Circumferential Strain Parameters Research Articles

Sex-based differences in late gadolinium enhancement among patients with acute myocarditis

ObjectiveThe aims of our study were to investigate the sex differences in late gadolinium enhancement (LGE) using cardiovascular magnetic resonance (CMR) in a single-centre cohort of consecutive patients with acute myocarditis (AM). MethodThis retrospective study performed CMR scans in 135 consecutive patients with AM that met the Lake Louise criteria. On CMR, LV ventricular strain functions were performed on conventional cine SSFP sequences. Besides myocardial strain measurements, myocardial scar location, extension, and size were assigned and quantified by LGE imaging. ResultsThere was no difference in age (age 42.51 ± 19.64 years vs 40.92 ± 19.94 years; p = 0.74) and cardiovascular risk profile between women and men. Despite similar comorbidities, women were more like to present with dyspnea (p = 0.001). Women demonstrated higher prevalence of septal LGE (p = 0.004) and increased global circumferential strain parameters (p = 0.008) in comparison with men. In multivariate analysis, female sex remained an independent determinant of septal LGE (β coefficient = −0.520, p = 0.001). ConclusionThis is the first study reporting sex differences in LGE localization in AM. Women have more septal LGE involvement independent of age, cardiovascular risk factors, and CMR parameters. These findings further emphasize the sex-based differences in cardiovascular diseases.

Evaluation of Left Ventricular Systolic Function Using Layer-Specific Strain in Rats Performing Endurance Exercise: A Pilot Study.

The functional characteristics of exercise-induced myocardial hypertrophy were studied in a rat model in conjunction with ultrasound layered strain technique to investigate the hidden changes in the heart brought about by exercise. Forty specific pathogen free (SPF) adult Sprague-Dawley rats were selected and randomly divided into two groups of 20 exercise and 20 control rats. The longitudinal and circumferential strain parameters were measured using the ultrasonic stratified strain technique. The differences between the two groups and the predictive effect of stratified strain parameters on left ventricular systolic function were analyzed. The exercise group had significantly higher global endocardial myocardial longitudinal strain (GLSendo), global mid-myocardial global longitudinal strain (GLSmid) and global endocardial myocardial global longitudinal strain (GCSendo) values than the control group (p < 0.05). Even though global mid-myocardial circumferential strain (GCSmid) and global epicardial myocardial circumferential strain (GCSepi) were higher in the exercise group than in the control group, statistical significance was not reached (p > 0.05). Conventional echocardiography parameters were well correlated with GLSendo, GLSmid, and GCSendo (p < 0.05). GLSendo was the best predictor of left ventricular myocardial contractile performance in athletes determined using the receiver operating characteristic curve, with an area under the curve of 0.97, sensitivity of 95% and specificity of 90%. Rats performing endurance exercise exhibited subclinical changes in the heart after prolonged high-intensity exercise. A stratified strain parameter, GLSendo, played an important role in the evaluation of LV systolic performance in exercising rats.

Evaluation of Left Ventricular Function in Healthy Retrievers Using Standard and 2D Speckle-Tracking Echocardiography.

