Diastolic Strain Research Articles

Predictive value of cardiac magnetic resonance imaging for adverse left ventricular remodeling after acute ST-segment elevation myocardial infarction

To assess the value of cardiac magnetic resonance (CMR) imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction (STEMI). We retrospectively analyzed the clinical data and serial CMR (cine and LGE sequences) images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention (PCI), including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling, defined as an increase of left ventricular end-systolic volume (LVESV) over 15% at the second CMR compared to the initial CMR. The CMR images were analyzed for LV volume, infarct characteristics, and global and infarct zone myocardial function. The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods. The initial CMR showed no significant differences in LV volume or LV ejection fraction (LVEF) between the two groups, but the infarct mass and microvascular obstructive (MVO) mass were significantly greater in adverse LV remodeling group (P < 0.05). Myocardial injury and cardiac function of the patients recovered over time in both groups. At the second CMR, the patients with adverse LV remodeling showed a significantly lower LVEF, a larger left ventricular end-systolic volume index (LVESVI) and a greater extent of infarct mass (P < 0.001) with lower global peak strains and strain rates in the radial, circumferential, and longitudinal directions (P < 0.05), infarct zone peak strains in the 3 directions, and infarct zone peak radial and circumferential strain rates (P < 0.05). The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass (AUC=0.793, 95% CI: 0.693-0.873; cut-off value: 30.67%), radial diastolic peak strain rate (AUC=0.645, 95% CI: 0.534-0.745; cut-off value: 0.58%), and RAAS inhibitor (AUC= 0.699, 95% CI: 0.590-0.793). The extent of infarct mass, peak radial diastolic strain rate, and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Role of Microtubule Network in the Passive Anisotropic Viscoelasticity of Healthy Right Ventricle.

Cardiomyocytes are viscoelastic and key determinants of right ventricle (RV) mechanics. Intracellularly, microtubules are found to impact the viscoelasticity of isolated cardiomyocytes or trabeculae; whether they contribute to the tissue-level viscoelasticity is unknown. Our goal was to reveal the role of the microtubule network in the passive anisotropic viscoelasticity of the healthy RV. Equibiaxial stress relaxation tests were conducted in healthy RV free wall (RVFW) under early (6%) and end (15%) diastolic strain levels, and at sub- and physiological stretch rates. The viscoelasticity was assessed at baseline and after the removal of microtubule network. Furthermore, a quasi-linear viscoelastic (QLV) model was applied to delineate the contribution of microtubules to the relaxation behavior of RVFW. After removing the microtubule network, RVFW elasticity and viscosity were reduced at the early diastolic strain level and in both directions. The reduction in elasticity was stronger in the longitudinal direction, whereas the degree of changes in viscosity were equivalent between directions. There was insignificant change in RVFW viscoelasticity at late diastolic strain level. Finally, the modeling showed that the tissue's relaxation strength was reduced by the removal of the microtubule network, but the change was present only at a later time scale. These new findings suggest a critical role of cytoskeleton filaments in RVFW passive mechanics in physiological conditions.

Temporal Responses of a Low-Energy Meal Replacement Plan or Exercise Training on Cardiovascular Function and Fibro-Inflammatory Markers in People with Type 2 Diabetes—A Secondary Analysis of the “Diabetes Interventional Assessment of Slimming or Training to Lessen Inconspicuous Cardiovascular Dysfunction” Study

Background: This study assesses the temporal responses of cardiovascular function, fibro-inflammation, and glucometabolic profiles in asymptomatic adults with type 2 diabetes, following a low-energy meal replacement plan (MRP) or exercise training. Methods: Secondary analysis of DIASTOLIC: a randomised, open-label, blinded-endpoint trial of 12 weeks MRP (~810 kcal/day) or exercise training. Cardiac magnetic resonance, plasma fibroinflammatory, and metabolic markers were undertaken at baseline, 4, and 12 weeks. Results: Out of 24 participants in the MRP group and 22 in exercise training, 18 and 11 completed all three visits. MRP resulted in early (0–4 weeks) improvement in insulin resistance (HOMA-IR: 10.82 to 4.32), decrease in FABP-4 (4.87 ± 0.19 to 5.15 ± 0.32 mg/L), and improvement in left ventricular remodelling LV mass: volume (0.86 ± 0.14 to 0.78 ± 0.11), all with large effect sizes. MMP8 levels increased moderately at 4–12 weeks. Peak early diastolic strain rate (cPEDSR) initially decreased, then improved. Exercise training led to minor improvements in insulin resistance and MMP-8 levels, with no significant changes in cPEDSR or LV remodelling. Conclusions: MRP resulted in early improvements in insulin resistance, cardiac remodelling, and inflammation, but with an initial decrease in diastolic function, improving by 12 weeks. Exercise training showed minor early benefits in insulin resistance and inflammation, but no significant cardiac changes.

