Comparison of Two Different Speckle Tracking Software Systems: Does the Method Matter?

Global longitudinal strain in heart transplantation recipients using different vendors: reliability and validity in a tertiary hospital in Colombia

Global Longitudinal Strain (GLS) is a useful tool to follow-up heart transplant (HT) recipients. Important inter-vendor variability of GLS measurements has been reported in healthy subjects and different conditions, but there is still limited evidence among HT patients. We assessed the reliability and validity of GLS using two vendors (General Electric and Philips) in a group of consecutive and stable adult HT recipients. Patients underwent two concurrent GLS analyses during their echocardiographic follow-up. We evaluated GLS inter-vendor reliability using Bland-Altman's limits of agreement (LOA) plots, computing its coverage probability (CP) and the intraclass correlation coefficient (ICC). Validity was assessed though receiver operating characteristics (ROC) curves, predictive values, sensitivity and specificity of GLS for each vendor to detect a normal left ventricle function. 78 pairs of GLS studies in 53 stable HT patients were analyzed. We observed a modest inter-vendor reliability with a broad LOA (less than 50% of values falling out our CP of 2% and an ICC of 0.49). ROC analyses (areas under the curve of 0.824 Vs. 0.631, p < 0.05) and diagnosis test indices (Sensitivity of 0.73 Vs. 0.64; and Specificity of 0.79 Vs. 0.50) favored GE over Philips. Inter-vendor variability for GLS analysis exceeded clinically acceptable limits in HT recipients. GLS from GE software seemed to show higher validity as compared to Philips'. The present study provides evidence to consider caution for the interpretation of GLS for clinical management in the follow-up of HT patients, especially when GLS is measured by different vendors.

Usefulness of left atrial speckle tracking echocardiography in predicting recurrence of atrial fibrillation after radiofrequency ablation: a systematic review and meta-analysis

The usefulness of peak atrial longitudinal strain (PALS) in identifying patients at high risk of atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA) has been investigated in several small AF populations. The aim of this systematic review and meta-analysis was to investigate whether PALS predicts recurrence of AF after RFA treatment. MEDLINE, EMBASE and the Cochrane Library were searched. Studies investigating the value of PALS in predicting successful RFA in AF patients were selected. Patients underwent echocardiography prior to RFA. Risk of bias was evaluated using the Quality in Prognosis Studies (QUIPS) Tool. Twelve studies and a total of 1025 patients suffering from paroxysmal or persistent AF were included. Odds ratios (OR) were assessed in a random and fixed effects model for univariable and multivariable pooled analyses respectively. PALS was found to be a significant predictor of AF recurrence after RFA across study populations (Univariable: OR: 1.17, CI95% [1.03-1.34], p = 0.018, per 1% decrease) (Multivariable: OR: 1.16, CI95% [1.09-1.24], p < 0.001, per 1% decrease). Patients with recurrence had significantly lower PALS prior to RFA than patients who maintained sinus rhythm (15.7 ± 5.7% vs. 23.0 ± 7.0%, p = 0.016). A pooled analysis of weighted mean differences (WMD) also showed a significant difference in PALS between the two groups (WMD: - 6.57, CI95% [- 8.49: - 4.65], p < 0.001). Lower values of PALS are associated with an increased risk of AF recurrence after RFA. PALS provides prognostic value in clinical practice.

Loss of base-to-apex circumferential strain gradient assessed by cardiovascular magnetic resonance in Fabry disease: relationship to T1 mapping, late gadolinium enhancement and hypertrophy

BACKGROUND

Cardiac involvement is common and is the leading cause of mortality in Fabry disease (FD). We explored the association between cardiovascular magnetic resonance (CMR) myocardial strain, T1 mapping, late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) in patients with FD.

METHODS

In this prospective study, 38 FD patients (45.0 ± 14.5 years, 37% male) and 8 healthy controls (40.1 ± 13.7 years, 63% male) underwent 3 T CMR including cine balanced steady-state free precession (bSSFP), LGE and modified Look-Locker Inversion recovery (MOLLI) T1 mapping. Global longitudinal (GLS) and circumferential (GCS) strain and base-to-apex longitudinal strain (LS) and circumferential strain (CS) gradients were derived from cine bSSFP images using feature tracking analysis.

RESULTS

Among FD patients, 8 had LVH (FD LVH+, 21%) and 17 had LGE (FD LGE+, 45%). Nineteen FD patients (50%) had neither LVH nor LGE (FD LVH- LGE-). None of the healthy controls had LVH or LGE. FD patients and healthy controls did not differ significantly with respect to GLS (- 15.3 ± 3.5% vs. - 16.3 ± 1.5%, p = 0.45), GCS (- 19.4 ± 3.0% vs. -19.5 ± 2.9%, p = 0.84) or base-to-apex LS gradient (7.5 ± 3.8% vs. 9.3 ± 3.5%, p = 0.24). FD patients had significantly lower base-to-apex CS gradient (2.1 ± 3.7% vs. 6.5 ± 2.2%, p = 0.002) and native T1 (1170.2 ± 37.5 ms vs. 1239.0 ± 18.0 ms, p < 0.001). Base-to-apex CS gradient differentiated FD LVH- LGE- patients from healthy controls (OR 0.42, 95% CI: 0.20 to 0.86, p = 0.019), even after controlling for native T1 (OR 0.24, 95% CI: 0.06 to 0.99, p = 0.049). In a nested logistic regression model with native T1, model fit was significantly improved by the addition of base-to-apex CS gradient (χ2(df = 1) = 11.04, p < 0.001). Intra- and inter-observer agreement were moderate to good for myocardial strain parameters: GLS (ICC 0.849 and 0.774, respectively), GCS (ICC 0.831 and 0.833, respectively), and base-to-apex CS gradient (ICC 0.737 and 0.613, respectively).

CONCLUSIONS

CMR reproducibly identifies myocardial strain abnormalities in FD. Loss of base-to-apex CS gradient may be an early marker of cardiac involvement in FD, with independent and incremental value beyond native T1.

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.

Variability among strain variables derived from two-dimensional speckle tracking echocardiography in dogs by use of various software

OBJECTIVE

To determine variability of global longitudinal strain (GLS) and strain rate (SR) measurements in dogs with and without cardiac disease derived from 2-D speckle tracking echocardiography (STE) by use of various software.

ANIMALS

2 cohorts comprising 44 dogs (23 cardiovascularly healthy and 21 with cardiac disease) and 40 dogs (18 cardiovascularly healthy and 22 with cardiac disease).

PROCEDURES

Transthoracic echocardiographic images in each cohort were analyzed with vendor-independent software and vendor-specific 2-D STE software for each of 2 vendors. Values for GLS and SR obtained from the same left parasternal apical views with various software were compared. Intraobserver and interobserver variability was determined, and agreement among results for the various software was assessed.

