Peak Strain Values Research Articles

Correlation of 99Tcm-MIBI gated myocardial perfusion SPECT imaging and two-dimensional speckle tracking imaging in swine model of myocardial infarction

Objective To evaluate the value of speckle tracking imaging(STI) by investigating the correlation and consistency between two-dimensional STI and 99Tcm-MIBI G-MPI in the assessment of myocardial injury and myocardial infarction (MI) of swine model. Methods Eight healthy and same-age adult female Tibetan swine were used to establish animal models of MI induced by open-chest ligation of the first diagonal branch of the left anterior descending coronary artery. The swine underwent ultrasonic cardiogram and G-MPI before and at 6, 24, 48, 72 and 96 h after the operation. The myocardial perfusion was evaluated. Ultrasonic sectional graphs were collected to analyze ultrasonic short-axis horizontal peak values of systolic radial strain (SR) and systolic circumferential strain (SC) and local myocardial rotation angle (Rot) of different segments of the left ventricle with off-line STI. Left ventricular (LV) EDV, LVESV, LVEF by G-MPI and ultrasonography were compared. Pearson correlation analysis and repeated measures analysis of variance were used. Results Six models were successfully constructed. Six hours after the coronary artery ligation, the G-MPI showed no significant or very few perfusion defects; 24, 48, 72 and 96 h after the ligation, G-MPI showed sparseness and defects at the anterior septum, anterior and lateral wall of apical segment of apical segment. The peak strain values of SR, SC and Rot at the anterior septal apical segment, the anterior and lateral wall of apical segment decreased at different time points after the ligation. Six hours after the coronary artery ligation, the STI was positive. For healthy swine, the LVEF measured with G-MPI and ultrasonic STI showed good correlation ((68±3)% vs (70±4)%, r=0.84, P<0.05). The LVEF values of G-MPI and ultrasonic STI at 6, 24, 48, 72, 96 h after the ligation were (79±1)%, (80±4)%, (58±2)%, (54±4)%, (57±4)%, and(76±2)%, (76±3)%, (57±3)%, (55±3)%, (68±6)% (r: 0.40-0.76, all P<0.05). LVEDV and LVESV measured by the two methods showed variation trends at different time points (F=64.104, 30.069, 35.186, 54.903, all P<0.01) with good consistency after the ligation. Conclusions Ultrasonic STI could estimate the myocardial injury at an earlier stage and measure the severity of damaged myocardium quantitatively, and the resluts are in good agreement with myocardial perfusion and function by G-MPI. Key words: Myocardial infarction; Tomography, emission-computed, single-photon; Ultrasonography; Swine; MIBI

Abstract 11125: Increasing Stimulus Strength of Coronary Sinus Pacing Improved Left Ventricular Mechanical Dyssynchrony and Contractile Function in Patients With Reduced Ejection Fraction

Introduction: Increasing stimulus strength of left ventricular (LV) coronary sinus pacing decreases QRS duration and inter-ventricular conduction time. Hypothesis: Increasing stimulus strength of LV coronary sinus pacing improves LV mechanical dyssynchrony and myocardial function. Methods: We studied 36 patients with 6±4 months after cardiac resynchronization therapy (LV ejection fraction: 39±11%). The LV pacing lead was positioned in lateral or posterolateral coronary sinus vein. We measured standard deviation (SD) of time to negative peak circumferential strain (time-CircS) in 6 segments and peak global circumferential strain value (CircS) using two-dimensional speckle-tracking echocardiography to evaluate LV mechanical dyssynchrony and myocardial contractile function, respectively. Low (1.3±0.6V), clinical (2.6±1.0V), and high (7.3±1.1V) voltage conditions of LV coronary sinus pacing were performed under right ventricular pacing-off. Results: SD of time-CircS and global CircS under high voltage LV coronary sinus pacing was significantly better than those under low and clinical voltage (78±38 vs. 90±48 and 92±43msec, p=0.014 and 0.016; 5.7±3.4 vs. 5.4±3.3 and 5.4±3.4%, p=0.007 and 0.003). Moreover, global CircS significantly correlated with SD of time-CircS (r= -0.54, p&lt;0.001, n=108). Conclusions: Increasing stimulus strength of LV coronary sinus pacing improved LV mechanical dyssynchrony and LV contractile function, leading clinical implication for better management of heart failure patients with cardiac resynchronization therapy.

