MD not present” (No). Log rank tests were performed on Kaplan-Meier curves for survival free of cardiac death. Cox proportional hazards regressions were used to compute the hazard-ratio (HR) for cardiac death within 5 years after implantation.

Results

Cardiac death occurred in 37 patients (17%). Patients with MD before CRT according to IVMD (p=0.003), SSI (p<0.001), MWI (p<0.001) or SFoAR (p<0.001) had a significantly better survival. The hazard ratios were 0.34 (95% CI, 0.19–0.75) for IVMD, 0.30 (95% CI, 0.15–0.57) for SSI, 0.26 (95% CI, 0.12–0.54) for MWI and, 0.28 (95% CI, 0.14–0.53) for SFoAR. The other markers for MD were not significant for survival.

Conclusion

The new markers for dyssynchrony are better than the old. Patients with mechanical dyssynchrony on echocardiography before CRT according to SSI, MWI or SFoAR are 3 to 4 times less likely to die within 5 years after CRT implantation. The presence of one of these markers in patients with a broad QRS (≥130ms) and reduced LVEF (≤35%) should prompt clinicians to refer for or to proceed to CRT.

Funding Acknowledgement

Type of funding sources: None.

The link between left atrial longitudinal reservoir strain and mitral apparatus geometry in patients with dilated cardiomyopathy

Background

4-Dimensional Automated Left Atrial Quantification (4D Auto LAQ) is a technique that uses 3D volume data to determine LA strain. 4-Dimensional Automated Mitral Valve Quantification (4D Auto MVQ) evaluates anatomical and functional mitral valve parameters. Our study evaluated patients with dilated cardiomyopathy and tried to find a correlation between LA strain and mitral apparatus geometry.

Methods

We enrolled 61 patients with dilated cardiomyopathy and 25 healthy volunteers. The evaluation consisted of clinical examination, laboratory tests, 12 leads electrocardiography. All participants underwent a complete transthoracic echocardiogram to determine cardiac structure and function according to the current guidelines. Measurement of LA strain and MV was performed using 4D Auto-quantification software. The study evaluated longitudinal strain during reservoir phase (LASr) and the parameters of the MV geometry that could interfere with left atrial function: annulus area, annulus perimeter, anteroposterior (A-P) diameter, posteromedial-anterolateral diameter (PM-AL), (the longest diameter of MV perpendicular to AP diameter); commissural diameter (CD), inter-trigonal distance, tenting height, tenting area, and tenting volume.

Results

1. The patients were divided in two groups: 26 with ischemic dilated cardiomyopathy and 35 with non-ischemic dilated cardiomyopathy. 2. Mean values of MV parameters in patients with dilated cardiomyopathy compare with healthy volunteers were: annulus area: 19.46 cm2 vs 11.85 cm2; annulus perimeter: 16.86 cm vs 12.71cm, A-P diameter 4.53 cm vs 3.45 cm, PM-AL diameter 4.84 cm vs 3.92 cm, CD 4.83 cm, vs 3.94 cm, inter-trigonal distance 3.9 cm vs 2.9 cm, tenting height 1.64 cm vs 1.05 cm, tenting area 4.82 cm2 vs 1.78 cm2, tenting volume 13.49 ml vs 4.27 ml. For LASr, mean values were 10.26 in patients with dilated cardiomyopathy vs 32.14 in healthy volunteers. Mean values of mitral valve parameters and LASr were comparable in ischemic vs non-ischemic cardiomyopathy patients. 3. LASr correlated with anatomical mitral valve parameters: annulus area: r=−0.6, annulus perimeter: r=−0.57, AP diameter: r=−0.58, PM-AL diameter: r=−0.58, commissural diameter: r=−0.66, inter-trigonal distance: r=−0.57, tenting height r=−0.53, tenting area r=−0.55 and tenting volume r=−0.54.

Conclusions

1. In patients with dilated cardiomyopathy phenotype, anatomical parameters of the mitral valve and LASr were altered. Results did not reveal significant differences between ischemic and non-ischemic etiology. 2. A correlation was found between the decrease in LASr and anatomical parameters of the mitral valve, suggesting a link between atrial function deterioration and deformity of mitral apparatus geometry in patients with dilated cardiomyopathy.

Funding Acknowledgement

Type of funding sources: None.

Testosterone and quality of life in patients with dilated cardiomyopathy

BACKGROUND

Testosterone is an important factor that influences the quality of life in men. The purpose of this study is to evaluate how testosterone level impacts the quality of life in patients with dilated cardiomyopathy.

METHODS

This cross-sectional single-center included 97 male patients with dilated cardiomyopathy, in whom serum testosterone was measured. Health-related quality of life was measured using the translated validated version of the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). We used correlation and multivariable regression to assess the association between KCCQ-12 score, serum testosterone level, and clinical and paraclinical variables.

RESULTS

The mean age of study participants was 58 (range 29-88). The mean LVEF was 25 ±8.61%. The average total serum testosterone level was 3.13 ±2.72 (range 0.19-13.5 ng/ml). The median global KCCQ-12 score was 44.8 (6.2-90.6) representing a poor to fair impairment in quality of life. There was an inverse correlation between the KCCQ-12 score and NYHA class (Pearson coefficient r = 0.847 p<0.001) and a direct correlation with LVEF (r=0.445, p<0.001). Also, the KCCQ-12 score correlated with hemoglobin level (r=0.214, p=0.037) and plasmatic creatinine level (r=-0.296 p= 0.004). In multivariable regression, the independent predictors of health-related quality of life were testosterone, LVEF, and NYHA class.

CONCLUSIONS

The results of this study showed for the first time a significant direct relationship between serum testosterone levels and quality of life in patients with dilated cardiomyopathy.

Echocardiographic assessment of mechanical dyssynchrony: are the new parameters better?

