Circumferential Strain Values Research Articles

O21-1 - Difference in Prognostic Value of Left Atrial Longitudinal and Circumferential Strain

Background: Left ventricular longitudinal strain (LVLS), Left atrial (LA) volume and functional indices measured by two dimensional echocardiography (2DE) have significant prognostic value for major cardiovascular events (MACE: cardiac death, stroke, nonfatal myocardial infarction and hospitalization for heart failure). Prognostic values of left atrial longitudinal and circumferential strain measured by three-dimensional speckle tracking analysis (3DSTA) were evaluated. Method: Two hundred eight patients (Male 61%, 65 ± 15yo) with various kind of cardiovascular diseases underwent standard 2DE and 3DSTA of left atrium. Maximum and minimum left atrial volume (LAVImax and LAVImin), left atrial emptying fraction (LAEmpF), peak global LA area strain (LAAS), circumferential strain (LACS) and longitudinal strain (LALS) were measured using 3DSTA. Serial changes of LACS and LALS were also recorded in 14 patietns hospitalized with heart failure. Results: During a mean follow-up of 611 ± 371 days, MACE developed in 23 patients. By multivariate analysis, CAD, CKD, 2DLVLS, 2DLAVImax, 2DLAmin and all LA indices were significant independent factors predicting MACE. The model added LALS or LAEmpF by 3DSTA had higher prognostic value (LALS <10.4%, AUC; 0.88, HR;7.45 CI:2.62–24.34, LAEmpF <2.7%: AUC; 0.88, HR:9.05, CI:2.93–37.53) than LACS. In patients with HF, LACS showed more rapid and greater change after therapy than LALS (rate of change: 108% vs 64%, P < .01). Conclusion: LALS is more robst predictor of future MACE than LACS.

Left Ventricular Systolic Myocardial Deformation: A Comparison of Two- and Three-Dimensional Echocardiography in Children

The clinical applicability and reliability of three-dimensional (3D) speckle-tracking echocardiography has not been well studied in pediatric patients. The aim of this study was to compare two-dimensional (2D) echocardiography and 3DE real-time full-volume-derived strain and rotation indices in healthy children and patients with dilated cardiomyopathy (DCM). Children with either normal function or DCM were prospectively recruited in an outpatient setting, and deformation indices, including circumferential, radial, and longitudinal strain and torsion, were measured by 2D and 3D echocardiography. Control subjects were compared with patients using the Mann-Whitney U test, correlations between 2D and 3D measurements were analyzed using Spearman correlation analysis, and reproducibility analyses are reported using intraclass correlation coefficients and coefficient of variations. The study cohort consisted of 15 patients (47%) with DCM and 17 control subjects (53%). The median age of the cohort was 13.4years (range, 5.7-19.3years). By both 2D and 3D analysis, magnitudes of global longitudinal (P=.01), circumferential (P=.007), and radial (P=.004) strain were significantly lower in patients with DCM in comparison with control subjects. Using receiver operating characteristic curves, lower values of absolute circumferential (area under the curve=0.95, P<.0001) and longitudinal (area under the curve=0.93, P<.0001) strain were associated with left ventricular dysfunction. No difference was noted in torsion between control subjects and patients. Three-dimensional analysis was superior to 2D analysis in terms of intraobserver, interobserver, and test-retest reliability. Left ventricular deformation shows significant changes while torsion is preserved in outpatients with DCM compared with control subjects. Three-dimensional global strain can discriminate subtle left ventricular dysfunction and has better reproducibility in comparison with 2D echocardiography. High-resolution 3D imaging is a useful clinical assessment tool for cardiac performance and may overcome some of the limitationsof 2D analysis.

Heterogeneity of systolic dysfunction in patients with severe aortic stenosis and preserved ejection fraction.

