scholarly journals Gradients of strain and strain rate in the hollow muscular organs of soft-bodied animals

2010 ◽  
Vol 6 (4) ◽  
pp. 482-485 ◽  
Author(s):  
Joseph T. Thompson ◽  
Kari R. Taylor ◽  
Christopher Gentile
Keyword(s):  
Strain Rate ◽  
Outer Surface ◽  
Circumferential Strain ◽  
Circular Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Cylindrical Shape ◽  
Strain And Strain Rate ◽  
Inner Surface ◽  
The Difference

The cylindrical shape of soft-bodied invertebrates is well suited to functions in skeletal support and locomotion, but may result in a previously unrecognized cost—large non-uniformities in muscle strain and strain rate among the circular muscle fibres of the body wall. We investigated such gradients of strain and strain rate in the mantle of eight long-finned squid Doryteuthis pealeii and two oval squid Sepioteuthis lessoniana . Transmural gradients of circumferential strain were present during all jets ( n = 312); i.e. for a given change in the circumference of the outer surface of the mantle, the inner surface experienced a greater proportional change. The magnitude of the difference increased with the amplitude of the mantle movement, with circular muscle fibres at the inner surface of the mantle experiencing a total range of strains up to 1.45 times greater than fibres at the outer surface during vigorous jets. Differences in strain rate between the circular fibres near the inner versus the outer surface of the mantle were also present in all jets, with the greatest differences occurring during vigorous jetting. The transmural gradients of circumferential strain and strain rate we describe probably apply not only to squids and other coleoid cephalopods, but also to diverse soft-bodied invertebrates with hollow cylindrical or conical bodies and muscular organs.

Improvement of Method and Mechanism for Conical and Paraboloid Springs Hardening

2021 ◽  
Vol 1037 ◽  
pp. 227-232
Author(s):  
Nikita A. Zemlyanushnov ◽  
Nadezhda Y. Zemlyanushnova
Keyword(s):  
New Method ◽  
Cylindrical Shape ◽  
Plastic Deformations ◽  
Conical Shape ◽  
Inner Surface ◽  
Hardening Mechanisms ◽  
The Difference ◽  
Compression Springs

The disadvantage of the known methods of hardening springs is the impossibility of their use when hardening springs of a conical shape or of a shape of a paraboloid of rotation, since they are intended only for cylindrical shape springs and are not suitable for conical shape springs or those of a shape of a paraboloid of rotation specifically because of the difference in the shape of the springs. One of the disadvantages of the known springs hardening mechanisms is the impossibility of hardening the inner surface of the conical compression springs. A new method of hardening springs is proposed, the unmatched advantage of which is the ability to create plastic deformations on the inner and outer surfaces of the spring coils compressed to contact and on the surfaces along the line of contact between the coils. A new advantageous mechanism for hardening springs is proposed, which makes it possible to harden the inner surface of compression springs having a conical shape or a paraboloid shape of rotation, in a compressed state.

Abstract 15057: Electromechanical Discoordination is Present in Patients With Duchenne Muscular Dystrophy Independent of Tissue Fibrosis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Alex Hoffner Heinike ◽  
Michal Schafer ◽  
Benjamin Frank ◽  
Dunbar D IVY ◽  
Alex Barker ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Strain Rate ◽  
Circumferential Strain ◽  
Ventricular Dysfunction ◽  
Strain And Strain Rate ◽  
Tissue Tracking ◽  
Diastolic Relaxation ◽  
Cardinal Symptom ◽  
Sensitive Marker