The worsening effect of paroxysmal atrial fibrillation on left ventricular function and deformation in type 2 diabetes mellitus patients: a 3.0 T cardiovascular magnetic resonance feature tracking study

BackgroundAtrial fibrillation (AF) has been linked to an increased risk of cardiovascular death, overall mortality and heart failure in patients with type 2 diabetes mellitus (T2DM). The present study investigated the additive effects of paroxysmal AF on left ventricular (LV) function and deformation in T2DM patients with or without AF using the cardiovascular magnetic resonance feature tracking (CMR-FT) technique.MethodsThe present study encompassed 225 T2DM patients differentiated by the presence or absence of paroxysmal AF [T2DM(AF+) and T2DM(AF−), respectively], along with 75 age and sex matched controls, all of whom underwent CMR examination. LV function and global strains, including radial, circumferential and longitudinal peak strain (PS), as well as peak systolic and diastolic strain rates (PSSR and PDSR, respectively), were measured and compared among the groups. Multivariable linear regression analysis was used to examine the factors associated with LV global strains in patients with T2DM.ResultsThe T2DM(AF+) group was the oldest, had the highest LV end‑systolic volume index, lowest LV ejection fraction and estimated glomerular filtration rate compared to the control and T2DM(AF−) groups, and presented a shorter diabetes duration and lower HbA1c than the T2DM(AF−) group. LV PS-radial, PS-longitudinal and PDSR-radial declined successively from controls through the T2DM(AF−) group to the T2DM(AF+) group (all p < 0.001). Compared to the control group, LV PS-circumferential, PSSR-radial and PDSR-circumferential were decreased in the T2DM(AF+) group (all p < 0.001) but preserved in the T2DM(AF−) group. Among all clinical indices, AF was independently associated with worsening LV PS-longitudinal (β = 2.218, p < 0.001), PS-circumferential (β = 3.948, p < 0.001), PS-radial (β = − 8.40, p < 0.001), PSSR-radial and -circumferential (β = − 0.345 and 0.101, p = 0.002 and 0.014, respectively), PDSR-radial and -circumferential (β = 0.359 and − 0.14, p = 0.022 and 0.003, respectively).ConclusionsIn patients with T2DM, the presence of paroxysmal AF further exacerbates LV function and deformation. Proactive prevention, regular detection and early intervention of AF could potentially benefit T2DM patients.

Abstract TP178: Impact of Fetal PCA on Ipsilateral Carotid Artery Stiffness: Results From Northern Manhattan Stroke Study (NOMAS)

Introduction: The wall stress is the major contributor of arterial stiffness, which is well-known risk factor for cardiovascular diseases. The interindividual variability of the Circle of Willis affects blood flow redistribution intracranially. The fetal posterior cerebral artery (fPCA) is associated with larger carotid arteries due to increased brain territory supplied by the anterior circulation. Thus, an fPCA increases blood flow in the ipsilateral carotid artery and could plausibly increase ipsilateral carotid artery stiffness. Methods: We included participants from the multi-ethnic community-based Northern Manhattan Stroke Study (NOMAS) cohort with available time-of-flight MRA. High-resolution B-mode ultrasound of the right common carotid artery (CCA) evaluated markers of arterial stiffness, including diastolic diameter (DD), strain (systolic diameter - DD/DD), cIMT (carotid intima-media thickness), and stiffness (systolic blood pressure - diastolic blood pressure/strain). We used multivariable regression analyses to calculate odds ratios and beta values, examining the association of fPCA and markers of stiffness. Results: Among 1,210 NOMAS (mean age 70 ± 9 years, 61% women, 66% Hispanic) participants with available MRA, 151 (12.5%) participants had a right fPCA, and 129 (10.7%) had a left fPCA. In models adjusted for demographics, vascular risk factors, and height, right fPCA was associated with a higher ipsilateral CCA diastolic diameter (B = 0.31, p=0.001) and strain (B=0.04, p=0.02). Notably, no similar association was found between the left fPCA and contralateral carotid measures (Table 1). Conclusion: A fetal PCA associated with ipsilateral markers of cervical carotid stiffness. This research provides valuable insight into the changes in demands resulting from the variability of the circle of Willis and the extracranial correspondence of such demand.

Evaluating left atrial strain and left ventricular diastolic strain rate as markers for diastolic dysfunction in patients with mitral annular calcification

BackgroundMitral annular calcification (MAC) poses many challenges to the evaluation of diastolic function using standard echocardiography. Left atrial (LA) strain and left ventricular early diastolic strain rate (DSr) measured by speckle-tracking echocardiography (STE) are emerging techniques in the noninvasive evaluation of diastolic function. We aim to evaluate the utility of LA strain and early DSr in predicting elevated left ventricular filling pressures (LVFP) in patients with MAC and compare their effectiveness to ratio of mitral inflow velocity in early and late diastole (E/A).MethodsWe included adult patients with MAC who presented between January 1 and December 31, 2014 and received a transthoracic echocardiogram (TTE) and cardiac catheterization with measurement of LVFP within a 24-h period. We used Spearman’s rank correlation coefficient to assess associations of LA reservoir strain and average early DSr with LVFP. Receiver operating characteristic (ROC) curves were computed to assess the effectiveness of LA strain and DSr in discriminating elevated LVFP as a dichotomized variable and to compare their effectiveness with E/A ratio categorized according to grade of diastolic dysfunction.ResultsFifty-five patients were included. LA reservoir strain demonstrated poor correlation with LVFP (Spearman’s rho = 0.03, p = 0.81) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.54, 95% CI 0.38–0.69). Categorical E/A ratio alone also demonstrated poor discriminatory ability (AUC = 0.53, 95% CI 0.39–0.67), and addition of LA reservoir strain did not significantly improve effectiveness (AUC = 0.58, 95% CI 0.42–0.74, p = 0.56). Average early DSr also demonstrated poor correlation with LVFP (Spearman’s rho = −0.19, p = 0.16) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.59, 95% CI 0.44–0.75). Addition of average early DSr to categorical E/A ratio failed to improve effectiveness (AUC = 0.62, 95% CI 0.46–0.77 vs. AUC = 0.54, 95% CI 0.39–0.69, p = 0.38).ConclusionsIn our sample, LA reservoir strain and DSr do not accurately predict diastolic filling pressure. Further research is required before LA strain and early DSr can be routinely used in clinical practice to assess filling pressure in patients with MAC.

