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Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: MRI‐derived left atrial (LA) longitudinal strain has been shown to be a marker for mitral regurgitation, but the utility of LA circumferential strain remains unclear. Purpose: To assess feasibility and reproducibility of LA circumferential strain, identify changes in mitral regurgitation patients compared to healthy volunteers, and determine strain's association with mitral regurgitation severity and cardiac function. Study Type: Retrospective. Population: 52 mitral regurgitation patients, 12 healthy volunteers. Field Strength/Sequence: Steady‐state free precession cine and 2D phase contrast sequences at 1.5T. Assessment: Peak LA circumferential strain was computed in each of three short‐axis slices (superior, mid, and inferior) and longitudinal strain computed from long‐axis slices using MRI feature‐tracking software. Strain test–retest reproducibility was determined from two repeat studies in healthy volunteers. Statistical Tests: LA circumferential strain test–retest reproducibility was assessed by intra‐class correlation coefficient (ICC). Strain was compared between cohorts using Student's t‐test or Mann–Whitney U. Mitral regurgitation severity association with strain and LV function was assessed using Spearman correlation and multivariable regression. Significance was defined as P < 0.05. Results: LA circumferential strain assessment was feasible in all subjects with moderate reproducibility in the superior (ICC = 0.74), mid LA (ICC = 0.71), and inferior LA (ICC = 0.63). In mitral regurgitation patients, LA circumferential strain was significantly lower in the superior (11.86% [6.5%,19.2%] vs. 18.73% ± 6.7%) and mid LA slices (18.41% ± 9.5% vs. 28.7% ± 10.4%) compared to healthy volunteers. Mitral regurgitation severity significantly associated with mid LA circumferential strain (β = −0.03) and LAV significantly associated with superior LA circumferential strain (β = −2.09), both independent of LA longitudinal strain and CO. Data Conclusion: LA circumferential strain assessment is feasible with moderate reproducibility. Compared to healthy volunteers, patients had significantly lower LA circumferential strain. Mitral regurgitation severity and LAV were significantly associated with LA circumferential strain independent of LA longitudinal strain. Evidence Level: 3 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Myocardial strain using cardiac magnetic resonance (CMR) is a sensitive marker for predicting adverse outcomes in many cardiac disease states, but the prognostic value in the general population has not been studied conclusively. The goal of this study was to assess the independent prognostic value of CMR feature tracking (FT)—derived LV global longitudinal (GLS), circumferential (GCS), and radial strain (GRS) metrics in predicting adverse outcomes (heart failure, myocardial infarction, stroke, and death). Participants from the UK Biobank population imaging study were included. Univariable and multivariable Cox models were used for each outcome and each strain marker (GLS, GCS, GRS) separately. The multivariable models were tested with adjustment for prognostically important clinical features and conventional global LV imaging markers relevant for each outcome. Overall, 45,700 participants were included in the study (average age 65 ± 8 years), with a median follow-up period of 3 years. All univariable and multivariable models demonstrated that lower absolute GLS, GCS, and GRS were associated with increased incidence of heart failure, myocardial infarction, stroke, and death. All strain markers were independent predictors (incrementally above some respective conventional LV imaging markers) for the morbidity outcomes, but only GLS predicted death independently: (HR: 1.18; 95% CI: 1.07-1.30). In the general population, LV strain metrics derived using CMR-FT in radial, circumferential, and longitudinal directions are strongly and independently predictive of heart failure, myocardial infarction, and stroke, but only GLS is independently predictive of death in an adult population cohort. [ABSTRACT FROM AUTHOR]

Objective: There is growing interest in speckle tracking echocardiography‐derived strain as a measure of left ventricular function in neonates. However, knowledge gaps remain regarding the effect of image acquisition and processing parameters on circumferential strain measurements. The aim of this study was to evaluate the effect of using different region of interest (ROI) widths on speckle tracking derived circumferential strain in healthy neonates. Methods: Thirty healthy‐term‐born neonates were examined with speckle‐tracking echocardiography in the short‐axis view. Circumferential strain values were acquired and compared using two different ROI widths. Furthermore, strain values in the different vendor‐defined wall layers were also compared. Results: Increasing ROI width led to a decrease in global circumferential strain (GCS) in the midwall and epicardial layers, the respective decreases in strain being ‐23.4 ±.6% to ‐22.0 ± 1.1%, p <.0001 and 18.5 ± 1.7% to ‐15.6 ± 2.0%, p <.0001. Segmental analyses were consistent with these results, apart from two segments in the midwall. There was no statistically significant effect on strain for the endocardial layer. A gradient was seen where strain increased from the epicardial to endocardial layers. Conclusion: Increasing ROI width led to a decrease in GCS in the midwall and epicardium. There is an increase in circumferential strain when moving from the epicardial toward the endocardial layer. Clinicians wishing to implement circumferential strain into their practice should consider ROI width variation as a potential confounder in their measurements. [ABSTRACT FROM AUTHOR]

Exploring the interaction of pipe-soil under frost heave effect is the key to solving the problem of frequent damage to buried pipes. In this study, the effects of ambient temperature (AT), buried depth of pipe (BDP) and initial water content (IWC) on the interaction of pipe-soil under the condition of roadbed frost heave are studiedby experimental test. The results show that the buried pipe seriously affects the soil temperature field and the migration of pore water during roadbed frost heaving. As the AT decreases, the final strain of pipes (FSP) gradually increases, and the flatness of the roadbed gradually deteriorates. When the BDP is 2D (outer diameter of the pipe), the flatness of the roadbed is the worst. The pore water in unfrozen area tends to migrate more toward soil around pipes during the roadbed frost heaving. The IWC of roadbed has a greater impact on the FSP than the BDP These could provide a guidance for the construction of pipes under frost heave in roadbed. [ABSTRACT FROM AUTHOR]

We have proposed the "Standard 4‐edge Curved Model" for the first time, which contains a standard geometric model based on superelliptic curves and a mapping relationship from a plane to a three‐dimensional surface. In this model, we can quantitatively compare the wrinkling risks of almost all known 4‐edge curved displays and provide the optimizations for the geometric parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

Aims: Cardiac left ventricular hypertrophy (LVH) is the most common manifestation of heart involvement in Anderson–Fabry disease (AFD). Conventional cardiac imaging is not sensitive enough to detect early signs of LVH in AFD. It remains uncertain whether enzyme replacement therapy (ERT) can prevent LVH progression and improve myocardial function. This study aimed to assess the effectiveness of two‐dimensional speckle tracking echocardiography (2D‐STE) in early detection of cardiac involvement in AFD and monitoring the efficacy of agalsidase alfa and agalsidase beta therapy. Methods and Results: Thirteen consecutive AFD patients and 12 healthy controls underwent standard transthoracic 2D, color Doppler, tissue Doppler echocardiography, and 2D strain analysis. Global longitudinal strain (GLS) and global circumferential strain (GCS) were measured. Diastolic strain rate (SR) was extracted. Compared to healthy subjects, AFD patients without LVH showed lower levels of GLS (p < 0.001) and SR (p = 0.01), while there was no difference in GCS (p = 0.82). Following treatment, apical circumferential strain (ACS) showed improvement (p = 0.01). Conclusion: In AFD patients without LVH, there was a decrease in global and segmental LS. Higher plasma Lyso‐GL‐3 concentrations were associated with elevated ACS values after ERT, indicating that ACS in AFD patients without LVH, albeit normal, is involved in early LV dysfunction. [ABSTRACT FROM AUTHOR]

