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Sample records for circumferential myocardial strain

  1. Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block

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    Zimetbaum Peter J

    2010-01-01

    Full Text Available Abstract Background Cardiac resynchronization therapy (CRT has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR to assess circumferential strain in this population. Methods We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls. Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined. Results Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10 of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 ± 6%, non-LBBB 10 ± 4% vs. healthy 19 ± 4%; both p Conclusions Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

  2. Assessment of Myocardial Contractile Function Using Global and Segmental Circumferential Strain following Intracoronary Stem Cell Infusion after Myocardial Infarction: MRI Feature Tracking Feasibility Study

    International Nuclear Information System (INIS)

    Background. Magnetic resonance imaging (MRI) strain analysis is a sensitive method to assess myocardial function. Our objective was to define the feasibility of MRI circumferential strain (εcc) analysis in assessing subtle changes in myocardial function following stem cell therapy. Methods and Results. Patients in the Amorcyte Phase I trial were randomly assigned to treatment with either autologous bone-marrow-derived stem cells infused into the infarct-related artery 5 to 11 days following primary PCI or control. MRI studies were obtained at baseline, 3, and 6 months. εcc was measured in the short axis views at the base, mid and apical slices of the left ventricle (LV) for each patient (13 treatments and 10 controls). Mid-anterior LV εcc improved between baseline −18.5 ± 8.6 and 3 months −22.6 ± 7.0, P = 0.03. There were no significant changes in εcc at 3 months and 6 months compared to baseline for other segments. There was excellent intraobserver and interobserver agreement for basal and mid circumferential strain. Conclusion. MRI segmental strain analysis is feasible in assessment of regional myocardial function following cell therapy with excellent intra- and inter-observer variability's. Using this method, a modest interval change in segmental εcc was detected in treatment group

  3. Magnetic resonance-derived circumferential strain provides a superior and incremental assessment of improvement in contractile function in patients early after ST-segment elevation myocardial infarction

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    Wong, Dennis T.L.; Psaltis, Peter J. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); South Australian Health and Medical Research Institute (SAHMRI), Adelaide (Australia); Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia); Leong, Darryl P.; Weightman, Michael J.; Richardson, James D.; Worthley, Matthew I.; Worthley, Stephen G. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); Dundon, Benjamin K.; Leung, Michael C.H.; Meredith, Ian T. [Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia)

    2014-06-15

    We evaluate whether circumferential strain derived from grid-tagged CMR is a better method for assessing improvement in segmental contractile function after STEMI compared to late gadolinium enhancement (LGE). STEMI patients post primary PCI underwent baseline CMR (day 3) and follow-up (day 90). Cine, grid-tagged and LGE images were acquired. Baseline LGE infarct hyperenhancement was categorised as ≤25 %, 26-50 %, 51-75 % and >75 % hyperenhancement. The segmental baseline circumferential strain (CS) and circumferential strain rate (CSR) were calculated from grid-tagged images. Segments demonstrating an improvement in wall motion of ≥1 grade compared to baseline were regarded as having improved segmental contractile-function. Forty-five patients (aged 58 ± 12 years) and 179 infarct segments were analysed. A baseline CS cutoff of -5 % had sensitivity of 89 % and specificity of 70 % for detection of improvement in segmental-contractile-function. On receiver-operating characteristic analysis for predicting improvement in contractile function, AUC for baseline CS (0.82) compared favourably to LGE hyperenhancement (0.68), MVO (0.67) and baseline-CSR (0.74). On comparison of AUCs, baseline CS was superior to LGE hyperenhancement and MVO in predicting improvement in contractile function (P < 0.001). On multivariate-analysis, baseline CS was the independent predictor of improvement in segmental contractile function (P < 0.001). Grid-tagged CMR-derived baseline CS is a superior predictor of improvement in segmental contractile function, providing incremental value when added to LGE hyperenhancement and MVO following STEMI. (orig.)

  4. 斑点追踪技术评价缺血心肌短轴缩短率和圆周应变%Evaluation of Regional Shortening Fraction and Circumferential Strain in Patients with Myocardial Ischemia by Speckle Tracking Imaging

    Institute of Scientific and Technical Information of China (English)