Role of the microtubule network in the passive anisotropic viscoelasticity of right ventricle with pulmonary hypertension progression

Cardiomyocytes are viscoelastic and contribute significantly to right ventricle (RV) mechanics. Microtubule, a cytoskeletal protein, has been shown to regulate cardiomyocyte viscoelasticity. Additionally, hypertrophied cardiomyocytes from failing myocardium have increased microtubules and cell stiffness. How the microtubules contribute to the tissue-level viscoelastic behavior in RV failure remains unknown. Our aim was to investigate the role of the microtubules in the passive anisotropic viscoelasticity of the RV free wall (RVFW) during pulmonary hypertension (PH) progression. Equibiaxial stress relaxation tests were conducted in the RVFW from healthy and PH rats under early (6%) and end (15%) diastolic strains, and at sub- (1Hz) and physiological (5Hz) stretch-rates. The RVFW viscoelasticity was also measured before and after the depolymerization of microtubules at 5Hz. In intact tissues, PH increased RV viscosity and elasticity at both stretch rates and strain levels, and the increase was stronger in the circumferential than longitudinal direction. At 6% of strain, the removal of microtubules reduced elasticity, viscosity, and the ratio of viscosity to elasticity in both directions and for both healthy and diseased RVs. However, at 15% of strain, the effect of microtubules was different between groups – both viscosity and elasticity were reduced in healthy RVs, but in the diseased RVs only the circumferential viscosity and the ratio of viscosity to elasticity were reduced. These data suggest that, at a large strain with collagen recruitment, microtubules play more significant roles in healthy RV tissue elasticity and diseased RV tissue viscosity. Our findings suggest cardiomyocyte cytoskeletons are critical to RV passive viscoelasticity under pressure overload. Statement of SignificanceThis study investigated the impact of microtubules on the passive anisotropic viscoelasticity of the right ventricular (RV) free wall at healthy and pressure-overloaded states. We originally found that the microtubules contribute significantly to healthy and diseased RV viscoelasticity in both (longitudinal and circumferential) directions at early diastolic strains. At end diastolic strains (with the engagement of collagen fibers), microtubules contribute more to the tissue elasticity of healthy RVs and tissue viscosity of diseased RVs. Our findings reveal the critical role of microtubules in the anisotropic viscoelasticity of the RV tissue, and the altered contribution from healthy to diseased state suggests that therapies targeting microtubules may have potentials for RV failure patients.

Association of Thyroid Dysfunction in Individuals ≥ 65 Years of Age With Subclinical Cardiac Abnormalities.

The relationship between thyroid dysfunction and measures of myocardial disease in older individuals remains to be defined. To evaluate the impact of thyroid dysfunction on structure and function of the left heart chambers and blood markers of cardiac disease. Cross-sectional analysis of the Cardiovascular Health Study, a community-based cohort of older individuals recruited from 4 urban areas in the United States. Of 3163 participants studied, 2477 were euthyroid, 465 had subclinical hypothyroidism (SCH), 47 overt hypothyroidism (OH), 45 endogenous (endo) subclinical hyperthyroidism (endo-SCT), and 129 had exogenous (exo) SCT due to thyroid hormone supplementation. Participants underwent clinical evaluation, blood sampling and biomarker measurement, 2-dimensional and speckle tracking echocardiography for assessment of left heart myocardial deformation, circulating biomarkers of diastolic overload (NT-proBNP), fibrosis (sST2, gal-3), and cardiomyocyte injury (hs-cTnT). SCH was associated with higher NT-proBNP (beta = 0.17, P = .004), whereas OH was associated with higher hs-cTnT (beta = 0.29, P = .005). There were also suggestive associations of SCH with higher sST2, as well as endo-SCT with higher gal-3 and lower (worse) left atrial reservoir strain. Left ventricular longitudinal strain and end diastolic strain rate did not differ significantly from euthyroid participants in SCH, OH, or exo-SCT. In this free-living elderly cohort, subclinical and overt hypothyroidism were associated with abnormalities of blood biomarkers consistent with diastolic overload and myocardial necrosis respectively, whereas subclinical hyperthyroidism tended to be associated with myocardial fibrosis and decreased left atrial strain. Our findings could represent stage B heart failure and illuminate distinct aspects of the pathobiology of heart disease related to thyroid gland dysfunction with potential clinical implications.