Left ventricular (LV) systolic strain has been shown to be an early marker of LV dysfunction in patients with severe aortic stenosis (AS) despite preserved ejection fraction (EF). Echocardiography has provided useful data on regional LV strain patterns, but is not as sensitive as magnetic resonance imaging (MRI). No prior studies have used MRI-based strain analysis to characterize regional three-dimensional strain in patients with severe AS. Twelve patients with severe AS and preserved EF underwent MRI-based multiparametric strain analysis. Circumferential and longitudinal strain values were calculated at individual points throughout the LV and analyzed in 12 discrete regions. Strain values were compared to a database of normal controls. Compared to control patients, circumferential strain in AS patients was significantly reduced at the base (P = 0.002), mid (P = 0.042), and inferior walls (P < 0.001). Longitudinal strain was significantly reduced at the base (P < 0.001), mid (P < 0.001), anterior (P < 0.001), and septal (P < 0.001) walls. Among patients with AS, there was heterogeneity in the location and severity of abnormalities in circumferential and longitudinal strains despite the presence of a preserved EF and lack of prior myocardial infarction. LV systolic strain is significantly impaired in patients with AS and preserved EF compared to healthy volunteers. Abnormalities in circumferential and longitudinal strains were heterogeneously distributed across the LV of patients with AS, allowing us to identify sentinel regions that may reflect the earliest signs of developing LV dysfunction.

Value of speckle tracking echocardiography for detection of clinically silent left ventricular dysfunction in patients with β-thalassemia

ABSTRACTObjective: β-Thalassemia is an inherited hemoglobin disorder resulting in chronic hemolytic anemia requiring chronic transfusion therapy. Cardiac involvement is the main cause of death in patients with thalassemia major. The narrow border is between overt myocardial dysfunction and clinically silent left ventricular (LV) dysfunction in patients with thalassemia. Therefore, we need novel parameters in different imaging techniques to discover cardiac involvement in an early and subtle stage. We explore to find a novel, straightforward and informative parameter in echocardiography as a noninvasive, economical and really routine in clinical practice.Methods: In this prospective study, 55 patients, who are known cases of β-thalassemia major, receiving long-term blood transfusions and undergoing iron chelation therapy were enrolled. Ferritin level, cardiac magnetic resonance (CMR) T2 * value, full conventional echocardiography and speckle tracking, LV regional circumferential and longitudinal strain values (%) and time-to-peak strain (ms) of 17 segments cardiac model in eyeball tomogram were measured.Results: There was a significant reduction in global longitudinal strain (GLS) (−20.9% ± 1.9 vs. −22.2 ± 1.03) and also basal segments longitudinal strain compared to normal subjects group (−17.4% ± 2.7 vs. −19.6% ± 1.2). There was no significant difference in circumferential strain value between thalassemia patients and normal control group. Interestingly, there was no significant correlation between GLS and CMR T2 * values showing no association between cardiac iron load and longitudinal strain.Conclusion: Speckle tracking echocardiography could be used as a feasible method for evaluating subclinical myocardial dysfunction in patients with thalassemia major. Echocardiography, using GLS, could predict clinically silent myocardial dysfunction independent of CMR (T2 * value) and extension of iron deposition. Our study also puts forward other causes such as chronic tissue hypoxia resulting from chronic anemia as a root cause and initiating factor for subsequent injury by the iron deposition. Speckle tracking can recognize the cardiac involvement in really early stages.

Comparative prognostic value of myocardial strain derived from DENSE CMR: the British Heart Foundation MR-MI study

BackgroundInfarct size assessed early after acute ST-segment elevation myocardial infarction (STEMI) can overestimate the true extent of infarction, limiting its usefulness as a prognostic biomarker. Myocardial strain derived from displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR) provides information on myocardial contractility with high precision and accuracy. We hypothesised that the prognostic value of peak circumferential strain is higher than infarct size. MethodsIn a prospective, single centre study, participants underwent 1·5T CMR 2 days and 6 months after myocardial infarction. The 5-SD technique was used to quantify late gadolinium enhancement (LGE) as proportion of left ventricular mass. Mid-left ventricular DENSE acquisitions were analysed using postprocessing software. During longer-term follow-up, major adverse cardiac events (MACE) were independently assessed by masked cardiologists. Participants provided written informed consent and ethics approval was given (reference 10/S0703/28). This study is registered with ClinicalTrials.gov, number NCT02072850. Findings300 patients underwent CMR (mean age 58·6 years [SD 13·2], 237 men [79%], 118 anterior myocardial infarction [39%], 30 with diabetes [10%], 284 with normal flow [Thrombolysis in Myocardial Infarction grade 3] after percutaneous coronary intervention [95%]). 259 of these patients had DENSE acquired, of whom 21 (8%) experienced a MACE at 3 years' follow-up. DENSE and baseline LGE had reasonable power for prediction of adverse events (area under the curve [AUC] DENSE 0·712, p=0·001; AUC LGE 0·644, p=0·028). For MACE (receiver operating characteristic analysis), optimal cut-offs for peak circumferential strain using DENSE was −10·51%, and LGE 24·05 g. Cox-regression analysis showed that DENSE (hazard ratio 1·175, 95% CI 0·036–1·334; p=0·012) offered an incremental prognostic benefit over LGE (1·040, 1·010–1·070; p=0·008) to predict MACE. InterpretationDENSE-derived peak circumferential strain offers an incremental prognostic benefit over infarct size revealed by LGE to predict MACE; a cut-off of −10·51% can identify STEMI patients at higher risk of events. This is the first time, to our knowledge, that CMR-derived strain has been shown to provide prognostic utility in patients with STEMI. FundingThis research was supported by project grants from the Chief Scientist Office (SC01), Medical Research Scotland (343 FRG), and the British Heart Foundation (BHF-PG/14/64/31043).