Funding Acknowledgements

Type of funding sources: None.

Introduction - The high cost and important non-response rate are preventing optimal use of cardiac resynchronization therapy (CRT). Assessing mechanical dyssynchrony on echocardiography in candidates for CRT could remove these barriers by improving patient selection. In 2008 the PROSPECT study compared several old parameters of dyssynchrony in search of a reproducible parameter capable of better predicting response to CRT. Unfortunately, the results were disappointing and the assessment of dyssynchrony became discredited. Promising new parameters have been developed but a comparison with the old parameters is currently missing.

Purpose - To compare the old and new parameters of mechanical dyssynchrony for (1) their effect on response to CRT as additional selection criteria, (2) predicting favourable long-term outcome after CRT and (3) their reproducibility.

Methods - 146 CRT patients were analysed retrospectively in a multicentre setting. Mechanical dyssynchrony was assessed using three old parameters: septal-to-posterior wall motion delay (SPWMD), left ventricular filling time/cardiac cycle ratio (LVFT/RR), and intraventricular mechanical delay (IVMD); and three new parameters: systolic stretch index (SSI), myocardial work index (MWI), and visual presence of septal flash or apical rocking (SFoAR). Response to CRT was defined as a ≥15% decrease in LV end-systolic volume 1 year after CRT. For each parameter patients were categorized using previously published cut-offs as ‘eligible’ or ‘non-eligible’. The ‘non-eligible’ were considered untreated. Results were compared to the guidelines (Fig. 1). The hazard ratio (HR) for cardiac death within 5 years after implantation was computed for all patients (Fig. 2), and intra- and interrater agreement was determined.

Results - 73% (n= 107) of patients showed response to CRT. The old parameters maintained less than 75% of the original responders. SFoAR preserved the highest proportion of responders (93%), while reducing the number of non-responders by 39% (Fig. 1). The prediction of cardiac death was significant for SFoAR (HR = 0.29; 95% CI: 0.12-0.74; P = 0.009) and IVMD (HR = 0.32; 95% CI: 0.13-0.79; P = 0.014) (Fig. 2). Intra- and interrater agreement was best for SFoAR (κ = 0.89; 95% CI: 0.67-1.0 and κ = 0.78; 95% CI: 0.50-1.0 respectively). Interrater agreement was poor for all old parameters (κ &lt; 0.6).

Conclusion - The new parameters for dyssynchrony are performing better. The visual presence of apical rocking or septal flash provided the most responders to CRT, predicted favourable long-term outcome and was highly reproducible. Our results show that future research should focus on the new parameters. Abstract Figure.  Abstract Figure.

Comparison between Nondedicated and Novel Dedicated Tracking Tool for Right Ventricular and Left Atrial Strain

BACKGROUND

Recently, dedicated speckle-tracking solutions for right ventricular (RV) and left atrial (LA) strain assessment have become commercially available. The purpose of this study was to assess the level of agreement between nondedicated (left ventricular [LV] tracking software) and novel dedicated tracking software for RV and LA strain.

METHODS

In 200 patients with various cardiovascular pathologies, we measured global longitudinal strain (GLS), free wall strain (FWS), and segmental values, as well as LA strain during reservoir, conduit, and contraction phases, by using the (1) LV-tracking software and (2) the novel dedicated tracking software for RV or LA strain analysis. Agreement between corresponding measurements obtained with the LV and dedicated RV or LA software was determined by using mean absolute difference (MAD) and Bland-Altman test. The intra- and interobserver reproducibility related to the nondedicated and novel dedicated tracking software was tested in 30 randomly selected subjects.

RESULTS

The dedicated RV-tracking software provided slightly lower strain values without reaching statistical significance. The agreement between software was best for RV GLS (MAD, 2.4 ± 1.8) and significantly poorer for segmental values (MAD ranging from 4.5 ± 3.8 to 5.1 ± 4.0; analysis of variance, P < .05). The intra- and interobserver reproducibility for RV measurements was similar with both software (P > .05 for all parameters). Left atrial mean values showed no statistical difference when obtained with the two tracking tools. The use of LA dedicated tracking software increased significantly the intra- and interobserver reproducibility for LA strain during reservoir and atrial contraction (P < .01 for both).

CONCLUSIONS

Our results suggest that the choice of tracking software does not significantly impact RV strain measurements. Nonetheless, the use of the same tracking software is recommended when performing serial measurements. The use of the dedicated software for LA strain analysis significantly improved the intra- and interobserver reproducibility.

Quality Assurance of Segmental Strain Values Provided by Commercial 2-D Speckle Tracking Echocardiography Using in Silico Models: A Report from the EACVI-ASE Strain Standardization Task Force

The aim of this study was to determine the accuracy and reproducibility of vendor-specific regional strain values by echocardiography using in silico data. Synthetic 2-D ultrasound gray-scale images of the left ventricle (LV) were generated with knowledge of the longitudinal segmental strain values from the underlying electromechanical LV model. Four of five models mimicked transmural infarctions with systolic segmental stretching in different vascular areas. Cine loops in the three apical views were synthetically generated at four noise levels. All in silico images were repeatedly analyzed by a single investigator and some by another investigator. The absolute errors varied significantly between vendors from 3.3 ± 3.1% to 11.2 ± 5.9%. The area under the curve for the identification of segmental stretching ranged from 0.80 (confidence interval: 0.77-0.83) to 0.96 (0.95-0.98). The levels of agreement for intra-investigator variability varied between -3.0% to 2.9% and -5.2% to 4.8%, and for inter-investigator variability, between -3.6% to 3.5% and -14.5% to 8.5%. Segmental strain analysis allows the identification of areas with segmental stretching with good accuracy. However, single segmental peak-strain values are not accurate and should be interpreted with caution. Nevertheless, our results indicate the usefulness of semiquantitative strain assessment for the detection of regional dysfunction.