Background: Late gadolinium enhancement (LGE) detected by cardiac MRI (CMR) has low correlation with low voltage zones (LVZs) detected by electroanatomical mapping (EAM). We aim to study correlation of myocardial strain by CMR- Feature Tracking (FT) alongside LGE with LVZs detected by EAM. Methods: Nineteen consecutive CMRs of patients with EAM were analyzed offline by CMR-FT. Peak value of circumferential strain (CS), longitudinal strain (LS), and LGE was measured in each segment of the left ventricle (17-segment model). The percentage of myocardial segments with CS and LS > −17% was determined. Percentage area of LGE-scar was calculated. Global and segment–wise bipolar and unipolar voltage was collected. Percentage area of bipolar LVZ (<1.5 mV) and unipolar LVZ (<8.3 mV) was calculated. Results: Mean age was 62±11 years. Mean LVEF was 37±13%. Mean global CS was −11.8±5%. Mean global LS was −11.2±4%. LGE-scar was noted in 74% of the patients. Mean percentage area of LGE-scar was 5%. There was significant correlation between percentage abnormality detected by LS with percentage bipolar LVZ (r = +0.5, p = 0.03) and combined percentage CS+LS abnormality with percentage unipolar LVZ (r = +0.5, p = 0.02). Per-unit increase in CS increased the percentage area of unipolar LVZ by 2.09 (p = 0.07) and per-unit increase in LS increased the percentage area of unipolar LVZ by 2.49 (p = 0.06). The concordance rates between CS and LS to localize segments with bipolar/unipolar LVZ were 79% and 95% compared to 63% with LGE. Conclusions: Myocardial strain detected by CMR-FT has a better correlation with electrical low voltage zones than the conventional LGE. [ABSTRACT FROM AUTHOR]

In order to realize the quantitative estimation of tire vertical force, the algorithm of heavy-loaded tire vertical force estimation based on circumferential strain analysis is studied. A finite element analysis model of 16.00R20 tire is established. A comparison of tire loading test and modal vibration test indicates that the vertical stiffness error and vibration frequency error of the model are less than 7.79% and 5.49% respectively, which verifies the validity of the model. Using the finite element method, the influence of vertical force on tire grounding characteristics and circumferential strain of inner liner is studied. The characterization index of tire contact angle is proposed and verified by circumferential strain analysis, and the errors of the three indexes are all less than 8%. Taking the grounding angle and grounding length as identification features, the vertical force estimation model is established by combining grey wolf optimization (GWO) and the support vector regression (SVR), and the estimation accuracy is verified by finite element simulation. The results indicate that the characterization index in combination with the of characteristic point spacing angle of zero-order, first-order and second-order derivative of strain curve can accurately estimate tire contact angle. The error between the estimated value of the vertical force estimation algorithm based on GWO-SVR and the finite element simulation value is less than 1.8%.

PurposeCardiac magnetic resonance imaging (cMRI) represents the gold standard to detect myocarditis. Left ventricular (LV) deformation imaging provides additional diagnostic options presumably exceeding conventional transthoracic echocardiography (TTE). The present study aimed to analyze the feasibility to detect myocarditis in patients (pts) with preserved LV ejection fraction (LVEF) by TTE compared to cMRI. It has been hypothesized that the number of pathological findings by deformation imaging correspond to findings in cMRI.Methods and resultsBetween January 2018 and February 2020 102 pts with acute myocarditis according to the modified Lake Louise criteria and early gadolinium enhancement (EGE) by cMRI were identified at the department of cardiology at the University Hospital Leipzig. Twenty-six pts were included in this retrospective comparative study based on specific selection criteria. Twelve pts with normal cMRI served as a control group. LV deformation was analyzed by global and regional longitudinal strain (GLS, rLS), global and regional circumferential and radial strain (GCS, rCS, GRS, rRS), and LV rotation (including layer strain analysis). All parameters were compared to findings of edema, inflammation, and fibrosis by cMRI according to Lake Louise criteria. All pts with acute myocarditis diagnosed by cMRI showed pathological findings in TTE. Especially rCS and LV rotation analyzed by regional layer strain exhibit a high concordance with pathological findings in cMRI. In controls no LV deformation abnormalities were documented. Mean values of GLS, GRS, and GCS were not significantly different between pts with acute myocarditis and controls.ConclusionThis retrospective analysis documents the feasibility of detecting regional deformation abnormalities by echocardiography in patients with acute myocarditis confirmed by cMRI. The detection of pathological findings due to myocarditis requires the determination of regional deformation parameters, particularly rCS and LV rotation. The assessment of global strain values does not appear to be of critical value.

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The winding process is one of the essential processes in the manufacturing of lithium-ion batteries (LIBs). Current collector failure frequently occurs in the winding process, which severely increases the production cost and reduces production efficiency. In order to solve this problem, we first analyze the relationship between different process parameters and the failure of the current collector, and put forward the standard to determine the failure of the current collector. Moreover, we conducted tensile experiments to validate the differences in the mechanical performance of the current collector under different thicknesses. Finally, the circumferential stress and strain of the current collector winding were calculated using finite element analysis. The accuracy of the proposed criterion for determining current collector failure was verified through experimental measurements of stress and strain. The results demonstrate that the criterion proposed in this study can accurately calculate the maximum stress during the current collector winding process, providing a powerful tool for addressing the issue of current collector failure in the winding process. [ABSTRACT FROM AUTHOR]

The potential utility of strain imaging as a tool for quantitative assessment of myocardial contractile function has already been demonstrated in many cardiac conditions. Numerous studies have explored its utility in patients with coronary artery disease (CAD) also. Almost the entire spectrum of CAD has been studied and several different strain parameters and indices derived from global or regional longitudinal, circumferential, radial and area strain as well as left ventricular rotation have been employed. These studies have mostly shown that strain imaging can have an incremental role in the diagnosis and prognosis assessment of CAD. However, a few important limitations are there. Most importantly, CAD involves the left ventricle in a segmental manner and unfortunately, segmental strain at present has significant measurement variability rendering it unsuitable for routine clinical use. Nevertheless, strain imaging has many potential uses in CAD. This review describes the current understanding about the role of strain imaging in the evaluation and management of CAD.