PP.08.16

Objective: Hypertension(HTN) has severe consequences to the heart, leading to morphological and functional remodeling of left atrium. We sought to assess left atrial(LA) mechanical function in a group of hypertensives, matching it with healthy controls. Design and method: We prospectively enrolled 35 consecutive hypertensive patients (mild, moderate and severe HTN but pharmacological treated subjects). The secondary causes of hypertension, as well as significant valvular disease, thyroid dysfunctions, diabetes mellitus or any other important organ abnormality were excluded. LA diameters(antero-posterior, tranverse and longitudinal) LA volumes were measured by echocardiography, using the modified biplane Simpson method: maximal LA(LAV max), preatrial contraction LA(LAV preA) and minimal LA volume(LAV min). LA emptying functions were calculated: LA total EF(LAV max-LAVmin)/LAV max, LA passive EF = (LAVmax-LAVpreA)/LAVmax and LA active EF(LAVpreA-LAVmin)/LAVpreA. Peak longitudinal strain of LA walls were analysed using 2D speckle-tracking echocardiography. The results were compared with a group of 37 age-matched healthy controls. Results: In the HTN group the mean time of arterial hypertension diagnosis was 33 months and the mean blood pressure(24 hour ambulatory blood pressure monitoring) was 139/74mmHg. LA antero-posterior diameter and all the volumes(LAVmax, LAVmin and LAVpreA) were significantly greater in hypertensives compared to controls(p < 0.0001), while the transversal and longitudinal diameters were similar. LA active EF was similar between the two groups, but we found significantly lower LA passive and total EF in hypertensives than in the control group(p < 0.0001). The peak strain values were also significantly lower in HTN group compared to control(22.7 versus 35.1, p < 0.0001). Conclusions: In our study, arterial hypertension was associated with increased LA size (anteroposterior diameter and volumes), a decrease in LA passive EF and in LA total EF, with preserved atrial pump function. LA dysfunction was also demonstrated through low peak strain values.

Strain field measurements around notches using SIFT features and meshless methods.

This work proposes a hybrid experimental-numerical technique with the aim to improve strain measurements at stress concentration regions. The novel technique is performed employing the computer vision scale invariant feature transform (SIFT) algorithm and meshless methods, here termed SIFT-meshless. The SIFT is applied to perform feature points matching in two images of the specimen surface at different stages of mechanical deformation. The output data are provided as a set of displacement measurements by tracking matched feature points. This information is then used to model displacement and strain field on the surface by means of a meshless formulation based on the moving least squares approximation. By applying the proposed SIFT-meshless method, the strain distribution around a semicircular notch in a plate under bending load was investigated. The experimental results were compared with those obtained by a digital image correlation technique based on a subset approach and to simulations from finite element analysis software. The experimental results demonstrated that the present method is capable of performing reliable strain measurements at distances close to the notch where the peak strain value is expected, even in the presence of high strain gradients.