Evaluation of left ventricular stiffness with echocardiography.

Half of patients with heart failure are presented with preserved ejection fraction (HFpEF). The pathophysiology of these patients is complex, but increased left ventricular (LV) stiffness has been proven to play a key role. However, the application of this parameter is limited due to the requirement for invasive catheterization for its measurement. With advances in ultrasound technology, significant progress has been made in the noninvasive assessment of LV chamber or myocardial stiffness using echocardiography. Therefore, this review aims to summarize the pathophysiological mechanisms, correlations with invasive LV stiffness constants, applications in different populations, as well as the limitations of echocardiography-derived indices for the assessment of both LV chamber and myocardial stiffness. Indices of LV chamber stiffness, such as the ratio of E/e' divided by left ventricular end-diastolic volume (E/e'/LVEDV), the ratio of E/SRe (early diastolic strain rates)/LVEDV, and diastolic pressure-volume quotient (DPVQ), are derived from the relationship between echocardiographic parameters of LV filling pressure (LVFP) and LV size. However, these methods are surrogate and lumped measurements, relying on E/e' or E/SRe for evaluating LVFP. The limitations of E/e' or E/SRe in the assessment of LVFP may contribute to the moderate correlation between E/e'/LVEDV or E/SRe/LVEDV and LV stiffness constants. Even the most validated measurement (DPVQ) is considered unreliable in individual patients. In comparison to E/e'/LVEDV and E/SRe/LVEDV, indices like time-velocity integral (TVI) measurements of pulmonary venous and transmitral flows may demonstrate better performance in assessing LV chamber stiffness, as evidenced by their higher correlation with LV stiffness constants. However, only one study has been conducted on the exploration and application of TVI in the literature, and the accuracy of assessing LV chamber stiffness remains to be confirmed. Regarding echocardiographic indices for LV myocardial stiffness evaluation, parameters such as epicardial movement index (EMI)/ diastolic wall strain (DWS), intrinsic velocity propagation of myocardial stretch (iVP), and shear wave imaging (SWI) have been proposed. While the alteration of DWS and its predictive value for adverse outcomes in various populations have been widely validated, it has been found that DWS may be better considered as an overall marker of cardiac function performance rather than pure myocardial stiffness. Although the effectiveness of iVP and SWI in assessing left ventricular myocardial stiffness has been demonstrated in animal models and clinical studies, both indices have their limitations. Overall, it seems that currently no echocardiography-derived indices can reliably and accurately assess LV stiffness, despite the development of several parameters. Therefore, a comprehensive evaluation of LV stiffness using all available parameters may be more accurate and enable earlier detection of alterations in LV stiffness.

Ethnic differences in cardiac structure and function assessed by MRI in healthy South Asian and White European people: A UK Biobank Study

BackgroundEchocardiographic studies indicate South Asian people have smaller ventricular volumes, lower mass and more concentric remodelling than White European people, but there are no data using cardiac MRI (CMR). We aimed to compare CMR quantified cardiac structure and function in White European and South Asian people. MethodsHealthy White European and South Asian participants in the UK Biobank Imaging CMR sub-study were identified by excluding those with a history of cardiovascular disease, hypertension, obesity or diabetes. Ethnic groups were matched by age and sex. Cardiac volumes, mass and feature tracking strain were compared. Results121 matched pairs (77 male/44 female, mean age 58 ± 8 years) of South Asian and White European participants were included. South Asian males and females had smaller absolute but not indexed left ventricular (LV) volumes, and smaller absolute and indexed right ventricular volumes, with lower absolute and indexed LV mass and lower LV mass:volume than White European participants. Although there were no differences in ventricular or atrial ejection fractions, LV global longitudinal strain was higher in South Asian females than White European females but not males, and global circumferential strain was higher in both male and South Asian females than White European females. Peak early diastolic strain rates were higher in South Asian versus White European males, but not different between South Asian and White European females. ConclusionsContrary to echocardiographic studies, South Asian participants in the UK Biobank study had less concentric remodelling and higher global circumferential strain than White European subjects. These findings emphasise the importance of sex- and ethnic- specific normal ranges for cardiac volumes and function.

