Abstract 2570: Effects Of Exercise On Left Ventricular Diastolic Function Depend On Homogenous Increase In Diastolic Strain Rates

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Teck Hwa Goh ◽  
Zoran B Popovic ◽  
Adisai Buakhamsri ◽  
Neil Greenberg ◽  
James D Thomas

Objectives: It has been speculated that early diastolic left ventricular (LV) suction depends on LV apex relaxing more promptly than LV base, and that these relationships are accentuated during exercise. In this study, we sought to determine impact of exercise on the relationship between parameters of LV diastolic mechanics (peak early longitudinal (E SrL), circumferential (E SrC) and radial (E SrR) strain rate, and peak LV untwisting velocity) and intraventricular pressure gradient (IVPG) as marker of diastolic suction. Methods: We studied 23 healthy volunteers (age 38 ± 10 years, 13 females) by Vivid 7 ultrasound machine (GE) during supine bicycle stress. Segmental diastolic strain rates and untwisting velocity were obtained by speckle tracking software (EchoPac, GE Medical) while IVPG was measured by applying the Euler equation to the transmitral color Doppler M mode of the LV inflow. Segmental diastolic strain rates were averaged over basal, mid, and apical levels. Results: Absolute values of E SrL, E SrC and E SrR homogenously increased during exercise (P<0.001 for all) by the same degree at all LV three levels (p=NS for the difference between levels). (see table ) Untwisting velocity during exercise increased from -1.54 ± 0.69 to -3.40 ± 1.54 rad/s while IVPG increased from 1.41 ± 0.67 to 3.90 ± 1.69 mmHg (p<0.001 for both). Out of strain parameters, average E SrL increase during exercise showed strongest correlation with IVPG (r=0.64, p<0.001) and untwisting velocity (r=0.62, p<0.001). Higher untwisting velocity was associated with the greater IVPG (r=0.70, p<0.001). Conclusions: Increase of suction during exercise is related to homogeneous augmentation of relaxation throughout left ventricle. Longitudinal strain rate was the best predictor of the increase of untwisting velocity and IVPG. These data could serve as a reference for diastolic stress testing.

1969 ◽  
Vol 8 (52) ◽  
pp. 107-129 ◽  
Author(s):  
G. Holdsworth

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°.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Vasiliki Bistola ◽  
Ioannis Paraskevaidis ◽  
Ignatios Ikonomidis ◽  
Ioannis Parissis ◽  
Gerasimos Filippatos ◽  
...  

Objective: Levosimendan improves symptoms and the hemodynamic profile in patients with acutely decompensated chronic heart failure (ADCHF). We aimed to investigate: the association of low dose dobutamine (DSE)-induced changes of two-dimensional strain parameters with the corresponding changes of left ventricular ejection fraction (LVEF) and left ventricular outflow tract velocity time integral (LVOT VTI) in patients with ADCHF, and whether left ventricular contractile reserve assessed by both conventional and speckle tracking echocardiography is associated with clinical and neurohumoral improvement after levosimendan treatment. Methods: Thirty one consecutive patients with ADCHF (mean age 65 ± 10 years, NYHA class 3.6 ± 0.3, LVEF 22 ± 6%) were studied by DSE (peak dose 20 μg/kg/min) prior to 24-hour infusion of levosimendan (0.01 μg/kg/min, without bolus). The LVEF, LVOT VTI, mean longitudinal, circumferential and radial strain and strain rate using speckle tracking imaging were measured. Results: Twenty-three patients (74%) had evidence of contractile reserve (increase of LVEF > 10% and LVOT VTI > 20% after peak dobutamine dose, CR+), and 8 (26%) showed no reserve (CR−). CR+ versus CR- patients demonstrated greater improvement of NYHA class (mean NYHA change: −1.0±0.5 vs −0.5±0.3 NYHA class, p=0.01), and reduction of b-type natriuretic peptide levels (− 34±30 vs + 4±31%, p <0.01) 48 hours after completion of treatment. By multivariate analysis, mean longitudinal systolic strain rate reserve (resting - peak longitudinal strain rate ΔLSR (%)) was the best predictor of improvement of NYHA class (p= 0.039) and BNP (p= 0.042) after levosimendan administration among the reserve of: LV FS, EF, LVOT VTI, longitudinal strain, circumferential and radial strain and strain rate. Conclusion: Dobutamine-induced reserve of 2-dimentional speckle tracking longitudinal systolic strain rate is associated with clinical and neurohumoral improvement after treatment with levosimendan in patients with ADCHF.