Simple SummaryStandard echocardiography is an essential diagnostic tool for the assessment of cardiac performance in healthy and diseased animals. Two-dimensional speckle-tracking echocardiography is an advanced echocardiographic technique that is useful for the assessment of myocardial function. Factors such as dog breed, age, and body weight (BW) are known to influence the echocardiographic parameters. This study aimed to evaluate the effect of breed, age, and BW on the echocardiographic parameters in healthy Retrievers, including Flat-coated, Golden, and Labrador Retrievers. The results showed that there were no significant associations between breed and echocardiographic parameters. On the other hand, they revealed that left ventricular dimensions increased with BW. Furthermore, parameters including peak aortic blood flow velocity, trans-mitral rapid ventricular filling flow, the ratio of trans-mitral rapid ventricular filling flow to atrial contraction, and global radial strain were influenced by age.Standard echocardiography is vital for the assessment of cardiac performance in healthy and diseased animals. Similarly, two-dimensional speckle-tracking echocardiography (2D-STE) is an advanced echocardiographic technique that is becoming increasingly important for the assessment of myocardial function. Breeds, age, and body weight (BW) are known to be important factors affecting the echocardiographic parameters; therefore, the aim of this study was to evaluate the effect of breed, age, and BW on the echocardiographic parameters in three breeds of clinically healthy Retrievers. A total of 46 Retrievers, including 16 Flat-coated Retrievers (FR), 16 Golden Retrievers (GR), and 14 Labrador Retrievers (LR) were included in the study. The comparison of the breeds revealed significant differences in the LV wall thickness of FR and GR, although further analysis using MLR showed that the differences were most likely associated with BW, similarly to the other LV dimensions. Functional parameters, including ejection fraction, fractional shortening, and left-atrial-to-aortic ratio, were independent of breed, age, and BW. On the other hand, peak aortic blood flow velocity, trans-mitral rapid ventricular filling flow, and the ratio of trans-mitral rapid ventricular filling flow to atrial contraction were influenced by age. The 2D-STE-derived radial and circumferential strain parameters were independent of breed, age, and BW, except for global strain in the radial direction.

2D speckle-tracking in assessment of myocardial strain in children with hypertrophic cardiomyopathy

Purpose: To assess the myocardial strain in children with hypertrophic cardiomyopathy (HCM).&#x0D; Methods: A total of 61 patients aged between 7 and 17 years with an asymmetric form of HCM underwent an ultrasound examination of the heart using standard techniques. An assessment of the left ventricular systolic function was performed using the two-dimensional (2D) speckle-tracking mode with analysis parameters that included global and segmental longitudinal, circumferential, and radial myocardial strains. Strain data for the subendocardial and subepicardial layers for each segment of the left ventricle, as well as their total values, were determined.&#x0D; Results: Global longitudinal strain and longitudinal strain rate were dec reased due to the impaired contractility of hypertrophied myocardial segments in 100% of cases of non-obstructive and obstructive HCM forms. A decrease in global, radial, and circumferential strain parameters and their rates has been observed in all children with an obstructive form of HCM and 39 (86.6%) patients with non-obstructive form. At the same time, there was a statistically significant difference between strains and strain rates in children with a non-obstructive form of HCM in comparison to those with an obstructive form of the disease.&#x0D; Conclusion: Changes in myocardial strains observed using the 2D speckle-tracking mode in children with HCM indicate early systolic dysfunction of the left ventricle. Longitudinal strain was the most sensitive compared to radial and circumferential types. It was statistically significantly different in children with an obstructive form of HCM compared to those with non-obstructive form of the disease. These results are important for early therapy initiation and, therefore, may improve prognosis in children with HCM.

Efficacy of Novel Noncontrast Cardiac Magnetic Resonance Methods in Indicating Fibrosis in Hypertrophic Cardiomyopathy.

Objective In hypertrophic cardiomyopathy (HCM), myocardial fibrosis is routinely shown by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) imaging. We evaluated the efficacy of 2 novel contrast-free CMR methods, namely, diffusion-weighted imaging (DWI) and feature-tracking (FT) method, in detecting myocardial fibrosis. Methods This cross-sectional study was conducted on 26 patients with HCM. Visual and quantitative comparisons were made between DWI and LGE images. Regional longitudinal, circumferential, and radial strains were compared between LGE-positive and LGE-negative segments. Moreover, global strains were compared between LGE-positive and LGE-negative patients as well as between patients with mild and marked LGE. Results All 3 strains showed significant differences between LGE-positive and LGE-negative segments (P < 0.001). The regional longitudinal and circumferential strain parameters showed significant associations with LGE (P < 0.001), while regional circumferential strain was the only independent predictor of LGE in logistic regression models (OR: 1.140, 95% CI: 1.073 to 1.207, P < 0.001). A comparison of global strains between patients with LGE percentages of below 15% and above 15% demonstrated that global circumferential strain was the only parameter to show impairment in the group with marked myocardial fibrosis, with borderline significance (P=0.09). A review of 212 segments demonstrated a qualitative visual agreement between DWI and LGE in 193 segments (91%). The mean apparent diffusion coefficient was comparable between LGE-positive and LGE-negative segments (P=0.51). Conclusions FT-CMR, especially regional circumferential strain, can reliably show fibrosis-containing segments in HCM. Further, DWI can function as an efficient qualitative method for the estimation of the fibrosis extent in HCM.