Ratio of transmitral early filling velocity to diastolic strain rate and prognosis in type-1 diabetes

BackgroundImpaired diastolic function is a hallmark of diabetic cardiomyopathy and a common feature in type 1 diabetes mellitus (T1DM). The ratio of transmitral early filling velocity to early diastolic strain rate (E/e'sr) has in recent studies proved to have strong prognostic value. This study aimed to investigate the prognostic value of E/e'sr compared to E/e’ in T1DM without known heart disease. MethodsIn this prospective cohort of T1DM patients, echocardiography was performed including two-dimensional speckle tracking. Follow-up was performed using nationwide registries. Outcomes were all-cause mortality and major cardiovascular events (MACE). ResultsIn total 1079 patients (age: 49.6 ± 14.5 years, 52.5% male, duration of diabetes 25.8 ± 14.6 years) were included in the study. During follow-up (median 6.3 years, IQR:5.7–6.9) 13.2% experienced MACE and 5.8% died. Following multivariable adjustment, both E/e'sr and E/e’ was significantly associated with both MACE (E/e'sr: HR 1.16 CI95%:[1.05–1.29], p = 0.005, per 10 cm increase) vs. (E/e’: HR 1.09 CI95%:[1.03–1.15], p = 0.001, per 1 unit increase) and all-cause mortality (E/e'sr: HR 1.20 [1.03–1.40], p = 0.016) vs. (E/e’: HR: 1.11 [1.02–1.20], p = 0.016). Sex modified the association between E/e'sr and MACE (p for interaction = 0.008) such that E/e'sr after multivariable adjustment only remained significantly associated with MACE in females (HR: 1.41 [1.19–1.67], p < 0.001) but not in males (HR: 1.06 [0.93–1.20], p = 0.42). In females, E/e'sr provided incremental information beyond the Steno T1 Risk Engine (Harrell's C-statistic: 0.78 (0.72–0.83) vs. 0.81 (0.75–0.86), p = 0.007). ConclusionIn patients with T1DM, both E/e'sr and E/e’ provides independent prognostic information regarding prognosis. E/e'sr seems to have stronger prognostic value in females with T1DM.

Evaluation of Intraoperative Left-Ventricular Diastolic Function by Myocardial Strain in On-Pump Coronary Artery Bypass Surgery

Left ventricular (LV) diastolic function strongly predicts outcomes after cardiac surgery, but there is no consensus about appropriate intraoperative assessment. Recently, intraoperative diastolic strain-based measurements assessed by transesophageal echocardiography (TEE) have shown a strong correlation with LV relaxation, compliance, and filling, but there are no reports about evaluation through the entire perioperative period. Therefore, the authors describe the intraoperative course of this novel assessment technique in patients who underwent coronary artery bypass grafting, and compare it with conventional echocardiographic measures and common grading algorithms of LV diastolic dysfunction (LVDD). Prospectively obtained data. A single university hospital. Thirty adult patients scheduled for isolated on-pump coronary artery bypass grafting surgery with preoperative preserved left and right ventricular systolic function, without significant heart valve disease and pulmonary hypertension, and an uneventful intraoperative course were included. Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed in stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min. Strain-based measurements of peak longitudinal strain rate during isovolumetric relaxation (SR-IVR) and during early (SR-E) and late (SR-A) LV filling were assessed using EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway). Evaluation of conventional echocardiographic parameters included transmitral Doppler measures of early (E) and late (A) LV filling, as well as lateral-tissue Doppler velocity assessed during early (e´) and late (a´) LV filling, tricuspid regurgitation, and left atrial dilatation. Evaluation and grading of LV diastolic function by myocardial strain was feasible in all included patients at all time points of assessment. Using conventional grading algorithms, however, a substantial number of patients could not be sufficiently graded, falling into an indeterminate zone and not reliably estimating LVDD (T1, 40%; T2, 33%; T3, 36%). There was significant impairment of LV diastolic function after bypass, as measured by SR-IVR (T1 v T2, 0.28 s-1 [IQR 0.23; 0.31) v 0.18 s-1 [IQR 0.14; 0.22]; p < 0.001), SR-E (T1 v T2, 0.95 ± 0.34 s-1v 1.28 ± 0.36 s-1; p < 0.001), and E/SR-IVR (T1 v T2, 2.3 ± 1.0 m v 4.5 ± 2.1 m; p < 0.001]. Conventional echocardiographic measures remained unchanged during the same period (E/A T1 v T2, 1.27 [IQR 0.94; 1.59] v 1.21 [IQR 1.03; 1.47] [p = 1] and E/e´ T1 v T2, 7.0 [IQR 5.3; 9.6] v 6.35 [IQR 5.7; 9.9] [p = 0.9]). There were no significant changes in the values of SR-IVR, SR-E, SR-A, E/SR-IVR, E/A, and E/e´ before and after sternal closure (T2 v T3). Intraoperative assessment of strain-based measurements of LV diastolic function and strain-based LVDD grading was feasible in this group of selected patients, whereas conventional parameters failed to describe LVDD sufficiently in a substantial number of patients. Diastolic strain-based measurements showed impairment of LV relaxation and compliance after bypass, which was not detected by conventional echocardiographic parameters. Therefore, diastolic myocardial strain analysis might be more sensitive in detecting myocardial diastolic dysfunction by TEE in the perioperative setting, with its dynamic changes of loading conditions, and might provide valuable and additional information on the perioperative changes of LV diastolic function.

Echocardiographic Parameters Associated With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors.