Background: Data on the impact of sacubitril/valsartan (SV) therapy on phasic left atrial (LA) and left ventricular (LV) strain in heart failure with reduced ejection fraction (HFrEF) are limited. The aim of this study was to evaluate changes in two-dimensional speckle tracking (2D-STE) parameters with SV therapy in HFrEF patients. Methods: Prospective evaluation of HFrEF patients receiving optimized medical therapy. Two-dimensional speckle tracking (2D-STE) parameters were assessed at baseline and after 6 months of SV therapy. LA strain and strain rate (SR) in reservoir, conduit, and contraction phases were compared with LV longitudinal, radial, and circumferential strain and SR and stratified according to heart rhythm and HFrEF etiology. Results: A total of 35 patients completed the 6-month follow-up, with a mean age of 59 ± 11 years, 40% in atrial fibrillation, 43% with ischemic etiology, and LVEF of 29 ± 6%. There were significant improvements in LA reservoir, conduit, and contractile strain and SR following SV therapy, particularly among patients in sinus rhythm. There were significant improvements in longitudinal, radial, and circumferential LV function indices. Conclusion: SV therapy in HFrEF was associated with improved longitudinal, radial, and circumferential function, particularly among patients in sinus rhythm. These findings can provide insights into the mechanisms underlying the improvement of cardiac function and help assess subclinical responses to the treatment. [ABSTRACT FROM AUTHOR]

Current echocardiographic criteria cannot accurately differentiate exercise induced left ventricular (LV) hypertrabeculation in athletes from LV non-compaction cardiomyopathy (LVNC). This study aims to evaluate the role of speckle tracking echocardiography (STE) in characterising LV myocardial mechanics in healthy adolescent athletes with and without LVNC echocardiographic criteria. Adolescent athletes evaluated at three sports academies between 2014 and 2019 were considered for this observational study. Those meeting the Jenni criteria for LVNC (end-systolic non-compacted/compacted myocardium ratio > 2 in any short axis segment) were considered LVNC+ and the rest LVNC-. Peak systolic LV longitudinal strain (S l), circumferential strain (S c), rotation (Rot), corresponding strain rates (SR l/c) and segmental values were calculated and compared using a non-inferiority approach. A total of 417 participants were included, mean age 14.5 ± 1.7 years, of which 6.5% were LVNC+ (n = 27). None of the athletes showed any additional LVNC clinical criteria. All average S l , SR l S c , SR c and Rot values were no worse in the LVNC+ group compared to LVNC- (p values range 0.0003–0.06), apart from apical SR c (p = 0.2). All 54 segmental measurements (S l /S c SR l /SR c and Rot) had numerically comparable means in both LVNC+ and LVNC-, of which 69% were also statistically non-inferior. Among healthy adolescent athletes, 6.5% met the echocardiographic criteria for LVNC, but showed normal LV STE parameters, in contrast to available data on paediatric LVNC describing abnormal myocardial function. STE could better characterise the myocardial mechanics of athletes with LV hypertrabeculation, thus allowing the transition from structural to functional LVNC diagnosis, especially in suspected physiological remodelling. The use of 2D speckle tracking echocardiography in athlete assessment. [Display omitted] • Even among healthy adolescent athletes, 6.5% meet echocardiographic criteria for left ventricular non-compaction. • These athletes have normal global and segmental myocardial mechanics despite apparent significantly remodelled LV. • Adding speckle tracking echocardiography to current criteria could improve screening in athletes with LV hypertrabeculation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels' reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53–6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication's occurrence. [ABSTRACT FROM AUTHOR]

In recent years, there is a worldwide growing interest in using concrete mixes with recycled concrete aggregates (RCA). Reinforced concrete is the composite of concrete and steel rebars, where the rebars provide relatively higher tensile strength and ductility, energy absorption capacity, and crack control. This composite action depends on the interfacial bond between the rebar and the concrete. The bond behavior is commonly evaluated from pull-out test results which yield the global relationship between the average bond-stress and the corresponding slip and depend on the concrete properties and the rebar geometry. The present study investigates the bond behavior in concrete with RCA in comparison to concrete with natural aggregates aiming at short bond lengths to obtain the local bond-slip behavior. Two major complementary aspects of the bond behavior in the longitudinal (bond stress-slip) and circumferential directions (circumferential strain-slip) are studied, and the post-test interior damage is investigated. The study found that the magnitudes of the maximum bond stress are not affected by the aggregate type and are in accordance with the concrete compressive strength, but different internal damage mechanisms develop in the specimens of the two aggregate types. The different internal damage mechanisms in RCA specimens affect the internal confinement level's development and the circumferential strains' magnitude, which are considerably different than in concrete with natural aggregates.

After establishment of an animal model of atherosclerosis, speckle tracking imaging was performed to analyze the correlation between ultrasound characteristics and pathological manifestations. Rabbits were divided into the normal control (NC) and atherosclerosis (AS) groups. Rabbits in the AS group were subjected to ultrasound-guided balloon injury of the abdominal aorta and fed a high-fat diet for 16 wk. Rabbits in the NC group were fed a normal diet for the same period. After 16 wk, all animals underwent serological tests, ultrasound and speckle tracking circumferential strain analysis. In the AS group, 28 hypo-echoic plaques had formed. The circumferential strain of six segments at the short axis of plaques in the AS group was lower than that in the NC group (p < 0.001), and global circumferential strain (GCS) in the AS group was significantly reduced compared with the NC group (p < 0.001). In the AS group, the area ratio of type I to type III collagen fibers was smaller than that in the NC group. The GCS of atherosclerotic plaques was positively correlated with the area ratio of type I to type III collagen fibers in plaques (r = 0.7181, p < 0.001). In conclusion, there is a significant positive correlation between the decreased circumferential strain and the decreased area ratio of type I to type III collagen fibers in hypo-echoic plaques. [ABSTRACT FROM AUTHOR]

A wide range of subclinical changes in left ventricular (LV) geometry and function can be observed, even in the early course of arterial hypertension (HTN). Aim of the study was to investigate if the appearance of isolated basal septal hypertrophy (BSH, septal bulge) in asymptomatic young and middle-aged adults with HTN could be a marker of incipient LV systolic dysfunction when other measures of global LV function are still normal. A total of 138 patients with primary arterial hypertension, aged less than 65 years, with no comorbidities and with preserved LV ejection fraction (EF) were included. Complete 2D transthoracic echocardiography study was preformed according to standardized protocol, as well as deformation study using speckle tracking echocardiography. Global and regional longitudinal strain was measured in apical 4-, 2- and 3-chamber views according to 18-segments model. Global and regional circumferential and radial strains were measured in short axis view. Average was taken from each of the six basal, middle and apical LV segments. Patients were divided into two groups according to BSH presence and values were compared. Basal septal hypertrophy was found in half of the patients (53.6%). The whole cohort had altogether normal LV global systolic function, as well as global indices of radial strain (GRS 43.86 ± 10.75%) and longitudinal strain (GLS - 19.73 ± 2.19%), while global circumferential strain (GCS) was mildly reduced (GCS - 19.5 ± 2.81%). BSH patients had more expressed LV geometry changes (LV mass: 89.19 ± 24.59 g/m2 vs 109.15 ± 25.33 g/m2, p < 0.001; relative wall thickness: 0.3 ± 0.08 vs 0.38 ± 0.11, p < 0.001) and also revealed a specific pattern of longitudinal deformation impairment in three LV segments (basal and mid interventricular septum, basal anteroseptum). "Strain gradient" from LV base to apex (basal < mid < apical) was observed in the whole population for longitudinal and circumferential strain, and it was more pronounced in the BSH group. This group had more impaired basal LS, while apical CS was improved. Subendocardial longitudinal strain was also more impaired in the BSH group. This study brings new meaning to basal septal hypertrophy (BSH) occurrence in hypertensive patients with discrete global concentric remodeling. Regional systolic dysfunction of the basal and mid LV segments is found, while apical segments increase in deformation. This specific "strain gradient" pattern was found to be more pronounced in patients with BSH. The recognition of BHS in apparently healthy hypertensive patients with no impairment in global systolic function may suggest latent target organ damage with regional impairment of systolic function and the need to imply more aggressive treatment approach. [ABSTRACT FROM AUTHOR]