2014 ◽  
Vol 2 (7) ◽  
pp. e12082 ◽  
Author(s):  
Hiroyuki Iwano ◽  
Min Pu ◽  
Bharathi Upadhya ◽  
Brett Meyers ◽  
Pavlos Vlachos ◽  
...  

2020 ◽  
pp. 1098612X2093225
Author(s):  
Keisuke Sugimoto ◽  
Takuma Aoki ◽  
Yoko Fujii

Objectives The purpose of this study was to determine the impact of ageing on the cardiovascular system of healthy adult cats. Methods Six experimental cats were used. Echocardiography and measurements of systolic blood pressure (SBP) were performed every year for 8 years (from 1 year of age to 8 years of age) in all cats. Age-related changes to left ventricular (LV) structures, LV systolic and diastolic function, and SBP were assessed. Results There were no significant changes in LV structures and SBP. Peak longitudinal strain rate during systole was decreased at 8 years of age, and peak longitudinal strain rate during diastole was decreased from 6 years of age. Conclusions and relevance This study revealed that some measures of cardiac function recorded in six healthy cats from 1 to 8 years of age were affected as the cats got older; however, there were no structural changes or changes in measurements that are routinely assessed in clinical practice.


1969 ◽  
Vol 8 (52) ◽  
pp. 107-129 ◽  
Author(s):  
G. Holdsworth

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 × 10−5 d−1, associated with a regional strain-rate gradient of 5 × 10−8 d−1 m−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 × 10−5 d−1, which is associated with a gradient of strain rate of about 3 × 10−9 d−1 m−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 spacing s varies from 2.7 d to 3.3 d, where d is the crevasse depth. In the cold ice, crevasse spacings are far more uniform, ranging from 57 m to 66 m. A value of s ≈ 2.5 d is 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°.


2016 ◽  
Vol 32 (5) ◽  
pp. 591-599 ◽  
Author(s):  
Kazunori Okada ◽  
Sanae Kaga ◽  
Taisei Mikami ◽  
Nobuo Masauzi ◽  
Ayumu Abe ◽  
...  

2021 ◽  
Author(s):  
Brett A. Meyers ◽  
Melissa C. Brindise ◽  
Shelby Kutty ◽  
Pavlos P. Vlachos

Abstract We present a new method for measuring global longitudinal strain and global longitudinal strain rate from 2D echocardiograms using a logarithmic-transform correlation (LTC) method. Traditional echocardiography strain analysis depends on user inputs and chamber segmentation, which yield increased measurement variability. In contrast, our approach is automated and does not require cardiac chamber segmentation and regularization, thus eliminating these issues. The algorithm was benchmarked against two conventional strain analysis methods using synthetic left ventricle ultrasound images. Measurement error was assessed as a function of contrast-to-noise ratio (CNR) using mean absolute error and root-mean-square error. LTC showed better agreement to the ground truth for strain (𝑹𝟐 = 𝟎. 𝟗1) and strain rate (𝑹𝟐 = 𝟎. 85) as compared to conventional algorithms (strain (𝑹𝟐 = 𝟎. 07), strain rate (𝑹𝟐 = 𝟎. 07)) and was unaffected by CNR. A 200% increase in strain measurement accuracy was observed compared to the conventional algorithms. Subsequently, we tested the method using a 54-subject clinical cohort (20 subjects diseased with cardiomyopathy, 34 healthy controls). Our method distinguished between normal and abnormal left ventricular function with an AUC = 0.85, a 10% improvement over the conventional GLS algorithms.


Author(s):  
Utku Pamuk ◽  
Hazım Gursu ◽  
Emine Azak ◽  
İlker Çetin

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.


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