Children's exposure to chemotherapeutic agents causes several long-term adverse effects but physical activity has been evidenced to be an effective strategy to improve cardiac function. This cross-sectional study aimed to explore the association between physical activity levels, cardiorespiratory fitness, and cardiac parameters measured by echocardiography. Participants were 216n childhood acute lymphoblastic leukemia survivors who underwent a maximal cardiopulmonary exercise test and self-reported their daily minutes of moderate to vigorous physical activity. They underwent a complete transthoracic echocardiographic assessment. Systolic and diastolic function analysis and strain images analysis were performed. The associations were studied through the preventive fraction (examined with univariate crude and adjusted logistic regression models) of regular physical activity (≥150min·wk-1) and adequate cardiorespiratory fitness levels (above the median ≥ 32.0mL·kg-1·min-1) on cardiac parameters. Crude analysis shows that regular physical activity was associated with a significant preventive fraction in mitral E/A ratio (56%; P = .013), while adjusted analyses highlighted a nonsignificant reduction of 74% to 37% in the prevalence of cardiac parameters associated with physical activity. Similar associations of adequate cardiorespiratory fitness on cardiac parameters were observed. Adjusted analyses revealed a nonsignificant reduction of 7% to 86% in the prevalence of cardiac parameters associated with cardiorespiratory fitness. This study reports that regular physical activity and adequate cardiorespiratory fitness were associated with a higher preventive fraction. Thus, engaging in physical activity prevents childhood acute lymphoblastic leukemia survivors' cardiac dysfunctions. These findings are novel and clinically relevant in pediatric cardiooncology and provide additional evidence to strengthen the benefits of exercise as long-term care in childhood cancer survivors.

Lifetime evaluation of left ventricular structure and function in male ApoE null mice after gamma and space-type radiation exposure.

The space radiation (IR) environment contains high charge and energy (HZE) nuclei emitted from galactic cosmic rays with the ability to overcome current shielding strategies, posing increased IR-induced cardiovascular disease risks for astronauts on prolonged space missions. Little is known about the effect of 5-ion simplified galactic cosmic ray simulation (simGCRsim) exposure on left ventricular (LV) function. Three-month-old, age-matched male Apolipoprotein E (ApoE) null mice were irradiated with 137Cs gamma (γ; 100, 200, and 400cGy) and simGCRsim (50, 100, 150cGy all at 500 MeV/nucleon (n)). LV function was assessed using transthoracic echocardiography at early/acute (14 and 28days) and late/degenerative (365, 440, and 660days) times post-irradiation. As early as 14 and 28-days post IR, LV systolic function was reduced in both IR groups across all doses. At 14days post-IR, 150cGy simGCRsim-IR mice had decreased diastolic wall strain (DWS), suggesting increased myocardial stiffness. This was also observed later in 100cGy γ-IR mice at 28days. At later stages, a significant decrease in LV systolic function was observed in the 400cGy γ-IR mice. Otherwise, there was no difference in the LV systolic function or structure at the remaining time points across the IR groups. We evaluated the expression of genes involved in hemodynamic stress, cardiac remodeling, inflammation, and calcium handling in LVs harvested 28days post-IR. At 28days post-IR, there is increased expression of Bnp and Ncx in both IR groups at the lowest doses, suggesting impaired function contributes to hemodynamic stress and altered calcium handling. The expression of Gals3 and β-Mhc were increased in simGCRsim and γ-IR mice respectively, suggesting there may be IR-specific cardiac remodeling. IR groups were modeled to calculate the Relative Biological Effectiveness (RBE) and Radiation Effects Ratio (RER). No lower threshold was determined using the observed dose-response curves. These findings do not exclude the possibility of the existence of a lower IR threshold or the presence of IR-induced cardiovascular disease (CVD) when combined with additional space travel stressors, e.g., microgravity.

Cardiac and Metabolic Effects of Bariatric Surgery Among Obese Patients in a Malaysian Tertiary Hospital: A 6-month Prospective Cohort Study.

Obesity is known to be associated with left ventricular diastolic dysfunction due to its effect on blood pressure and glucose tolerance. We aimed to investigate whether weight loss after bariatric surgery might improve diastolic dysfunction through in-depth echocardiographic examination. We recruited twenty-eight patients who were about to undergo bariatric surgery by purposive sampling. They underwent echocardiography at baseline and 6 months after surgery with a focus on diastolic function measurements and global longitudinal strain (GLS). They also had fasting serum lipid and glucose measurements pre- and post-surgery. The mean weight loss after surgery was 24.1 kg. Out of the 28 subjects, fifteen (54%) initially had diastolic dysfunction before surgery. Only two had persistent diastolic dysfunction 6 months after surgery. The mean indexed left atrial volume 6 months post-surgery was 27.1 from 32 ml/m2 prior to surgery. The average E/e' is 11.78 post-surgery from 13.43 pre-surgery. The left ventricular GLS became (-)25.7% after surgery from (-)21.2% prior to surgery. Their post-surgery fasting serum lipid and glucose levels also showed significant improvement. Our study reinforced the existing evidence that bariatric surgery significantly improved echocardiographic parameters of diastolic function and left ventricular global longitudinal strain, along with various metabolic profiles.

Ratio of early transmitral inflow velocity to early diastolic strain rate predicts atrial fibrillation following acute myocardial infarction.