SAT-620 Left Ventricular Myocardial Deformation in T2DM Is Associated with Chronic Hyperglycemia but Not Myocardial Perfusion: A Study Based on Magnetic Resonance Imaging

Background: Diabetic cardiomyopathy is accompanied by left ventricular diastolic dysfunction. Abnormal glucose metabolism plays an important role in the pathogenesis of diabetic cardiomyopathy. However, it’s still not clear whether the influence of hyperglycemia on LV dysfunction is directly affects cardiomyocytes or is related to impaired myocardial perfusion. In this work, we focus on investigating the association between HbA1c and myocardial dysfunction, and if it is independent of myocardial perfusion reserve. Materials and Methods: 64 type 2 diabetic patients were recruited at the endocrine clinic. They are divided into two group, well blood glucose-controlled group (HbA1c<7) and poor glucose-controlled group (HbA1c≥7) T2DM group, according to their HbA1c level. All of the T2DM patients and age-matched healthy volunteers (normal glucose metabolism group, NGM group) underwent CMR to acquire normal values for myocardial strain and perfusion reserve. Results: Well blood glucose-controlled group owned lower global circumferential PSSR than NGM group (p=0.037). Global circumferential PS (p=0.011), global longitudinal PS (p=0.004), global radial PDSR (p=0.005), circumferential PDSR (p=0.001), longitudinal PDSR (p=0.001), global circumferential PSSR (p=0.049), longitudinal PSSR (p=0.041) were significantly lower in the poor glucose-controlled group compared to the NGM group. In the multivariable linear regression analysis, HbA1c existed in all equations except the global circumferential PSSR equation and p<0.05, and Slope, Max SI and Tpeak did not show dependent association with longitudinal and circumferential strain parameters. Conclusion: In subclinical cardiac dysfunction T2DM patients, diastolic dysfunction is more common, but systolic dysfunction is still exist. Poor blood glucose control which is defined as HbA1c ≥ 7% is an independent risk factor for LV deformation for T2DM patients. Subclinical myocardial dysfunction is not triggered by myocardial perfusion reserve.

Association of cardiovascular magnetic resonance-derived circumferential strain parameters with the risk of ventricular arrhythmia and all-cause mortality in patients with prior myocardial infarction and primary prevention implantable cardioverter defibrillator

BackgroundImpaired 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).MethodsPatients 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.ResultsA 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).ConclusionsIn 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.

Speckle-Tracking Echocardiography for Monitoring Acute Rejection in Transplanted Heart

BackgroundThe diagnosis of acute cellular rejection (ACR) is a major objective in the management of heart transplant recipients. The aim of this study was to assess the utility of speckle-tracking derived parameters in identifying patients at risk of graft rejection. MethodsA prospective, single-center study was carried out involving 45 consecutive heart transplant patients who underwent a total of 220 routine endomyocardial biopsies (EMBs) with correlative echocardiographic examination. ResultsNo significant ACR (grade 0-1R) was seen in 190 biopsies (81.2% of the ACR-free group), and moderate ACR requiring specific treatment (grade 2R) was detected in 30 biopsies (13.6% of the ACR group). Grade 3R was not observed. All longitudinal left ventricular (LV) and right ventricular (RV) strain parameters were greater in the ACR-free group than in patients with ACR, while no differences were observed between radial and circumferential strain parameters. In our analysis, we selected RV free wall longitudinal strain (RV FW) ≤ 16.8% and 4-chamber longitudinal strain (4CH LS) ≤ 13.8%, which related to the presence of ACR requiring treatment. We assigned 1 point for each parameter (minimum 0, maximum 2 points) and derived a new echocardiographic index, the Strain Rejection Score (SRS). Our proposed approach—a combination of the 2 abovementioned indices—for screening patients at risk of ACR ≥ 2R, when expressed by a score 2 points, showed good specificity, strong negative predictive value, and the highest area under the curve. ConclusionsOur study demonstrated that combination of 4CH LS and RV FW as a new echocardiographic index, the Strain Rejection Score, can be useful as a noninvasive assessment of ACR during the first year of follow-up after heart transplant.