RESULTS

Strain analysis was not feasible with vendor-independent software for 20% of images obtained with the ultrasonography system of vendor 1. Intraobserver and interobserver coefficient of variation was < 10% for GLS values, whereas SR measurements had higher variance. There was a significant difference in GLS and SR obtained for each cohort with different software. Evaluation of Bland-Altman plots revealed wide limits of agreement, with variance for GLS of up to 6.3 units in a single dog.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of longitudinal strain analysis were not uniform among software, and GLS was the most reproducible measurement. Significant variability in results among software warrants caution when referring to reference ranges or comparing serial measurements in the same patient because changes of < 6.5% in GLS might be within measurement error for different postprocessing software.

Lower limit of normality and clinical relevance of left ventricular early diastolic strain rate for the detection of left ventricular diastolic dysfunction

Aims

The aim of the present study was to determine the lower limit of normality and the clinical relevance of left ventricular (LV) early diastolic strain rate (LVSRe) for the detection of LV diastolic dysfunction (LVDD).

Methods and results

Using 2D speckle-tracking echocardiography, we analysed 377 healthy subjects and 475 patients with risk for LVDD with preserved LV ejection fraction (LVEF). The normal range of LVSRe analysing the healthy subjects was 1.56 ± 0.28 s-1, with a lower limit of normality at 1.00 s-1. Using this cut-off, LVSRe was able to detect high rates of LV diastolic alterations (rate 71.1%), which was significantly better than using indirect diastolic parameters such as left atrial volume index (LAVI) and tricuspid regurgitation velocity (TR) (rates 22.9% and 9.1%) and similar to annular mitral parameters such as lateral and septal e' velocity (rates 70.9% and 72.4%). In line, adding LVSRe to the current evaluation of LVDD increased significantly the rate of detection of LVDD (absolute rate of increase 18.9%; rate of detection of LVDD: from 14.3% to 33.2%, P < 0.01). Regarding the clinical relevance of LVSRe, patients with abnormal LVSRe (i.e. <1.00 s-1) had significantly worse New York Heart Association functional class and symptomatic status than those with normal LVSRe. In addition, in a retrospective post hoc analysis, we found that an abnormal LVSRe had a significant association with the risk of heart failure hospitalization at 2 years (odds ratio 5.0, 95% confidence interval 1.3-18.4), which was better than using conventional diastolic parameters such as septal and lateral e' velocity, LAVI and TR velocity.

Conclusion

The findings from this multicentre study provide important data regarding the normal range of LVSRe and highlight the potential clinical relevance of using this new diastolic parameter in the detection of LVDD in patients with preserved LVEF.

Velocity vector imaging for the assessment of segmental ventricular function in children with a single right ventricle after cavopulmonary anastomosis

OBJECTIVE

Ventricular function assessment is very important for the treatment and prognostic classification of children with a single right ventricle (SRV) after cavopulmonary anastomosis (CPA). However, unusual ventricular shapes can result in inaccurate measurements. The aim of this study was to evaluate velocity vector imaging (VVI) for assessing segmental ventricular function in children with SRV after CPA.

METHODS

Twenty-one children with SRV after CPA and 21 age- and sex-matched children with normal biventricular anatomy and function were included. The longitudinal velocity, displacement, strain and strain rate were measured in the two groups in six segments by VVI. The velocity, displacement, strain and strain rate of the SRVs were compared with max(dp/dt) measured during simultaneous cardiac catheterization in the SRV subjects.

RESULTS

The control group consisted of 13 males and 8 females (69% males) with a mean age of 6.7 ± 3.5 years and mean weight of 20.5 ± 6.5 kg, and the study group consisted of 13 males and 8 females with a mean age 6.7 ± 3.7 years and mean weight of 20.6 ± 6.8 kg. Age, weight and sex distribution were similar between the groups (all, p > .05). Strain and strain rate values in all six segments were significantly lower in the study group than in the control group (all, p < .05). The max(dp/dt) of the SRV was 522.84 ± 158.32 mmHg/s, and the strain rate of the basal segment at the rudimentary chamber correlated best with max(dp/dt) (r = 0.74, p < .01).

CONCLUSIONS

Segmental ventricular dysfunction was present in children with SRV after CPA, and it could be assessed using VVI.

Potential Usefulness and Clinical Relevance of Adding Left Atrial Strain to Left Atrial Volume Index in the Detection of Left Ventricular Diastolic Dysfunction

OBJECTIVES

The purpose of this study was to analyze the potential usefulness and clinical relevance of adding left atrial (LA) strain to left atrial volume index (LAVI) in the detection of left ventricular diastolic dysfunction (LVDD) in patients with preserved left ventricular ejection fraction (LVEF).

BACKGROUND

Recent studies have suggested that LA strain could be of use in the evaluation of LVDD. However, the potential utility and clinical significance of adding LA strain to LAVI in the detection of LVDD remains uncertain.

METHODS

Using 2-dimensional speckle-tracking echocardiography, we analyzed a population of 517 patients in sinus rhythm at risk for LVDD such as those with arterial hypertension, diabetes mellitus, or history of coronary artery disease and preserved LVEF.

RESULTS

In patients with LV diastolic alterations and estimated elevated LV filling pressures, the rate of abnormal LA strain was significantly higher than an abnormal LAVI (62.4% vs. 33.6%, p < 0.01). In line with this, in patients with normal LAVI, high rates of LV diastolic alterations and abnormal LA strain were present (rates 80% and 29.4%, respectively). In agreement with these findings, adding LA strain to LAVI in the current evaluation of LVDD increased significantly the rate of detection of LVDD (relative and absolute increase 73.3% and 9.9%; rate of detection of LVDD: from 13.5% to 23.4%; p < 0.01). Regarding the clinical relevance of these findings, an abnormal LA strain (i.e., <23%) was significantly associated with worse New York Heart Association functional class, even when LAVI was normal. Moreover, in a retrospective post hoc analysis an abnormal LA strain had a significant association with the risk of heart failure hospitalization at 2 years (odds ratio: 6.6 [95% confidence interval: 2.6 to 16.6]) even adjusting this analysis for age and sex and in patients with normal LAVI.

CONCLUSIONS

The findings from this study provide important insights regarding the potential usefulness and clinical relevance of adding LA strain to LAVI in the detection of LVDD in patients with preserved LVEF.

Subclinical Anthracycline-Induced Cardiotoxicity in the Long - Term Follow-Up of Lymphoma Survivors: A Multi-Layer Speckle Tracking Analysis

Background

Anthracycline generates progressive left ventricular dysfunction associated with a poor prognosis.

Objectives

The purpose of this study was to evaluate whether layer-specific strain analysis could assess the subclinical left ventricular dysfunction after exposure to anthracycline.