Localizing myocardial scar on echocardiography. How good does it work in the presence of conduction delays?

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation - Flanders (FWO)

Introduction

Myocardial scar detection with echocardiography in patients with ischemic heart disease typically relies on semi-quantitative evaluation of regional systolic wall thickening. In patients scheduled for cardiac resynchronization therapy (CRT) however, such echo scar estimation is complicated by the presence of dyssynchronous contraction and differential regional remodelling. Visual assessment of myocardial shortening during systole may be an alternative approach. We tested this against cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) in patients without and with conduction delay.

Methods

122 patients with ischemic heart disease were included (n = 58 without, and n = 64 with conduction delay). Scar burden of the LV was determined in all patients on a segmental level in both CMR and echo. Reading of echo was blinded for CMR data and vice versa. Myocardial scar was defined as LGE &gt; 50% of transmural thickness. On echo, scar was assessed visually, and defined as thin, echogenic myocardium with no visible shortening during systole. Analysis was performed per segment (18 segment model), and per region (6 walls with basal and mid segment and the apex region consisting of all apical segments). An additional analysis was performed with a tolerance of one adjacent segment in order to account for potential image misalignment between modalities.

Results

2196 segments were available for comparison between echo and CMR. On CMR, 548 of those segments were defined as having &gt;50% transmural scar. In echo, 565 segments were detected as having scar. On a segmental level, no difference was found for the correct assignment of segments by echo as having scar or not between patients without or with conduction delay (AUC 0.79 vs. 0.79; p = 0.968) (Figure, top panels). See Figure for sensitivity and specificity. If one segment tolerance was allowed, segments were correctly assigned with equal accuracy in both patient groups (AUC 0.98 vs. 0.96; p = 0.999) (see Figure; w. tolerance). Agreement on the level of LV regions was comparable. 295 regions had a scar on CMR while 286 regions were identified by echo. Echo correctly identified a scar in the same LV wall or apex as compared to CMR similarly in patients without or with conduction delay (AUC 0.79 vs. 0.77; p = 0.698). If one segment tolerance was allowed, correct identification improved further and was not different between both groups (AUC 0.93 vs. 0.91; p = 0.999). The extent of a scar was slightly underestimated (9%) by echocardiography in comparison to CMR in patients without, and slightly overestimated (3%) in patients with conduction delays.

Conclusions

Scars can be localized on echocardiography with good agreement to CMR-LGE as gold standard. The match between echo and CMR was similar for patients with and without conduction delay. Our findings demonstrate that echo can provide a valid impression of localization and extent of myocardial scar, even in the presence of conduction delays.

Abstract Figure.

Vendor-independent software shows limited variability in speckle tracking strain measurements on images of different vendors

Funding Acknowledgements

Type of funding sources: None.

Background

Vendors use proprietary speckle tracking software algorithms for echocardiographic strain measurements, which results in high inter-vendor variability. Little is known about potential advantages or disadvantages of using vendor-independent software in clinical practice.

Purpose

We therefore investigated the reproducibility, accuracy, and ability to identify scar of strain measurements on images from different vendors by using a vendor-independent software.

Methods

A vendor-independent software (TomTec Image Arena) was used to analyze datasets of 63 patients which were obtained on four ultrasound machines from different vendors (GE, Philips, Siemens, Toshiba). We measured the tracking feasibility, inter-vendor bias, the relative and absolute test-re-test variability of strain measurements and their ability to detect scar. Cardiac magnetic resonance delayed enhancement images were used as the reference standard of scar definition.

Results

Tracking feasibility differed depending on the image source (p &lt; 0.05). Variability of global longitudinal strain (GLS) (Figure 1A) was similar (ANOVA p = 0.124) among the images of different vendors whereas variability of segmental longitudinal strain (SLS) (Figure 1B) showed modest difference (ANOVA- peak systolic strain (PS); p = 0.077, end-systolic strain (ES); p = 0.171, post-systolic strain (PSS); p = 0.020). Relative test-re-test variability of GLS showed no differences (ANOVA p = 0.360). Absolute test-re-test errors of SLS measurements showed modest differences among images of different vendors (ANOVA- PS; p = 0.018, ES; p = 0.001, PSS; p = 0.090). No relevant difference in scar detection capability was observed (Figure 1C).

Conclusions

Vendor independent software leads to low bias among strain measurements on images from different vendors. Likewise, measurement variability and the ability to identify scar becomes similar. Our findings suggest that a vendor independent speckle tracking software could help to overcome inter-vendor bias. To which extend such measurements would be more accurate compared to vendor specific software remains to be determined.

Abstract Figure 1

Inter-vendor variability in strain measurements depends on software rather than image characteristics

Despite standardization efforts, vendors still use specific proprietary software algorithms for echocardiographic strain measurements, which result in high inter-vendor variability. Using vendor-independent software could be one solution. Little is known, however, how vendor specific image characteristics can influence tracking results of such software. We therefore investigated the reproducibility, accuracy, and scar detection ability of strain measurements on images from different vendors by using a vendor-independent software. A vendor-independent software (TomTec Image Arena) was used to analyse datasets of 63 patients which were obtained on machines from four different ultrasound machine vendors (GE, Philips, Siemens, Toshiba). We measured the tracking feasibility, inter-vendor bias, the relative test-re-test variability and scar discrimination ability of strain measurements. Cardiac magnetic resonance delayed enhancement images were used as the reference standard of scar definition. Tracking feasibility on vendor datasets were significantly different (p < 0.001). Variability of global longitudinal strain (GLS) measurements was similar among the vendors whereas variability of segmental longitudinal strain (SLS) showed modest difference. Relative test-re-test variability of GLS and SLS showed no relevant differences. No significant difference in scar detection capability was observed. Average GLS and SLS values were similar among vendors. Reproducibility of GLS measurements showed no difference among vendors and was in acceptable range. SLS reproducibility was high but similar for all vendors. No relevant difference was found for identifying regional dysfunction. Tracking feasibility showed a substantial difference among images from different vendors. Our findings demonstrate that tracking results depend mainly on the software used and show little influence from vendor specific image characteristics.