Normal range of myocardial layer-specific strain using two-dimensional speckle tracking echocardiography.

BackgroundNewer 2D strain software has a potential to assess layer-specific strain. However, normal reference values for layer-specific strain have not been established. We aimed to establish the normal ranges of layer-specific longitudinal and circumferential strain (endocardial global longitudinal strain (GLS), transmural GLS, epicardial GLS, endocardial global circumferential strain (GCS), transmural GCS, and epicardial GCS).Methods and resultsWe retrospectively analyzed longitudinal and circumferential strain parameters in 235 healthy subjects, with use of layer-specific 2D speckle tracking software (GE). The endocardial strain/epicardial strain (Endo/Epi) ratio was also measured to assess the strain gradient across the myocardium. The endocardial, transmural, and epicardial GLS values and the Endo/Epi ratio in the normal subjects were -23.1±2.3, -20.0±2.0, -17.6±1.9, and 1.31±0.07, respectively. The corresponding values of GCS were -28.5±3.0, -20.8±2.3, -15.3±2.0, and 1.88±0.17, respectively. The layer-specific global strain parameters exhibited no age dependency but did exhibit gender dependency except for endocardial GCS. A subgroup analysis revealed that basal and middle levels of endocardial LS was decreased in the middle and elderly aged group. However, apical endocardial LS was preserved even in the elderly subjects.ConclusionsWe proposed normal reference values for layer-specific strain based on both age and gender. This detailed strain analysis provides layer-oriented information with the potential to characterize abnormal findings in various cardiovascular diseases.

Hypertrophic cardiomyopathy and left ventricular hypertrophy in hypertensive heart disease with mildly reduced or preserved ejection fraction: insight from altered mechanics and native T1 mapping

To explore the relationship between extracellular volume (ECV), native T1, and systolic strain in hypertrophic cardiomyopathy (HCM) and hypertensive patients with left ventricular hypertrophy (HTN LVH) with mildly reduced or preserved ejection fraction. T1 mapping was performed in 45 patients with late gadolinium enhancement positive (LGE+) HCM (mean age, 53±6 years), 11 patients with LGE- (LGE-) HCM (mean age, 56±5 years), and 20 patients with HTN LVH (mean age, 55±6 years) on at 3 T magnetic resonance imaging (MRI) using the modified look-locker inversion-recovery (MOLLI) pulse sequence. Mean T1 value, ECV and circumferential strain parameters were determined for each patient. Overall, the HCM patients had higher native T1 values (1242.92±68.94) and ECV (0.31±0.05) in comparison to those of the HTN LVH patients (1197±46.80, 0.27±0.04; p<0.05). In the subgroup analysis, the HCM LGE+ patients had the highest native T1 values among the three groups. The HCM LGE+ patients had higher ECV than the LGE- patients. HCM LGE- patients had higher ECV than HTN LVH patients (p<0.05). Peak systolic circumferential strain and early diastolic strain rates were reduced in the HCM LGE+ patients in comparison to the HCM LGE- and HTN LVH patients (p<0.05). Reduced peak systolic and early diastolic circumferential strain rates were associated with increased levels of ECV and native T1 values among all the patients. HCM LGE+ patients had higher native T1 values, higher ECV, and an associated reduction in early diastolic strain rates and peak systolic circumferential strains when compared to the HCM LGE- and HTN LVH patients with mildly reduced or preserved ejection fraction.