Introduction: Infarct size (IS) is a fundamental determinant of left-ventricular (LV) remodelling (end-systolic and end-diastolic volume change, ΔESV, ΔEDV) and adverse clinical outcomes after myocardial infarction (MI). Our prior work found that myocardial uptake of transcoronary-delivered progenitor cells is governed by IS. Aim: To evaluate the relationship between IS, stem cell uptake, and the magnitude of LV remodelling in patients receiving transcoronary administration of progenitor cells shortly after MI. Material and methods: Thirty-one subjects (age 36-69 years) with primary percutaneous coronary intervention (pPCI)-treated anterior ST-elevation MI (peak CK-MB 584 [181-962] U/l, median [range]) and sustained left ventricle ejection fraction (LVEF) = 45% were studied. On day 10 (median) 4.3 × 106 (median) autologous CD34+ cells (50% labelled with 99mTc-extametazime) were administered via the infarct-related artery (left anterior descending). ΔESV, ΔEDV, and mid circumferential myocardial strain (mCS) were evaluated at 24 months. Results: Infarct mass (cMRI) was 57 [11-112] g. Cell label myocardial uptake (whole-body Δ-scans) was proportional to IS (r = 0.62), with a median 2.9% uptake in IS 1st tercile (= 45 g), 5.2% in 2nd (46-76 g), and 6.7% in 3rd (> 76 g) (p = 0.0006). Cell uptake in proportion to IS attenuated the IS-ΔESV (p = 0.41) and IS-ΔEDV (p = 0.09) relationship. At 24 months, mCS improved in IS 2nd tercile (p = 0.028) while it showed no significant change in smaller (p = 0.87) or larger infarcts (p = 0.58). Conclusions: This largest human study with labelled CD34+ cell transplantation shortly after MI suggests that cell uptake (proportional to IS) may attenuate the effect of IS on LV adverse remodelling. To boost this effect, further strategies should involve cell types and delivery techniques to maximize myocardial uptake. [ABSTRACT FROM AUTHOR]

The mechanical behavior of buried HDPE double-wall corrugated pipes is mainly affected by the material and the structure of the pipe wall. Here we studied a peculiar material that added fly ash (FA) in high density polyethylene (HDPE) to develop composites. We have conducted research on FA/HDPE composites with different mix proportions. When 5% compatibilizer was added to the 10% FA masterbatch/HDPE composite, the Young's Modulus of FA/HDPE composite was higher. This paper mainly studies the mechanical behavior of the structure of pipe walls for materials with this proportion of the ingredients. The mechanical behavior of double-wall corrugated pipes with different ratios of interior and exterior wall thicknesses is studied by keeping the sum of the interior and exterior wall thicknesses unchanged. Pipes with six different ratios of interior and exterior wall thicknesses are simulated; the results show that the strain of crest and liner gradually decreased and the valley strain gradually increased with the increase of the exterior wall thickness. By comparing inner and outer wall thickness ratios from 0.67 to 2.33, it is found that the structural performance and economic advantage for the double-wall corrugated pipes is best when the thickness ratio of the interior wall and the exterior wall is controlled to be from 1.3 to 1.8. This paper expounds the deformation mechanism of double-wall corrugated pipes from the perspective of mechanical behavior and structural characteristics, and provides a reference for material selection and structural design of double-wall corrugated pipes. [ABSTRACT FROM AUTHOR]

Aims: No previous research provided a complete biventricular and multidirectional left ventricular (LV) functional assessment by two-dimensional (2D) speckle tracking echocardiography (STE) in infants of gestational diabetic mothers (IGDM) Methods: A total of 30 consecutive IGDM and 30 infants of healthy mothers were examined between March 2021 and July 2021. Both groups of infants underwent evaluation by neonatologist and 2D transthoracic echocardiography (TTE) implemented with 2D-STE quantification of LV-global longitudinal strain (GLS), LV-global circumferential strain (GCS), LV-global radial strain (GRS) and right ventricular (RV)-GLS, within 3 days of life and at 40 days after birth. Predictors of persistent subclinical myocardial dysfunction, defined as a LVGLS less negative than -20% at 40-day follow-up, in IGDM population, were determined. Results: At 2.2 ± 1.3 days after birth, LV-GLS (− 17.2 ± 1.9 vs. − 23.9 ± 3.8%), LV-GCS (− 17.9 ± 2.7 vs. − 27.3 ± 3.4%), LV-GRS (25.6 ± 3.4 vs. 35.8 ± 3.6%) and RV-GLS (− 17.6 ± 3.6 vs. − 22.6 ± 3.8%) were significantly impaired in IGDM than controls (all p < 0.001). At 36.8 ± 5.2 days of life, LV-GLS was still impaired (less negative than -20%) in 26.6% of IGDM. Maternal third trimester body mass index (BMI) (OR 1.89, 95%CI 1.05–3.39) and third trimester glycosylated hemoglobin (HbA1C) (OR 1.59, 95%CI 1.08–2.19) were independently associated with persistent LV-GLS impairment in IGDM. Maternal BMI ≥ 30 Kg/m2 and HbA1C ≥ 38 mmol/mol showed the maximum of sensitivity and specificity for predicting persistent subclinical myocardial dysfunction in IGDM at 40 days of life. Conclusions: IGDM have diffuse pattern of myocardial dysfunction during perinatal period. This dysfunction may be persistent up to 40 days of life in infants of GDM women with obesity and uncontrolled diabetes. [ABSTRACT FROM AUTHOR]

Background: A novel application of cine Displacement ENcoding with Stimulated Echoes Magnetic Resonance Imaging (DENSE MRI) has recently been described to assess regional heterogeneities in circumferential strain around the aortic wall in vivo; however, validation is first required for successful clinical translation. Purpose: To validate the quantification of regional circumferential strain around the wall of an aortic phantom using DENSE MRI. Study Type: In vitro phantom study. Population: Three polyvinyl alcohol aortic phantoms with eight axially oriented nitinol wires embedded evenly around the walls. Field Strength/Sequence: 3 T; gradient‐echo aortic DENSE MRI with spiral cine readout, gradient‐echo phase‐contrast MRI (PCMR) with Cartesian cine readout. Assessment: Phantoms were connected to a pulsatile flow loop and peak DENSE‐derived regional circumferential Green strains at 16 equally spaced sectors around the wall were assessed according to previously published algorithms. "True" regional circumferential strains were calculated by manually tracking displacements of the nitinol wires by two independent observers. Normalized circumferential strains (NCS) were calculated by dividing regional strains by the mean strain. Finally, DENSE‐derived regional strain was corrected by multiplying regional DENSE NCS by the mean strain calculated from the diameter change on the PCMR. Statistical Tests: One‐sample t‐test, Paired‐sample t‐test, and analysis of variance with Bonferroni correction, coefficient of variation (CoV), Bland–Altman analysis; P < 0.05 was considered statistically significant. Results: Aortic DENSE MRI significantly overestimated circumferential strain compared to the wire‐tracking method (mean difference and SD 0.030 ± 0.014, CoV 0.31). However, NCS demonstrated good agreement between DENSE and wire‐tracking data (mean difference 0.000 ± 0.172, CoV 0.15). After correcting the DENSE‐derived regional strain, the mean difference in regional circumferential strain between DENSE and wire‐tracking was significantly reduced to 0.006 ± 0.008, and the CoV was reduced to 0.18. Data Conclusion: For aortic phantoms with mild spatial heterogeneity in circumferential strain, the previously published aortic DENSE MRI technique successfully assessed the regional NCS distribution but overestimated the mean strain. This overestimation is correctable by computing a more accurate mean circumferential strain using a separate cine scan. Level of Evidence: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