The ratio of early transmitral filling velocity to early diastolic strain rate (E/SRe) has been proposed as a new non-invasive measurement of left ventricular filling pressure. We aimed to investigate the ability of E/SRe to predict atrial fibrillation (AF) after ST-elevation myocardial infarction (STEMI). This was a prospective cohort study of patients (n = 369) with STEMI. Patients underwent an echocardiographic examination a median of two days after pPCI. By echocardiography, transmitral early filling velocity (E) was measured by pulsed-wave Doppler, and early diastolic strain rate (SRe) was measured by speckle tracking of the left ventricle. E was indexed to SRe and the early myocardial relaxation velocity (e') to obtain the E/SRe and E/e', respectively. The endpoint was new-onset AF. During follow-up (median 5.6years, IQR: 5.0-6.1years), 23 (6%) of the 369 patients developed AF. In unadjusted analyses, both E/SRe and E/e' were significantly associated with AF [E/SRe: HR = 1.06; (1.03-1.10); p < 0.001, per 10 increase] and [E/e': HR = 1.11 (1.05-1.17); p < 0.001, per 1 increase] and had equal Harrell's C-statistic of 0.71. However, only E/SRe remained an independent predictor after multivariable adjustments for clinical and echocardiographic parameters [E/SRe: HR = 1.06 (1.00-1.11); p = 0.044, per 10 increase]. E/SRe was further significantly associated with AF in patients with E/e' < 14 HR = 1.09 (1.01-1.17); p = 0.030, per 10 increase), also after multivariable adjustments. E/SRe is an independent predictor of AF in STEMI patients, even in subjects with seemingly normal filling pressure.

Prognostic implications of right ventricular systolic and diastolic strain in heart failure

Abstract Background 2D- speckle-tracking echocardiography (2D-STE) has recently be used to assess subclinical myocardial dysfunction, however its utility in heart failure with reduced ejection fraction (HFrEF) has been specifically focusing on the longitudinal systolic function of the left ventricle (LV). Aim To assess the prognostic relation between right ventricular (RV) systolic and diastolic strain parameters with clinical outcome in patients with advanced heart failure (HFrEF). Methods and results Of the initial 2217 HFrEF patients screened for this study only 562 consecutive patients with HFrEF were eligible and retrospectively enrolled, and 2D-STE strain parameters assessed on the 2D-TTE images. All patients were prospectively followed for development of new outcome/cardiac events which included hospitalization for acute HF, CVS-related death, heart transplantation, or need for ventricular assist device implantation. Conventional TTE was performed in all subjects and reviewed. RV longitudinal strain parameters (RVLS, RVLD) by 2D-STE were assessed and averaged in all segments (apical 4CV, global RVLS and RVLD) and also averaged free-wall. Of the 562 patients at baseline, 263 had 117 new events during a mean follow-up of 1.4 ± 0.7 years. RV free wall and global RV systolic and diastolic strain parameters, elevated NT Pro-BNP, RV fractional area change, low TAPSE, LV end-diastolic volume and the presence of at least moderate TR, and PASP &amp;gt; 40mmHg were independently predictive of combined outcomes ( p &amp;lt;.001). Overall, the best performance parameters predictive of cardiovascular events were for RV Free Wall systolic and diastolic strain (AUC: 0.84 and 74), global RV systolic and diastolic strain (AUC: 0.77 and 70) and RV fractional area change (AUC: 0.67). The strongest association between the degree of RV dysfunction and the risk of cardiovascular events was only evident for RV strain (free wall &amp;gt; global strain). Conclusion Patients with HFrEF, RV strain parameters are stronger predictors of outcome than other conventional parameters and should be included for regular clinical screening as these parameters provide a stronger prognostic stratification.

Standardized longitudinal strain curves stratified by age and sex in healthy individuals: The Copenhagen City Heart Study

Abstract Introduction Speckle-tracking echocardiography has gained widespread use, and strain parameters such as global longitudinal strain (GLS) and strain rates are strongly associated with risk of heart failure and cardiovascular death. Such strain measures, however, only represent limited features of the complete longitudinal strain (LS) curve. Thus, interpretation of entire curves might provide additional insight. Purpose To establish normal standardized LS curves over an entire heart cycle for healthy subjects stratified by age and sex. Furthermore, to assess how these curves vary with age and to compare this with conventional strain measures. Methods The study population consisted of 1790 healthy subjects free of cardiovascular disease and risk factors including diabetes mellitus and hypertension at baseline. Subjects were stratified by sex and further by age in groups as defined in the SCORE risk chart. Subjects underwent echocardiography, and LS curves from the apical four-chamber view were derived and standardized in length using linear interpolation. Terms to describe qualitative findings in the standardized strain curves were established (Figure 1). Early diastolic strain (EDS) was defined as the difference in strain from peak LS to maximal curvature after early diastolic filling, while late diastolic strain (LDS) was defined as the difference in strain from the plateau phase in late passive diastole to maximal curvature in active diastole. Conventional strain measures included GLS, systolic strain rate (SRS), early diastolic strain rate (SRE), and late diastolic strain rates (SRA). The association between these and age group were investigated using univariable linear regression for each sex. Results In the study population, 1101 (61.5%) subjects were female. The standardized strain curves (Figure 2) showed that aging primarily manifested in the diastolic part of the strain curve. Decreasing EDS was associated with increasing age group, while the opposite was true for LDS. In linear regression, both SRE (female: beta=-0.13; p&amp;lt;0.001, male: beta=-0.1; p&amp;lt;0.001) and SRA (female: beta=0.09; p&amp;lt;0.001, male: beta=0.09; p&amp;lt;0.001) were associated with age group for both sexes. Peak LS did not change notably with age, and in linear regression, GLS and SRS were only significantly associated with age for women (GLS: beta=0.12; p&amp;lt;0.001, SRS: beta=0.01; p&amp;lt;0.001). Conclusion We derived normal standardized LS curves for healthy individuals stratified by age and sex, which can serve as normal values in future studies. In addition, these showed that age was primarily associated with changes in the diastolic part of the strain curve in both sexes, which was consistent with conventional strain measures.Figure 1:Overview of termsFigure 2Standardized longitudinal strai