Methods

Forty-two anthracycline-treated survivors of large B-cell non-Hodgkin lymphoma, aged 55.83 ± 17.92 years (chemotherapy group) and 27 healthy volunteers, aged 51.39 ± 13.40 years (control group) were enrolled. The cumulative dose of epirubicin in chemotherapy group was 319.67 ± 71.71mg/m². The time from last dose of epirubicin to the echocardiographic examination was 52.92 ± 22.32 months. Global longitudinal (GLS), circumferential (GCS) and radial strain (GRS), subendocardial, mid and subepicardial layer of longitudinal (LS-ENDO, LS-MID, LS-EPI) and circumferential strain (CS-ENDO, CS-MID, CS-EPI) values were analyzed. Transmural strain gradient was calculated as differences in peak systolic strain between the subendocardial and subepicardial layers. A value of p < 0.05 was considered significant.

Results

Conventional parameters of systolic and diastolic function showed no significant difference between two groups. Compared with controls, patients had significantly lower GCS and GLS. Multi-layer speckle tracking analysis showed significant reduction of circumferential strain of subendocardial layer, transmural CS gradient and longitudinal strain of all three layers. In contrast, the two groups did not differ in transmural longitudinal strain gradient and radial strains.

Conclusions

It proved the preferential impairment of subendocardial deformation in long-term survivors after exposure to anthracycline. Multi-layer speckle tracking echocardiography might facilitate the longitudinal follow-up of this at-risk patient cohort.

Latent myopathy is more pronounced in patients with low flow versus normal flow aortic stenosis with normal left ventricular ejection fraction who are undergoing surgical aortic valve replacement: Multicenter study with a brief review of the literature

BACKGROUND

Midwall fibrosis and low stroke volume are independent predictors of mortality in severe aortic stenosis (AS) with preserved LV ejection fraction (LVEF). The role of speckle tracking echocardiography (STE) to identify latent myopathy pre- and post- aortic valve replacement (AVR) in high risk AS patients with normal LVEF is limited.

METHODS

Demographic, 2D echocardiographic, and STE data were analyzed in patients with severe AS and preserved LVEF who underwent tissue AVR. Velocity vector imaging (VVI) was used to assess regional and global peak systolic longitudinal strain (GLS). Low flow (LF) was defined as an indexed LV stroke volume <35 mL/m² .

RESULTS

Between December 2008 and May 2011, 37 patients (75 ± 9 years, 51% male) had both pre- and post-AVR echos within 6.6 ± 6.5 months (median = 4 months; range = 2.5-9.5) of surgery. Compared with pre-AVR, GLS (-6.9 ± 4.9% vs -11.1 ± 4.1%; P < .001) and strain rate (-0.72 ± 0.3s^-1 vs -0.87 ± 0.3s^-1 ; P = .01) improved post-AVR. Pre-AVR mid-segments showed a similar myopathy as the basal segments (-9.5 ± 4.3% vs -9.0 ± 4.2%;P = .3). The 16 (43%) LF patients in this study had lower pre- and post-AVR strain compared to NF patients (GLS Pre-AVR:LF vs NF: -5.1 ± 4.1% vs -8.4 ± 4.9% (P = .04) and GLS Post-AVR:LF vs NF: -9.2 ± 3.7% vs -12.5 ± 3.9% (P = .01)). However, there was no difference in absolute and %change improvement in GLS post-AVR (LF vs NF:∆ -4.2 ± 3.5% vs ∆-4.1 ± 5.3% (P = .90) and 193 ± 214% vs 143 ± 230% change (P = .5)). The lowest GLS was seen in LF/HG AS followed by LF/LG, NF/LG and NF/HG AS; P = .03.

CONCLUSIONS

Latent myopathy is more pronounced in LF AS both pre- and post-AVR. Our study provides evidence of improvement in myopathy in LF AS despite a persistent worse myopathy compared to NF patients post-AVR.

Towards Standardization of Quantitative Retinal Vascular Parameters: Comparison of SIVA and VAMPIRE Measurements in the Lothian Birth Cohort 1936

Purpose

Semiautomated software applications derive quantitative retinal vascular parameters from fundus camera images. However, the extent of agreement between measurements from different applications is unclear. We evaluate the agreement between retinal measures from two software applications, the Singapore "I" Vessel Assessment (SIVA) and the Vessel Assessment and Measurement Platform for Images of the Retina (VAMPIRE), and examine respective associations between retinal and systemic outcomes.

Method

Fundus camera images from 665 Lothian Birth Cohort 1936 participants were analyzed with SIVA and VAMPIRE. Intraclass correlation coefficients (ICC) and Bland-Altman plots assessed agreement between retinal parameters: measurements of vessel width, fractal dimension, and tortuosity. Retinal-systemic variable associations were assessed with Pearson's correlation, and intersoftware correlation magnitude differences were examined with Williams's test.

Results

ICC values indicated poor to limited agreement for all retinal parameters (0.159-0.410). Bland-Altman plots revealed proportional bias in the majority, and systematic bias in all measurements. SIVA and VAMPIRE measurements were associated most consistently with systemic variables relating to blood pressure (SIVA r's from -0.122 to -0.183; VAMPIRE r's from -0.078 to -0.177). Williams's tests indicated significant differences in the magnitude of association between retinal and systemic variables for 7 of 77 comparisons (P < 0.05).

Conclusions

Agreement between two common software applications was poor. Further studies are required to determine whether associations with systemic variables are software-dependent.

Translational Relevance

Standardization of the measurement of retinal vascular parameters is warranted to ensure that they are reliable and application-independent. This would be an important step towards realizing the potential of the retina as a source of imaging-derived biomarkers that are clinically useful.

Subclinical reduction in left ventricular function using triplane and 2D speckle tracking echocardiography after anthracycline exposure in children

Objective:

Speckle tracking echocardiography (STE) enables global and regional evaluation of the left ventricle (LV); therefore, it is the most useful method for detecting subclinical dysfunction in patients exposed to cardiotoxic agents. A novel technique triplane (3P) echocardiography also allows single beat assessment of LV global longitudinal strain values. We firstly aimed to demonstrate both two-dimensional (2D)- and 3P-STE-derived LV global longitudinal strain measurements in children after anthracycline exposure.

Methods:

This study included 23 cross-sectionally enrolled asymptomatic pediatric cancer patients who received anthracycline chemotherapy and 17 healthy controls matched by age, gender, and body surface area. All subjects underwent detailed 2D, Doppler, 2D-STE, and 3P-STE for assessment of LV function. The patients had received a median cumulative dose of 150 mg/m².

Results:

1. From “Pulsed” Doppler-based measurements, only pulmonary vein flow ratio showed a significant difference between the groups. 2. When measurements were taken from the interventricular septum, the patients’ ejection time values decreased significantly and their myocardial performance index values increased significantly; when the measurements were taken from the LV free wall, the peak systolic velocities showed a statistically significant difference. 3. Both 2D- and 3P-STE-derived longitudinal myocardial deformation values of LV were lower in the patient group. 4. 2D-STE-derived LV circumferential strain values were decreased in the patient group, whereas radial strain values were not significantly different compared with matched controls.

Conclusion:

Using Doppler and 2D- and 3P-STE methods, this study confirmed the subclinical LV dysfunction in patients after anthracycline exposure.

