Differences In Myocardial Deformation Research Articles

Regional Analysis of Myocardial Strain to Wall Thickness Ratio in Cardiac Amyloidosis and Hypertrophic Cardiomyopathy.

Increased left ventricular wall thickness is a hallmark of cardiac amyloidosis (CA). Several other disease states, including hypertrophic cardiomyopathy (HCM), share this common feature. Myocardial strain has emerged as a diagnostic and prognostic tool to differentiate causes of increased left ventricular wall thickness. We sought to determine if regional strain differences were present in CA when compared with HCM when indexed to wall thickness as well as adjusting for important factors such as ejection fraction (EF), age, sex, and hypertension. We performed a multicenter, retrospective analysis of 122 patients in 3 groups: CA (n=40), HCM (n=44), and controls (n=38). Using commercially available software, we determined peak systolic strain measurements in the base, mid, and apical segments in all 3 cardinal directions of radial strain, circumferential strain, and longitudinal strain. The regional strain was indexed to wall thickness to create a strain to wall thickness (STT) ratio. Analysis of Variance was performed to examine the association of each strain parameter with the disease group, adjusting for age, sex, hypertension, and EF. Multinomial logistic regression was performed to determine which combination of variables can potentially be used to best model the disease group. Ratios of STT at all 3 levels were significantly different with respect to the cardinal directions of radial, circumferential, and longitudinal strain in a multivariable analysis adjusting for age, sex, and hypertension. Specifically, with respect to the basal segments, the STT ratio across CA, HCM, and normal were significantly different in radial (1.13±0.34 vs. 3.79±0.22 vs. 4.12±0.38; P <0.0001), circumferential (-0.79±0.10 vs. -1.62±0.07 vs. -2.25±0.11; P <0.0001), and longitudinal directions (-0.41±0.09 vs. -1.03±0.06 vs. -1.41±0.10; P <0.0001). When adjusting for age, sex, hypertension and EF, only the base was significantly different between the CA and HCM groups in the radial (1.49±0.37 vs. 3.53±0.24; P <0.0001), circumferential -1.04±0.10 vs. -1.44±0.06; P <0.005), and longitudinal (-0.55±0.10 vs -0.94±0.06; P =0.007) directions. Using multinomial logistic regression, the use of age, left ventricular EF, global longitudinal strain, and basal radial strain yielded a diagnostic model with an area under the receiver operating characteristic curve (AUC) of 0.98. A model excluding age, despite being likely an independent predictor in our cohort, yielded an overall AUC of 0.90. When excluding age, the overall AUC was 0.91 and specifically when discriminating CA from HCM was 0.95. Regional myocardial strain indexed to wall thickness with an STT ratio can differentiate between etiologies of increased left ventricular wall thickness. Differences in myocardial deformation may be independent of wall thickness. Differences in basal strain when indexed to wall thickness in all 3 cardinal directions between CA and HCM are independent of EF. Multinomial logistic regression analysis using strain parameters differentiates CA and HCM with excellent diagnostic accuracy.

Racial differences in myocardial deformation in obese children: Significance of inflammatory state

Background and aimsThe association between racial differences in myocardial deformation and cardiometabolic risk factors is unknown in obese children. Our objective was to: 1) investigate for racial differences in myocardial deformation between white and black obese children and 2) identify biomarkers associated with these observed racial differences. We hypothesized that decreased myocardial deformation observed in black obese children could be accounted for by the differences in the markers of metabolic syndrome between the groups. Methods and resultsObese children were recruited prospectively. All clinical and laboratory tests for the metabolic syndrome were conducted during a single assessment using a standardized protocol. Speckle-tracking echocardiography was performed to obtain longitudinal and circumferential measures of deformation. 310 patients were included in the analysis; 158 (51%) white and 152 (49%) black. The median age was 11.3 years (IQR 5.9). Blacks demonstrated worse longitudinal strain (−14.7 ± 2.7% vs. −15.4 ± 2.9%, p = 0.04). There was no difference in circumferential strain between the groups. Multivariable linear regression showed a significant relationship between longitudinal strain and hsCRP (β = 0.16, p = 0.03) and HOMA-IR (β = 0.15, p = 0.04); there was no independent association between longitudinal strain and race. ConclusionBlack subjects demonstrated worse longitudinal strain than whites. Only hsCRP and HOMA-IR levels, not race, had an independent association with longitudinal strain, suggesting that the observed racial differences in longitudinal strain may be secondary to differences in inflammation and insulin resistance between the groups.