Incremental value of resting three-dimensional speckle-tracking echocardiography in detecting coronary artery disease

The aim of the present study was to investigate the incremental value of resting three-dimensional speckle-tracking echocardiography (3D-STE) in the detection of early-stage left ventricular dysfunction in patients with coronary artery disease (CAD). A total of 110 patients suspected of having CAD were recruited. All patients underwent 3D-STE and coronary artery angiography (CAG). They were divided to a CAD group and a normal group according to the results of CAG. Using 3D-STE software, the peak values of longitudinal strain (LS), circumferential strain (CS), radial strain (RS) and area strain (AS) and the time to peak value of these strains (T-LS, T-CS, T-RS and T-AS) were measured. A receiver operator characteristic curve (ROC) was used to analyze the sensitivity of these strains for the diagnosis of CAD. ROC analysis indicated that T-LS and composite indices combining the peak strain value and time to peak of LS, CS and AS have diagnostic value for the early detection of CAD; the area under the curve (AUC) values were 0.667, 0.692, 0.621 and 0.672 respectively (P<0.005). The composite index of longitudinal strain demonstrated the highest diagnostic value for CAD with 62% sensitivity and 76% specificity. These results indicate that 3D-STE has incremental value for the diagnosis of CAD in patients at rest.

Effects of exercise training on systo–diastolic ventricular dysfunction in patients with hypertension: an echocardiographic study with tissue velocity and strain imaging evaluation

There is a lack of detailed data regarding the effect of exercise training in pharmacologically treated hypertensive patients. Therefore, the aim of this study was to evaluate the effects of exercise training on left and right ventricular morphologic and functional parameters by means of conventional echocardiography and sensitive new echocardiographic techniques including tissue Doppler velocity and strain imaging, that were performed in pharmacologically treated hypertensive patients at baseline and at the end of a specific exercise training protocol for primary prevention of cardiovascular disease. We selected 116 pharmacologically treated hypertensive patients who completed the exercise training protocol. All patients underwent a clinical history and examination; transthoracic echocardiography and exercise testing were performed at baseline and at the end of the exercise training protocol. Conventional echocardiography revealed a mild degree of diastolic dysfunction without significant differences or variations from baseline to the end of the exercise training protocol. In contrast, tissue Doppler velocity and strain imaging measurements demonstrated and highlighted the positive influence of exercise training: for both left and right ventricle myocardial early peak diastolic velocities (Em), the ratio of myocardial early-late peak diastolic velocity (Em/Am), myocardial peak systolic velocities (Sm) and peak strain and strain rate values significantly increased at the end of the exercise training protocol, suggesting a relationship between exercise capacity and both left and right ventricular systo-diastolic function. Our study, by means of newer more sensitive echocardiographic techniques, clearly demonstrated the positive impact of exercise training on both left and right ventricular systo-diastolic function, in terms of adjunctive subclinical improvement, in pharmacologically treated hypertensive patients.

Relationship of left atrial global peak systolic strain with left ventricular diastolic dysfunction and brain natriuretic peptide level in patients presenting with non-ST elevation myocardial infarction.

BackgroundIn patients presenting with non-ST elevation myocardial infarction, we investigated the relationship of left atrial deformational parameters evaluated by 2-dimensional speckle tracking imaging (2D-STI) with conventional echocardiographic diastolic dysfunction parameters and brain natriuretic peptide level.Material/MethodsWe enrolled 74 non-ST segment elevation myocardial infarction patients who were treated with percutaneous coronary intervention and 58 healthy control subjects. Non-ST segment elevation myocardial infarction patients had echocardiographic examination 48 h after the percutaneous coronary intervention procedure and venous blood samples were drawn simultaneously. In addition to conventional echocardiographic parameters, left atrial strain curves were obtained for each patient. Average peak left atrial strain values during left ventricular systole were measured.ResultsBNP values were higher in non-ST segment elevation myocardial infarction patients compared to controls. Mean left atrium peak systolic global longitudinal strain in Group 2 (the control group) was higher than in the non-ST segment elevation myocardial infarction group. Left atrium peak systolic global longitudinal strain was significantly correlated with left ventricular ejection fraction. There was a significant inverse correlation between left atrium peak systolic global longitudinal strain and brain natriuretic peptide level, left atrium volume maximum, and left atrium volume minimum.ConclusionsOur study shows that Left atrium peak systolic global longitudinal strain values decreased consistently with deteriorating systolic and diastolic function in non-ST segment elevation myocardial infarction patients treated with percutaneous coronary intervention. Left atrium peak systolic global longitudinal strain measurements may be helpful as a complimentary method to evaluate diastolic function in this patient population.