Left ventricular longitudinal systolic function analysed by 2D speckle-tracking echocardiography in heart failure with preserved ejection fraction: a meta-analysis

BACKGROUND

The purpose of this meta-analysis was to confirm if the global longitudinal systolic function of the left ventricle (LV) is altered in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS

We searched in different databases (Medline, Embase and Cochrane) studies that analysed LV global longitudinal systolic strain (GLS) in patients with HFpEF and in controls (such as healthy subjects or asymptomatic patients with arterial hypertension, diabetes mellitus or coronary artery disease).

RESULTS

Twenty-two studies (2284 patients with HFpEF and 2302 controls) were included in the final analysis. Patients with HFpEF had significantly lower GLS than healthy subjects (mean -15.7% (range -12% to -18.9%) vs mean -19.9% (range -17.1% to -21.5%), weighted mean difference -4.2% (95% CI -3.3% to -5.0%), p < 0.001, respectively). In addition, patients with HFpEF had also significantly lower GLS than asymptomatic patients (mean -15.5% (range -13.4% to -18.4%) vs mean -18.3% (range -15.1% to -20.4%), weighted mean difference -2.8%(95% CI -1.9% to -3.6%), p < 0.001, respectively). In line, 10 studies showed that the rate of abnormal GLS was significantly higher in patients with HFpEF (mean 65.4% (range 37%-95%)) than in asymptomatic subjects (mean 13% (range 0%-29.6%)). Regarding the prognostic relevance of abnormal GLS in HFpEF, two multicentre studies with large sample size (447 and 348) and high number of events (115 and 177) showed that patients with abnormal GLS had worse cardiovascular (CV) outcomes than those with normal GLS (HR for CV mortality and HF hospitalisation 2.14 (95% CI 1.26 to 3.66) and 1.94 (95% CI 1.22 to 3.07)), even adjusting these analyses for multiples clinical and echocardiographic variables.

CONCLUSION

The present meta-analysis analysing 2284 patients with HFpEF and 2302 controls confirms that the longitudinal systolic function of the LV is significantly altered in high proportion of patients with HFpEF. Further large multicentre studies with the aim to confirm the prognostic role of abnormal GLS in HFpEF are warranted.

Left ventricular longitudinal function assessment in rabbits after acute occlusion of left anterior descending coronary artery by two-dimensional speckle tracking imaging

Background

To evaluate the left ventricular (LV) longitudinal function changes in rabbits after acute occlusion of the left anterior descending artery (LAD) by two-dimensional speckle tracking imaging (2D–STI).

Methods

Forty-eight New Zealand white rabbits underwent echocardiography examination. EchoPAC was used to measure LV peak systolic longitudinal strain (LS) of the endocardium, middle myocardium, and epicardium, peak longitudinal strain rate (LSr), segmental and global longitudinal rotation (LR) degrees. Ligated the LAD and repeated all measurements after 10 min.

Results

Peak LS and LSr were significantly different between the preoperative and postoperative rabbits among most LV walls (P < 0.05). In apical four-chamber view, there was significant difference in the degrees of rotation of the LV lateral wall in preoperative and postoperative rabbits (P < 0.05). In apical three-chamber view, the rotation degrees of the posterior wall and the LR were significantly lower in the postoperative than in the preoperative (P < 0.001). In apical two-chamber view, the rotation degrees of the inferior wall and the LR were significantly lower in the postoperative (P < 0.05).

Conclusions

Left ventricular function was impaired after acute occlusion of LAD. Segmental rotational degrees and changes in LR could be useful indicators of cardiac function during the early phases of acute myocardial ischemia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0655-6) contains supplementary material, which is available to authorized users.

Comparison of two-dimensional strain analysis using vendor-independent and vendor-specific software in adult and pediatric patients

INTRODUCTION

Two-dimensional strain analysis is a powerful analysis modality, however, clinical utilization has been limited by variability between different analysis systems and operators. We compared strain in adults and children using vendor-specific and vendor-independent software to evaluate variability.

METHODS

One hundred and ten subjects (50/110 pediatric, 80/110 normal left ventricular function) had echocardiograms with a General Electric ultrasound scanner between September 2010 and January 2012. Left ventricular longitudinal strain was derived with EchoPAC (General Electric, v10.8.1), a vendor-specific software, and Velocity Vector Imaging (Siemens, v3.5), which is vendor-independent. Three independent readers analyzed all the echocardiograms yielding 330 datasets.

RESULTS

Mean left ventricular global longitudinal Lagrangian strain was -18.1 ± SD 4.4% for EchoPAC and -15.3 ± SD 4.1% for Velocity Vector Imaging. Velocity Vector Imaging yielded lower absolute global longitudinal Lagrangian strain by mean 2.9 (±SD 2.7, p < 0.0001), and lower regional longitudinal strain. These differences persisted in normal subjects versus those with cardiomyopathy. Longitudinal strain differences were slightly higher in the pediatric cohort. There was no significant difference in inter-observer longitudinal strain and a small difference in intra-observer strain between analysis systems. On repeat measurements, a significant change in global longitudinal Lagrangian strain occurred after the difference exceeded 3-5 strain points for EchoPAC and Velocity Vector Imaging, respectively.

CONCLUSION

Velocity Vector Imaging produces lower left ventricular longitudinal strain values versus EchoPAC for the same echo images. Both systems have similar inter-observer variability, Velocity Vector Imaging slightly higher intra-observer variability. A statistically significant change in global longitudinal Lagrangian strain occurs with changes >3-5 strain points on repeat measurements. Strain values between the systems are not interchangeable.

Prognostic Utility of Right Ventricular Free Wall Strain in Low Risk Patients After Orthotopic Heart Transplantation

Global longitudinal strain (GLS) by speckle-tracking echocardiography is a sensitive measure of regional left and right ventricular (LV and RV) dysfunction, before onset of overt systolic dysfunction. We sought to evaluate the prognostic utility of measuring LV-GLS and RV free wall strain (FWS) in low risk patients at 1 year after orthotopic heart transplantation (OHT). We retrospectively studied 96 OHT recipients (age 52 ± 14 years, 64% men) free of antibody-mediated rejection or moderate to severe coronary allograft vasculopathy (CAV, grade 2 to 3) at 1 year after transplant. LV-GLS and RV-FWS were calculated using EchoPAC software. Cox models were developed after adjusting for the Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score (post-transplant risk score), with the primary outcome of death, moderate to severe CAV, or treated rejection. At 1 year after transplant, LV ejection fraction and RV fractional area change (FAC) were 58 ± 7% and 42 ± 10%, respectively. LV-GLS was -17.0 ± 3.3% and RV-FWS -16.4 ± 4.5%. At an average follow-up of 4.5 years, 28 patients met the primary end point (10 death, 5 vasculopathy, 17 rejection). In sequential Cox models, markers of RV function were associated with the primary outcome (RV-FAC, p = 0.012; RV-FWS, p = 0.022), while LV ejection fraction and LV-GLS were not. We conclude that in low risk patients 1 year after OHT, markers of RV function (RV-FAC and RV-FWS) are independently associated with incident rejection, CAV, and death. Markers of RV dysfunction could potentially be incorporated into risk scores and future prospective studies to risk stratify patients after OHT.

