scholarly journals Regional right ventricular function in rats: a novel magnetic resonance imaging method for measurement of right ventricular strain

2020 ◽  
Vol 318 (1) ◽  
pp. H143-H153
Author(s):  
Emil K. S. Espe ◽  
Jan M. Aronsen ◽  
Einar S. Nordén ◽  
Lili Zhang ◽  
Ivar Sjaastad
Keyword(s):  
Molecular Markers ◽  
Right Ventricular ◽  
Strain Rate ◽  
Longitudinal Strain ◽  
Myocardial Strain ◽  
Area Under The Curve ◽  
Strain Rates ◽  
Pulmonary Congestion ◽  
Right Ventricular Strain ◽  
Rv Function

The function of the right ventricle (RV) is linked to clinical outcome in many cardiovascular diseases, but its role in experimental heart failure remains largely unexplored due to difficulties in measuring RV function in vivo. We aimed to advance RV imaging by establishing phase-contrast MRI (PC-MRI) as a robust method for measuring RV function in rodents. A total of 46 Wistar-Hannover rats with left ventricular (LV) myocardial infarction and 10 control rats (sham) were examined 6 wk after surgery. Using a 9.4-T preclinical MRI system, we utilized PC-MRI to measure strain/strain rate in the RV free wall under isoflurane anesthesia. Cine MRI was used to measure RV volumes. LV end-diastolic pressure (LVEDP) was measured and used to identify pulmonary congestion. The infarct rats were divided into two groups: those with signs of pulmonary congestion (PC), with LVEDP ≥ 15 mmHg ( n = 26) and those without signs of pulmonary congestion (NPC), with LVEDP < 15 mmHg ( n = 20). The NPC rats exhibited preserved RV strains/strain rates, whereas the PC rats exhibited reduced strains/strain rates (26–48% lower than sham). Of the strain parameters, longitudinal strain and strain rate exhibited the highest correlations to LVEDP and lung weight (rho = 0.65–0.72, P < 0.001). Basal longitudinal strain was most closely associated with signs of pulmonary congestion and indexes of RV remodeling. Longitudinal RV strain had higher area under the curve than ejection fraction for detecting subtle RV dysfunction (area under the curve = 0.85 vs. 0.67). In conclusion, we show for the first time that global and regional RV myocardial strain can be measured robustly in rodents. Reduced RV strain was closely associated with indexes of pulmonary congestion and molecular markers of RV remodeling. NEW & NOTEWORTHY Global and regional right ventricular myocardial strain can be measured with high reproducibility and low interobserver variability in rodents using tissue phase mapping MRI. Reduced right ventricular strain was associated with indexes of pulmonary congestion and molecular markers of right ventricular remodeling. Regional strain in the basal myocardium was considerably higher than in the apical myocardium.

Abstract 1966: Comparison of Right Ventricular Strain and Strain Rate in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy, Right Ventricular Outflow Tract Tachycardia, and Matched Controls

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Omid Salehian ◽  
Andrew P Klug ◽  
Jeffrey Healey ◽  
Ian G Burwash
Keyword(s):  
Right Ventricular ◽  
Strain Rate ◽  
Task Force ◽  
Arrhythmogenic Right Ventricular Cardiomyopathy ◽  
Myocardial Strain ◽  
Strain Rates ◽  
Systolic Strain ◽  
Ventricular Cardiomyopathy ◽  
Strain And Strain Rate ◽  
Fatty Replacement