Assessment of left ventricular functions and myocardial iron load with tissue Doppler and speckle tracking echocardiography and T2* MRI in patients with β-thalassemia major.

The purpose of this study is to determine early myocardial dysfunction in β-thalassemia major (BTM) patients. Where the myocardial dysfunction cannot be detected by conventional echocardiography, it could be detected by tissue Doppler imaging (TDI) or speckle tracking echocardiography (STE). In this study, we analyzed 60 individuals, 30 of whom were BTM patients and the other 30 of whom were the control group. T2* magnetic resonance imaging (MRI) was used to measure cardiac iron deposition. The myocardial functions were evaluated by conventional echocardiography, TDI and STE. When basal lateral left ventricular and basal septal wall TDI values were compared between the patient group and control group, only isovolumic contraction time values were significantly longer in the patients. The global circumferential strain was significantly lower in the patients. When evaluated as segmental, longitudinal strain values of basal inferoseptum and circumferential strain values of anteroseptum, anterior, and inferolateral segments were significantly lower in the patients. In the patients, global longitudinal and circumferential strains in the group who had pathological T2* values were significantly lower than the group who did not. In addition, circumferential strain values in anteroseptum, anterolateral, inferior, and inferoseptum segments were significantly lower in the patients with T2* values<20ms than those with T2* values≥20ms. Although T2* MRI is the most sensitive test detecting myocardial iron load, TDI and STE can be used for screening myocardial dysfunction. The abnormal strain values, especially circumferential, may be detected as the first finding of abnormal iron load and related to T2* values.

Twist deformation for predicting postoperative left ventricular function in patients with mitral regurgitation: A speckle tracking echocardiography study.

Postoperative LV dysfunction is associated with poor prognosis and increased mortality in patient with mitral regurgitation undergoing surgery. With this study, we aimed to investigate the predictive value of classic and speckle tracking echocardiographic (STE) LV deformational parameters for estimating postoperative LV dysfunction. Fifty-nine asymptomatic patients with severe mitral regurgitation (MR) due to mitral valve prolapse, who had sinus rhythm and LV ejection fraction (EF) ≥50%, were included. Patients underwent comprehensive and speckle tracking echocardiographic examination before and 6months after the surgical procedure. Patients were divided into two groups according to postoperative LV function: group A postoperative LV EF≥50% and group B postoperative LV EF<50%. Patients in group A were found to have higher LV twist (19.7±6.8° vs 11.9±4.2°; P<.001), LV global longitudinal peak strain (GLPS) (-21.7±4 vs -16.5±3.4%; P<.001), and circumferential strain (-19.5±5.2 vs -14.4±5.1%; P=.004) values but lower end-systolic diameter (ESD) (3.2±0.6 vs 4.1±0.9cm; P<.001) when compared to group B. Multivariate logistic regression analysis revealed that GLPS, ESD, and twist were independent predictors of postoperative LV functions. In the ROC analysis, GLPS ≥18.4% and twist>14.4° predicted postoperative LVEF ≥50%. GLPS and twist measured by 2DSTE are predictors of LV preservation after surgery in severe MR. These parameters may also be used as prognostic predictors and optimal timing of operation in this patient population.

Cardiac magnetic resonance feature tracking in Kawasaki disease convalescence.