Diastolic function assessment with left atrial strain in long-term survivors of childhood acute lymphoblastic leukemia

Abstract Background Survivors of childhood cancer might be at increased risk of diastolic dysfunction at follow-up due to cardiotoxic treatment exposure. Although diastolic function assessment is challenging in this relatively young population, left atrial strain might provide a novel insight into this evaluation. Purpose To examine diastolic function in a cohort of long-term survivors of childhood acute lymphoblastic leukemia survivors using left atrial strain and conventional echocardiographic parameters. Methods Long-term survivors who were diagnosed at a single center between 1985-2015 and a control group of healthy siblings were recruited. Conventional diastolic function parameters and strain were compared, the latter measured during the three atrial phases: reservoir (PALS), conduit (LACS) and contraction (PACS). Inverse probability of treatment weighting was used to account for differences between the groups. Results 90 survivors (24.6±9.7 years, time since diagnosis 18 [11-26] years) and 58 controls were analyzed. PALS and LACS were significantly reduced compared to the control group: 46.4±11.2 vs 52.1±11.7 (p=0.003) and 32.5±8.8 vs 38.2±9.3 (p=0.003), respectively (figure 1B). Conventional diastolic parameters and PACS were similar between the groups (figure 1A). The reductions in PALS and LACS were associated to cardiotoxic treatment exposure in age and sex adjusted analysis (≥ moderate risk, low risk, controls): 45.4±10.5, 49.5±12.9, 52.1±11.7 (padj=0.003) and 31.7±9.0, 35.2±7.5, 38.2±9.3 (padj=0.001), respectively (figure 2). Conclusions Long-term childhood leukemia survivors showed a subtle impairment in diastolic function that was detected using atrial strain but not with conventional measurements. This impairment was more pronounced in those with higher cardiotoxic treatment exposure.Figure 1Figure 2

Predicting incident atrial fibrillation in patients with embolic stroke of undetermined source

Abstract Introduction Atrial fibrillation (AF) is an important potential embolic source in patients who have suffered an embolic stroke of undetermined source (ESUS). AF has been detected in over 40% of patients when monitored with an implantable loop recorder (ILR). Recent clinical trials, however, have suggested that empirical anticoagulation of all patients with an ESUS is not an effective approach to reduce stroke risk. Thus predicting which patients are most likely to develop AF is of increased importance. Risk models for predicting incident AF exist but they do not incorporate modern techniques such as advanced echocardiographic parameters to create a comprehensive risk model. Purpose We sought to create a multi-parametric risk score for the prediction of incident AF in patients with ESUS. Methods This was a single-centre retrospective study. Consecutive adult patients referred for ILR implantation following ESUS, between March 2009 and November 2019, without prevalent AF or atrial flutter, were included. Patients’ notes were reviewed for clinical and anthropometric data. Each patients’ echo was re-reviewed both for conventional measures, and advanced parameters including left atrial strain using speckle-tracking (figure 1) and atrial electromechanical delay utilising the time from onset of the electrocardiographic P-wave to the lateral tissue Doppler A’ wave- "lateral PA". Univariate and multivariable analyses were performed, and a subsequent Lasso regression analysis used to develop a risk prediction model. Bootstrapping was used to perform internal validation. Results A total of 323 patients with ESUS who underwent a loop recorder implantation were included. Incident AF was detected in 142 patients (47.1%). Increased duration of the time between the electrocardiographic P-wave and the lateral tissue Doppler A’ wave (greater lateral PA), older age, higher diastolic blood pressure, abnormal left atrial reservoir strain were most strongly associated with increased AF risk. These were combined to form the PADS score below. Model discrimination was good, with an area under the curve of 0.72. Conclusion(s) The PADS score is a novel risk score for the prediction of incident AF in patients who have suffered an ESUS, based on the duration of the P-wave to the lateral tissue Doppler A’ wave, Age, Diastolic blood pressure and left atrial strain reservoir . Further work is required to assess whether the PADS score can be used to risk stratify patients into a high risk group which would derive benefit from immediate anticoagulation, an intermediate risk group who require prolonged continuous monitoring and a low risk group who can continue on conventional management for their stroke.PADS formulaLA strain using speckle strain analysis