Left atrial strain predicts recurrence of atrial arrhythmias after catheter ablation of persistent atrial fibrillation

Introduction

Success rates of catheter ablation (CA) of persistent atrial fibrillation (AF) are very variable. Identifying patients in whom sinus rhythm maintenance cannot be achieved after CA is a critical issue.

Methods

2D speckle-tracking echocardiography was performed before the first CA procedure in consecutive patients with persistent AF. Left atrial (LA) strain was correlated with recurrence of atrial arrhythmias during the follow-up period of 15 months after one CA procedure with or without antiarrhythmic drugs (primary endpoint). In a secondary analysis, recurrences after two CA procedures were analysed.

Results

102 patients were included. Patients with recurrence of atrial arrhythmias after one CA procedure (n=55) had significantly lower LA strain than those without recurrence (LA strain 9.7±2.4% vs 16.2±3.0%; p<0.001). Recurrence rate was significantly higher in patients with LA strain <10% than in those with LA strain between 10% and 14.5% and >14.5% (97.7%, 42.1% and 10.3%, respectively; p<0.001). In Cox regression analysis including age, comorbidities, left ventricular dysfunction and LA enlargement, low LA strain (<10%) was the strongest factor associated with recurrence of AF (HR 6.4 (2.4–16.9), p<0.001). Even after inclusion of a second CA procedure, LA strain <10% maintained a high predictive value for recurrence of atrial arrhythmias (86.4% (95% CI 73.3% to 93.6%)).

Conclusion

In patients with persistent AF, LA strain imaging could be very useful to select those patients who have a high risk of not benefiting from CA.

Segmental Analysis of Cardiac Short-Axis Views Using Lagrangian Radial and Circumferential Strain

Accurate description of myocardial deformation in the left ventricle is a three-dimensional problem, requiring three normal strain components along its natural axis, that is, longitudinal, radial, and circumferential strains. Although longitudinal strains are best estimated from long-axis views, radial and circumferential strains are best depicted in short-axis views. An algorithm that utilizes a polar grid for short-axis views previously developed in our laboratory for a Lagrangian description of tissue deformation is utilized for radial and circumferential displacement and strain estimation. Deformation of the myocardial wall, utilizing numerical simulations with ANSYS, and a finite-element analysis-based canine heart model were adapted as the input to a frequency-domain ultrasound simulation program to generate radiofrequency echo signals. Clinical in vivo data were also acquired from a healthy volunteer. Local displacements estimated along and perpendicular to the ultrasound beam propagation direction are then transformed into radial and circumferential displacements and strains using the polar grid based on a pre-determined centroid location. Lagrangian strain variations demonstrate good agreement with the ideal strain when compared with Eulerian results. Lagrangian radial and circumferential strain estimation results are also demonstrated for experimental data on a healthy volunteer. Lagrangian radial and circumferential strain tracking provide accurate results with the assistance of the polar grid, as demonstrated using both numerical simulations and in vivo study.

Prognosis of Light Chain Amyloidosis With Preserved LVEF: Added Value of 2D Speckle-Tracking Echocardiography to the Current Prognostic Staging System

OBJECTIVES

This study evaluated whether 2-dimensional speckle-tracking echocardiography (2D-STE) has incremental value for prognosis over traditional clinical, echocardiographic, and serological markers-with main focus on the current prognostic staging system-in light-chain (AL) amyloidosis patients with preserved left ventricular ejection fraction.

BACKGROUND

Cardiac amyloidosis (CA) is the major determinant of outcome in AL amyloidosis. The current prognostic staging system is based primarily on serum levels of cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and free light chain differential (FLC-diff).

METHODS

Consecutive patients with biopsy-proven AL amyloidosis and left ventricular ejection fraction ≥55% were divided into group 1 with CA (n = 63) and group 2 without CA (n = 87). Global longitudinal strain (GLS) by 2D-STE was performed with Vivid E9 (GE Healthcare Co., Milwaukee, Wisconsin) and syngo Velocity Vector Imaging (VVI) software (Siemens Medical Solutions USA, Inc., Malvern, Pennsylvania) (GLS_GE and GLS_VVI, respectively).

RESULTS

Thirty-two deaths (51%) occurred in group 1 and 13 (15%) in group 2 (p ≤ 0.001). Group 1 had thicker walls, lower early diastolic tissue Doppler velocity at septal mitral annulus, and greater left ventricular mass, left atrial volume, glomerular filtration rate, FLC-diff, cTnT, and NT-proBNP (p < 0.001). For the entire cohort, GLS_GE ≥ -14.81, GLS_VVI ≥-15.02, cTnT, NT-proBNP, FLC-diff, age, left ventricular wall thickness, early diastolic tissue Doppler velocity at septal mitral annulus, diastolic dysfunction grade, glomerular filtration rate, deceleration time, and left atrial volume were univariate predictors of death. In a multivariate Cox model, GLS_GE ≥-14.81 (hazard ratio [HR]: 2.68; 95% confidence interval [CI]: 1.07 to 7.13; p = 0.03), FLC-diff, NT-proBNP, and age were independent predictors of survival. There was also a strong trend for GLS_VVI ≥-15.02 (HR: 2.44; 95% CI: 0.98 to 6.33; p = 0.055). Using a nested logistic regression model, GLS_GE (p = 0.03) and GLS_VVI (p = 0.05) provided incremental prognostic value over cTnT, NT-proBNP, and FLC-diff. For survival analysis limited to group 2 (non-CA), GLS_GE and GLS_VVI both predicted all-cause mortality (GLS_GE HR: 1.23; 95% CI: 1.03 to 1.47 [p = 0.02]; GLS_VVI HR: 1.22; 95% CI: 1.01 to 1.49 [p = 0.04], respectively).

CONCLUSIONS

2D-STE predicted outcome and provided incremental prognostic information over the current prognostic staging system, especially in the group without CA.

Strain Echocardiography in Acute Cardiovascular Diseases

Echocardiography has become a critical tool in the evaluation of patients presenting to the emergency department (ED) with acute cardiovascular diseases and undifferentiated cardiopulmonary symptoms. New technological advances allow clinicians to accurately measure left ventricular (LV) strain, a superior marker of LV systolic function compared to traditional measures such as ejection fraction, but most emergency physicians (EPs) are unfamiliar with this method of echocardiographic assessment. This article discusses the application of LV longitudinal strain in the ED and reviews how it has been used in various disease states including acute heart failure, acute coronary syndromes (ACS) and pulmonary embolism. It is important for EPs to understand the utility of technological and software advances in ultrasound and how new methods can build on traditional two-dimensional and Doppler techniques of standard echocardiography. The next step in competency development for EP-performed focused echocardiography is to adopt novel approaches such as strain using speckle-tracking software in the management of patients with acute cardiovascular disease. With the advent of speckle tracking, strain image acquisition and interpretation has become semi-automated making it something that could be routinely added to the sonographic evaluation of patients presenting to the ED with cardiovascular disease. Once strain imaging is adopted by skilled EPs, focused echocardiography can be expanded and more direct, phenotype-driven care may be achievable for ED patients with a variety of conditions including heart failure, ACS and shock.