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibro-fatty replacement of RV myocardium leading to ventricular tachycardia and sudden death in otherwise healthy individuals. Diagnosis is challenging as there are no diagnostic tests with adequate accuracy. Current diagnosis of ARVC is made by the task force criteria. One of the main diagnostic dilemmas continues to be distinguishing ARVC from a relatively benign entity of right ventricular out flow tract tachycardia (RVOT VT). Assessment of myocardial strain and strain rate has been used to study patients with ischemic heart disease and has shown utility in identifying subtle myocardial dysfunction not detected by routine wall motion assessment. The goal of this study was to compare myocardial strain and strain rates in patients with ARVC, RVOT VT and matched controls. Methods: We prospectively enrolled 12 patients with ARVC (based on task force criteria), 10 with RVOT VT, and 22 age and gender matched controls. Echo studies (including tissue Doppler derived myocardial strain echocardiography) were performed with commercially available systems (GE, Vivid 7). Peak systolic RV myocardial strain and strain rate were measured at base, mid, and apical RV free wall and compared. Results: ARVC patients had significantly lower peak systolic RV strain compared to both RVOT VT patients and matched controls (Table ). There was also significantly lower peak systolic strain rate at the apical RV myocardium in patients with ARVC compared to both those with RVOT VT (p=0.02) and controls (p=0.01). Conclusions: Patients with ARVC have abnormally low RV systolic strain and strain rates when compared to matched controls as well as those with RVOT VT. This modality can be routinely used in assessing patients suspected of ARVC as it might assist in earlier diagnosis as well as help in distinguishing patients with ARVC from those with RVOT VT. P<0.05 compared to controls, † P<0.05 compared to RVOT VT group

scholarly journals Assessment of Myocardial Mechanics in Acute Rheumatic Fever Using Speckle Tracking Echocardiography

2021 ◽  
Author(s):  
Utku Pamuk ◽  
Hazım Gursu ◽  
Emine Azak ◽  
İlker Çetin
Keyword(s):  
Right Ventricular ◽  
Strain Rate ◽  
Acute Phase ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Acute Rheumatic Fever ◽  
Speckle Tracking Echocardiography ◽  
Global Longitudinal Strain ◽  
Left Ventricular ◽  
Strain Rates

Objectives: This study aims to evaluate the role of speckle tracking echocardiography (STE) to identify myocardial deformation abnormalities in acute rheumatic fever. Methods: Twenty-seven patients and twenty-seven healthy children were studied prospectively. The patients were divided into two subgroups as moderate/severe carditis and mild/no carditis according to valve involvement. The left ventricular global longitudinal strain (LVGLS) and strain rate (LVGLSR), left ventricular global circumferential strain (LVGCS) and strain rate (LVGCSR), and right ventricular global longitudinal strain (RVGLS) and strain rate (RVGLSR) were examined by STE. Results: Left ventricular global longitudinal strain, LVGLSR, LVGCS, LVGCSR, RVGLS and RVGLSR were significantly lower in patients in acute phase of disease than controls. There were no differences in strain and strain rates between patient subgroups before treatment. After acute phase, statistically significant improvements were found in LVGLS, LVGLSR, LVGCSR values of the patients with moderate/severe carditis and LVGLS, LVGCS, LVGCSR, RVGLS, RVGLSR values of the patients with mild/no carditis. The strain parameters of the patients and controls did not differ significantly after the treatment. Conclusions: In acute phase of rheumatic heart disease, patients have reduced left and right ventricular strain and strain rates, which shows improvements after treatment.

scholarly journals Erebus Glacier Tongue, Mcmurdo Sound, Antarctica

1974 ◽  
Vol 13 (67) ◽  
pp. 27-35 ◽  
Author(s):  
G. Holdsworth
Keyword(s):  
Shear Stress ◽  
Strain Rate ◽  
Shear Strain ◽  
Longitudinal Strain ◽  
Strain Rates ◽  
Shear Strain Rate ◽  
Mcmurdo Sound ◽  
Glacier Tongue ◽  
The Past ◽  
Image Position

Examination of the past and present behaviour of the Erebus Glacier tongue over the last 60 years indicates that a major calving from the tongue appears to be imminent. Calculations of the regime of the tongue indicate that bottom melt rates may exceed 1 m a−1. By successive mapping of the ice tongue between the years 1947 and 1970, longitudinal strain-rates were determined using the change in distance between a set of 15 teeth, which are a prominent marginal feature of the tongue. Assuming a flow law for ice of the form where τ is the effective shear stress and is the effective shear strain-rate, values of the exponent n = 3 and B = 1 × 108 N m−2 are determined. These are in fair agreement with published values.