All over the world cardiovascular diseases are one of the main reason of morbidity and mortality in the structure of non-communicable diseases, and myocardial infarction has a leading role. Markers of modern advanced ultrasound techniques, speckle tracking echocardiography, play significant role in the detection and assessment of cardiovascular disease. Deviation of them can detect myocardial ischemia, hypertrophy, dystrophy and infiltration, severe systemic diseases, cardiotoxicity of the drugs, etc. This technology significantly improves diagnostic capabilities of transthoracic echocardiography, it allows to assess myocardial function in all three planes (longitudinal, circumferential and radial), in which myocardium moves during cardiac cycle. Speckle tracking echocardiography can determine the volume of myocardial damage, differentiate subendocardial and transmural myocardial infarction, identify viable and fibrous areas of the myocardium, that is confirmed by the results of magnetic resonance imaging. Besides, this method helps to detect and assess mechanical dyssynchrony and also predict the risk of pathological left ventricular remodeling and life-threatening adverse cardiovascular events (arrhythmias, increasing of heart failure, recurrent myocardial infarction, stroke, death, etc.), that is important for patients with acute myocardial infarction to identify high-risk patients. The most studied markers of this technique are longitudinal, circumferential and radial strain, mechanical dispersion and postsystolic shortening. Markers of this ultrasound technique significantly complete other markers of transthoracic echocardiography, such as left ventricular ejection fraction, to assess risk stratification of cardiovascular complications. The value of speckle-tracking echocardiography markers has been demonstrated alone or in combination with other markers.

Abstract Background Duchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial. Objectives We hypothesized that native T1 mapping and/or circumferential (εcc) and longitudinal (εls) strain can detect myocardial fibrosis. Methods 156 CMRs with gadolinium were performed in 66 DMD boys and included: (1) left ventricular ejection fraction (LVEF), (2) LGE, (3) native T1 mapping and myocardial tagging (εcc-tag measured using harmonic phase analysis). LGE was graded as: (1) presence/absence by segment, slice, and globally; (2) global severity from 0 (no LGE) to 4 (severe); (3) percent LGE using full width half maximum (FWHM). εls and εcc measured using feature tracking. Regression models to predict LGE included native T1 and either εcc-tag or εls and εcc measured at each segment, slice, and globally. Results Mean age and LVEF at first CMR were 14 years and 54%, respectively. Global εls and εcc strongly predicted presence or absence of LGE (OR 2.6 [1.1, 6.0], p = 0.029, and OR 2.3 [1.0, 5.1], p = 0.049, respectively) while global native T1 did not. Global εcc, εls, and native T1 predicted global severity score (OR 2.6 [1.4, 4.8], p = 0.002, OR 2.6 [1.4, 6.0], p = 0.002, and OR 1.8 [1.1, 3.1], p = 0.025, respectively). εls correlated with change in LGE by severity score (n = 33, 3.8 [1.0, 14.2], p = 0.048) and εcc-tag correlated with change in percent LGE by FWHM (n = 34, OR 0.2 [0.1, 0.9], p = 0.01). Conclusions Pre-contrast sequences predict presence and severity of LGE, with εls and εcc being more predictive in most models, but there was not an observable advantage over using LVEF as a predictor. Change in LGE was predicted by εls (global severity score) and εcc-tag (FWHM). While statistically significant, our results suggest these sequences are currently not a replacement for LGE and may only have utility in a very limited subset of DMD patients.

Background: Data on the impact of sacubitril/valsartan (SV) therapy on phasic left atrial (LA) and left ventricular (LV) strain in heart failure with reduced ejection fraction (HFrEF) are limited. The aim of this study was to evaluate changes in two-dimensional speckle tracking (2D-STE) parameters with SV therapy in HFrEF patients. Methods: Prospective evaluation of HFrEF patients receiving optimized medical therapy. Two-dimensional speckle tracking (2D-STE) parameters were assessed at baseline and after 6 months of SV therapy. LA strain and strain rate (SR) in reservoir, conduit, and contraction phases were compared with LV longitudinal, radial, and circumferential strain and SR and stratified according to heart rhythm and HFrEF etiology. Results: A total of 35 patients completed the 6-month follow-up, with a mean age of 59 ± 11 years, 40% in atrial fibrillation, 43% with ischemic etiology, and LVEF of 29 ± 6%. There were significant improvements in LA reservoir, conduit, and contractile strain and SR following SV therapy, particularly among patients in sinus rhythm. There were significant improvements in longitudinal, radial, and circumferential LV function indices. Conclusion: SV therapy in HFrEF was associated with improved longitudinal, radial, and circumferential function, particularly among patients in sinus rhythm. These findings can provide insights into the mechanisms underlying the improvement of cardiac function and help assess subclinical responses to the treatment.

Multisystem inflammatory syndrome in children (MIS-C) is one of the most significant sequela of coronavirus disease 2019 (COVID-19) in children. Emerging literature has described myocardial dysfunction in MIS-C patients using traditional and two-dimensional speckle tracking echocardiography in the acute phase. However, data regarding persistence of subclinical myocardial injury after recovery is limited. We aimed to detect these changes with deformation imaging, hypothesizing that left ventricular global longitudinal (GLS) and circumferential strain (GCS) would remain impaired in the chronic phase despite normalization of ventricular function parameters assessed by two-dimensional echocardiography. A retrospective, single-institution review of 22 patients with MIS-C was performed. Fractional shortening, GLS, and GCS, along with regional longitudinal (RLS) and circumferential strain (RCS) were compared across the acute, subacute, and chronic timepoints (presentation, 14–42, and > 42 days, respectively). Mean GLS improved from − 18.4% in the acute phase to − 20.1% in the chronic phase (p = 0.4). Mean GCS improved from − 19.4% in the acute phase to − 23.5% in the chronic phase (p = 0.03). RCS and RLS were impaired in the acute phase and showed a trend towards recovery by the chronic phase, with the exception of the basal anterolateral segment. In our longitudinal study of MIS-C patients, GLS and GCS were lower in the acute phase, corroborating with left ventricular dysfunction by traditional measures. Additionally, as function globally recovers, GLS and GCS also normalize. However, some regional segments continue to have decreased strain values which may be an important subclinical marker for future adverse events. [ABSTRACT FROM AUTHOR]

Although cardiac strain has been used as a practical mechanical indicator to estimate cardiac functions, measurement of strain is still difficult due to the need for operator proficiency and special equipment to perform echocardiography and magnetic resonance imaging (MRI). Hence, a modified indicator that can be calculated more easily at the bedside is needed to assess cardiac function based on cardiac morphology. The circumferential strain of the left ventricular (LV) wall and the contraction potential energy were numerically investigated in this study using a thick-walled cylindrical model under different myocardial thicknesses, stiffnesses, and diastolic pressures for given specific ejection fractions (EFs) or end-diastolic volumes. The LV wall was modeled as a visco-hyperelastic, continuous material. We proposed the modified ejection fraction (mEF), which is the product of EF and the contractility percentage of the internal volume within the epicardium, as an indicator of circumferential strain. Calculated peak circumferential strain was better estimated by mEF than EF. Furthermore, the contraction potential energy correlated well with circumferential strain and mEF. Our results regarding mEF are consistent with those obtained in 7 previous clinical studies. mEF may be a useful and practical indicator of the reduced contraction potential energy of the local myocardium and of heart failure, regardless of imaging modalities and vendors.