Testosterone, cardiomyopathies, and heart failure: a narrative review

Testosterone exerts an important regulation of cardiovascular function through genomic and nongenomic pathways. It produces several changes in cardiomyocytes, the main actor of cardiomyopathies, which are characterized by pathological remodeling, eventually leading to heart failure. Testosterone is involved in contractility, in the energy metabolism of myocardial cells, apoptosis, and the remodeling process. In myocarditis, testosterone directly promotes the type of inflammation that leads to fibrosis, and influences viremia with virus localization. At the same time, testosterone exerts cardioprotective effects that have been observed in different studies. There is increasing evidence that low endogenous levels of testosterone have a negative impact in some cardiomyopathies and a protective impact in others. This review focuses on the interrelationships between testosterone and cardiomyopathies and heart failure.

Speckle tracking deformation imaging to detect regional fibrosis in hypertrophic cardiomyopathy: a comparison between 2D and 3D echo modalities

AIMS

We aimed at directly comparing three-dimensional (3D) and two-dimensional (2D) deformation parameters in hypertrophic hearts and depict which may best reflect underlying fibrosis in hypertrophic cardiomyopathy (HCM), defined by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

METHODS AND RESULTS

We included 40 HCM [54.1 ± 14.3 years, 82.5% male, maximum wall thickness (MWT) 19.3 ± 4.8 mm] and 15 hypertensive (HTN) patients showing myocardial hypertrophy (58.1 ± 15.6 years, 80% male, MWT 12.8 ± 1.4 mm) who have consecutively undergone 2D-, 3D-speckle tracking echocardiography and LGE CMR. Deformation parameters (2D and 3D) presented overall poor to moderate correlations, with 3D_longitudinal strain (LS) and 3D_circumferential strain (CS) values being constantly higher compared to 2D derivatives. By regression analysis, hypertrophy substrate (HCM vs. hypertension) and hypertrophy magnitude were the parameters to influence 2D-3D LS and CS strain correlations (R2 = 0.66, P < 0.001 and R2 = 0.5, P = 0.001 accordingly). Among segmental deformation indices, 2D_LS showed the best area under the curve [AUC = 0.78, 95% confidence intervals (CI) (0.75-0.81), P < 0.0005] to detect fibrosis, with 3D deformation parameters showing similar AUC (0.65) and 3D_LS presenting the highest specificity [93.1%, 95% CI (90.6-95.1)].

CONCLUSIONS

In hypertrophic hearts, 2D and 3D deformation parameters are not interchangeable, showing modest correlations. Thickness, substrate, and tracking algorithm calculating assumptions seem to induce this variability. Nevertheless, among HCM patients 2D_peak segmental longitudinal strain remains the best strain parameter for tissue characterization and fibrosis detection.

Experimental validation of the prestretch-strain relationship as a non-invasive index of left ventricular myocardial contractility

Background

The slope of the relationship between segmental PreS and total systolic shortening (S) has been proposed as a non-invasive index of left ventricular contractility. The aim of this study was to correlate this novel parameter to invasive gold standard measurements of contractility and to investigate how it is influenced by afterload.

Methods

In domestic pigs, afterload was increased by either balloon inflation in the aorta or by administration of phenylephrine while contractility was increased by dobutamine infusion. During all interventions, left ventricular pressure-volume measurements and trans-diaphragmatic two-dimensional echocardiographic images were acquired. The PreS-S slope was constructed from 18 segmental strain curves obtained by speckle tracking analysis and compared to the slope of the end systolic PV relationship (E_max) and the pre-load recruitable stroke work (PRSW).

Results

Sixteen datasets of increased contractility and afterload were analyzed. During dobutamine infusion, the LV volumes decreased (p<0.05) while ejection fraction increased (p<0.05). Emax, PRSW and the slope of the intra-ventricular PreS-S relation increased significantly during dobutamine infusion. Afterload increase led to increase in systolic blood pressure (105±16mmHg vs. 138±25mmHg; p<0.01) and decrease of LV stroke volume and ejection fraction (p<0.01). The PreS-S slope was not influenced by loading conditions in concordance with the PRSW findings. The absolute values of the PreS-S slope did not correlate with Emax or PRSW. However, the change of the PreS-S slope in relation with different interventions demonstrated good correlation with changes in PRSW or Emax, (r = 0.66, p<0.05 and r = 0.69, p<0.05).

Conclusions

The slope of the PreS-S relationship is sensitive to changes in inotropy and is less load-dependent than conventional non-invasive parameters of left ventricular function. The magnitude of the change of this slope correlates well with changes in invasive contractility measurements making it an attractive parameter to assess contractile reserve or contractile changes during longitudinal follow-up of patients.

1181 A novel insight into pathophysiology of hypertrophic cardiomyopathy using simultaneous three-dimensional volume-strain loops

Funding Acknowledgements

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

Background

Strain assessment offers a robust evaluation of myocardial mechanics and systolic function, however reporting only peak strain values in hypertrophic cardiomyopathy (HCM) may impose limitations in the conception of its complex remodeling. Therefore, combined plotting of deformation parameters against other indices [e.g. arterial pressure, left ventricular (LV) volume] might offer additional insights into the pathophysiology of the disease.