P674Behavior of 2D and 3D derived ejection fraction and strain in patients with Hodgkin and non-Hodgkin lymphoma undergoing anthracycline-based chemotherapy, a prospective study

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L F Nhola ◽  
T Daramola ◽  
S Barros-Gomes ◽  
J S Rico-Mesa ◽  
M C Arciniegas ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Right Ventricular ◽  
Strain Rate ◽  
Circumferential Strain ◽  
Area Under The Curve ◽  
Left Ventricular Ejection ◽  
Systolic Strain ◽  
Peak Systolic Strain ◽  
Diastolic Strain Rate ◽  
2D And 3D

Abstract Background Anthracyclines are one of the most effective chemotherapeutic agents but can lead to a decline in cardiac function. Two-dimensional (2D) speckle tracking echocardiography derived strain can predict cancer therapeutics-related cardiac dysfunction (CTRCD). However, little is known about the role of three-dimensional (3D) strain imaging in this setting. Purpose To evaluate different methods of Left Ventricular Ejection Fraction (LVEF) and strain, and to identify the best strain parameter for the prediction of CTRCD in this group of patients during treatment with anthracycline based chemotherapy. Methods Patients with Hodgkin's or non-Hodgkin's lymphoma receiving anthracycline based chemotherapy were enrolled. 2D-and 3D echocardiography was performed at 3 time points: baseline, at the completion of chemotherapy and at 1 year. 2D- and 3D LVEF (2D Modified Quinones, M-mode, 2D Biplane, 3D Philips, 3D GE and 3D TomTec), peak systolic left and right ventricular longitudinal, radial and circumferential strain and strain rate were measured. CTRCD was defined as a decrease in LVEF >10% to an absolute value of <53%. Lin's Concordance Correlation Coefficient (CCC) was calculated to compare LVEF methods. ANOVA, uni and multivariate analysis was performed. Results A total of 130 patients (79 males, mean age 57±16 years) were enrolled; 104 non-Hodgkin.3D Philips and GE (CCC 0.88 [0.84, 0.92]), 3D Philips and biplane (CCC 0.84 [0.79, 0.89]), 3D Philips and Modified Quinones (CCC 0.86 [0.82, 091]) as well as 3D Philips and M-mode (CCC 0.77 [0.70, 0.85]) showed strong correlation for LVEF. 15 patients (12%) developed CTRCD. Mean cumulative anthracycline dose was 263±65 mg/m2. 2D and 3D global longitudinal and circumferential peak systolic strain, 2D global longitudinal systolic and early diastolic strain rate, 2D global early diastolic strain rate, 2D right ventricular longitudinal peak systolic strain and systolic strain rate, 2D global radial peak systolic strain and systolic strain rate measured at the completion of chemotherapy were independent predictors of the development of CTRCD at 1 year post-chemotherapy. The strongest predictors of CTRCD were 3D global longitudinal and circumferential strain either individually (area under the curve, 0.90 and 0.95 respectively) or combined (area under the curve, 0.95) at the completion of chemotherapy; a cutoff value of <-18% in 3D global longitudinal strain had a sensitivity of 82% and specificity of 99%, while for 3D global circumferential peak systolic strain of <-24% had a sensitivity of 82% and specificity of 95%. Conclusions To our knowledge this is the first prospective trial that shows that 3D EF correlates well with other EF methods and 3D strain predicts cardiac toxicity in this group of patients with a very good sensitivity and specificity. Acknowledgement/Funding Department of Cardiovascular Medicine-Mayo Clinic Rochester MN

scholarly journals Primary Transverse Crevasses

1969 ◽  
Vol 8 (52) ◽  
pp. 107-129 ◽  
Author(s):  
G. Holdsworth
Keyword(s):  
Strain Rate ◽  
Longitudinal Strain ◽  
Critical Strain ◽  
Strain Rates ◽  
A Value ◽  
Regional Strain ◽  
Critical Strain Rate ◽  
Rate Gradient ◽  
Lines Of Evidence ◽  
Longitudinal Strain Rate