Objective:The objective of this study was to determine whether left ventricular (LV) myocardial deformation indices can detect subclinical abnormalities in Kawasaki disease convalescence. We hypothesized that subclinical myocardial abnormalities due to inflammation represent an early manifestation of the disease that persists in convalescence.Background:Myocardial inflammation has been described as a global finding in the acute phase of Kawasaki disease. Despite normal systolic function by routine functional measurements, reduced longitudinal strain and strain rate have been detected by echocardiography in the acute phase.Methods and Results:Peak systolic LV myocardial longitudinal, radial, and circumferential strain and strain rate were examined in 29 Kawasaki disease convalescent patients (15 males; mean [standard deviation] age: 11 [6.6] years; median interval from disease onset: 5.8 [5.4] years) and 10 healthy volunteers (5 males; mean age: 14 [3.8] years) with the use of cardiac magnetic resonance (CMR) feature tracking. Routine indices of LV systolic function were normal in both groups. Comparisons were made between normal controls and (i) the entire Kawasaki disease group, (ii) Kawasaki disease subgroup divided by coronary artery involvement. Average longitudinal and circumferential strain at all levels was lower in patients compared to normal controls. In subgroup analysis, both Kawasaki disease patients with and without a history of coronary involvement had similar longitudinal and circumferential strain at all levels and lower when compared to controls. There were lower circumferential and longitudinal values in Kawasaki disease patients with persisting coronary artery lesions when compared to those with regressed ones.Conclusion:In this CMR study in Kawasaki disease convalescent patients with preserved routine functional indices, we detected lower circumferential and longitudinal strain values compared to normal controls, irrespective of the coronary artery status.

Altered Regional Myocardial Mechanics in Transplanted Hearts: Influence of Time and Transplantation.

Background Global longitudinal strain is reduced in heart transplant recipients, but little is known about regional contractility of the transplanted heart. Moreover, it is unclear if factors such as time after transplant and ischemic time have an influence on regional contractility. To test for regional changes in myocardial deformation, we assessed regional myocardial deformation using three-dimensional speckle tracking echocardiography in heart transplant recipients and controls. Methods Global and regional longitudinal, circumferential, and radial strain was assessed in 51 heart transplant recipients and a control group of healthy individuals (n = 26). Moreover, we correlated regional contractility with clinical characteristics and compared subgroups of heart transplant recipients with normal (n = 32) and reduced left ventricular ejection fraction (n = 32). Results Global longitudinal and circumferential strain was significantly reduced in all heart transplant recipients, as well as in the transplant group with normal ejection fraction compared with the control group (p < 0.001). Global radial strain (GRS) was elevated in both transplant groups, but was significantly higher in transplant recipients with normal ejection fraction compared with the control group (p < 0.01). Both transplant groups revealed lower longitudinal and circumferential strain values in the mid- and apical regions (p < 0.001), whereas longitudinal and circumferential strain was higher in the basal region (p < 0.01). In both groups, transplanted hearts showed increased radial strain in the basal (p < 0.05, p < 0.01) and midregions (p = 0.22; p < 0.01) and did not differ in the apical regions. Cold ischemic time (150 ± 12.6 minutes) was independently associated with reduction in circumferential strain. Time since transplantation ranging from 18 days to 21 years had no effect on myocardial deformation parameters. Conclusion Left ventricular mechanics in transplanted hearts display significantly different systolic deformation patterns than native hearts. Strain capability forms a regional gradient from the base toward the apex. The presence of a time-independent deformation pattern and the correlation with cold ischemic time suggest damage induced by the transplantation itself. These findings might be important for understanding pseudo-abnormal echocardiograms in heart transplant patients.

Monitoring elbow isometric contraction by novel wearable fabric sensing device

Fabric-based wearable technology is highly desirable in sports, as it is light, flexible, soft, and comfortable with little interference to normal sport activities. It can provide accurate information on the in situ deformation of muscles in a continuous and wireless manner. During elbow flexion in isometric contraction, upper arm circumference increases with the contraction of elbow flexors, and it is possible to monitor the muscles’ contraction by limb circumferential strains. This paper presents a new wireless wearable anthropometric monitoring device made from fabric strain sensors for the human upper arm. The materials, structural design and calibration of the device are presented. Using an isokinetic testing system (Biodex3®) and the fabric monitoring device simultaneously, in situ measurements were carried out on elbow flexors in isometric contraction mode with ten subjects for a set of positions. Correlations between the measured values of limb circumferential strain and normalized torque were examined, and a linear relationship was found during isometric contraction. The average correlation coefficient between them is 0.938 ± 0.050. This wearable anthropometric device thus provides a useful index, the limb circumferential strain, for upper arm muscle contraction in isometric mode.