Introduction: Progressive ventricular dysfunction is a cardinal symptom in Duchenne Muscular Dystrophy (DMD). Some of the earliest signs of cardiomyopathy in DMD are myocardial fibrotic deposition and LV strain defects. Electromechanical discoordination, as measured by Systolic Stretch Fraction (SSF) and Diastolic Relaxation Fraction (DRF), has been shown to be a sensitive marker of ventricular dysfunction. The presence of this discoordination in relation to fibrotic deposition in DMD has yet to be elucidated. Hypothesis: Patients with DMD will have abnormal SSF and DRF on cardiac MRI (CMR) tissue tracking analysis and associated with fibrotic deposition. Methods: Patients with DMD (n=31)(mean age: 14 ± 4 yrs) and controls (n=20) (mean age: 15 ± 3 yrs) underwent CMR for volumetric and functional analysis as well as Gadolinium (Gd) enhancement to evaluate the presence of fibrosis. Circumferential strain and strain rate indices from each segment were used to calculate electromechanical discoordination. Strain rate data was used to calculate SSF and DRF. Results: Patients with DMD showed increased median LV SSF compared to controls [0.027 (IQR: 0.015-0.041) vs 0.007 (IQR:0.005-0.013), P = 0.002] as well as increased median LV DRF [0.371 (IQR: 0.310-0.473) vs 0.300 (IQR: 0.264-0.325), P < 0.001] (Figure). When comparing Gd(+) (n=14) vs Gd(-) (n=17) DMD patients, there was no difference between groups in either SSF [0.027 (IQR: 0.016-0.042) vs 0.026 (IQR: 0.008-0.040), P= 0.929] or DRF [0.371 (IQR: 0.309-0.537) vs 0.379 (IQR: 0.322-0.464), P= 0.931]. The SSF was associated with ESVi (R=0.71, P<0.001), EDVi (R=0.65, P< 0.001) and inversely associated with EF (R=-0.63, P<0.001). Conclusion: Patients with DMD showed increased levels of LV electromechanical discoordination independent of qualitative presence of fibrosis noted by Gd enhancement. This allows speculation that changes in electromechanical discoordination may precede visible fibrotic change in DMD.

Reference values for two-dimensional myocardial strain echocardiography of the left ventricle in healthy children

2019 ◽  
Vol 29 (3) ◽  
pp. 325-337
Author(s):  
Laurens P. Koopman ◽  
Bas Rebel ◽  
Devi Gnanam ◽  
Mirthe E. Menting ◽  
Willem A. Helbing ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Strain Rate ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Left Ventricular ◽  
Myocardial Deformation ◽  
Healthy Children ◽  
Deformation Parameters ◽  
Strain And Strain Rate ◽  
Echocardiographic Parameters

AbstractBackgroundMyocardial deformation by speckle tracking echocardiography provides additional information on left ventricular function. Values of myocardial deformation (strain and strain rate) depend on the type of ultrasound machine and software that is used. Normative values for QLAB (Philips) are scarce, especially for children. It is important to evaluate the influence of age and body size on myocardial deformation parameters, since anthropometrics strongly influence many standard echocardiographic parameters. The aim of this study was to provide comprehensive normal values for myocardial deformation of the left ventricle using a Philips platform and to evaluate the association with anthropometric and standard echocardiographic parameters.MethodsHealthy children between 1 and 18 years of age were prospectively examined using a standard echocardiographic protocol. Short-axis and apical four-chamber, two-chamber, and three-chamber views were used to measure peak systolic circumferential and longitudinal strain and systolic and early diastolic strain rate of the left ventricle using dedicated software.ResultsA total of 103 children were included with a mean age of 10.8 and inter-quartile range 7.3–14.3 years. Global circumferential strain values (±SD) were −24.2±3.5% at basal, −25.8±3.5% at papillary muscle, and −31.9±6.2% at apex levels. Global left ventricular longitudinal strain values were −20.6±2.6% in apical four-chamber view, −20.9±2.7% in apical two-chamber, and −21.0 ±2.7% in apical three-chamber. Age was associated with longitudinal strain, longitudinal systolic and early diastolic strain rate, but not with circumferential strain.ConclusionsNormal values for left ventricular deformation parameters in children are obtained using a Philips platform. Age partly explains normal variation of strain and strain rate.

Gross anatomy of the muscle systems and associated innervation of Apatemon cobitidis proterorhini metacercaria (Trematoda: Strigeidea), as visualized by confocal microscopy

Parasitology ◽  
2003 ◽  
Vol 126 (3) ◽  
pp. 273-282 ◽  
Author(s):  
M. T. STEWART ◽  
A. MOUSLEY ◽  
B. KOUBKOVÁ ◽  
š. šEBELOVÁ ◽  
N. J. MARKS ◽  
...  
Keyword(s):  
Nervous System ◽  
Oral Sucker ◽  
Body Wall ◽  
Circular Muscle ◽  
Gross Anatomy ◽  
The Body ◽  
Muscle Fibres ◽  
Filamentous Actin ◽  
Attachment Structures ◽  
A Site