Objectives: We aimed to use speckle‐tracking echocardiography (STE) to quantify circumferential aortic strain of abdominal aortic aneurysms (AAA) with different size. Methods: A total of 87 AAA patients were included. The morphological variables, including aortic maximum diameter (MD), end systolic area (ESA), end diastolic area (EDA), and thickness and area of intraluminal thrombus (ILT), were measured by ultrasound. STE was applied to calculate circumferential strain (CS) at 6 equally divided segments of the aorta at MD. We evaluated the mean value of peak strain along the 6 segments as global circumferential strain (GCS). Results: Large AAA (≥5.5 cm) patients had higher MD, ESA, EDA, AAA length, ILT thickness, and area, but lower fractional area change, GCS, and segmental CSs than small AAA (<5.5 cm) subjects (all P <.05). Compared with AAA <4.5 cm group, AAA patients ≥4.5 cm possessed increased MD, ESA, EDA, AAA length, ILT thickness, and area, which results were also reflected in the comparison between AAA <6.5 and ≥6.5 cm group. In small AAA patients, GCS and regional strains in CS1, CS3, and CS5 segments were lower in AAA subjects ≥4.5 cm than those <4.5 cm (all P<.05). However, no significant differences in the GCS and regional CS between ≥6.5 and <6.5 cm group were found. Correlation analysis revealed a significant negative association of GCS with MD, ESA, and EDA, even after adjusting the potential confounding factors (all P <.05). Conclusions: Our findings may yield insight into the structural strain characteristics of AAA wall with different size, which adds the benefit of using simple echocardiography‐derived biomechanics to stratify AAA patients. [ABSTRACT FROM AUTHOR]

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels’ reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53–6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication’s occurrence.

In a recent experimental research, the authors measured the circumferential strains on the cylindrical envelope of concrete specimens during pull‐out tests. This paper presents a theoretical approach, complementing the previous experimental study, aiming at predicting these measured circumferential strains and developing the understanding of the three‐dimensional behavior of the concrete cylinder. The proposed approach accounts for the specimen materials and geometrical parameters including the ribs and strain gauges locations and proposes an expression for the normalized and absolute circumferential strains along the specimen circumference due to ribs actions. This paper presents a new three‐dimensional model of the specimen behvior during a pull‐out test, which provides new insight on bond mechanics and illuminates the role of the radial pressures developed as part of the bond action. Several simulations were performed on specimens with three different diameters, two concrete strengths, and a different number of bonded ribs. All the simulations show very good agreement with the measured strain data. This study enhances the understanding of bond resistance during a pull‐out process and contributes to the understanding of the ring action that is developed in a concrete cylinder during a pull‐out test. [ABSTRACT FROM AUTHOR]

The mechanical behavior of buried HDPE double-wall corrugated pipes is mainly affected by the material and the structure of the pipe wall. Here we studied a peculiar material that added fly ash (FA) in high density polyethylene (HDPE) to develop composites. We have conducted research on FA/HDPE composites with different mix proportions. When 5% compatibilizer was added to the 10% FA masterbatch/HDPE composite, the Young’s Modulus of FA/HDPE composite was higher. This paper mainly studies the mechanical behavior of the structure of pipe walls for materials with this proportion of the ingredients. The mechanical behavior of double-wall corrugated pipes with different ratios of interior and exterior wall thicknesses is studied by keeping the sum of the interior and exterior wall thicknesses unchanged. Pipes with six different ratios of interior and exterior wall thicknesses are simulated; the results show that the strain of crest and liner gradually decreased and the valley strain gradually increased with the increase of the exterior wall thickness. By comparing inner and outer wall thickness ratios from 0.67 to 2.33, it is found that the structural performance and economic advantage for the double-wall corrugated pipes is best when the thickness ratio of the interior wall and the exterior wall is controlled to be from 1.3 to 1.8. This paper expounds the deformation mechanism of double-wall corrugated pipes from the perspective of mechanical behavior and structural characteristics, and provides a reference for material selection and structural design of double-wall corrugated pipes.

2D speckle tracking echocardiography (2DSTE) is established to analyse left ventricular (LV) longitudinal function. The analysis of LV rotational deformation is challenging and requires standardization of image acquisition as well as postprocessing analysis. The aim of this study was to test the feasibility to analyse LV rotational deformation using 2DSTE by introducing a novel algorithm for the detection of artefacts. The study was performed in 20 healthy subjects serving as a control group and in 53 competitive sportsmen. Circumferential, radial strain (CS, RS) and LV rotation were analysed by 2DSTE in parasternal short axis views. The stepwise algorithm to exclude potential artefacts starts with the visual estimation of the image quality with respect to complete visualization of all myocardial segments during the entire cardiac cycle followed by the exclusion of data sets in participants with conduction abnormalities. The next step is the optimization of tracking areas and a cross-check of implausible strain waveforms in multiple acquired comparable cineloops. The last step is the exclusion of strain curves with persisting implausible waveforms if standardization failures and incorrect LV wall tracking are fixed. Plausible physiological strain curves were observed in 89% (n = 65/73) of all subjects. In controls all implausible waveforms could be verified as artefacts. The algorithm was applied in 53 professional athletes to test and confirm its feasibility. Abnormal CS waveforms were documented in 25 athletes, verified as artefacts due to tracking failures in 22 athletes and due to incorrect image acquisition in 3 athletes. CS artefacts were mostly located in the basal posterior and lateral LV segments. (endocardial: 6%, n = 4/70; p < 0.05) and basal posterior (endocardial: 8%, n = 5/70; p < 0.05) segments were highly susceptible to artefacts. 2DSTE of parasternal short axis views to analyse circumferential and radial deformation as well as LV rotation is feasible in athletes. The proposed algorithm helps to avoid artefacts and might contribute to standardization of this technique. 2DSTE might provide an interesting diagnostic tool for the detection of viral myocarditis, e.g. in athletes. [ABSTRACT FROM AUTHOR]

The current collector fracture failure of lithium-ion batteries (LIBs) occurs during its winding production process frequently, and the consequent damages are usually large, but little research has been conducted on this phenomenon. This work stems from the difficulty and obstacles in the winding process of actual production of LIBs. The fracture failure of the current collectors is easily caused by the evolution and mutation of the mechanical behavior during the winding process, resulting in safety hazards and poor efficiency. The purpose of this work is to reveal the evolution and distribution mechanism of circumferential strain of the current collectors on the fracture failure under the constraint of winding process. Experimental tests, finite element calculations and theoretical model are used to study the evolution and distribution of circumferential strain. The dynamic evolution process of circumferential strain is tested accurately, and the mechanism of fracture failure of current collectors is revealed. The criterion for current collector strength is proposed based on the results of strain analysis and SEM observation. [ABSTRACT FROM AUTHOR]