Evaluation of Myocardial Strain in Patients With Amyloidosis Using Cardiac Magnetic Resonance Feature Tracking

PurposeTo study the use of cardiac magnetic resonance (CMR) feature tracking technique in evaluation of myocardial amyloidosis. Materials and MethodsCMR scans of 28 patients with biopsy proven myocardial amyloidosis and 35 controls were reviewed. Conventional short axis, vertical long axis, and 4-chamber cine steady-state free precession images from CMR scans were used to generate radial, circumferential, and longitudinal myocardial strain maps using feature tracking software. Global and regional peak radial, circumferential, and longitudinal strain values were computed. ResultsThere were significant decreases in radial, circumferential, and longitudinal strains in patients with myocardial amyloidosis globally and across layers (all P < 0.001). Strain was relatively preserved for the apex and most affected for the basal level. The area under the receiver operating characteristic curve for base peak radial, circumferential, and longitudinal strain 0.899, 0.884, and 0.866 and cut offs of 22.9, −13.3, and −10.9, respectively, were determined by receiver operating characteristic analysis. CMR feature tracking strain analysis of base-level strain parameters was able to differentiate patients with myocardial amyloidosis from those without myocardial amyloid with high sensitivity (82.5%) and specificity (82.9%) particularly for radial strain. The maximum sensitivity (89.3%) was achieved if any of the 3 parameters were abnormal, and the maximum specificity (88.6%) when all 3 parameters were abnormal. ConclusionMyocardial amyloidosis produces significant changes in regional and global strain parameters, and the peak radial and circumferential strain are the most affected at the basal layer.

Layer-specific myocardial strain analysis: investigation of regional deformation in a rabbit model of diabetes mellitus during different stages.

The purpose of the present study was to determine the characteristics of myocardial damage at different stages of diabetes mellitus (DM) using layer-specific myocardial strain. Thirty six New Zealand white rabbits were randomly divided into either the control group (n =18) or the DM group (induced with alloxan) (n=18). For the myocardial deformation studies echocardiography and layer-specific strain were performed at baseline and after 3, 6, and 9 months in all of the rabbits. Three-layer longitudinal strain (LS) was calculated in the apical 4-chamber view, and three-layer circumferential strain (CS) in the short-axis view at the level of mitral valve. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium and epicardium. For histomorphological study of the heart structure, the rabbits were sacrificed at 3, 6 and 9 months. Routine hematoxylin and eosin staining was performed. The highest absolute values of left ventricular longitudinal strain (LS) and circumferential strain (CS) were registered in the endocardium and the lowest in the epicardium in both groups. At 3 months, there was no significant difference in three-layer LS and CS (p>0.05), but at 6 months the LS of endocardium (LSendo) and CS of endocardium (CSendo) were lower in the DM group compared with the control group; at 9 months, the rest of the parameters were also decreased (p<0.05). Moreover, in ROC analysis at 6 months LSendo yielded better sensitivity and specificity in the detection of diabetic cardiomyopathy (AUC of LSendo was 0.897 and AUC of CSendo was 0.617). With the progression of untreated diabetes, the histopathological abnormalities intensified gradually beginning at 6 months. The progressive impairments in LV myocardial deformation and structure occurs early in diabetic rabbits, the myocardial damage may be nontransmural, and endocardial function is more susceptible to be affected by DM. Layer-specific myocardial strain echocardiography may identify subtle myocardial dysfunction in the early stages of DM.

Global Longitudinal Strain and Strain Rate in Type Two Diabetes Patients with Chronic Heart Failure: Relevance to Osteoprotegerin.