The major muscle systems of the metacercaria of the strigeid trematode, Apatemon cobitidis proterorhini have been examined using phalloidin as a site-specific probe for filamentous actin. Regional differences were evident in the organization of the body wall musculature of the forebody and hindbody, the former comprising outer circular, intermediate longitudinal and inner diagonal fibres, the latter having the inner diagonal fibres replaced with an extra layer of more widely spaced circular muscle. Three orientations of muscle fibres (equatorial, meridional, radial) were discernible in the oral sucker, acetabulum and paired lappets. Large longitudinal extensor and flexor muscles project into the hindbody where they connect to the body wall or end blindly. Innervation to the muscle systems of Apatemon was examined by immunocytochemistry, using antibodies to known myoactive substances: the flatworm FMRFamide-related neuropeptide (FaRP), GYIRFamide, and the biogenic amine, 5-hydroxytryptamine (5-HT). Strong immunostaining for both peptidergic and serotoninergic components was found in the central nervous system and confocal microscopic mapping of the distribution of these neuroactive substances revealed they occupied separate neuronal pathways. In the peripheral nervous system, GYIRFamide-immunoreactivity was extensive and, in particular, associated with the innervation of all attachment structures; serotoninergic fibres, on the other hand, were localized to the oral sucker and pharynx and to regions along the anterior margins of the forebody.

scholarly journals Left ventricular systolic function impairment in children after balloon valvuloplasty for congenital aortic stenosis assessed by 2D speckle tracking echocardiography

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248862
Author(s):  
Krzysztof Godlewski ◽  
Paweł Dryżek ◽  
Elżbieta Sadurska ◽  
Bożena Werner
Keyword(s):  
Strain Rate ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Systolic Function ◽  
Global Longitudinal Strain ◽  
Left Ventricular ◽  
Strain And Strain Rate ◽  
Eccentric Hypertrophy

Aims The aim of the study was to evaluate left ventricular (LV) remodeling and systolic function using two-dimensional speckle tracking echocardiographic (2D STE) imaging in children at a long-term (more than 36 months, 107.5±57.8 months) after balloon valvuloplasty for aortic stenosis (BAV). Methods and results 40 patients (mean age 9,68 years, 75% male) after BAV and 62 control subjects matched to the age and heart rate were prospectively evaluated. The 2D STE assessment of LV longitudinal and circumferential strain and strain rate was performed. Left ventricular eccentric hypertrophy (LVEH) was diagnosed in 75% of patients in the study group. Left ventricular ejection fraction (LVEF) was normal in all patients. In study group, global longitudinal strain (GLS), global longitudinal strain rate (GLSr) were significantly lower compared with the controls: GLS (-19.7±2.22% vs. -22.3±1.5%, P< 0.001), GLSr (-0.89±0.15/s vs. -1.04 ±0.12/s, P < 0.001). Regional (basal, middle and apical segments) strain and strain rate were also lower compared with control group. Global circumferential strain (GCS), global circumferential strain rate (GCSr) as well as regional (basal, middle and apical segments) strain and strain rate were normal. Multivariable logistic regression analysis included: instantaneous peak systolic Doppler gradient across aortic valve (PGmax), grade of aortic regurgitation (AR), left ventricular mass index (LVMI), left ventricular relative wall thickness (LVRWT), left ventricular end-diastolic diameter (LVEDd), peak systolic mitral annular velocity of the septal and lateral corner (S’spt, S’lat), LVEF before BAV and time after BAV and showed that the only predictor of reduced GLS was LV eccentric hypertrophy [odds ratio 6.9; (95% CI: 1.37–12.5), P = 0.045]. Conclusion Patients at long-term observation after BAV present the subclinical LV systolic impairment, which is associated with the presence of its remodeling. Longitudinal deformation is the most sensitive marker of LV systolic impairment in this group of patients.

Abstract 5736: Diagnosis of Chronic Myocardial Ischemia by Speckle Tacking Echocardiography -A Comparative Animal Study-

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Koichi Kimura ◽  
Katsu Takenaka ◽  
Kansei Uno ◽  
Aya Ebihara ◽  
Katsuhito Fujiu ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Strain Rate ◽  
Speckle Tracking ◽  
Circumferential Strain ◽  
Radial Strain ◽  
Peak Strain ◽  
Short Axis ◽  
Short Axis View ◽  
Strain And Strain Rate ◽  
Axis View