Does the internal jugular vein affect the elasticity of the common carotid artery?

BackgroundArterial stiffness is an early marker of atherosclerosis. The carotid arteries are easily accessible by ultrasound and are commonly used for the evaluation of atherosclerosis development. However, this stiffness assessment is based on the elastic properties of the artery, which may be influenced by the adjacent internal jugular vein (IJV).The aim of the present study is to evaluate the influence of internal jugular vein morphology on the stiffness of the common carotid artery.MethodsBilateral carotid ultrasound was performed in 248 individuals. When no carotid plaque was detected (90.9 % cases), the distensibility coefficient and β - stiffness index were calculated. The global and segmental circumferential strain parameters of the carotid wall were evaluated with 2D-Speckle Tracking. The cross-sectional area of the IJV and degree of its adherence to the carotid wall (angle of adherence) were measured.ResultsThe morphology of the IJV did not influence the standard stiffness parameters nor the global circumferential strain. However, segmental analysis found the sector adjacent to the IJV to have significantly higher strain parameters than its opposite counterpart. In addition, the strain correlated significantly and positively with IJV cross-sectional area and angle of adherence.ConclusionsThe movement of the carotid artery wall caused by the passage of the pulse wave is not homogeneous. The greatest strain is observed in a segment adjacent to the IJV, and the degree of wall deformation is associated with the size of the vein and the degree of its adherence.

Increased Extracellular Volume and Altered Mechanics Are Associated With LVH in Hypertensive Heart Disease, Not Hypertension Alone

ObjectivesThe goal of this study was to assess the relationship among extracellular volume (ECV), native T1, and systolic strain in hypertensive patients with left ventricular hypertrophy (HTN LVH), hypertensive patients without LVH (HTN non-LVH), and normotensive controls. BackgroundDiffuse myocardial fibrosis in HTN LVH patients, as reflected by increased ECV and native T1, may be an underlying mechanism contributing to increased cardiovascular risk compared with HTN non-LVH subjects and controls. Furthermore, increased diffuse fibrosis in HTN LVH subjects may be associated with reduced peak systolic and early diastolic strain rate compared with the other 2 groups. MethodsT1 mapping was performed in 20 HTN LVH (mean age, 55 ± 11 years), 23 HTN non-LVH (mean age, 61 ± 12 years), and 22 control subjects (mean age, 54 ± 7 years) on a Siemens 1.5-T Avanto (Siemens Healthcare, Erlangen, Germany) using a previously validated modified look-locker inversion-recovery pulse sequence. T1 was measured pre-contrast and 10, 15, and 20 min after injection of 0.15 mmol/kg gadopentetate dimeglumine, and the mean ECV and native T1 were determined for each subject. Measurement of circumferential strain parameters were performed using cine displacement encoding with stimulated echoes. ResultsHTN LVH subjects had higher native T1 compared with controls (p < 0.05). HTN LVH subjects had higher ECV compared with HTN non-LVH subjects and controls (p < 0.05). Peak systolic circumferential strain and early diastolic strain rates were reduced in HTN LVH subjects compared with HTN non-LVH subjects and controls (p < 0.05). Increased levels of ECV and native T1 were associated with reduced peak systolic and early diastolic circumferential strain rate across all subjects. ConclusionsHTN LVH patients had higher ECV, longer native T1 and associated reduction in peak systolic circumferential strain, and early diastolic strain rate compared with HTN non-LVH and control subjects. Measurement of ECV and native T1 provide a noninvasive assessment of diffuse fibrosis in hypertensive heart disease.