Measurements of strain-rates on a temperate glacier in a region of initial transverse fracturing indicate a critical strain-rate of 3.5±0.5 × 10−5d−1, associated with a regional strain-rate gradient of 5 × 10−8d−1m−1. At only one section of the glacier is the theoretical longitudinal strain-rate (Nye, 1959[c]) in approximate agreement with the value measured at the surface at that point. Corresponding measurements on a polar glacier (temperature −27.9°C at 10 m depth during the summer) indicate that the critical strain-rate is about 0.6±0.05 × 10−5d−1, which is associated with a gradient of strain rate of about 3 × 10−9d−1m−1. At one section there is close agreement between the theoretical and measured longitudinal strain-rate. For the temperate glacier crevasse depths ranged from 23.5 to 28 m; in the polar glacier one crevasse was 23.9±0.5 m deep, assuming a wedge form. Only an approximate agreement with the measured values of depth is obtained by using the regional strain-rate values in Nye’s crevasse-depth formula.Over a distance of 1.2 km the temperate glacier transverse crevasse spacings are very variable, ranging from 30 m to 96 m, but initially the spacings range from 55 m to 96 m, and for the first four cases the spacingsvaries from 2.7dto 3.3d, wheredis the crevasse depth. In the cold ice, crevasse spacings are far more uniform, ranging from 57 m to 66 m. A value ofs≈ 2.5dis obtained in only one case. This greater uniformity of spacing may be explained in terms of the dynamics of flow. Despite large differences in thermal, dimensional and strain-rate parameters between the two glaciers, (1) the crevasse depths are closely similar, and (2) the spacings of crevasses are similar. It has been demonstrated from two lines of evidence that the assumption that the strain on an intercrevasse block is negligible is not correct. The direction of the principal extending strain-rate is, in the most reliable cases, perpendicular to the crevasse traces within 2° to 7°.

scholarly journals Reproducibility and feasibility of right ventricular strain and strain rate (SR) as determined by myocardial speckle tracking during high-intensity upright exercise: a comparison with tissue Doppler-derived strain and SR in healthy human hearts

2014 ◽  
Vol 1 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Rachel N Lord ◽  
Keith George ◽  
Helen Jones ◽  
John Somauroo ◽  
David Oxborough
Keyword(s):  
Right Ventricular ◽  
Strain Rate ◽  
Exercise Intensity ◽  
Speckle Tracking ◽  
Tissue Doppler ◽  
Healthy Human ◽  
Velocity Imaging ◽  
Strain And Strain Rate ◽  
Right Ventricular Strain ◽  
Progressive Exercise

This study aimed to establish feasibility for myocardial speckle tracking (MST) and intra-observer reliability of both MST and tissue velocity imaging (TVI)-derived right ventricular (RV) strain (ε) and strain rate (SR) at rest and during upright incremental exercise. RV ε and SR were derived using both techniques in 19 healthy male participants. MST-derived ε and SR were feasible at rest (85% of segments tracked appropriately). Feasibility reduced significantly with progressive exercise intensity (3% of segments tracking appropriately at 90% maximum heart rate (HRmax)). Coefficient of variations (CoVs) of global ε values at rest was acceptable for both TVI and MST (7–12%), with low bias and narrow limits of agreement. Global SR data were less reliable for MST compared with TVI as demonstrated with CoV data (systolic SR=15 and 61%, early diastolic SR=16 and 17% and late diastolic SR=26 and 31% respectively). CoVs of global RV ε and SR obtained at 50% HRmax were acceptable using both techniques. As exercise intensity increased to 70 and 90% HRmax, reliability of ε and SR values reduced with larger variability in MST. We conclude that RV global and regional ε and SR data are feasible, comparable and reliable at rest and at 50% HRmax using both MST and TVI. Reliability was reduced during higher exercise intensities with only TVI acceptable for clinical and scientific use.

scholarly journals Right ventricular strain

2020 ◽  
Vol 4 (Issue 1) ◽  
pp. 16
Author(s):  
Oben Baysan ◽  
İlke Akyıldız
Keyword(s):  
Right Ventricular ◽  
Strain Rate ◽  
Ventricular Function ◽  
Right Ventricular Function ◽  
Rate Analysis ◽  
Right Ventricular Strain

This review is devoted to comprehensive echocardiographic analysis of right ventricular function -  right ventricular strain rate analysis.

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