A number of systolic and diastolic indexes for ischemic damage can be measured by 2D speckle tracking echocardiography (STE) including radial strain and strain rate as well as circumferential strain and strain rate on LV short-axis view. In addition, they could be derived from the subendocardium, subepicardium, mid-layer or total layer of the LV wall with new tracking software. The aim of our study is to compare the diagnostic abilities of these indexes in animal experiments. An Ameroid constrictor was placed around the left circumflex coronary artery in 19 pigs. Before and 4 weeks after the surgery, LV short-axis images were obtained at rest by transthoracic 2D echocardiography. Three pigs that had died after the surgery and 2 that had focal infarction in pathological studies were excluded from the study. Thus, in 14 pigs with 99% stenosis on coronary angiograms, we measured peak strain, peak S′, peak E′, time from QRS to peak strain, time from QRS to E′, and incidence of post-systolic shortening (PSS) in the endocardium, midcardium, and epicardium of the LV posterior wall using a new prototype speckle tracking software. None of the time indexes and PSS showed statistically significant results. ROC curve analysis (Table ) revealed that endocardial circumferential strain is the most diagnostic index of ischemia, which showed 79% sensitivity and 93% specificity. Endocardial circumferential strain measured by STE on LV short-axis view was the most useful index for detecting chronic severe myocardial ischemia. Table. Results of measurement in chronic ischemia(mean±SD)

Description of growth in the tropical cuttlefish Sepia elliptica using muscle tissue

1999 ◽  
Vol 79 (2) ◽  
pp. 317-321 ◽  
Author(s):  
P. Martínez ◽  
N.A. Moltschaniwskyj
Keyword(s):  
Muscle Tissue ◽  
Size Range ◽  
Muscle Growth ◽  
Growth Dynamics ◽  
Block Size ◽  
Circular Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Growth Mechanisms ◽  
Radial Muscle

The mantle muscle tissue of cuttlefish is predominantly made up of circular muscle fibres which run around the body. This circular muscle tissue is divided into discrete blocks by radial fibres, which run perpendicular to the main axis of the body. Growth of mantle muscle tissue was described in the tropical cuttlefish Sepia elliptica by examining muscle block size and the density and size distribution of muscle fibres. Changes in these variables were assessed in juvenile and adult cuttlefish. Generation of new muscle fibres, both within new and existing muscle blocks, occurred as animals grew across the size range. Anterior muscle blocks were smaller than muscle blocks in the middle and posterior regions of the mantle, suggesting that new blocks were generated anteriorly. Muscle blocks were also created in the middle and posterior regions by division of existing large blocks into small blocks by generation of circular and radial muscle fibres. The examination of cuttlefish muscle growth dynamics provided an alternative way of assessing cephalopod growth mechanisms.

scholarly journals Reduction of left atrial strain and strain rate during conduit phase as the earliest marker of left ventricular diastolic disfunction

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
A Savelev ◽  
OV Solovev ◽  
MA Baturova ◽  
YV Shubik
Keyword(s):  
Strain Rate ◽  
Left Atrial ◽  
Area Under The Curve ◽  
Left Ventricular ◽  
Left Atrial Strain ◽  
Single Plane ◽  
Strain And Strain Rate ◽  
Significant Difference ◽  
The Difference ◽  
Grade 3