Longitudinal Myocardial Deformation Does Not Predict Single Ventricle Ejection Fraction Assessed by Cardiac Magnetic Resonance Imaging in Children with a Total Cavopulmonary Connection

Survival of children with single ventricle heart defects after the total cavopulmonary connection (TCPC) has improved, but impaired cardiac function remains a major cause of morbidity and mortality. Cardiac magnetic resonance imaging (cMRI) is the gold standard in assessing single ventricle volume and function, but high costs and limited availability hamper its routine use. A cheaper and more available alternative is echocardiography. Myocardial function can be studied in more detail using speckle tracking echocardiography (STE). The purpose of the study was to describe the association between myocardial deformation assessed by speckle tracking echocardiography (STE) and single ventricle function assessed by cMRI and to evaluate differences in myocardial deformation in children with single left and single right ventricular morphology. Cross-sectional, multicenter study in 77 children after TCPC was conducted. STE segmental and global longitudinal peak strain and systolic strain rate (SR) of the dominant ventricle were measured. Impaired SV function by cMRI was defined as ejection fraction (EF) < 45%. Mean age was 11.8 (range 9.7–14.3) years. Pearson R for cMRI EF versus global longitudinal strain and SR was − 0.25 (p = 0.06) and − 0.03 (p = 0.82), respectively. Global single ventricle longitudinal strain and SR was similar in patients after TCPC with single left and single right ventricular morphology (− 19.0 ± 3.1% vs 19.2 ± 3.2%, p = 0.94). STE myocardial deformation parameters do not correlate with single ventricle ejection fraction assessed by cMRI.

Sustained Chronic Maternal Hyperoxygenation Increases Myocardial Deformation in Fetuses with a Small Aortic Isthmus at Risk for Coarctation

We aimed to assess differences in myocardial deformation in fetuses at risk for coarctation (CoA) and the effects of maternal hyperoxygenation on deformation. Fetal echocardiography and velocity vector imaging were performed prospectively and serially in 48 fetuses with a small aortic isthmus and 48 gestation age-matched normal fetuses. Fetuses with a small aortic isthmus were randomly divided into two groups: one group with and the other group without maternal supplemental oxygen administration. The strain (S) and strain rate (SR) in the left ventricle (LV) and right ventricle (RV) were measured and compared between the groups. Regression analyses were performed to identify potential factors associated with myocardial deformation. Compared with normal fetuses, fetuses with a small aortic isthmus exhibited a lower S and SR at baseline. A negative correlation was found between aortic isthmus velocity-time integrals and S and SR at baseline (P<.05). In the group that received supplemental oxygen therapy, the S and SR in both the LV and RV increased as a function of time, especially 4weeks after the initiation of oxygen therapy (P<.05). The duration of oxygen therapy and increased combined cardiac index were associated with increased myocardial deformation (P<.05). Myocardial deformation appears abnormal in those at risk for CoA beginning in utero, and chronic oxygen therapy appears to increase deformation measures. These findings may improve patient counseling and perinatal management.

Myocardial Damage Detected by Two-Dimensional Speckle-Tracking Echocardiography in Patients with Extracardiac Sarcoidosis: Comparison with Magnetic Resonance Imaging

The aim of this study was to determine whether two-dimensional speckle-tracking echocardiography can identify the myocardial damage detected by delayed enhancement (DE) magnetic resonance imaging via the differences in myocardial deformation in patients with extracardiac sarcoidosis who showed no structural and functional abnormalities in the heart. Forty-five patients with biopsy-proven extracardiac sarcoidosis were analyzed retrospectively. Patients with abnormal electrocardiographic and echocardiographic findings, including ventricular arrhythmias, heart block, regional wall motion abnormalities, valvular heart disease, and cardiomyopathy, were excluded. Ten age-matched healthy control subjects were recruited as a control group. Comprehensive echocardiography and DE magnetic resonance imaging were performed, and circumferential, longitudinal, and radial strain were consecutively assessed using two-dimensional speckle-tracking echocardiographic software in a 16-segment model of the left ventricle in accordance to the presence (DE+) or absence (DE-) of DE. Among the 45 patients, 36 segments in 13 patients showed DE. DE+ segments had lower peak circumferential strain than DE- and control segments (-14±5% vs -28±7% vs -30±7%, P<.0001). Peak longitudinal strain in DE+ segments was significantly decreased compared with control segments (-19±4% vs -23±5%, P=.005). However, peak radial strain was similar among the three groups: 41±17% in DE+ segments, 45±23% in DE- segments, and 46±18% in control segments (P=.50). Circumferential and longitudinal strain via two-dimensional speckle-tracking echocardiography can identify the myocardial damage detected by DE magnetic resonance imaging in patients with extracardiac sarcoidosis.