Speckle Tracking Echocardiography Detects Uremic Cardiomyopathy Early and Predicts Cardiovascular Mortality in ESRD

Cardiovascular mortality is high in ESRD, partly driven by sudden cardiac death and recurrent heart failure due to uremic cardiomyopathy. We investigated whether speckle-tracking echocardiography is superior to routine echocardiography in early detection of uremic cardiomyopathy in animal models and whether it predicts cardiovascular mortality in patients undergoing dialysis. Using speckle-tracking echocardiography in two rat models of uremic cardiomyopathy soon (4-6 weeks) after induction of kidney disease, we observed that global radial and circumferential strain parameters decreased significantly in both models compared with controls, whereas standard echocardiographic readouts, including fractional shortening and cardiac output, remained unchanged. Furthermore, strain parameters showed better correlations with histologic hallmarks of uremic cardiomyopathy. We then assessed echocardiographic and clinical characteristics in 171 dialysis patients. During the 2.5-year follow-up period, ejection fraction and various strain parameters were significant risk factors for cardiovascular mortality (primary end point) in a multivariate Cox model (ejection fraction hazard ratio [HR], 0.97 [95% confidence interval (95% CI), 0.95 to 0.99; P=0.012]; peak global longitudinal strain HR, 1.17 [95% CI, 1.07 to 1.28; P<0.001]; peak systolic and late diastolic longitudinal strain rates HRs, 4.7 [95% CI, 1.23 to 17.64; P=0.023] and 0.25 [95% CI, 0.08 to 0.79; P=0.02], respectively). Multivariate Cox regression analysis revealed circumferential early diastolic strain rate, among others, as an independent risk factor for all-cause mortality (secondary end point; HR, 0.43; 95% CI, 0.25 to 0.74; P=0.002). Together, these data support speckle tracking as a postprocessing echocardiographic technique to detect uremic cardiomyopathy and predict cardiovascular mortality in ESRD.

Longitudinal follow-up of ventricular performance in healthy neonates

BackgroundSpecific follow-up of newly introduced echocardiographic parameters in healthy neonates and infants is limited. AimTo prospectively describe follow-up of left ventricular (LV) tissue Doppler imaging (TDI) and speckle tracking strain parameters in healthy subjects up to two months after birth. DesignThis is a longitudinal follow-up study. SubjectsTwenty-eight (10 male) healthy newborns were included and underwent transthoracic echocardiography 1–3days, 3weeks and 6–7weeks after birth. Outcome measuresIn each echocardiogram, parameters describing cardiac growth, including LV mass (LVM), were assessed. Additionally, TDI derived peak systolic velocity (S′) and peak early (E′) and late (A′) diastolic velocities were assessed in the basal LV free wall and interventricular septum (IVS). Finally LV longitudinal, radial and circumferential global peak strain parameters were assessed using speckle tracking strain imaging. ResultsLVM significantly increased during follow-up (7.6±2.4 versus 12.4±3.2g, p=0.002). Similarly at 1–3days versus 6–7weeks after birth, an increase in LV and IVS systolic (LV S′ 4.1±1.5 versus 6.3±1.5cm/s, p=0.001; IVS S′ 3.6±0.9 versus 6.4±1.3cm/s, p<0.001) and diastolic (LV E′ 6.1±2.2 versus 9.7±2.9cm/s, p=0.002; IVS E′ 5.1±1.4 versus 10.7±3.3cm/s, p<0.001) TDI parameters was observed. In contrast, global peak longitudinal, radial and circumferential strain parameters did not significantly change during follow-up. ConclusionsA significant increase in LV systolic and diastolic TDI parameters was observed up to two months after birth. Yet this increase may be (cardiac) growth-dependent. No significant changes were observed in speckle tracking strain derived global peak strain parameters; this may render the technique particularly valuable in evaluation of LV systolic performance during periods of significant growth, such as the neonatal period.

Altered Left Ventricular Tissue Velocities, Deformation and Twist in Children and Young Adults with Acute Myocarditis and Normal Ejection Fraction