Abstract Funding Acknowledgements Type of funding sources: None. Left atrial (LA) functional abnormalities, including LA strain (LAS) and strain rate (LASR) reduction, are observed in patients with left ventricular diastolic disfunction (LVDD). However, the degree of reduction at different stages of LVDD is not fully clarified. We aimed to assess the interdependence between LAS and LASR parameters and LVDD grades in subjects of advanced age with preserved ejection fraction (EF). Material and methods Consecutive patients, who underwent echocardiography within 12 months, were screened and included into the study in case of age older than 65 years, preserved EF, sinus rhythm at the time of study and preserved dataset of sufficient quality for speckle tracking analysis. LAS and LASR parameters, including LAS and peak LASR during reservoir, conduit, and contractile phases were calulated with single plane apical 4-chamber view assessment. One-way ANOVA analysis with Bonferroni correction was used to assess the difference between groups. Results Among 153 patients (mean age 74 ± 7 years; 105 female, mean EF 64 ± 5%) included in the study there were 38 patients with no evidence of LVDD, 67 with LVDD grade 1, 40 with LVDD grade 2, and 5 with LVDD grade 3. The values of LAS and LASR parameters for these groups are summarized in Table. All parameters were significantly reduced in grade 2 and 3 LVDD patients comparing to the patients with no LVDD. Contractile phase LAS and LASR were slightly higher in grade 1 than in no LVDD patients. Reservoir and conduit phase LAS and LASR were lower in grade 1 LVDD comparing to no LVDD, but only for conduit phase parameters the difference was significant. In ROC analysis for conduit phase LAS and LASR to be associated with the presence of LVDD of any grade the  area under the curve was 0,707 (p &lt; 0.001) and 0,742 (p &lt; 0.001) respectively. Conclusion Impaired LA function is seen in patients with LVDD. Whereas measurements characterizing LA reservoir and contractile functions demonstrate significant decrease at advanced stages of LVDD, conduit function is significantly reduced at grade 1 LVDD, providing the possibility for early detection of LVDD. Group LAS (%) LASR (1/sec) reservoir conduit contractile reservoir conduit contractile No LVDD, n = 38 29,7 ± 9,3 †‡ 15,1 ± 6,6 §†‡ 14,6 ± 5,4 †‡ 1,28 ± 0,37 †‡ 1,18 ± 0,44 §† 1,68 ± 0,60 †‡ Grade 1, n = 69 28,6 ± 8,9 †‡ 11,6 ± 6,2 ƒ 17,0 ± 5,7 †‡ 1,23 ± 0,43 ‡ 0,90 ± 0,38 ƒ 1,99 ± 0,71 †‡ Grade 2, n = 40 19,1 ± 7,1 ƒ§ 9,2 ± 4,5 ƒ 9,9 ± 4,4 ƒ§ 0,87 ± 0,26 ƒ§ 0,72 ± 0,27 ƒ 1,07 ± 0,44 ƒ§ Garde 3, n = 5 13,8 ± 3,6 ƒ§ 7,7 ± 2,5 ƒ 6,1 ± 2,2 ƒ§ 0,8 ± 0,29 ƒ 0,75 ± 0,28 0,67 ± 0,27 ƒ§ Significant difference (p &lt; 0,05): ƒ – with No LVDD, § – with Grade 1 LVDD, † – with Grade 2 LVDD, ‡ – with Grade 3 LVDD

scholarly journals Two-dimensional speckle tracking echocardiography in goats: repeatability, variability, and validation of the technique using an exercise test and an experimentally induced acute ischemic cardiomyopathy.

2019 ◽  
Author(s):  
Aurelia A Leroux ◽  
Marie Moonen ◽  
Frédéric Farnir ◽  
Stefan Deleuze ◽  
Charlotte Sandersen ◽  
...  
Keyword(s):  
Strain Rate ◽  
Rotation Rate ◽  
Speckle Tracking ◽  
Ischemic Cardiomyopathy ◽  
Animal Species ◽  
Circumferential Strain ◽  
Radial Strain ◽  
Two Dimensional ◽  
Pathological Changes ◽  
Strain And Strain Rate

Abstract Background : Two-dimensional speckle tracking (2DST) technique has been validated in numerous animal species, but neither studies of repeatability nor measurements after exercise or in animals with cardiac disease have been reported in goats. Goats are an attractive candidate for animal models in human cardiology because they are easy to handle and have a body and heart size comparable to that of humans. Therefore, the aim of this study was to validate this technique in goats for further clinical and experimental applications in this species. Methods: This study was divided into several steps. First, a standardized echocardiographic protocol was performed and 5 cineloops of a right parasternal short-axis view at papillary muscles level were recorded three times at one-day intervals in ten healthy adult unsedated Saanen goats to test repeatability and variability of 2DST measurements. Then, the same measurements were performed immediately before and after a standardized exercise on treadmill in seven of the goats, and at 24h after induction of an experimental ischemic cardiomyopathy in five of the goats, to test the reliability of the technique to assess physiological and pathological changes. Average and regional measurements of radial and circumferential strain and strain rate, radial displacement, rotation and rotation rate were obtained. Comparisons were performed using ANOVA II (p<0.05). Results: Caprine 2DST average measurements have demonstrated a good repeatability with a low to moderate variability for all measurements except for the diastolic peaks of the circumferential strain rate, radial strain rate and rotation rate. Segmental 2DST measurements were less repeatable than average measurements. Time effect of ANOVA II was significant for anteroseptal segment diastolic peaks measurements, rotation and rotation rate measurements. Overall variability of segmental measurements was moderate or high. Segmental and average peak values obtained after exercise and after myocardial ischemia were significantly different than curves obtained at baseline. Conclusions: The results of this study are consistent with those previously described in other animal species and humans. 2DST echocardiography is a valid technique to evaluate physiological and pathological changes in myocardial function in goats, despite the technical limitations observed in this species.

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