Strain analysis of wall motion in abdominal aortic aneurysms.

In this exploratory study, we used ultrasound speckle-tracking methods, originally used for analyzing cardiac wall motion, to evaluate aortic wall motion. We compared 19 abdominal aortic aneurysm (AAA) patients with 10 healthy volunteers (diameter, 48 mm vs. 15 mm). Motion pictures of the axial view of the aneurysm using ultrasonography were analyzed. Circumferential strain and strain rate at 6 equally divided segments of the aorta were semiautomatically calculated. We termed 'peak' strain and strain rate as the maximum of strain and strain rate in a cardiac cycle for each segment. We also evaluated the coefficient of variation of peak strain rate for the six segments. In the aneurysm and control groups, the mean values of peak strain along the 6 segments were 1.5% ± 0.6% vs. 4.7% ± 1.6% (p <0.0001), respectively. The coefficient of variation of the peak strain rate was higher in the AAA group (0.74 ± 0.20) than in the control group (0.56 ± 0.12; p <0.05). Aortic wall compliance decreased in the more atherosclerotic AAA group. The higher relative dispersion of strain rates in the AAA group is indicative of the inhomogeneous movement of the aortic wall.

Abstract 9642: An Image Based Evaluation of Dynamic Heart Function Following Different Cardiopulmonary Bypass Techniques, Using New High-Resolution 4D Echocardiography

Background: In this study, we evaluated the impact of different cardiopulmonary bypass methods on dynamic heart function. Methods: We studied 12 open-chest piglets (3-5kg). Body temperature, oxygen saturation, blood gases and vital signs were continually monitored. Baseline 4D full volume image loops were acquired from the heart surface with a 4Z1c matrix transducer on a Siemens SC 2000 ultrasound system at frame rate &gt; 30 VPS. Five piglets were subjected to cross-circulation cardiopulmonary bypass for 2 hours using an adult matched donor. Seven piglets were subjected to conventional bypass for the same duration, 3 with matched blood at body temperature (normothermic) and 4 with matched hypothermic blood. After 2 hours of bypass, normal circulation was restored, 4D images acquired after stabilization and images were analyzed offline using VMM motion analysis software from Siemens. Results: In piglets with cross-circulation, average peak apical and basal rotation was slightly increased (0.25-0.95°) and average peak strain (both circumferential and longitudinal) values were diminished in all segments (2.25-4.15%, p=0.039). Piglets with normothermic cardiopulmonary bypass showed similar mechanical changes in LV strain and rotation (p=0.017). Piglets with hypothermic bypass, however, showed a greater increase in LV rotation (1.25-1.75°) and greater depression of strain values (4.25-6.15%). Conclusion: New 4D echo is feasible to monitor dynamic heart function after cardiopulmonary bypass.

GW24-e0648 Clinical application of left ventricular systolic function in patients with rheumatic disease by three-dimensional ultrasound speckle tracking imaging

ObjectivesThe aim of our study is to assess left ventricular global and regional systolic function in patients with pure mild to moderate rheumatic mitral stenosis (MS) by 3-dimensional ultrasound speckle...