Practical application of DENSE in ischemic heart disease

Background In clinical practice, perfusion, viability and systolic myocardial function are fundamental to the evaluation of ischemic patients. Deformation of muscle expresses active contraction and can be represented by strain in various directions. Improvements to the “DENSE” technique, “Displacement Encoding with Stimulated Echoes”, have shown high accuracy warranting its application to clinical patients. The purpose of this study was to explore potential differences in myocardial deformation determined in patients with various extent of myocardial scar as well as in the corresponding segments of coronary patients without scar.

Gender-Specific Differences in Myocardial Deformation and Aortic Stiffness at Rest and Dobutamine Stress

Elderly women have increased aortic and ventricular stiffness but preserved global systolic function. Possible gender differences in ventricular deformation attributed to increased aortic stiffness at rest or with positive inotropic stress remain unknown. Eighty-four subjects (mean age: 63±8 years) were assessed for aortic stiffness by pulse wave velocity and ventricular deformation at rest and during dobutamine stress using magnetic resonance. At rest, women (n=40) had greater aortic stiffness and ventricular deformation than men (P<0.05). In men, dobutamine increased longitudinal (mean±SD: 3.3±4.1%; P<0.01) and circumferential deformation (2.9±5.1%; P=0.007), whereas women showed an increase in circumferential deformation only (4.8±6.3%; P<0.01). In men there was an inverse association between longitudinal deformation and pulse wave velocity at rest (r=-0.51; P=0.002) and linear at stress (r=0.52; P=0.001). In women there were no significant relations at rest, whereas at stress longitudinal deformation was inversely associated with pulse wave velocity (r=-0.43; P=0.02). We demonstrate gender-specific differences in the relationship between aortic stiffness and ventricular deformation at rest and during dobutamine stress. Although at rest longitudinal deformation is inversely related to aortic stiffness in men, there is no such relationship in women. At stress, men improve longitudinal function, whereas in women such response is limited.

Myocardial deformation (strain) measured by DENSE reliably detects myocardial scar

Summary The purpose of this study was to explore the differences in myocardial deformation by DENSE determined in healthy myocardium and in segments variously affected by myocardial infarction. There was a significant difference in both radial and circumferential strain between normal and infarcted myocardium. Background The purpose of this study was to explore the differences in myocardial deformation by DENSE determined in healthy myocardium and in segments variously affected by myocardial infarction. There was a significant difference in both radial and circumferential strain between normal and infarcted myocardium. Methods By using a 1.5T scanner have 68 patients with a high likelihood of coronary artery disease been included. The following MRI protocol was used: cine SSFP, single slice multiphase Displacement ENcoding with Stimulated Echoes (DENSE) during breath holding, perfusion during adenosine stress and at rest and late gadolinium enhancement. Ejection fraction was calculated from the short axis cine and wall motion was assessed in terms of normal, hypokinetic, akinetic and dyskinetic according to guidelines. Perfusion was assessed as normal or reduced in parts of the thickness of the wall. Late gadolinium enhancement was also graded in terms of transmurality (scar percentage of the wall thickness). All measurements were applied to segments of the AHA seventeen segment model, excluding the apical cap. DENSE post processing was performed with an in-house developed software calculating radial strain and circumferential strain. Healthy myocardium was determined if scar was absent and, wall motion and perfusion were normal (n=11). Significant myocardial infarction was defined as positive gadolinium enhancement in excess of fifty percent wall thickness (n=27). Segments were aggregated according to the coronary perfusion territories. Results Data are shown for healthy/scared areas (p<0.0005). LCX area: radial strain 23% / 15%, circumferential strain was -11%/ -4% RCA area: radial strain 24% / 18%, circumferential strain -10% / -6%. LAD area: radial strain 20% / 10% and circumferential strain -10% / -4%. The means and the standard deviation is shown in fig.1. The standard deviation in the strain values for the infarcted vessel areas depend on the added segments and the 50% cut-off value for transmurality. Conclusions Myocardial infarction more than 50% transmurality can be identified by strain measurements using DENSE.