Increased apical rotation in severe aortic stenosis is associated with reduced survival: a speckle-tracking study

BACKGROUND

Patients with severe aortic stenosis (AS) are known to have increased left ventricular apical rotation (ApRot) during systole, but its clinical relevance is unknown. The aim of this study was to assess the association of ApRot with patient symptoms and total mortality.

METHODS

A retrospective analysis was performed on 82 patients (mean age, 77 ± 14 years; 40% men) with newly diagnosed severe AS with indexed aortic valve areas ≤ 0.6 cm(2)/m(2) and left ventricular ejection fractions ≥ 50%. Sixty-three percent of patients were symptomatic. ApRot was calculated using speckle-tracking echocardiography. Patients were divided into two groups on the basis of ApRot: high ApRot (>4.0°, n = 41) and low ApRot (≤4.0°, n = 41).

RESULTS

There were 33 deaths and 30 aortic valve replacement procedures after 33 ± 17 months of follow-up. Patients in the high-ApRot group had smaller indexed aortic valve areas (P = .021) and increased valvuloarterial impedance (P = .014). There was no difference in overall symptoms, but the low-ApRot group experienced more syncope (P = .020). Patients in the high-ApRot group had reduced survival with medical therapy (log-rank P = .018) after aortic valve replacement (log-rank P = .039) and overall (log-rank P = .009). Asymptomatic patients with low ApRot had the best survival, while asymptomatic patients with high ApRot had similar survival to that of symptomatic patients (log-rank P = .008). On adjusted Cox regression, ApRot ≥ 6.0° was independently associated with death (hazard ratio, 3.06; P = .003). On receiver operating characteristic curve analysis, ApRot added incremental prognostic value to indexed aortic valve area, symptom status, and aortic valve replacement status.

CONCLUSION

Increased ApRot is independently associated with poor survival and may represent a compensatory mechanism to preserve cardiac output against severe obstruction to flow and high systolic load.

Comparative myocardial deformation in 3 myocardial layers in mice by speckle tracking echocardiography

BACKGROUND

Speckle tracking echocardiography (STE) using dedicated high-resolution ultrasound is a relatively new technique that is useful in assessing myocardial deformation in 3 myocardial layers in small animals. However, comparative studies of STE parameters acquired from murine are limited.

METHODS

A high-resolution rodent ultrasound machine (VSI Vevo 2100) and a clinically validated ultrasound machine (GE Vivid 7) were used to consecutively acquire echocardiography images from standardized parasternal long axis and short axis at midpapillary muscle level from 13 BALB/c mice. Speckle tracking strain (longitudinal, circumferential, and radial) from endocardial, myocardial, and epicardial layers was analyzed using vendor-specific offline analysis software.

RESULTS

Intersystem differences were not statistically significant in the global peak longitudinal strain (-16.8 ± 1.7% versus -18.7 ± 3.1%) and radial strain (46.8 ± 14.2% versus 41.0 ± 9.5%), except in the global peak circumferential strain (-16.9 ± 3.1% versus 27.0 ± 5.2%, P < 0.05). This was corroborated by Bland Altman analysis that revealed a weak agreement in circumferential strain (mean bias ± 1.96 SD of -10.12 ± 6.06%) between endocardium and midmyocardium. However, a good agreement was observed in longitudinal strain between midmyocardium/endocardium (mean bias ± 1.96 SD of -1.88 ± 3.93%) and between midmyocardium/epicardium (mean bias ± 1.96 SD of 3.63 ± 3.91%). Radial strain (mean bias ± 1.96 SD of -5.84 ± 17.70%) had wide limits of agreement between the two systems that indicated an increased variability.

CONCLUSIONS

Our study shows that there is good reproducibility and agreement in longitudinal deformation of the 3 myocardial layers between the two ultrasound systems. Directional deformation gradients at endocardium, myocardium, and epicardium observed in mice were consistent to those reported in human subjects, thus attesting the clinical relevance of STE findings in murine cardiovascular disease models.

Normal values and clinical relevance of left atrial myocardial function analysed by speckle-tracking echocardiography: multicentre study

AIMS

The aim of this multicentre study was to determine the normal range and the clinical relevance of the myocardial function of the left atrium (LA) analysed by 2D speckle-tracking echocardiography (2DSTE).

METHODS AND RESULTS

We analysed 329 healthy adult subjects prospectively included in 10 centres and a validation group of 377 patients with left ventricular diastolic dysfunction (LVDD). LA myocardial function was analysed by LA strain rate peak during LA contraction (LA-SRa) and LA strain peak during LA relaxation (LA-Strain). The range of values of LA myocardial function in healthy subjects was LA-SRa -2.11 ± 0.61 s(-1) and LA-Strain 45.5 ± 11.4%, and the lowest expected values of these LA analyses (calculated as -1.96 SD from the mean of healthy subjects) were LA-SRa -0.91 s(-1) and LA-Strain 23.1%. Concerning the clinical relevance of these LA myocardial analyses, LA-SRa and LA-Strain detected subtle LA dysfunction in patients with LVDD, even though LA volumetric measurements were normal. In addition, in these patients we found that the functional class (dyspnoea-NYHA classification) was inversely related to both LA-Strain and LA-SRa.

CONCLUSION

In the present multicentre study analysing a large cohort of healthy subjects and patients with LVDD, the normal range and the clinical relevance of the myocardial function of the LA using 2DSTE have been determined.

Strain analysis from 4-D cardiac CT image data

Strain is a discriminative parameter of regional myocardial dysfunction. Despite the large body of research on myocardial strain analysis in echocardiography and MR images, such techniques have not often been applied to cardiac CT data. Reasons for this include the challenges of sparse image deformation clues and the low temporal resolution. In the current study, we propose an algorithm that uses cardiac CT data to evaluate the mechanical function of the left ventricle. The algorithm is based on a deformable LV model that contains both the myocardium and the blood pool regions and that accounts for the elasticity and incompressibility of the myocardium with the rapid contraction of the blood pool. Our algorithm uses the image intensities of the trabeculle and papillary muscles as well as the border edges in an optical flow manner to extract the 3-D velocities. The resulting strains and rotational values derived from a set of normal patients correlate highly with values from the research literature. We validated our algorithm against 2-D speckle tracking analysis and against visual scores obtained by an expert. Our study shows that strain analysis using CT data can be used in clinical practice.

Diastolic function improves after resolution of takotsubo cardiomyopathy

BACKGROUND

Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) systolic dysfunction. However, the diastolic function (DF) manifestations of TTC have not been widely investigated. We performed a bicentric study with retrospective analysis of DF in patients with TTC, during onset and at follow-up.