1047Cardiac MR left ventricular myocardial strain derived from deformation fields using balanced steady state free precession cine imaging in patients with cardiac amyloidosis

Background: Prior work with speckle tracking echocardiography (STE) has demonstrated that changes in myocardial strain can precede declines in left ventricular (LV) systolic function in infiltrative heart disease. The purpose of this study is to evaluate CMR-derived strain parameters using bright blood cine imaging in a cohort of patients with cardiac amyloidosis, comparing CMR LV strain parameters with those from STE. Methods: Retrospective analysis of 16 consecutive patients (12 males, avg age 62 years) with systemic amyloidosis, 7 (44%) of which with a confirmatory cardiac biopsy. All subjects had CMR findings diagnostic of cardiac amyloidosis. All patients were imaged on a 1.5T scanner (Magnetom Avanto or Aera, Siemens Healthcare, Erlangen, Germany). Balanced steady state free precession (bSSFP) cine short axis and four-chamber images (TR/TE 42/1.2, FA 79 degrees, BW 930, 1.7 x 1.7 x 6 mm3, parallel imaging factor 2) were analyzed using prototype software (Siemens Corp., Corporate Technology, Princeton, New Jersey). As with speckle tracking, the spatio-temporal deformation of LV muscle on cine images was used to derive deformation fields and quantify radial, circumferential, and longitudinal strain indices. Peak CMR and STE values were compared by correlation analysis. Results: Strain analyses were successful on all CMR datasets. Peak CMR systolic strain values, by heart segment and slice, for each direction are shown in Figure 1. CMR peak circumferential, radial, and longitudinal strains demonstrated modest to good correlation with STE (r = 0.57, 0.36, and 0.64) respectively, although the technique significantly underestimated the value of peak strain compared to STE (-7.8% vs. -21.7%, 15.6% vs 34.7%, and -4.3% vs -12.4%, respectively). Mean (standard deviation) peak radial (A), circumferential (B), and longitudinal (C) strain (%) by segment. Mean (standard deviation) peak radial (A), circumferential (B), and longitudinal (C) strain (%) by segment.

Study on Flow Stress Characteristics of AZ31B under Multi-Stage Hot Deformation

In order to improve the understanding of the rheological behavior of magnesium alloy AZ31B under multi-stage hot deformation, a series of isothermal compressing experiments with height reduction of 60% were performed at the temperatures of 250°C, 300°C, 350°C and 400°C and the strain rates of 0.01 s−1and 0.1 s−1 on a Gleeble 1500 thermo-mechanical simulator. The effects of temperature (jump), strain rate (jump), deformation degree and deformation interval time on the flow stress characteristics are investigated and discussed. It is shown that in the dual-stage deformation process with temperature jump or strain rate jump, values of peak stress and peak strain at the second-stage are lower than those at single-stage. The reason for this change is due to the deformation stored energy still retained in the material after its release during the first-stage deformation and deformation interval, such as dynamic recrystallization, meta-dynamic recrystallization, static recovery and static recrystallization The deformation resistance of the multi-stage deformation of AZ31B can be reduced by increasing the deformation degree at the first-stage or the deformation interval because it leads to adequate release of deformation stored energy, which improves the plastic formability of magnesium alloy.

Young Investigator Award session - Basic Science * Intracardiac flows and pressures

Young Investigator Award session - Basic Science * Intracardiac flows and pressures

CLINICAL APPLICATION OF LEFT VENTRICULAR SYSTOLIC FUNCTION IN PATIENTS WITH RHEUMATIC MILD TO MODERATE MITRAL STENOSIS BY THREE-DIMENSIONAL ULTRASOUND SPECKLE TRACKING IMAGING

ObjectivesTo assess left ventricular (LV) global and regional systolic function in patients with pure mild to moderate rheumatic mitral stenosis (MS) by 3-dimensional ultrasound speckle tracking imaging (3D-STI)MethodsFifty patients with...