Purpose

Aim of this study was i) to apply strain-volume loops in HCM based on simultaneous frame-by-frame strain and volume changes’ recordings acquired by means of three-dimensional (3D) speckle tracking imaging and ii) to take advantage of the previous methodology to gain further insights into HCM pathophysiology.

Methods

We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build a strain–volume loop. Peak of radial, longitudinal, and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), and strain to end-diastolic volume (EDV) ratio (Rs/V, Ls/V, Cs/V) were computed for the analysis (panel A). Additionally, burden of fibrosis (percentage of LV mass) was defined by LGE extent (&gt;5 standard deviations compared to nulled myocardium) in CMR slices.

Results

All HCM patients had preserved EF (60.5 ± 5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO &gt; 30 mm Hg at rest). Mean LV mass index was 78.9 ± 14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2 ± 4.5% of LV mass. Concerning strain-volume loops the following values were recorded for radial (Rsp 30.8 ± 9.8%, RsSl 0.4 ± 0.13 and Rs/V 0.25 ± 0.09), longitudinal (Lsp -9.4 ± 3.7%, LsSl 0.12 ± 0.06 and Ls/V 0.08 ± 0.04) and circumferential deformation (Csp -14.2 ± 3.5%, CsSl 0.18 ± 0.05 and Cs/V 0.11 ± 0.03). Among typical HCM characteristics tested (LV mass, LVOTO and LGE), only LV mass presented significant correlations with LsSl (r=-0.41, p &lt; 0.01). Interestingly, HCM patients with smaller LVMI and without LGE presented steeper and narrower (difference between systolic and diastolic strain for the same volume) longitudinal strain-volume loops compared to patients with larger LVMIs and fibrosis (panel B).

Conclusions

Strain-volume loop is an innovative application of 3D deformation imaging in HCM. According to this new non-invasive method, increase of LVMI in HCM is accompanied by less longitudinal contribution to stroke volume, whereas absence of fibrosis and severe hypertrophy is accompanied by better systolic-diastolic coupling.

Abstract 1181 Figure.

P984 A head-to-head comparison between 2D and 3D segmental strain parameters in hypertrophic cardiomyopathy

Funding Acknowledgements

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

Background

Previous studies have suggested that in normal and ischemic hearts three- (3D) and two-dimensional (2D) strain values present a moderate agreement which is prone to technical considerations. However, the level of agreement between 2D and 3D-strain imaging has never been adequately addressed in hypertrophic hearts, nor has it been validated against a "ground truth". Especially in hypertrophic cardiomyopathy (HCM), the magnitude and eccentricity of hypertrophy set additional challenges in standardization and measurement of regional 3D deformation parameters.

Purpose

Aims of this study were i) to investigate the consistency between 3D and 2D regional deformation parameters in HCM and ii) to test their accuracy in identifying regional fibrosis as this is defined by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Methods

We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 2D-,3D-speckle tracking echocardiography and CMR. Segmental circumferential (SCS) and longitudinal (SLS) strain have been calculated from 2D acquisitions and 3D full volume data, where additionally radial (SRS) and area (SAS) strain have been extracted using an 18 segment left ventricle model. Accordingly, segmental fibrosis was defined by LGE in corresponding CMR slices.

Results

Out of 720 segments evaluated, 134 (19.7%) were enhanced and 95(13.2%) thickened (thickness &gt; 12 mm). Two dimensional LS and CS analysis was feasible in 719 (99.9%) and 678 (94.2%) segments respectively, while 686 segments (95.3%) were appropriate for 3D tracking. 3D_SLS values were -7.9 ± 6.8% less negative compared to 2D_SLS values [level of agreement (LOA)(-21.1-5.4%)], while the bias for SCS values was even higher -8.5 ± 8.6 [LOA(-25.4-8.4%)]. Absolute agreement between 2D and 3D deformation imaging modalities was poor to moderate [Intra-class Correlation Coefficient (ICC)= 0.46, 95%CI (0.15-0.68), p &lt; 0.0005 for SLS and ICC = 0.19, 95%CI(0.07-0.38), p &lt; 0.0005 for SCS] (Panel A). Following regression analysis, regional thickness was the only segmental factor to influence the correlation between 3D and 2D_SLS [R2 = 0.504, B = 0.33, 95%CI(0.22-0.44), p &lt; 0.0005)], without, however, being a significant regressor for the other 2D vs 3D correlations. Among deformation indices, 2D_SLS showed the best area under the curve [(AUC)=0.78, 95%CI(0.75-0.81), p &lt; 0.0005] to detect segmental fibrosis identified by CMR LGE, with 3D_SLS, 3D_SAS and 3D_SRS showing similar AUC (0.65) and 3D_SLS presenting the highest specificity [93.1%, 95%CI(90.6-95.1)] (Panel B).

Conclusions

In HCM, 2D and 3D deformation parameters are not interchangeable, showing modest agreement. Thickness and tracking algorithm calculating assumptions seem to induce this inconsistency. Among HCM patients, 2D_SLS remains the most accurate strain parameter to detect regional fibrosis.

Abstract P984 Figure.

Myocardial Function Assessed by Multi-Layered Two-Dimensional Speckle Tracking Analysis in Asymptomatic Young Subjects with Diabetes Mellitus Type 1

BACKGROUND

Diabetes mellitus type 1 (DM1) is associated with a high risk for cardiovascular disease, and early detection of myocardial dysfunction is crucial for the prevention of cardiac complications.

OBJECTIVES

The aim of this study was to evaluate left ventricular (LV) and right ventricular (RV) function by using both conventional echocardiography as well as multi-layered speckle tracking echocardiography (STE) in young adults with DM1.

METHODS

We included 50 young asymptomatic adults diagnosed with DM1 (mean interval from diagnosis 9 ± 6 years) and 80 healthy controls. STE was acquired using the GE Vivid S60 equipment. The LV longitudinal strain (LS), layer-specific strains of the endocardium, myocardium, and epicardium (global longitudinal strain [GLS]endo, GLSmyo, GLSepi) as well as RV strain were obtained using the EchoPAC BT13 workstation.