Biomechanical stress and inflammatory biomarkers relate to global contractility dysfunction; however, adding these biomarkers into a risk model constructed on clinical data does not improve its prediction value in chronic heart failure (CHF). The aim of this study was to evaluate whether biomarkers predict declining of left ventricular global contractility function in diabetic patients with ischemia-induced CHF. The study retrospectively evolved 54 diabetic patients who had systolic or diastolic ischemia-induced CHF that was defined as left-ventricular ejection fraction (LVEF) ≤45% or 46-55% respectively assessed by quantitative echocardiography and other conventional criteria according to current clinical guidelines. Two-dimensional transthoracic echocardiography and tissue Doppler imaging were performed according to a conventional method. Radial, longitudinal, and circumferential strain and strain rate values were obtained by speckle-tracking Imaging analysis of both LV short axis and long axis views. Serum adiponectin, NT-pro brain natriuretic peptide (BNP), osteoprotegerin, and hs- C-reactive protein (CRP) were determined at baseline by ELISA. We found lower global longitudinal strain and strain rate in diabetic patients with LVEF <45% than these in diabetic patients that did not have LVEF (Р=0.001 for all cases). Multivariate logistic regression analysis showed that NT-proBNP (r=0.432; P=0.001 and r=0.402; P=0.001, respectively), osteoprotegerin (r=0.422; P=0.001 and r=0.401; P=0.001, respectively), hs-CRP (r=0.408; P=0.001 and r=0.404; P=0.001, respectively) were independently inversely associated with global longitudinal strain and strain rate in CHF patients. We suggest that osteoprotegerin may be useful in improving the NT-proBNP based model as predictor of decreased global contractility function in diabetic patients with CHF.

OS 37-09 LAYER-SPECIFIC QUANTIFICATION OF MYOCARDIAL DEFORMATION MAY DISCLOSE THE SUBCLINICAL SYSTOLIC DYSFUNCTION AND THE MECHANISM OF RESERVED EJECTION FRACTION IN PATIENTS WITH HYPERTENSION

Objective: Hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore the subclinical left ventricular systolic dysfunction and mechanism of preserved EF using layer-specific quantification of myocardial deformation in patients with HTN. Design and Method: The routine 2D (frame rate >50 Hz) data sets were acquired using GE E9 system in 120 hypertensive patients (73 male, 54 ± 13years, blood pressure = 165 ± 20/ 96 ± 117 mmHg) and 120 age and gender matched normal subjects (124 ± 9/80 ± 8mmHg). The relative wall thickness (RWT) was calculated as the sum of anterior septal and posterior wall thickness divided by the LV end-diastolic dimension. Analysis of 2D strain was performed by EchoPac software. The RWT, LV mass index, and EF, as well as the values of 2D LV global and layer longitudinal and circumferential strains were all analyzed. Results: The LVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN than normal group (0.40 ± 0.07 vs 0.35 ± 0.03, p < 0.0001; 91 ± 26 vs 84 ± 8 g/m2, p < 0.0001). The absolute value of layer and global longitudinal strain was significantly decreased (−24 ± 3vs −26 ± 3 %, p < 0.0001;. −21 ± 3vs −23 ± 3%, respectively, p < 0.0001) and global circumferential strain (−40 ± 6vs −35 ± 5 %, −31 ± 7 vs −27 ± 4 % respectively, p < 0.0001), and the LV twist (23 ± 5 vs 18 ± 6 degree, p < 0.0001) were higher in HTN group than in normals. Conclusions: This study revealed that hypertension results in increased RWT and LV mass. The absolute value of layer and global longitudinal strain was significantly decreased in HTN patients than control group, which may implicate the early systolic dysfunction due to the endomyocardium function impaired. The absolute value of circumferential strain, and LV twist were significantly increased, which may be a compensatory mechanism to maintain LVEF.

OP.8D.05] LAYER-SPECIFIC QUANTIFICATION OF MYOCARDIAL DEFORMATION MAY DISCLOSE THE SUBCLINICAL SYSTOLIC DYSFUNCTION AND THE MECHANISM OF RESERVED EJECTION FRACTION IN HYPERTENSIVE PATIENTS

Objective: Hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore the subclinical left ventricular systolic dysfunction and the mechanism of preserved EF using layer-specific quantification of myocardial deformation in patients with HTN. Design and method: The routine 2D (frame rate > 50 Hz) data sets were acquired using GE E9 system in 120 hypertensive patients (73 male, 54 ± 13years, blood pressure =165 ± 20/ 96 ± 16 mmHg) and 120 age and gender matched normal subjects (124 ± 9/80 ± 8mmHg). The relative wall thickness (RWT) was calculated as the sum of anterior septal and posterior wall thickness divided by the LV end-diastolic dimension. Analysis of 2D strain was performed by EchoPac software. The RWT, LV mass index, and EF, as well as the values of 2D LV global and layer longitudinal and circumferential strains were all analyzed. Results: The LVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN than normal group (0.40 ± 0.07 vs 0.35 ± 0.03, p < 0.0001; 91 ± 26 vs 84 ± 8 g/m2, p < 0.0001). The absolute value of layer and global longitudinal strain was significantly decreased (−24 ± 3vs −26 ± 3 %, p < 0.0001;. −21 ± 3vs −23 ± 3%, respectively, p < 0.0001) and global circumferential strain (−40 ± 6vs −35 ± 5 %, −31 ± 7 vs −27 ± 4 % respectively, p < 0.0001), and the LV twist (23 ± 5 vs 18 ± 6 degree, p < 0.0001) were higher in HTN group than in normals. Conclusions: This study revealed that hypertension results in increased RWT and LV mass. The absolute value of layer and global longitudinal strain was significantly decreased in HTN patients than control group, which may implicate the early systolic dysfunction due to the endomyocardium function impaired. The absolute value of circumferential strain, and LV twist were significantly increased, which may be a compensatory mechanism to maintain LVEF.

