Recent advances in the assessment of myocardial function have facilitated the direct measurement of atrial function using speckle-tracking echocardiography. Currently, normal reference ranges for ...atrial function using speckle-tracking echocardiography are based on a few initial studies, with variations among modestly sized (n = 100-350) studies.
The authors searched the PubMed, Embase, and Scopus databases for the key terms "left atrial/atrial/atrium" and "strain/function/deformation/stiffness" and "speckle tracking/Velocity Vector Imaging/edge tracking." Studies of global left atrial function using speckle-tracking were selected if they involved >30 normal or healthy participants without any cardiac risk factors. Normal ranges for reservoir strain, conduit strain, and contractile strain were computed using a random-effects model. Meta-regression and subgroup analysis was performed to explore between-study heterogeneity.
Forty studies (2,542 healthy subjects) satisfied the inclusion criteria. Meta-analysis revealed a normal reference range for reservoir strain of 39% (95% CI, 38%-41%, from 40 articles), for conduit strain of 23% (95% CI, 21%-25%, from 14 articles), and for contractile strain of 17% (95% CI, 16%-19%, from 18 articles). Meta-regression identified heart rate (P = .02) and body surface area (P = .003) as contributors to this heterogeneity. Subgroup analyses revealed heterogeneity due to sample size (n > 100 vs N < 100, P = .02).
The normal reference ranges for the three components of left atrial function are demonstrated. The between-study heterogeneity is explained partly by heart rate, body surface area, and sample size.
Abstract Objectives The aim of this study was to perform a systematic review and meta-analysis to estimate the normal ranges of magnetic resonance imaging (MRI)-based feature tracking (FT) and to ...identify sources of variations. Similar analyses were also performed for strain encoding, displacement encoding with stimulated echoes, and myocardial tagging. Background MRI-FT is a novel technique for quantification of myocardial deformation using MRI cine images. However, the reported 95% confidence intervals (CIs) from the 2 largest studies have no overlaps. Methods Four databases (EMBASE, SCOPUS, PUBMED, and Web of Science) were systematically searched for MRI strains of the left (LV) and right (RV) ventricles. The key terms for MRI-FT were “tissue tracking,” “feature tracking,” “cardiac magnetic resonance,” “cardiac MRI,” “CMR,” and “strain.” A random effects model was used to pool LV global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and RVGLS. Meta-regressions were used to identify the sources of variations. Results 659 healthy subjects were included from 18 papers for MRI-FT. Pooled mean of LVGLS was −20.1% (95% CI: −20.9 to −19.3), LVGCS −23% (−24.3 to −21.7), LVGRS 34.1% (28.5 to 39.7), and RVGLS −21.8% (−23.3 to −20.2). Although there were no publication biases except for LVGCS, significant heterogeneities were found. Meta-regression showed that variation of LVGCS was associated with field strength (β = 3.2; p = 0.041). Variations of LVGLS, LVGRS, and RVGLS were not associated with any of age, sex, software, field strength, sequence, LV ejection fraction, or LV size. LVGCS seems the most robust in MRI-FT. Among the MRI-derived strain techniques, the normal ranges were mostly concordant in LVGLS and LVGCS but varied substantially in LVGRS and RVGLS. Conclusions The pooled means of 4 MRI-derived myocardial strain methods in normal subjects are demonstrated. Differences in field strength were attributed to variations of LVGCS.
Assessment of left ventricular systolic function is necessary during trastuzumab-based chemotherapy because of potential cardiotoxicity. Deformation indices have been proposed as an adjunct to ...clinical risk factors and ejection fraction (EF), but the optimal parameter and optimal cutoffs are undefined. The aim of this study was to determine the best means of early detection of subsequent reduction of EF in patients with breast cancer treated with trastuzumab.
Eighty-one consecutive women (mean age, 50 ± 11 years) receiving trastuzumab were prospectively studied, 37 of whom received concurrent anthracyclines. Conventional echocardiographic indices (mitral annular systolic s' and diastolic e' velocities) and myocardial deformation indices (global longitudinal peak systolic strain GLS, global longitudinal peak systolic strain rate GLSR-S, and global longitudinal early diastolic strain rate GLSR-E) were measured at baseline and at 6 and 12 months. Cardiotoxicity was defined as a >10% decline as a percentage of baseline EF in 12 months.