RESULTS

No significant intergroup differences in LV ejection fraction were noted. GLSendo and GLSmyo were reduced in the DM1 group (-20.6 ± 2.7 vs. -22.0 ± 2.3 and -18.0 ± 2.4 vs. -19.1 ± 1.9, respectively, p < 0.05) compared to controls. Mechanical dispersion was higher in the diabetes group (34 ± 11 vs. 29 ± 7, p < 0.05). RV strain measurements showed no significant difference between the groups.

CONCLUSIONS

Young adults with DM1 and without known heart disease have subclinical myocardial dysfunction with lower LV endocardium and myocardium LS and higher mechanical dispersion demonstrated by multi-layered STE.

P4364A direct comparison between 2D and 4D deformation imaging in hypertrophic hearts. An agreement of disagreement

Background

Previous studies have directly compared 2-dimensional (2D) and 4-dimensional (4D) deformation imaging in normal and ischemic hearts suggesting a moderate agreement prone to technical considerations. However, the level of agreement between 2D and 4D-strain imaging has never been adequately addressed in hypertrophic hearts, nor has it been validated against a “ground truth”.

Purpose

We aimed at directly comparing 4D and 2D global and regional deformation parameters and depict which may best reflect underlying segmental fibrosis in hypertrophic cardiomyopathy (HCM), as defined by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Methods

We included 40 HCM patients (54.1±14.3 years, 82.5% male, maximum wall thickness 19.3±4.8mm) who have consecutively undergone 2D-,4D-speckle tracking echocardiography and CMR. Global and segmental circumferential (CS) and longitudinal (LS) strain have been calculated from 2D acquisitions and 4D full volume data, where additionally radial (RS) and area (AS) strain have been extracted using an 18 segment left ventricle model. Accordingly, segmental fibrosis was defined by LGE in corresponding CMR slices.

Results

Deformation parameters (2D and 4D, global and regional) presented overall poor to moderate agreement (Figure A+B) with regional 4D_LS and 4D_CS values being constantly less negative compared to 2D derivatives (−7.29±6.94% and −8.53±8.8% accordingly). In regional analysis, 720 segments were evaluated of which 134 (19.7%) were enhanced and 95 of them thickened (68.8%) (thickness>12 mm), with segments presenting both characteristics showing the greatest impairment both in 2D and 4D strain values. Among segmental deformation indices, 2D_SLS showed the best area under the curve [(AUC)=0.78, 95% CI (0.75–0.81), p<0.0005] to detect segmental fibrosis, with 2D_SCS and all 4D deformation indices presenting significantly lower AUC (Figure C).

Conclusions

In HCM, 2D and 4D deformation parameters are not interchangeable, showing modest agreement. Thickness and tracking algorithm calculating assumptions seem to induce this variability. Nevertheless, among HCM patients 2D_SLS remains the best strain parameter for tissue characterization and fibrosis detection.

Acknowledgement/Funding

Supported with a scholarship by the Greek State Scholarship Foundation (IKY).

A rare case of familial restrictive cardiomyopathy, with mutations in MYH7 and ABCC9 genes

Restrictive cardiomyopathy is the least common type of cardiomyopathy, being defined by diastolic dysfunction and often unimpaired systolic function. Restrictive cardiomyopathies can be classified as familial or non-familial. Patients with familial restrictive cardiomyopathy can develop signs and symptoms of this condition anytime from childhood to adulthood. The evolution of the disease is towards signs and symptoms of pulmonary and systemic congestion and, without treatment, there is a five-year mortality rate of approximately 30% in these patients. We discuss the case of a 43-year-old patient diagnosed with familial restrictive cardiomyopathy with positive genetic tests for mutations of MYH7 gene and ABCC9 gene, who was first hospitalized in 2011 for palpitations. The echocardiography performed in evolution showed a continuous alteration of right ventricle function, without important differences of left ventricular function.  She developed heart failure symptoms six years after diagnosis and she had seven hospitalizations in the past two years, currently with an increasing need of diuretics and persistent hepatic dysfunction. Cardiac transplantation or left ventricular assist device therapy should be considered in patients with severe heart failure symptoms and no longer effective treatment. However, elevated pulmonary vascular resistance excludes the patient from cardiac transplantation.

Impact of apical foreshortening on deformation measurements: a report from the EACVI-ASE Strain Standardization Task Force

Aims

Foreshortening of apical views is a common problem in echocardiography. It results in an abnormally thick false apex and a shortened left ventricular (LV) long axis. We sought to evaluate the impact of foreshortened (FS) on LV ejection fraction (LVEF) and layer-specific 2D speckle tracking based segmental (S) and global (G) longitudinal strain (LS) measurements.

Methods and results

We examined 72 participants using a GE Vivid E9 system. FS apical views were collected from an imaging window one rib-space higher than the optimal images. Ejection fraction as well as layer-specific GLS and SLS measurements were analysed by GE EchoPAC v201 and TomTec Image Arena 4.6 and compared between optimal and FS images. On average, LV long axis was 10% shorter in FS images than in optimal images. FS induced a relative change in LVEF of 3.3% and 6.9% for GE and TomTec, respectively (both, P < 0.001). Endocardial GLS was 9.0% higher with GE and 23.2% with TomTec (P < 0.001). Midwall GLS measurements were less affected (7.8% for GE and 14.1% for TomTec, respectively, both P < 0.001). Segmental strain analysis revealed that the mid-ventricular and apical segments were more affected by foreshortening, and endocardial measurements were more affected than midwall.