Differences in myocardial deformation between donor and recipient in twin-twin transfusion syndrome using vector velocity imaging

Objective To investigate the differences in myocardial deformation between donor and recipient in twin-twin transfusion syndrome(TTTS) using vector velocity imaging( VVI). Methods Digital dynamic two-dimensional four chamber views were interrogated off-line using VVI software. Global longitudinal strain(S) , systolic strain rate(SRs) and diastolic strain rate(SRd) were measured in the left ventricles(LV) and right ventricles (RV) of 30 fetal pairs with TTTS and compared to 30 gestational age-matched normal controls. Results Donor LV-SRs was higher, while donor RV-SRd was significantly lower than controls. Recipient S, SRs and SRd were significantly lower for both LV and RV in comparison to controls. Conclusions In TTTS,donor LV systolic function is hyperdynamic while the RV diastolic function is low. Recipient RV and LV are both globally depressed with systolic and diastolic dysfunction. Key words: Ultrasonography; Fetofetal transfusion; Ventricular function

Advanced speckle tracking echocardiography allowing a three-myocardial layer-specific analysis of deformation parameters

Different layers of myocardium may contribute differently to myocardial deformation. Speckle tracking based on high resolution two-dimensional (2D) echocardiography has been used to define myocardial deformation parameters of whole left ventricular (LV) segments. This study evaluated with a Novell analysis modality allowing layer-specific analysis of deformation if there are differences in myocardial deformation between different layers of myocardium. In 30 normal subjects and 20 patients with impaired myocardial function 2D parasternal short-axis echocardiographic views of the LV were acquired at the basal, mid-papillary, and apical levels. Using a Novell automatic frame-to-frame tracking system of natural acoustic echocardiographic markers (EchoPAC, GE Ultrasound, Haifa, Israel), circumferential strain (CS) and strain rate of the endocardial, mid-myocardial and epicardial layer was calculated for each LV segment in an 18-segment model. Wall motion for each segment was defined as normokinetic, hypokinetic, and akinetic based on 2D echocardiographic images. Peak systolic CS could be analysed in 837 segments (93%). In the normal subjects peak systolic CS was greatest in the endocardial layer, lower in the mid-myocardial layer, and lowest in the epicardial layer (38.1+/-9.0%, 28.9+/-9.3%, and 24.0+/-9.4%, respectively, P<0.001). In the patients with impaired LV function 151 segments were hypokinetic and 92 segments akinetic by visual analysis. In all myocardial layers peak systolic CS and strain rate decreased with decreasing segmental function. Decreasing myocardial deformation from endocardial to epicardial layers can be demonstrated with the use of an advanced analysis system allowing definition of deformation parameters for three myocardial layers. Myocardial deformation is reduced in all layers of segments with impaired wall motion.

Gender Based Variance in Tissue Velocity Does Not Reflect Differences in Myocardial Deformation