In the 24 patients (30%) who later developed cardiotoxicity, myocardial deformation indices decreased at 6 months (GLS, P < .001; GLSR-S, P = .009; GLSR-E, P = .002 vs baseline), but e' was unchanged. The strongest predictor of cardiotoxicity was ΔGLS (area under the curve, 0.84); an 11% reduction (95% confidence interval, 8.3%-14.6%) was the optimal cutoff, with sensitivity of 65% and specificity of 94%. In sequential models, the clinical model (χ(2) = 10.2) was improved by GLSR-S (χ(2) = 14.7, P = .03) and even more so by GLSR-E (χ(2) = 18.0, P = .005) or GLS (χ(2) = 21.3, P = .0008). Discrimination improvement by adding GLS was confirmed by an integrated discrimination improvement of 18.6% (95% confidence interval, 8.6%-28.6%; P = .0003). A net 29% of the patients without events were reclassified into lower risk categories, and a net 48% of the patients with events were reclassified into higher risk categories, resulting in a total continuous net reclassification improvement (>0) of 0.77 (95% confidence interval, 0.33-1.22; P = .036).
GLS is an independent early predictor of later reductions in EF, incremental to usual predictors in patients at risk for trastuzumab-induced cardiotoxicity.
Abstract Objectives This study sought to show the degree to which experience and training affect the precision and validity of global longitudinal strain (GLS) measurement and to evaluate the ...variability of strain measurement after feedback. Background The application of GLS for the detection of subclinical dysfunction has been recommended in an expert consensus document and is being used with increasing frequency. The role of experience in the precision and validity of GLS measurement is unknown, as is the efficacy of training. Methods Fifty-eight readers, divided into 4 groups on the basis of their experience with GLS, calculated GLS from speckle strain analysis of 9 cases with various degrees of image quality. Intraclass correlation coefficients (ICCs), mean difference, standard deviation (SD), and coefficient of variation (CV) were compared against the measurements of a reference group that had experience with >1,000 cases of strain measurement. Individualized feedback was distributed, and repeat measurements were performed by 40 readers. Comparisons with the baseline variation provided information about whether feedback was effective. Results The ICC for GLS was significantly greater than that for ejection fraction regardless of image quality. Experience with strain measurement affected the concordance in strain values among the readers; the group with the highest level of experience showed significantly better ICC than those with no experience, although the ICC of the inexperienced readers was still very good (0.996 vs. 0.975, p = 0.0002). As experience increased, the mean difference, SD, and CV became significantly smaller. The CV of segmental strain analysis showed significant improvement after training, regardless of experience. Conclusions The favorable interobserver agreement of GLS makes it more attractive than ejection fraction for follow-up of left ventricular function by multiple observers. Although experience is important, the precision of GLS was high for all groups. Training appears to be of most value for the assessment of segmental strain.
Background An updated 2016 echocardiographic algorithm for diagnosing left ventricular (LV) diastolic dysfunction (DD) was recently proposed. We aimed to assess the reliability of the 2016 ...echocardiographic LVDD grading algorithm in predicting elevated LV filling pressure and clinical outcomes compared to the 2009 version. Methods We retrospectively identified 460 consecutive patients without atrial fibrillation or significant mitral valve disease who underwent transthoracic echocardiography within 24 hours of elective heart catheterization. LV end-diastolic pressure (LVEDP) and the time constant of isovolumic pressure decay (Tau) were determined. The association between DD grading by 2009 LVDD Recommendations and 2016 Recommendations with hemodynamic parameters and all-cause mortality were compared. Results The 2009 LVDD Recommendations classified 55 patients (12%) as having normal, 132 (29%) as grade 1, 156 (34%) as grade 2, and 117 (25%) as grade 3 DD. Based on 2016 Recommendations, 177 patients (38%) were normal, 50 (11%) were indeterminate, 124 (27%) patients were grade 1, 75 (16%) were grade 2, 26 (6%) were grade 3 DD, and 8 (2%) were cannot determine. The 2016 Recommendations had superior discriminatory accuracy in predicting LVEDP ( P < .001) but were not superior in predicting Tau. During median follow-up of 416 days (interquartile range: 5 to 2004 days), 54 patients (12%) died. Significant DD by 2016 Recommendations was associated with higher risk of mortality ( P = .039, subdistribution HR1.85 95% CI, 1.03-3.33) in multivariable competing risk regression. Conclusions The grading algorithm proposed by the 2016 LV diastolic dysfunction Recommendations detects elevated LVEDP and poor prognosis better than the 2009 Recommendations.
Disagreement of strain measurements among different vendors has provided an obstacle to the clinical use of strain. A joint standardization task force between professional societies and industry was ...initiated to reduce intervendor variability of strain. Although feedback from this process has been used in software upgrades, little is known about the effects of efforts to improve conformity. The aim of this study was to assess whether intervendor agreement for global longitudinal strain (GLS) has improved after standardization initiatives.