METHODS

Twenty-eight patients with TTC (64 ± 10 years, F 24) were included. All underwent echocardiograms acutely and at the recovery phase (average three months later). Diastolic and systolic function parameters were recorded, including E-wave velocity (E), A-wave velocity, E/A ratio, relaxation (e') and contractility (S') based on tissue Doppler velocities of the mitral annuli, ejection fraction (EF), left atrial (LA) size and DF stages.

RESULTS

Recovery, including the mean difference with 95% confidence interval, was associated with tending improvement (i.e. uncorrected significance) in E [13 cm s(-1) (-24, -2·3), P = 0·02] and in E/A ratio [0·2 (-0·41, -0·02), P = 0·04], as well as significant improvement (after multiple comparison correction) in mean e' [2·0 cm s(-1) (-3·3, -1·2), P<0·001] and in A-wave duration [29 ms (-46·7, -12·7), P = 0·002]. LA area tended to decrease during recovery [-2 cm² (0·33, 2·4), P = 0·01]. Improvement in DF stages was significant between the phases (21% versus 58% defined as normal DF, P = 0·016). Improvement in LVEF correlated with improvement in mean e' (r = 0·52, P = 0·02).

CONCLUSIONS

TTC is associated with an acute impairment of conventional DF variables, which improves during recovery. DF recovery seems to occur in parallel with systolic recovery in patients with TTC.

Perioperative assessment of myocardial deformation

Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation that reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis by using transthoracic echocardiography are (mean ± SD) -19.7% ± 0.4%, while radial and circumferential strain are 47.3% ± 1.9% and -23.3% ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages -1.10 ± 0.16 s. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to assess components of myocardial systolic and diastolic function. Myocardial deformation analysis is based on either Doppler or a non-Doppler technique, called speckle-tracking echocardiography. Myocardial deformation analysis provides quantitative measures of global and regional myocardial function for use in the perioperative care of the surgical patient. For example, coronary graft occlusion after coronary artery bypass grafting is detected by an acute reduction in strain in the affected coronary artery territory. In addition, assessment of left ventricular mechanics detects underlying myocardial pathology before abnormalities become apparent on conventional echocardiography. Certainly, patients with aortic regurgitation demonstrate reduced longitudinal strain before reduction in LVEF occurs, which allows detection of subclinical left ventricular dysfunction and predicts increased risk for heart failure and impaired myocardial function after surgical repair. In this review, we describe the principles, techniques, and clinical application of myocardial deformation analysis.

New universal strain software accurately assesses cardiac systolic and diastolic function using speckle tracking echocardiography

BACKGROUND

We have developed new universal strain software (USS) that can be used to perform speckle tracking of any Digital Imaging and Communications in Medicine (DICOM) image, regardless of the ultrasound system used to obtain it.

METHODS

Fifty patients prospectively underwent echocardiography immediately prior to cardiac catheterization. Biplane peak global longitudinal strain (GLS), peak systolic longitudinal strain rate (SSR), peak early diastolic longitudinal strain rate (DSR), and peak early diastolic circumferential strain rate (DCSR) were determined using conventional strain software (CSS) that uses raw data, and using the new USS applied to DICOM images.

RESULTS

Universal strain software correlated with CSS for GLS (r = 0.78, P < 0.001), SSR (r = 0.78, P < 0.001), DSR (r = 0.54, P < 0.001), and DCSR (r = 0.43, P = 0.019). GLS and SSR using USS correlated with left ventricular ejection fraction (LVEF) (r = -0.67 and -0.71, respectively) as well as using CSS (r = -0.66 and -0.71). Patients with diastolic dysfunction had significantly lower DSR (0.61 vs. 0.87/sec, P = 0.02) and DCSR (0.89 vs. 1.23/sec, P = 0.03), and less negative GLS (-10.8 vs. -16.1%, P = 0.002) using USS in all patients, as well as among those with LVEF ≥ 50%. Receiver-operating characteristic (ROC) analysis for detection of diastolic dysfunction revealed a sensitivity and specificity of 82% and 83% for DCSR < 1.09/sec (area under the curve [AUC = 0.80]) and 85% and 83% for GLS > -13.7% (AUC = 0.84) using USS.

CONCLUSION

Universal strain software can be used to accurately assess LV systolic and diastolic function using speckle tracking echocardiography.

Inter-vendor variability of left ventricular volumes and strains determined by three-dimensional speckle tracking echocardiography

BACKGROUND

Inter-vendor discordance in three-dimensional speckle-tracking echocardiography (3DS) remains uncharacterized. We aimed to examine inter-vendor discordance of left ventricular (LV) volumes, and functional parameters and their reproducibilities between two commercially available 3DS systems.

METHODS

Echocardiographic examinations with 3DS were performed in 26 healthy subjects (age 34 ± 13 years, 85% men) using a Vivid E9 system (V1) with 4V probe (GE Health Care) and Artida (V2) with PST-25SX probe (Toshiba Medical Systems) on the same day. LV variables and global LV longitudinal, circumferential, radial, and area strains were measured by vendor-specific softwares, 4D strain EchoPAC BT11 (for V1) and 3D WMT (for V2), respectively. Reproducibility of data was assessed by an intra-class correlation coefficient (ICC).

RESULTS

The mean time required for 3DS analysis was 5.4 ± 1.5 min for V1, being 21% less than that for V2 (6.8 ± 1.9 min, P < 0.01). Reproducibilities of all LV strains were comparable between V1 (ICC 0.50-0.82) and V2 (ICC 0.51-0.76), except for intra-observer and inter-observer reproducibilities of radial strain being lower in V2 (ICC for V1 0.82 and 0.82 and ICC for V2 0.44 and 0.40, respectively). LV strains in all directions and area were significantly different between V1 and V2, though LV volumes and ejection fraction were comparable.

CONCLUSIONS

Global longitudinal, circumferential, and area LV strains are reproducible in both 3DS vendors. However, values of three-dimensional LV strains by 3DS are highly vendor-dependent.

Imaging of congenital heart disease in adults: choice of modalities

Major advances in noninvasive imaging of adult congenital heart disease have been accomplished. These tools play now a key role in comprehensive diagnostic work-up, decision for intervention, evaluation for the suitability of specific therapeutic options, monitoring of interventions and regular follow-up. Besides echocardiography, magnetic resonance (CMR) and computed tomography (CT) have gained particular importance. The choice of imaging modality has thus become a critical issue. This review summarizes strengths and limitations of the different imaging modalities and how they may be used in a complementary fashion. Echocardiography obviously remains the workhorse of imaging routinely used in all patients. However, in complex disease and after surgery echocardiography alone frequently remains insufficient. CMR is particularly useful in this setting and allows reproducible and accurate quantification of ventricular function and comprehensive assessment of cardiac anatomy, aorta, pulmonary arteries and venous return including complex flow measurements. CT is preferred when CMR is contraindicated, when superior spatial resolution is required or when "metallic" artefacts limit CMR imaging. In conclusion, the use of currently available imaging modalities in adult congenital heart disease needs to be complementary. Echocardiography remains the basis tool, CMR and CT should be added considering specific open questions and the ability to answer them, availability and economic issues.