Abstract Background Impaired left ventricular (LV) contraction and relaxation may further promote adverse remodeling and may increase the risk of ventricular arrhythmia (VA) in ischemic cardiomyopathy. We aimed to examine the association of cardiovascular magnetic resonance (CMR)-derived circumferential strain parameters for LV regional systolic function, LV diastolic function and mechanical dispersion with the risk of VA in patients with prior myocardial infarction and primary prevention implantable cardioverter defibrillator (ICD). Methods Patients with an ischemic cardiomyopathy who underwent CMR prior to primary prevention ICD implantation, were retrospectively identified. LV segmental circumferential strain curves were extracted from short-axis cine CMR. For LV regional strain analysis, the extent of moderately and severely impaired strain (percentage of LV segments with strain between − 10% and − 5% and > − 5%, respectively) were calculated. LV diastolic function was quantified by the early and late diastolic strain rate. Mechanical dispersion was defined as the standard deviation in delay time between each strain curve and the patient-specific reference curve. Cox proportional hazard ratios (HR) (95%CI) were calculated to assess the association between LV strain parameters and appropriate ICD therapy. Results A total of 121 patients (63 ± 11 years, 84% men, LV ejection fraction (LVEF) 27 ± 9%) were included. During a median (interquartile range) follow-up of 47 (27;69) months, 30 (25%) patients received appropriate ICD therapy. The late diastolic strain rate (HR 1.1 (1.0;1.2) per − 0.25 1/s, P = 0.043) and the extent of moderately impaired strain (HR 1.5 (1.0;2.2) per + 10%, P = 0.048) but not the extent of severely impaired strain (HR 0.9 (0.6;1.4) per + 10%, P = 0.685) were associated with appropriate ICD therapy, independent of LVEF, late gadolinium enhancement (LGE) scar border size and acute revascularization. Mechanical dispersion was not related to appropriate ICD therapy (HR 1.1 (0.8;1.6) per + 25 ms, P = 0.464). Conclusions In an ischemic cardiomyopathy population referred for primary prevention ICD implantation, the extent of moderately impaired strain and late diastolic strain rate were associated with the risk of appropriate ICD therapy, independent of LVEF, scar border size and acute revascularization. These findings suggest that disturbed LV contraction and relaxation may contribute to an increased risk of VA after myocardial infarction.

In this study, a hoop-strain sensor was developed by embedding a bare fiber Bragg grating (FBG) sensor inside 3D printed Polylactic Acid (PLA) filament. Fabrication process of the hoop-strain sensor indicates that the initial temperature of the melted PLA is around 50 °C which is obviously lower than the printing temperature of the printer nozzle (around 200°C). A typical residual wavelength was found after the fabrication process of the hoop-strain sensor. The shrinkage deformation of the present sensor was around 208 με after fabrication. The hoop-strain sensor was flexible and can be used to measure both circumferential strain change and contact pressure between hoop-strain sensors and cylinders. Calibration tests for elongation measurement indicate that the sensitivity and minimum resolution with respect to strain change are 4.04 nm/% and 3.574 με, respectively. The obtained measurement sensitivity and resolution for pressure measurement were 0.0035 nm/kPa, and 0.286 kPa, respectively. The maximum measurement ranges of the hoop-strain sensor for strain and pressure measurement are larger than 1% and 800 kPa, respectively.

Background: Duchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial. Objectives: We hypothesized that native T1 mapping and/or circumferential (εcc) and longitudinal (εls) strain can detect myocardial fibrosis. Methods: 156 CMRs with gadolinium were performed in 66 DMD boys and included: (1) left ventricular ejection fraction (LVEF), (2) LGE, (3) native T1 mapping and myocardial tagging (εcc-tag measured using harmonic phase analysis). LGE was graded as: (1) presence/absence by segment, slice, and globally; (2) global severity from 0 (no LGE) to 4 (severe); (3) percent LGE using full width half maximum (FWHM). εls and εcc measured using feature tracking. Regression models to predict LGE included native T1 and either εcc-tag or εls and εcc measured at each segment, slice, and globally. Results: Mean age and LVEF at first CMR were 14 years and 54%, respectively. Global εls and εcc strongly predicted presence or absence of LGE (OR 2.6 [1.1, 6.0], p = 0.029, and OR 2.3 [1.0, 5.1], p = 0.049, respectively) while global native T1 did not. Global εcc, εls, and native T1 predicted global severity score (OR 2.6 [1.4, 4.8], p = 0.002, OR 2.6 [1.4, 6.0], p = 0.002, and OR 1.8 [1.1, 3.1], p = 0.025, respectively). εls correlated with change in LGE by severity score (n = 33, 3.8 [1.0, 14.2], p = 0.048) and εcc-tag correlated with change in percent LGE by FWHM (n = 34, OR 0.2 [0.1, 0.9], p = 0.01). Conclusions: Pre-contrast sequences predict presence and severity of LGE, with εls and εcc being more predictive in most models, but there was not an observable advantage over using LVEF as a predictor. Change in LGE was predicted by εls (global severity score) and εcc-tag (FWHM). While statistically significant, our results suggest these sequences are currently not a replacement for LGE and may only have utility in a very limited subset of DMD patients. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease affects about 30% of the population and it has a growing tendecy with the increasing incidence of obesity. Currently, a large amount of clinical evidence has shown that cardiovascular disease represents the main cause of mortality in patients suffering from non-alcoholic fatty liver disease. Objective: In this study we investigated the structural and functional changes of the left ventricle in young adults with hepatic steatosis using modern echocardiographic techniques. Methods:By using tissue Doppler imaging and also Speckle tracking echocardiography the left ventricle systolic function was assessed. Results: All patients included in the study had a normal left ventricular ejection fraction but, when the longitudinal function of the left ventricle was assessed using the tissue Doppler technique (maximum systolic velocity S) statistically significant differences were found in both the group of patients with non-alcoholic fatty liver as well as in the group of patients associated with diabetes. Using speckle tracking echocardiography, we found a statistically significant decrease of the global longitudinal strain in the endocardium, in the group of patients with non-alcoholic liver disease but also in the group of those with diabetes. The overall longitudinal strain at the myocardium was significantly reduced only in the group of patients with non-alcoholic fatty liver disease and diabetes, while the overall longitudinal strain at the epicardium showed no changes in any of the groups studied. Also, no changes were observed at the circumferential strain. Conclusion: Nonalcoholic fatty liver disease, diagnosed in asymptomatic young adults may be a risk factor for remodeling the left ventricle over time, being associated with subclinical myocardial dysfunction, regardless of the presence of other cardiovascular risk factors. [ABSTRACT FROM AUTHOR]

Women with ischemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Left ventricular (LV) circumferential strain (CS) is often lower in INOCA compared to healthy controls; however, it remains unclear whether CS differs between INOCA women with and without CMD. We hypothesized that CS would be lower in women with CMD, consistent with CMD-induced LV mechanical dysfunction. Cardiac magnetic resonance (cMR) images were examined from women enrolled in the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction Project. CS by feature tracking in INOCA women with CMD, defined as myocardial perfusion reserve index (MPRI) <1.84 during adenosine-stress perfusion cMR, was compared with CS in women without CMD. In a subset who had invasive coronary function testing (CFT), the relationship between CS and CFT metrics, LV ejection fraction (LVEF) and cardiovascular risk factors was investigated. Among 317 women with INOCA, 174 (55%) had CMD measured by MPRI. CS was greater in women with CMD compared to those without CMD (23.2 ± 2.5% vs. 22.1 ± 3.0%, respectively, P = 0.001). In the subset with CFT (n = 153), greater CS was associated with increased likelihood of reduced vasodilator capacity (OR = 1.33, 95%CI = 1.02–1.72, p = 0.03) and discriminated abnormal vs. normal coronary vascular function compared to CAD risk factors, LVEF and LV concentricity (AUC: 0.82 [0.73–0.96 95%CI] vs. 0.65 [0.60–0.71 95%CI], respectively, P = 0.007). The data indicate that LV circumferential strain is related to and predicts CMD, although in a direction contrary with our hypothesis, which may represent an early sign of LV mechanical dysfunction in CMD. [ABSTRACT FROM AUTHOR]