Eighty-two subjects (mean age, 52 ± 21 years; 55% men) prospectively underwent two sequential examinations using two most common ultrasound systems (Vivid E9 and iE33). GLS was calculated using proprietary software (EchoPAC-PC BT12 E12 and BT13 E13 vs QLAB version 8.0 Q8, QLAB version 9.0 Q9, and QLAB version 10.0 Q10). Agreements in GLS were evaluated with Bland-Altman plots. Coefficients of variation (CVs) were compared using the Friedman test and compared with CVs of left ventricular volumes and ejection fraction (LVEF).
Median GLS using E12 was -19.2% (interquartile range IQR, -15.2% to -23.2%), compared with -19.3% (IQR, -14.9% to -23.7%) for E13, -15.7% (IQR, -11.4% to -20%) for Q8, -19% (IQR, -15.7% to -22.3%) for Q9, and -18.7% (IQR, -15.7% to -21.7%) for Q10. The CVs of prestandardization GLS (12 ± 8% E12/Q8 and 14 ± 8 E13/Q8) were significantly larger than that of LVEF (5 ± 5) (P < .001). Since standardization, the CVs of GLS have shown improvement (6 ± 4 E12/Q9, 7 ± 4 E12/Q10, 6 ± 4 E13/Q9, and 7 ± 4 E13/Q10) and are similar to those of LVEF.
Subsequent to the joint standardization task force, there has been improvement in between-vendor concordance in GLS between two leading ultrasound manufactures, the variability of which is now analogous to that of LVEF. The removal of concerns about measurement variability should allow wider use of GLS.
Although two-dimensional (2D) strain is widely used to assess left ventricular mechanics, the strain values derived from vendor-specific 2D speckle-tracking software are different even for the same ...subjects and are therefore not interchangeable. The aim of this study was to test the hypothesis that vendor-independent software would produce lower intervendor variability between 2D strain measurements and overcome this limitation.
Two sets of three apical images were acquired using two of three types of ultrasound machines (GE, Philips, and Toshiba) in 81 healthy volunteers (GE vs Philips in 26 subjects, Philips vs Toshiba in 31 subjects, and GE vs Toshiba in 24 subjects). Two-dimensional global longitudinal strain (GLS) was measured using vendor-specific software and two vendor-independent software packages (TomTec and Epsilon) in each set of apical images, and GLS values were directly compared with one another.
The upgrades of vendor-specific software yielded different values of GLS compared with the previous versions of the software. The correlations between the GLS values determined using vendor-specific software exhibited a wide range of r values (r = 0.23, r = 0.42, and r = 0.72), with significant bias, with the exception of one comparison. The vendor-independent software provided modest degrees of correlation (TomTec: r = 0.65, r = 0.65, and r = 0.77; Epsilon: r = 0.65, r = 0.74, and r = 0.77), with limits of agreement (range, ±3% to ±4.5%) that were not negligible.
Although the vendor-independent 2D strain software provided moderate correlations between the GLS values of the ultrasound images obtained from the same subjects using different vendors, relatively large limits of agreement remain a relevant problem. These results suggest that the same ultrasound machine and the same 2D speckle-tracking software should be used for longitudinal analysis of strain values in the same subjects and for cross-sectional studies.
Global longitudinal strain (GLS) is a robust and sensitive marker of left-ventricular systolic function, reflecting longitudinal shortening of the ventricle. A growing body of evidence indicates its ...superiority in identifying subclinical, early alterations in cardiac function compared to traditional markers, such as ejection fraction. Therefore, there is a growing demand to assess GLS in clinical settings, but limited availability on how to obtain GLS accurately and appropriately in the current literature. This review summarizes key aspects of GLS measurement, including image acquisition, post-processing, and training/experience needed to facilitate the clinical implication with standardization.
Progress in cancer therapy has led to improved prognosis of patients with cancer and thus to a continuous rise of cancer survivors. However, it has simultaneously increased cardiovascular morbidity ...and mortality rates due to direct and/or indirect side effects of anticancer treatment. Similar to the rapid rise of patients with adult congenital disease, the number of patients suffering or at risk of cardiotoxicity has been steeply increasing and getting an emerging issue. Among the many facets of chemotherapy-induced cardiovascular toxicity, this review attempts to summarize echocardiographic evaluation of cardiac function after cancer chemotherapy by reviewing the definition, risk factors, brief history, limitation of left ventricular ejection fraction and myocardial strain imaging, as well as the limitations of this technique.
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