Evaluation of coronary steal in myocardium supplied by coronary collaterals: the role of speckle tracking analysis in resting and stress echocardiography

Coronary steal could develop in patients with chronic coronary artery disease (CAD) with collateral circulation, and adversely affect ventricular function and long-term clinical outcome. Poorly developed collaterals are more prone than well-developed collaterals to withdrawing their blood support to the collateralized myocardium due to higher collateral pathway resistance and lower vasodilatory reserve of the collateral bed. Even with well-developed coronary collaterals, coronary steal could still occur when perfusion pressure in the donor artery becomes low, or the recipient microvasculature is maximally dilated with exhaustion of vasodilatory reserve. The evaluation of distinctive coronary collateral function with or without steal provides important therapeutic and prognostic information in patients with chronic CAD. However, due to lack of reliable assessment methods, the detection and quantitative measurement of coronary steal remains a challenge. In this article, we present typical clinical scenarios to illustrate the major mechanisms underlying coronary steal in patients with chronic CAD and coronary collateral circulation, and review invasive and noninvasive methods currently available to assess coronary steal in myocardium supplied by coronary collaterals. We specifically focus on recent advances in the resting and stress echocardiography with speckle tracking techniques.

Optimizing benefit from CRT: role of speckle tracking echocardiography, the importance of LV lead position and scar

Cardiac resynchronization therapy is demonstrated to be effective in patients with advanced heart failure. Correcting mechanical dyssynchrony is proposed as the predominant mechanism of response. Achieving optimum left ventricular lead position, at the site of maximal mechanical dyssynchrony but away from transmural scar, is identified as one of the main determinants of both symptomatic and prognostic benefit. Strategies employing multimodality cardiac imaging techniques have been used to identify this optimal pacing site, in addition to any potential anatomical limitations to successful implantation. Speckle tracking echocardiography offers prospective lead targeting, incorporating pathophysiological determinants of cardiac resynchronization therapy response. This review considers the key factors in defining optimum left ventricular lead location, emphasizing the role of myocardial scar. The use of speckle tracking echocardiography and the potential for this technique to be incorporated into routine practice to guide the implant strategy in an individual patient is discussed.

Changes in myocardial mechanics in patients with obesity following major weight loss after bariatric surgery

OBJECTIVE

The purpose of this study was to evaluate myocardial mechanics in obese subjects using 2D-speckle tracking echocardiography (2D-STE).

DESIGN AND METHODS

63 obese individuals, including 28 who underwent bariatric surgery for weight loss (BMI 51 ± 9 kg/m2) and 35 managed conservatively (BMI 43 ± 7 kg/m2 ) were included. Changes in strain (S) and strain rate (SR) measured by 2D-STE. Mean follow-up was 23 ± 10 months.

RESULTS

The surgery group had a significant weight loss (BMI 37 ± 10 kg/m2 , P < 0.0001), but no change was noted in the nonsurgery group (BMI 42 ± 7 kg/m2 , P = 0.1). For the surgery group, S and SR in early diastole (SRe) improved significantly in the longitudinal left ventricle (LV) (S: P = 0.0004, SRe: P = 0.02) and right ventricle (RV) (S: P = 0.02, SRe: P = 0.009), whereas no changes were seen in LV ejection fraction (LVEF). In the nonsurgery group, there was no change in S, SR, or body weight. For all patients, weight changes correlated significantly with changes in LV S (r = 0.43, P = 0.0005).

CONCLUSIONS

The improvement of S after bariatric surgery suggests that weight loss could improve myocardial performance, despite the lack of change in LVEF.

Assessment of intraventricular time differences in healthy children using two-dimensional speckle-tracking echocardiography

BACKGROUND

Parameters describing intraventricular time differences are increasingly assessed in both adults and children. However, to appreciate the implications of these parameters in children, knowledge of the applicability of adult techniques in children is essential. Hence, the aim of this study was to assess the applicability of speckle-tracking strain-derived parameters in children, paying special attention to age and heart rate dependency.

METHODS

One hundred eighty-three healthy subjects (aged 0-19 years) were included. Left ventricular global peak strain, time to global peak strain, and parameters describing intraventricular time differences were assessed using speckle-tracking strain imaging in the apical two-chamber, three-chamber, and four-chamber views (longitudinal strain) and the parasternal short-axis view (radial and circumferential strain). Parameters describing intraventricular time differences included the standard deviation of time to peak strain and differences in time to peak strain between two specified segments. Age and heart rate dependency were evaluated using regression analysis, and intraobserver and interobserver variability were tested.

RESULTS

Acquisition and analysis of longitudinal six-segment time-strain curves was successful in 94.8% of subjects and radial and circumferential time-strain curves in 89.5%. No clinically significant linear relation was observed between age or heart rate and parameters describing intraventricular time differences. The coefficient of variation of time to global peak strain parameters was <10, while it was >10 for parameters describing intraventricular time differences.

CONCLUSIONS

The feasibility of speckle-tracking strain analysis in children is relatively good. Furthermore, no linear relation was observed between age or heart rate and parameters describing intraventricular time differences. However, the limited reproducibility of some parameters describing intraventricular time differences will confine their applicability in clinical practice.

Independent role of left ventricular global longitudinal strain in predicting prognosis of chronic heart failure patients

AIMS

To evaluate the independent prognostic role of two-dimensional (2D) strain measures reflecting global longitudinal left ventricular (LV) systolic function in outpatients affected by chronic heart failure (CHF).

METHODS AND RESULTS

Global longitudinal LV systolic strain (GLS) was assessed in 308 outpatients affected by CHF, by analyzing standard views with 2D speckle tracking technique. During a mean follow-up of 26 ± 13 months 37 patients died (29 due to cardiovascular causes), 10 patients underwent heart transplantation, and 75 patients experienced at least 1 episode of hospitalization due to acute decompensated heart failure (ADHF). Thirty-one patients without a history of major ventricular arrhythmic events experienced the occurrence of ventricular fibrillation and/or tachycardia or sudden death was observed. Multivariate Cox regression analysis showed that GLS was significantly associated with all-cause mortality (HR: 1.15; 95%CI: 1.02-1.30; P: 0.026), cardiovascular death (HR: 1.20; 95%CI: 1.04-1.39; P: 0.011), cardiovascular death or heart transplantation (HR: 1.24; 95%CI: 1.09-1.41; P: 0.001), ADHF-related hospitalizations (HR: 1.15; 95%CI: 1.05-1.25; P: 0.003), and arrhythmic events (HR: 1.17; 95%CI: 1.03-1.33; P: 0.018).

CONCLUSIONS

Quantifying LV longitudinal systolic function in CHF outpatients on the basis of 2D speckle tracking analysis provides a new parameter that independently predicts patient outcome, thus, strengthening its possible role in current clinical practice.