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Aim. To study the potential of global strain analysis using two-dimensional speckletracking echocardiography to predict the heart failure (HF) in patients with ST-segment elevation myocardial infarction (STEMI) based on the 6-month follow-up after revascularization.Material and methods. The study included 114 STEMI patients aged 52 (44; 59) years. Two-dimensional echocardiography was performed with analysis of standard parameters and speckle tracking with analysis of strain and rotational characteristics of the myocardium. Concentration of brain natriuretic peptide was determined. The endpoint was the presence of heart failure (HF) after 6-month follow-up. observation. The analysis of HF risk was carried out using ROC-curves based on 3 criteria. Strain parameters with the maximum sum of sensitivity and specificity were chosen as a cutoff point.Results. Six months after STEMI, depending on the ejection fraction (EF) value, the patients were divided into 3 groups: group 1 — patients with reduced EF (

Background: Ebstein's anomaly (EA) is a rare congenital heart abnormality that remain as an ignored abnormality. Due to the lack of efficient and precise diagnostic methods, diagnosis of this disease become a little difficult. Hence, using a precise and non-invasive method like tracking feature of left and right ventricular strain including radial, longitudinal and circumferential can be a promising diagnostic way for diagnosis of ebstein's anomaly. Material and methods: for mentioned reason, in this study we observed 18 ebstein's anomaly patients with mean age of 24.83 ± 13.34 (8 men and 10 women) along with 15 healthy control with mean age of 29.27 ± 12.54 (7 men and 8 women). We determined the radial, longitudinal and circumferential strain of left and right ventricular using CMR. Results: CMR imaging was performed for both of study groups. The results showed that there was a significant difference between the Radial-Strain-LV of patients and controls. The Radial-Strain-LV of patients was significantly lower than controls (P =0.002). Also, the global longitudinal strain of right ventricular in patients was significantly lower than controls (P = 0.001). There were any significant differences between other criteria between patients and controls. Conclusion: Among different ways for diagnosis of ebstein's anomaly using CMR imaging of different strain of ventricular can be considered as a promising method. Through different strains Radial-Strain-LV and Longitudinal Strain-RV may be the best variants in diagnosis process. [ABSTRACT FROM AUTHOR]

Background: Ischemic mitral regurgitation (IMR) imposes volume overload on the left ventricle (LV), accelerating adverse LV remodeling. In this study, we sought to investigate the impact of volume overload due to IMR on regional myocardial contractile mechanics., Methods: Ten Yorkshire swine were induced with myocardial infarction (MI) by occluding the left circumflex coronary artery (LCx). Cardiac MRI was performed at baseline (BL) and 2.5 months (2.5M) post-MI. IMR was quantified with epicardial echocardiography 3 months post-MI. The animals were then assigned to 2 groups: no/mild MR (nmMR, n  = 4) and moderate/severe MR (msMR, n  = 6). MRI images were analyzed to assess infarction size, end-diastolic and end-systolic volume (EDV and ESV, respectively), ejection fraction (EF), longitudinal strain (LS), circumferential strain (CS), and systolic dyssynchrony index (SDI). The myocardial region was divided into infarction, border, and remote zones based on the LCx-supplied region., Results: There was no difference in the infarction size. Group-wise comparison of LS and CS between BL and 2.5M demonstrated that LS and CS in the infarction zone and the border zone decreased at 2.5M in both groups. However, LS and CS in the remote zone were elevated only in the msMR group (LS: -9.81 ± 3.96 vs. -12.58 ± 5.07, p  < 0.01; CS; -12.78 ± 3.81 vs. -16.09 ± 3.33, p  < 0.01) at 2.5M compared to BL. The SDI of CS was significantly elevated in the msMR group (0.1255 vs. 0.0974, p  = 0.015) at 2.5M compared to BL., Conclusions: Elevated LS and CS in the remote zone were observed in moderate/severe MR and ventricular dyssynchrony. These elevated cardiac strains, coupled with ventricular dyssynchrony, may contribute to the progression of MR, thereby accelerating heart failure., Competing Interests: MP reports stock ownership, board directorship and employment in Nyra Medical Inc. MP also received personal consulting fees from Heart Repair Technologies, and research grants from Heart Repair Technologies. MP led this work when he was at Emory University. DO received personal consulting fees from Nyra Medical Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Kikuchi, Onohara, Silverman, King, Tom, Govin, Guyton and Padala.)

Abstract Background Myocardial strain is increasingly recognized as an important assessment for myocardial function. In addition, it also improves outcome prediction. However, there is lack of standardization in strain evaluation by cardiovascular magnetic resonance (CMR). In this study we compared strain values using multiple techniques and multiple vendor products. Methods Prospectively recruited patients with cardiomyopathy of diverse etiology (N = 77) and healthy controls (N = 10) underwent CMR on a 1.5 T scanner. Tagging, displacement encoding with stimulated echoes (DENSE) and balanced stead state free precession cine imaging were acquired on all subjects. A single matched mid left ventricular (LV) short axis plane was used for the comparisons of peak circumferential (Ecc) and radial strain (Err) and a 4-chamber view for longitudinal strain (Ell). Tagging images were analyzed using harmonic phase (HARP) and displacement encoding with stimulated echoes (DENSE) images using a proprietary program. Feature tracking (FT) was evaluated using 3 commercially available software from Tomtec Imaging Systems, Cardiac Image Modeller (CIM), and Circle Cardiovascular Imaging. Tagging data were used as reference. Statistic analyses were performed using paired t-test, intraclass correlation coefficient (ICC), Bland Altman limits of agreement and coefficient of variations. Results Average LV ejection fraction was 50% (range 32 to 62%). Regional LV wall motion abnormalities were present in 48% of the analyzed planes. The average Ecc was − 13 ± 4%, − 13 ± 4%, − 16 ± 6%, − 10 ± 3% and − 14 ± 4% for tagging, DENSE, Tomtec, CIM and Circle, respectively, with the best agreement seen in DENSE and Circle with tagging. The Err was highly varied with poor agreement across the techniques, 32 ± 24%, 40 ± 28%, 47 ± 26%, 64 ± 33% and 23 ± 9% for tagging, DENSE, Tomtec, CIM and Circle, respectively. The average Ell was − 14 ± 4%, − 8 ± 3%, − 13 ± 5%, − 11 ± 3% and − 12 ± 4% for tagging, DENSE, Tomtec, CIM and Circle, respectively with the best agreement seen in Tomtec and Circle with tagging. In the intra- and inter-observer agreement analysis the reproducibility of each technique was good except for Err by HARP. Conclusions Small but important differences are evident in Ecc and Ell comparisons among vendors while large differences are seen in Err assessment. Our findings suggest that CMR strain values are technique and vendor dependent. Hence, it is essential to develop reference standard from each technique and analytical product for clinical use, and to sequentially compare patient data using the same software.