Conclusion

Optimal image geometry is crucial for accurate LV function assessment. Foreshorhening of apical views has a substantial impact on longitudinal strain measurements, predominantly in the apex and in the endocardial layer. Our data suggest that measuring midwall strain might therefore be the more robust approach for clinical routine use.

Variability of longitudinal strain measurements: levelling the playing field

Speckle tracking echocardiography offers a unique opportunity to evaluate myocardial function, and global longitudinal strain (GLS) is currently recommended as a measurement of global left ventricular function. To facilitate clinical applicability of the method, collective efforts have been made to standardise strain measurements and to raise awareness of the potential sources of variability. The purpose of this review is to familiarise the reader with the most common sources of variability of longitudinal strain measurements and detail the possible measures to increase the accuracy and reproducibility of strain parameters.

NT-proBNP and Echocardiographic Parameters in Liver Cirrhosis - Correlations with Disease Severity

determined. Liver disease severity in patients with cirrhosis was established by Child-Pugh class, MELD score and presence/absence of ascites. Results: Plasma levels of NT-proBNP were significantly higher in cirrhotic patients than in the healthy subjects. NT-proBNP levels were also significantly elevated in Child-Pugh class C patients compared to those in class B and A. Left atrium size, diastolic function, left ventricular wall thickness and left ventricular ejection fraction were significantly altered in cirrhotic patients compared to controls. Advanced cirrhosis and high levels of NT-proBNP were significantly associated with increased left atrium volume and signs of cardiac diastolic dysfunction. We also observed significant differences between quartile groups of MELD score for the following: NT-proBNP, Troponin I, left atrium volume, left ventricle wall thickness, lateral wall and septum systolic tissue doppler velocities and global longitudinal strain. Conclusion: NT-proBNP is increased in patients with cirrhosis and is correlated with the severity of liver disease as established by Child-Pugh class, MELD score and presence of ascites.

The Significance of Right Ventricle in Young Subjects with Diabetes Mellitus Type 1. An echocardiographyic study

BACKGROUND

Diabetes mellitus type 1 (DM1) is associated with high risk for cardiovascular disease and early detection of myocardial dysfunction is very important for the prevention of cardiac complications. Although the functionality of right ventricule is important in a lot of disease affecting long time prognosis and progression, in diabetic type 1 patients has not been studied in depth yet.

OBJECTIVES

To evaluate the right ventricular function by using both conventional echocardiography as well as speckle tracking echocardiography (STE) in young adults with diabetes mellitus type 1.

METHODS

We included 60 young asymptomatic adults diagnosed with diabetes mellitus type 1 (mean interval from diagnosis 9±6 years) and 90 healthy controls. Conventional and STE Echocardiography was acquired using the GE Vivid S60 equipment. The longitudinal right ventricular strain 6 segments (RV GLS global) and 3 segments (RVFW GLS) of right ventricle (RV GLSbazal, RV GLSmid, RV GLSapex) as well were obtained using the EchoPAC BT13 workstation.

RESULTS

No significant intergroup differences in EF were noted. Conventional echocardiographic parameters revealed lower tricuspid annular velocities Et, At and Et/At ratio compared to controls suggesting a diastolic disfunction in diabetes group. RV speckle tracking strain measurements showed no significant difference between the groups.

CONCLUSIONS

Young adults with type 1 diabetes mellitus and without known heart disease have diastolic right ventricular dysfunction. The subclinical myocardial systolic function is preserved in early stages.

Comparison of Feasibility, Accuracy, and Reproducibility of Layer-Specific Global Longitudinal Strain Measurements Among Five Different Vendors: A Report from the EACVI-ASE Strain Standardization Task Force

BACKGROUND

Despite standardization efforts, vendors still use information from different myocardial layers to calculate global longitudinal strain (GLS). Little is known about potential advantages or disadvantages of using these different layers in clinical practice. The authors therefore investigated the reproducibility and accuracy of GLS measurements from different myocardial layers.

METHODS

Sixty-three subjects were prospectively enrolled, in whom the intervendor bias and test-retest variability of endocardial GLS (E-GLS) and midwall GLS (M-GLS) were calculated, using software packages from five vendors that allow layer-specific GLS calculation (GE, Hitachi, Siemens, Toshiba, and TomTec). The impact of tracking quality and the interdependence of strain values from different layers were assessed by comparing test-retest errors between layers.

RESULTS

For both E-GLS and M-GLS, significant bias was found among vendors. Relative test-retest variability of E-GLS values differed significantly among vendors, whereas M-GLS showed no significant difference (range, 5.4%-9.5% [P = .032] and 7.0%-11.2% [P = .200], respectively). Within-vendor test-retest variability was similar between E-GLS and M-GLS for all but one vendor. Absolute test-retest errors were highly correlated between E-GLS and M-GLS for all vendors.

CONCLUSIONS

E-GLS and M-GLS measurements showed no relevant differences in robustness among vendors, although intervendor bias was higher for M-GLS compared with E-GLS. These data provide no technical argument in favor of a certain myocardial layer for global left ventricular functional assessment. Currently, the choice of which layer to use should therefore be based on the available clinical evidence in the literature.

Echo Parameters for Differential Diagnosis in Cardiac Amyloidosis: A Head-to-Head Comparison of Deformation and Nondeformation Parameters

BACKGROUND

A plethora of echo parameters has been suggested for distinguishing cardiac amyloidosis (CA) from other causes of myocardial thickening with, however, scarce data on their head-to-head comparison. This study aimed at comparing the diagnostic accuracy of various deformation and conventional echo parameters in differentiating CA from other hypertrophic substrates, especially in the gray zone of mild hypertrophy (maximum wall thickness ≤16 mm) or normal ejection fraction (EF).

METHODS AND RESULTS

=0.0002, respectively) independent of the CA type.