Strain by Nuclear Magnetic Resonance in Hypertrophic Cardiomyopathy

Background: New techniques have been developed for the quantitative analysis of myocardial deformation by cardiovascular magneticresonance from cine-sequences (as feature tracking) or from sequences with myocardial saturation bands (tagging), enabling areliable evaluation of the true systolic function in patients with hypertrophic cardiomyopathy.Objectives: The aim of this study was to assess systolic function expressed as evaluation of ejection fraction and myocardial deformationby new analysis techniques in a population with hypertrophic cardiomyopathy.Methods: Forty patients with hypertrophic cardiomyopathy were retrospectively included in the study between April 2009 and April2016. Wall thickness values were estimated and endocardial and epicardial borders were traced for calculation of ventricular volumesand mass. Four-chamber and short-axis cine and tagging sequences defined the borders to analyze deformation or myocardialstrain by feature tracking and myocardial tagging; values of global longitudinal, circumferential and radial strain were obtained andsegmental strain curves were established.Results: Mean ejection fraction in the overall population was 72%±9%. In the analysis of myocardial deformation by feature-trackingfrom 4-chamber and short-axis cine sequences, mean global longitudinal strain was -9.9%±3%, circumferential strain -14%±5%and radial strain 33%±10%. In the values obtained by myocardial tagging, mean global longitudinal and circumferential strainswere -7%±3% and -17%±3%, respectively.Conclusions: A global preserved ejection fraction was estimated in this population with hypertrophic cardiomyopathy, despite havinga significant decrease in longitudinal, circumferential and radial myocardial deformation. That is why the new analysis techniquesby cardiac MRI allow a deeper understanding of the real systolic function of patients suffering from this disease.

89-05: Validation of NOGA-derived assessment of left ventricular function against MRI

Purpose: Measurements of left ventricular (LV) systolic function, in particular strain, are gaining popularity as predictor of CRT effectiveness. Also, spatially accurate strain mapping, may help guiding intramyocardial biological therapy delivery and assessment. We recently developed a method for the simultaneous assessment of the LV electrical and mechanical activity. We sought to compare volume and strain measurements derived from electromechanical anatomical mapping (EMAM) with the gold standard technique, MRI. Methods: In 22 patients, EMAM maps (NOGA XP, BDS) and MRI images (3.0 T Magnetom Skyra, Siemens) were obtained within 1 month. MRI images were analyzed to obtain end-systolic (ESV), end-diastolic volumes (EDV) and ejection fractions (EF) from cine images and circumferential strain (CS) from MRI tagging images. EMAM was analyzed using custom software: volumes were calculated as the volume enclosed by the convex surface fitting the catheter tip positions, while CS was derived from the motion field of the catheter tip at the different locations. Regional peak CS values were averaged over points belonging to the same cardiac sector (6 sectors for the basal, mid and apical levels). Inter-technique agreement was tested through correlation and Bland-Altman analysis. Conclusion: This is the first study demonstrating the feasibility of assessing ventricular systolic function based on EMAM, and validating it against the current reference technique. The proposed approach allows the combined assessment of the electrical and mechanical activities without the need of error-prone separate strain and electrical imaging. EMAM-based strain analysis may be extended to the entire cardiac cycle, overcoming the limitations associated with the fading MRI tags.

Mitigation of Variability among 3D Echocardiography-Derived Regional Strain Values Acquired by Multiple Ultrasound Systems by Vendor Independent Analysis.