significantly higher baseline strain/WS ratio (−0.20± 0.1 versus −0.28± 0.1, P= 0.02) compared to the tertile who deteriorated (deformation decrease of 6.9± 5.4%). EndsystolicWSwas similar betweengroups (58.8± 18.7 versus 66.2± 23.4 dynes/cm2, P= 0.28). Conclusion: Inappropriately low tissue deformation for the level of end-systolic wall stress is associated with progression of myocardial dysfunction in treated hypertensive patients. Strain/wall stress relationships may aid in prognostication in these patients. doi:10.1016/j.hlc.2007.06.107 103 Tissue Deformation is Associated with LV Geometry in Hypertensive Patients J.L. Hare ∗, M. Bansal, J.K. Brown, T.H. Marwick University of Queensland, Brisbane, Australia Background:Different patterns of abnormal LV geometry are associatedwith variations inprognosis, but themechanisms of these effects remain undefined. We investigated the functional associations of these findings using measures of tissue deformation, specifically strain and strain rate (SR). Methods: 2D echocardiography in 60 unselected hypertensive patients (age 58± 12 years, 52% male). LV mass 104 Gender Based Variance in Tissue Velocity Does Not Reflect Differences in Myocardial Deformation D.J. Holland1,2,∗, J.E. Sharman1,2, R.L. Leano1, T.H. Marwick1 1Department of Medicine, University of Queensland, Brisbane 4102, Australia; 2 School of Human Movement Studies, University of Queensland, Princess Alexandra Hospital, Brisbane 4102, Australia Background: Reports regarding the impact of gender on myocardial velocity and deformation are inconsistent. In this study, we sought the mechanism of the effect of gender on Doppler indices of left ventricular (LV) function in healthy individuals and patients with type 2 diabetes mellitus. Methods: LV deformation (strain and strain rate), systolic (Sm) and diastolic (Em) tissue velocities weremeasured in thebasal septumby tissueDoppler in a total of 276patients (148 men; aged 54± 11 years). All subjects had preserved systolic function, normal stress echo and had no history of coronary artery disease. Results: Sm was significantly higher in men compared to women (5.5± 1.10 versus 4.8± 1.15; p< 0.001) however Em, Strain and Strain Rate were not significantly different betweengenders.Onmultiple regression analysis, gender index (LVMI) and regional wall thickness were used to assign into groups with normal geometry (NG), concentric remodelling (CR), concentric hypertrophy (CH) and eccentric hypertrophy (EH). Strain/SRwasmeasured from basal septum in the apical four chamber view using velocity vector imaging (VVI, Siemens, Erlangen, Germany). Results: VVI was feasible in 57 studies (95%). Analysis of LV geometry revealed NG in 10 patients (17%), CR in 15 (25%), CH in 28 (47%) and EH in 7 (11%). Overall strain was −14.0± 4.8 % and SR was −0.73± 0.70 /s. Strain was significantly lower in patients with CR (−13.1± 4.1 %) or CH (−12.3± 4.3 %), compared to patients with NG (−18.5± 5.5 %, P≤ 0.05). Results were independent of blood pressure (MAP 113± 15mmHg), with no significant differences between groups (P= 0.29). SR was non-significantly reduced in patients with CR and CH (−0.64± 0.25 /s, −0.56± 0.19 /s) compared to NG (−0.85± 0.33 /s, P=NS), but significantly lower in patients withCHversus patientswith EH (−1.40± 1.86 /s, P≤ 0.05). Conclusions: Tissue deformation is related to LV geometry, independent of BP, in treated hypertensive patients. doi:10.1016/j.hlc.2007.06.108 was identified as themost significant independent predictorofSm(β = 0.23;p= 0.001), and remainedsignificant after correcting for body mass index (BMI), age, mean arterial pressure, LV mass and LV end diastolic and end systolic volumes. Inclusion of central hemodynamics such as augmentation index (AIx) and central systolic blood pressure had no effect on the significance of gender in the model. BMI, end diastolic volume (EDV) and end systolic volume (ESV) were also significant predictors in the model. Conclusions: Men have significantly higher LV systolic tissue velocity than women, independent of differences in myocardial deformation measured by strain and strain rate. Male (n= 148) Female (n= 129) p-value Sm (cm/s) 5.4 ± 1.1 4.8 ± 1.2 <0.001 Strain (%) 20.5 ± 3.7 20.7 ± 3.5 NS SR (/s) 1.31 ± 0.37 1.29 ± 0.25 NS EDV (mL) 83 ± 20 60 ± 14 <0.001 ESV (mL) 32 ± 9 22 ± 7 <0.001 doi:10.1016/j.hlc.2007.06.109

Anterior and posterior left ventricular sarcomere lengths behave similarly during ejection

Previous studies of regional differences in myocardial deformation between the anterior and posterior walls of the canine left ventricle were based on strain, which is not an absolute measure of deformation. We thus compared sarcomere lengths at anterior and posterior sites during ejection in isolated dog hearts. Cineradiographic imaging of regional deformation with radiopaque markers implanted near the midwall in five hearts and just below the epicardium in six hearts, combined with postmortem histology, allowed sarcomere length reconstruction throughout the cardiac cycle. The amount of sarcomere shortening accompanying left ventricular ejection was similar in both walls of the left ventricle for sarcomeres located at epicardial and midwall sites. The mean sarcomere length (taken at the middle of the ejecting range) was also similar between the anterior and posterior sites when averaged over all hearts. The similarity of sarcomere function held not only at end systole but throughout ejection and over wide ranges of ventricular pre- and afterloads. Hence functional measurements of relative myocardial shortening may not be indicative of regional sarcomere length heterogeneity.