Acute myocarditis is a significant cause of sudden death in young adults, and accurate screening for subclinical disease is needed. The aim of this study was to test the hypothesis that newer measures of tissue deformation and twist can detect ventricular dysfunction in patients with myocarditis and preserved left ventricular ejection fractions (LVEFs). Twenty-eight consecutive patients (median age, 26.5 years; interquartile range, 19.3-33.8 years) with normal LVEFs and cardiovascular magnetic resonance features of myocarditis were prospectively recruited. Left ventricular tissue velocities, deformation, and twist were measured and compared with values in 64 healthy controls (median age, 25.1 years; interquartile range, 13.5-31.7 years). Patients with myocarditis had reduced annular e' velocity and longitudinal and circumferential strain parameters (P < .01) but similar LVEFs. Reduced lateral e' velocity (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.34-2.34), longitudinal strain (OR, 1.81; 95% CI, 1.38-2.38), circumferential early diastolic strain rate (OR, 1.31; 95% CI, 1.08-1.71), increased twist rate (OR, 1.02; 95% CI, 1.01-1.04), and earlier time to peak twist (OR, 0.80; 95% CI, 0.72-0.88) were identified as independent predictors of myocarditis, with abnormalities in any two of five predictors having 93% sensitivity and 91% specificity. Longitudinal strain parameters and lateral e' velocity were improved at 1 year (P ≤ .03) but remained reduced compared with controls (P≤ .02). Patients with acute myocarditis and normal LVEFs had detectable left ventricular systolic and diastolic dysfunction on echocardiography. Tissue velocity, deformation, and twist parameters have the potential to improve the detection of patients with myocarditis and preserved LVEFs.

Acute Mechanical Effect of Right Ventricular Pacing at Different Sites Using Velocity Vector Imaging

Velocity vector imaging (VVI) allows noninvasive measurement of left ventricular (LV) strain and rotation angle-independently. We investigated strain, rotation and myocardial synchrony when pacing at different sites in the right ventricle to determine which site yields the most physiological pacing, as determined with VVI imaging. Thirty-one patients with normal LV function referred for elective electrophysiology exam were used in this study. Catheters (6F quadripolar) were positioned in the right atrium, right ventricular apex, right ventricular outflow tract, and His bundle after electrophysiology exam was done. Regional and global LV circumferential strain (CS), radial strain (RS), and LV rotation of LV short-axis measurements were obtained. Two dyssynchrony parameters (AS-P delay and SDt(6S)) of CS and RS were obtained. Compare these values among each pacing, respectively. CS, RS, and twist, which represent the LV systolic function, were significantly reduced in RVOT pacing and RVA pacing than RA pacing. Two dyssynchrony parameters (AS-P delay and SDt(6S)) were significantly longer in response to RVOT or RVA pacing compared to RA pacing. No significant differences were found between RVOT pacing and RVA pacing. CS and RS were obviously reduced in the regions surrounding the pacing site. There was no significant difference in CS, RS, twist, and mechanical dyssynchrony parameters when comparing His and RA pacing. Among these alternate right ventricular pacing locations, His bundle pacing is most like physiological pacing. Both RVOT pacing and RVA pacing worsen the normal LV systolic function with regard to strain, twist, and mechanical dyssynchrony along the LV short axis.

Evaluation of early changeof left ventricular systolic function in type 2 diabetes mellitus by ultrasound speckletracking imaging

：Objective To evaluatethe early change of left ventricular (LV) systolic function in patients with type 2diabetes mellitus(T2DM) by ultrasound speckle tracking imaging. Methods Ninety-fivesubjects were included:40 T2DM with normal LV ejection fraction (LVEF≥50%,group A),20 T2DM with abnormal LVEF (LVEF 0.05), peak systolic circumferential strain of partsegments, average peak strain of each plane and global strain were reduced (P <50.05～0.001),and LV peak systolic rotation of all apical segments, peak systolic global rotation atthe levels of mitral annulus and apex,and peak systolic global twist were significantlyincreased (P <0.05～0.001). Compared with control group and group A,allLV systolic radial strain and circumferential strain parameters, LV systolic global andsegmental rotation and peak systolic global twist in group B were significantly reduced (P<0.05 ～ 0.001).Conclusions Speckle tracking imaging could be used to evaluate the early change of LVtorsional deformation and LV systolic function in T2DM. Key words: Echocardiography; Diabetes mellitus,type 2 ; Ventricularfunction,left; Speckle tracking imaging