IntroductionThis study compared the variability of 3D echo derived circumferential and longitudinal strain values computed from vendor-specific and vendor-independent analyses of images acquired using ultrasound systems from different vendors.MethodsTen freshly harvested porcine hearts were studied. Each heart was mounted on a custom designed phantom and driven to simulate normal cardiac motion. Cardiac rotation was digitally controlled and held constant at 5°, while pumped stroke volume (SV) ranged from 30-70ml. Full-volume image data was acquired using three different ultrasound systems from different vendors. The image data was analyzed for longitudinal and circumferential strains (LS, CS) using both vendor-specific and vendor-independent analysis packages.ResultsGood linear relationships were observed for each vendor-specific analysis package for both CS and LS at the mid-anterior segment, with correlation coefficients ranging from 0.82–0.91 (CS) and 0.86–0.89 (LS). Comparable linear regressions were observed for results determined by a vendor independent program (CS: R = 0.82–0.89; LS: R = 0.86–0.89). Variability between analysis packages was examined via a series of ANOVA tests. A statistical difference was found between vendor-specific analysis packages (p<0.001), while no such difference was observed between ultrasound systems when using the vendor-independent program (p>0.05).ConclusionsCircumferential and longitudinal regional strain values differ when quantified by vendor-specific analysis packages; however, this variability is mitigated by use of a vendor-independent quantification method. These results suggest that echocardiograms acquired using different ultrasound systems could be meaningfully compared using vendor-independent software.

Left Ventricular Strain and Rotation by 2-D Speckle Tracking Echocardiography Identify Early Alcoholic Cardiomyopathy

This study assessed whether 2-D speckle tracking echocardiography (STE) derived from left ventricular (LV) strain and rotation is capable of detecting LV dysfunction associated with alcoholic cardiomyopathy. Ninety-two male chronic alcoholic patients were grouped by alcohol intake amount and duration: mild (n = 30; >90 mg ethanol daily, 3–5 d per wk for 5–8 y); moderate (n = 30; >90–150 mg ethanol daily, 3–5 d per wk for 9–20 y); and severe (n = 32; >150 mg ethanol daily, 6–7 d per wk for >10 y). Thirty non-drinkers were recruited as healthy controls. Rotation and twist values were lower in the severe group compared with the other groups (p < 0.05). The moderate and severe alcohol groups demonstrated lower longitudinal, circumferential and radial strain values and early to late filling (E/A) ratios compared with the mild group and non-drinkers (all p < 0.05). 2-D STE–derived strain and rotation are reliable echocardiographic markers for detecting left ventricular dysfunction in patients at risk of developing alcoholic cardiomyopathy.

22 Intra-ventricular myocardial deformation strain analysis in healthy volunteers: regional variation and implications for regional myocardial disease processes

Ejection fraction (EF) is a traditional marker of systolic function. However, it may not detect early, subtle cardiac disease with regional predilection. The aim of this study was to define regional intra-ventricular variation in myocardial strain in a cohort of healthy volunteers using Tissue-tracking cardiac magnetic resonance (CMR). Methods Healthy volunteers were recruited (n = 94, age range 20–79 years, 54% male). CMR at 1.5T was performed. Tissue-tracking software (CVI42, Circle Cardiovascular Imaging Inc.) estimated myocardial strain from the long-axis and the short-axis steady-state free precession (SSFP) cine images (Figure 1). The entire cohort was analysed by two independent readers. Inter-observer variability was also assessed. Myocardial segments were defined in accordance to the American Heart Association 16-segment model. Regional variations in circumferential and radial strain between basal, mid-cavity and apical segments as well as between left ventricle walls were assessed. Statistical analysis was performed using paired t test (p Results Inter-observer reproducibility analyses were excellent for mid-cavity and apical radial and circumferential strain values. On the other hand, reproducibility was not as good for basal segments for both deformation directions. Regional variations in strain (Table 1) revealed a statistically significant increase in deformation of the apical segments compared to the basal and mid-cavity ones for both radial and circumferential strain. Analysis of the different LV walls deformations indicated lowest values in the septum in all subjects, as well as across all age and gender subgroups. Conclusion This is the first study to demonstrate that there is a positive gradient toward the apex in both circumferential and radial strain using CMR-derived myocardial strain analysis. Furthermore, we also showed that the interventricular septum is the segment with lowest deformation values. These findings are important, as a comprehensive understanding of normal intra-ventricular regional variation is needed before this new tool can be implemented in routine clinical practice.