CONCLUSIONS

Our study demonstrated that in patients with thickened hearts, EF global longitudinal strain ratio has the best accuracy in detecting CA, even among the most "challenging" patient subgroups as those with mild hypertrophy and normal EF.

Right ventricular remodelling after transcatheter pulmonary valve implantation

OBJECTIVES

To define the optimal timing for percutaneous pulmonary valve implantation (PPVI) in patients with severe pulmonary regurgitation (PR) after Fallot's Tetralogy (ToF) correction.

BACKGROUND

PPVI among the aforementioned patients is mainly driven by symptoms or by severe right ventricular (RV) dilatation/dysfunction. The optimal timing for PPVI is still disputed.

METHODS

Twenty patients [age 13.9 ± 9.2 years, (range 4.3-44.9), male 70%] with severe PR (≥3 grade) secondary to previous correction of ToF, underwent Melody valve (Medtronic, Minneapolis, MN) implantation, after a pre-stent placement. Full echocardiographic assessment (traditional and deformation analysis) and cardiovascular magnetic resonance evaluation were performed before and at 3 months after the intervention. 'Favorable remodelling' was considered the upper quartile of RV size decrease (>20% in 3 months).

RESULTS

After PPVI, indexed RV effective stroke volume increased from 38.4 ± 9.5 to 51.4 ± 10.7 mL/m² , (P = 0.005), while RV end-diastolic volume and strain indices decreased (123.1 ± 24.1-101.5 ± 18.3 mL/m² , P = 0.005 and -23.5 ± 2.5 to -21 ± 2.5%, P = 0.002, respectively). After inserting pre-PPVI clinical, RV volumetric and deformation parameters in a multiple regression model, only time after last surgical correction causing PR remained as significant regressor of RV remodelling [R²  = 0.60, beta = 0.387, 95%CI(0.07-0.7), P = 0.019]. Volume reduction and functional improvement were more pronounced in patients treated with PPVI earlier than 7 years after last RV outflow tract (RVOT) correction, reaching close-to-normal values.

CONCLUSIONS

Early PPVI (<7 years after last RVOT operation) is associated with a more favorable RV reverse remodelling toward normal range and should be considered, before symptoms or RV damage become apparent. © 2017 Wiley Periodicals, Inc.

Spatiotemporal registration of multiple three-dimensional echocardiographic recordings for enhanced field of view imaging

The use of three-dimensional (3-D) echocardiography is limited by signal dropouts and narrow field of view. Data compounding is proposed as a solution to overcome these limitations by combining multiple 3-D recordings to form a wide field of view. The first step of the solution requires registration between the recordings both in the spatial and temporal dimension for dynamic organs such as the heart. Accurate registration between the individual echo recordings is crucial for the quality of compounded volumes. A temporal registration method based on a piecewise one-dimensional cubic B-spline in combination with multiscale iterative Farnebäck optic flow method for spatial registration was described. The temporal registration method was validated on in vivo data sets with annotated timing of mitral valve opening. The spatial registration method was validated using in vivo data and compared to registration with Procrustes analysis using manual contouring as a benchmark. The spatial accuracy was assessed in terms of mean of absolute distance and Hausdorff distance between the left ventricular contours. The results showed that the temporal registration accuracy is in the range of half the time resolution of the echo recordings and the achieved spatial accuracy of the proposed method is comparable to manual registration.

Recent advances in echocardiography: strain and strain rate imaging

Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications.

Standardized Evaluation System for Left Ventricular Segmentation Algorithms in 3D Echocardiography

Real-time 3D Echocardiography (RT3DE) has been proven to be an accurate tool for left ventricular (LV) volume assessment. However, identification of the LV endocardium remains a challenging task, mainly because of the low tissue/blood contrast of the images combined with typical artifacts. Several semi and fully automatic algorithms have been proposed for segmenting the endocardium in RT3DE data in order to extract relevant clinical indices, but a systematic and fair comparison between such methods has so far been impossible due to the lack of a publicly available common database. Here, we introduce a standardized evaluation framework to reliably evaluate and compare the performance of the algorithms developed to segment the LV border in RT3DE. A database consisting of 45 multivendor cardiac ultrasound recordings acquired at different centers with corresponding reference measurements from three experts are made available. The algorithms from nine research groups were quantitatively evaluated and compared using the proposed online platform. The results showed that the best methods produce promising results with respect to the experts' measurements for the extraction of clinical indices, and that they offer good segmentation precision in terms of mean distance error in the context of the experts' variability range. The platform remains open for new submissions.

Integration of Multi-Plane Tissue Doppler and B-Mode Echocardiographic Images for Left Ventricular Motion Estimation

Although modern ultrasound acquisition systems allow recording of 3D echocardiographic images, tracking anatomical structures from them is still challenging. In addition, since these images are typically created from information obtained across several cardiac cycles, it is not yet possible to acquire high-quality 3D images from patients presenting varying heart rhythms. In this paper, we propose a method to estimate the motion field from multi-plane echocardiographic images of the left ventricle, which are acquired simultaneously during a single cardiac cycle. The method integrates tri-plane B-mode and tissue Doppler images acquired at different rotation angles around the long axis of the left ventricle. It uses a diffeomorphic continuous spatio-temporal transformation model with a spherical data representation for a better interpolation in the circumferential direction. This framework allows exploiting the spatial relation among the acquired planes. In addition, higher temporal resolution of the transformation in the beam direction is achieved by uncoupling the estimation of the different components of the velocity field. The method was validated using a realistic synthetic dataset including healthy and ischemic cases, obtaining errors of 0.14 ± 0.09 mm for displacements, 0.96 ± 1.03% for longitudinal strain and 3.94 ± 4.38% for radial strain estimation. In addition, the method was also demonstrated on a healthy volunteer and two patients with ischemia.