Quantitative Analysis of Endocardial and Epicardial Left Ventricular Myocardial Deformation—Comparison of Strain-Encoded Cardiac Magnetic Resonance Imaging with Two-Dimensional Speckle-Tracking Echocardiography

Quantitative analysis of segmental myocardial deformation of different myocardial layers has become possible using strain-encoded cardiac magnetic resonance imaging (SENC) and speckle-tracking echocardiography (STE). We evaluated and compared the quantitative analysis of myocardial deformation using SENC and STE. In 44 patients (age 61 ± 13 years, 34 men), SENC by cardiac magnetic resonance imaging using a 1.5-Tesla whole-body scanner and two-dimensional STE were performed prospectively. Quantitative layer-specific analysis of segmental left ventricular function was performed to determine the peak circumferential and peak longitudinal systolic strain values using SENC and STE of an endocardial and epicardial myocardial layer. In addition, segmental function was defined as normokinetic, hypokinetic, or akinetic by visual analysis of the magnetic resonance imaging cine sequences. The endocardial and epicardial strain defined by SENC or STE differed significantly between the visually defined segmental function states. The correlation of the peak circumferential endocardial strain by SENC versus STE (intraclass correlation coefficient [ICC] 0.493, 95% CI 0.358-0.597) tended to be better than the correlation of the circumferential epicardial strain using both methods (ICC 0.321, 95% CI 0.238-0.399). The correlation of the peak longitudinal endocardial strain by SENC and STE was similar (ICC 0.472, 95% CI 0.398-0.541), in contrast to the longitudinal epicardial strain analysis by both techniques (ICC 0.554, 95% CI 0.417-0.655). Circumferential strain analysis by STE allowed better distinction of the hypokinetic or akinetic segments from the normokinetic segments than did the circumferential strain analysis by SENC of the endocardial layer (area under the receiver operating characteristic curve [AUC ROC] 0.946 vs 0.884; P < .001) or epicardial layer (AUC ROC 0.884 vs 0.782; P < .001). Longitudinal strain analysis using STE and SENC of theendocardial layer (AUC ROC 0.851 vs 0.839; P= .5838) and epicardial layer (AUC ROC 0.849 vs 0.833; P= .4321) had similar diagnostic value for identifying the presence of hypokinetic and akinetic segments. Quantitative analysis of segmental deformation by SENC and STE allowed accurate distinction of myocardial segments with different functional states. Circumferential endocardial strain analysis by STE allowed the best distinction of segments with impaired function from the normokinetic segments.

In regard to: “In vivo strain analysis of the intact supraspinatus tendon by ultrasound speckles tracking imaging” (Journal of Orthopaedic Research, Vol. 29, No. 12, pp. 1931–1937, May 2011)

In regard to: “In vivo strain analysis of the intact supraspinatus tendon by ultrasound speckles tracking imaging” (Journal of Orthopaedic Research, Vol. 29, No. 12, pp. 1931–1937, May 2011)

Does screw–bone interface modelling matter in finite element analyses?

The effect of screw–bone interface modelling strategies was evaluated in the setting of a tibial mid-shaft fracture stabilised using locking plates. Three interface models were examined: fully bonded interface; screw with sliding contact with bone; and screw with sliding contact with bone in an undersized pilot hole. For the simulation of the last interface condition we used a novel thermal expansion approach to generate the pre-stress that the bone would be exposed to during screw insertion. The study finds that the global load-deformation response is not influenced by the interface modelling approach employed; the deformation varied by less than 1% between different interaction models. However, interface modelling is found to have a considerable impact on the local stress–strain environment within the bone in the vicinity of the screws. Frictional and tied representations did not have significantly different peak strain values (<5% difference); the frictional interface had higher peak compressive strains while the tied interface had higher tensile strains. The undersized pilot hole simulation produced the largest strains. The peak minimum principal strains for the frictional interface were 26% of those for the undersized pilot hole simulation at a load of 770 N. It is concluded that the commonly used tie constraint can be used effectively when the only interest is the global load-deformation behaviour. Different contact interface models, however, alter the mechanical response around screw holes leading to different predictions for screw loosening, bone damage and stress shielding.

Oral Abstract Sessions: Young Investigator Award session * Thursday 8 December 2011, 12:45-13:45 * Location: Pecs

Oral Abstract Sessions: Young Investigator Award session * Thursday 8 December 2011, 12:45-13:45 * Location: Pecs

Abstract 8915: Utility of Transmural Myocardial Strain Profile to Predict Early Left Ventricular Dysfunction in Patients with Duchenne Muscular Dystrophy

Background: Myocardial damage in Duchenne muscular dystrophy (DMD) leads to lethal outcome. Therefore, early detection of myocardial changes in DMD is important because earlier treatment might help to prevent the development of myocardial fibrosis. Transmural myocardial strain distribution can be obtained as a form of transmural strain profile using myocardial tissue Doppler strain imaging. Accordingly, the aim of this study was to test the hypothesis that transmural strain profile (TMSP) analysis can predict future left ventricular (LV) dysfunction in DMD patients with preserved ejection fraction (EF). Methods: We studied 57 consecutive DMD patients who did not have LV wall motion abnormality; EF 60±7% (all ≥ 55%), aged 11±3 years. Echocardiography was performed at baseline and 1-year follow-up. TMSP was evaluated in the posterior wall from mid-LV short-axis view (Aplio-XG Toshiba Corp.). Results: Thirty-seven patients (65%) had normal TMSP pattern (Group 1), and the remaining 20 patients (35%) were classified as TMSP with a notch (Group 2). The peak strain value in the posterior wall and EF were similar between two groups. Of 20 patients in Group 2, 8 patients (40%) had wall motion abnormality in the posterior wall at 1-year follow-up. On the other hand, no patient in Group 1 had wall motion abnormality at 1-year follow-up (p&lt;0.001 vs. Group 2). Conclusions: Subclinical LV dysfunction can be detected with TMSP in DMD patients who do not have wall motion abnormalities by conventional echocardiography. TMSP with notch was useful at evaluating early subtle changes in DMD patients, and may be useful for predicting future LV dysfunction.

Relationship Between Strain Levels and Permeability of the Plasma Membrane in Statically Stretched Myoblasts

Deep tissue injury (DTI) is a life-threatening type of pressure ulcer which initiates subdermally with muscle necrosis at weight-bearing anatomical locations, where localized elevated tissue strains exist. Though it has been suggested that excessive sustained soft tissue strains might compromise cell viability, which then initiates the DTI, there is no experimental evidence to describe how specifically such a process might take place. Here, we experimentally test the hypothesis that macroscopic tissue deformations translated to cell-level deformations and in particular, to localized tensile strains in the plasma membrane (PM) of cells, increase the permeability of the PM which could disrupt vital transport processes. In order to determine whether PM permeability changes can occur due to static stretching of cells we measured the uptake of fluorescein isothiocyanate (FITC)-labeled Dextran (molecular weight = 4 kDa) by deformed vs. undeformed myoblasts, using a fluorescence-activated cell sorting (FACS) method. These PM permeability changes were then correlated with tensile strains in the PM which correspond to the levels of substrate tensile strain (STS) that were applied in the experiments. The PM strains were evaluated by means of confocal-microscopy-based cell-specific finite element (FE) modeling. The FACS studies demonstrated a statistically significant rise in the uptake of the FITC-labeled Dextran with increasing STS levels in the STS ≤ 12% domain, which thereby indicates a rise in the permeability of the PM of the myoblasts with the extent of the applied cellular deformation. The cell-specific FE modeling simulating the experiments further demonstrated that applying average PM tensile strains which exceed 3%, or, applying peak PM tensile strains over 9%, substantially increases the permeability of the PM of myoblasts to the Dextran. Moreover, the permeability of the PM grew rapidly with any further increase in PM strains, though there were no significant changes in the uptake above average and peak PM tensile strain values of 9 and 26%, respectively. These results provide an experimental basis for studying the theory that cell-level deformation-diffusion relationships may be involved in determining the tolerance of soft tissues to sustained mechanical loading, as relevant to the etiology of DTI.