    何艳; 王东平; 陈金国; 张娜; 杨体霞; 张军; 周利民

    2012-01-01

    目的 运用斑点追踪技术(STI)测量缺血心肌的短轴缩短率和圆周应变值,探讨其在诊断心肌缺血,评价心肌功能中的应用价值.方法 对29例心肌缺血患者(冠状动脉狭窄≥75%)和28例正常对照组(冠状动脉没有狭窄)分别行超声心动图检查,采集并记录左室短轴观(二尖瓣水平)的高帧频动态二维灰阶图像,应用二维应变分析软件进行脱机分析,系统自动将左室短轴分为前间隔、前壁、侧壁、后壁、下壁、后间隔6个节段,并给出应变曲线,分别测量各节段心肌的短轴缩短率和圆周应变值.结果 正常对照组的圆周应变曲线是负向峰值曲线,短轴缩短率曲线是正向峰值曲线,整组曲线排列较整齐;而心肌缺血组的应变曲线形态不规则.心肌缺血组圆周应变和短轴缩短率均低于正常对照组,差异有统计学意义(P<0.05).结论 斑点追踪技术能对心肌的二维应变进行定量分析,为临床诊断心肌缺血,评价心肌功能提供了无创性新方法.%Objective To evaluate the clinical value of speckle tracking imaging in the measurement of regional shortening fraction and circumferential strain in patients with myocardial ischemia. Methods Twenty-nine patients with myocardial ischemia and twenty-eight healthy subjects underwent echocardiography,high frame rate two-dimensional images were recorded from the left ventricular short-axis views at the levels of mitral annulus, regional shortening fraction and circumferential strain were measured in the left ventricular short-axis views using two-dimensional strain software. Results Circumferential strain curve, regional shortening fraction curve in healthy group changed regularly, while in myocardial ischemia patients, the curve changed irregularly. Regional shortening fraction and circumferential strain in myocardial ischemia patients showed significant reduction compared with normal myocardium(P<0.05). Conclusion Speckle

  5. Accelerated circumferential strain quantification of the left ventricle using CIRCOME: simulation and factor analysis

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    Moghaddam, Abbas N.; Finn, J. Paul

    2008-03-01

    Circumferential strain of the left ventricle reflects myocardial contractility and is considered a key index of cardiac function. It is also an important parameter in the quantitative evaluation of heart failure. Circumferential compression encoding, CIRCOME, is a novel method in cardiac MRI to evaluate this strain non-invasively and quickly. This strain encoding technique avoids the explicit measurement of the displacement field and does not require calculation of strain through spatial differentiation. CIRCOME bypasses these two time-consuming and noise sensitive steps by directly using the frequency domain (k-space) information from radially tagged myocardium, before and after deformation. It uses the ring-shaped crown region of the k-space, generated by the taglines, to reconstruct circumferentially compression-weighted images of the heart before and after deformation. CIRCOME then calculates the circumferential strain through relative changes in the compression level of corresponding regions before and after deformation. This technique can be implemented in 3D as well as 2D and may be employed to estimate the overall global or regional circumferential strain. The main parameters that affect the accuracy of this method are spatial resolution, signal to noise ratio, eccentricity of the center of radial taglines their fading and their density. Also, a variety of possible image reconstruction and filtering options may influence the accuracy of the method. This study describes the pulse sequence, algorithm, influencing factors and limiting criteria for CIRCOME and provides the simulated results.

  6. Magnetic resonance imaging characterization of circumferential and longitudinal strain under various coronary interventions in swine

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    Mohammed; SA; Suhail; Mark; W; Wilson; Steven; W; Hetts; Maythem; Saeed

    2013-01-01

    AIM:To compare the acute changes in circumferential and longitudinal strain after exposing a coronary artery to various interventions in swine.METHODS:Percutaneous balloon angioplasty catheter was guided to location aid device(LAD)under X-ray fluoroscopy to create different patterns of ischemic insults.Pigs(n=32)were equally divided into 4 groups:controls,90 min LAD occlusion/reperfusion,LAD microembolization,and combined LAD occlusion/microembolization/reperfusion.Three days after interventions,cine,tagged and viability magnetic resonance imaging(MRI)were acquired to measure and compare left and right circumferential strain,longitudinal strain and myocardial viability,respectively.Measurements were obtained using HARP and semi-automated threshold method and statistically analyzed using unpaired t-test.Myocardial and vascular damage was characterized microscopically.RESULTS:Coronary microemboli caused greater impairment in l left ventricular(LV)circumferential strain and dyssynchrony than LAD occlusion/reperfusion despite the significant difference in the extent of myocardial damage.Microemboli also caused significant decrease in peak systolic strain rate of remote myocardium and LV dyssynchrony.Cine MRI demonstrated the interaction between LV and right ventricular(RV)at 3 d after interventions.Compensatory increase in RV free wall longitudinal strain was seen in response to all interventions.Viability MRI,histochemical staining and microscopy revealed different patterns of myocardial damage and microvascular obstruction.CONCLUSION:Cine MRI revealed subtle changes in LV strain caused by various ischemic insults.It also demonstrated the interaction between the right and left ventricles after coronary interventions.Coronary microemboli with and without acute myocardial infarction(AMI)cause complex myocardial injury and ventricular dysfunction that is not replicated in solely AMI.

  7. Circumferential 2D-strain imaging for the prediction of long term response to cardiac resynchronization therapy

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    Baumann Gert

    2008-06-01

    Full Text Available Abstract Background Cardiac Resynchronization Therapy (CRT leads to hemodynamic and clinical improvement in heart failure patients. The established methods to evaluate myocardial asynchrony analyze longitudinal and radial myocardial function. This study evaluates the new method of circumferential 2D-strain imaging in the prediction of the long-term response to CRT. Methods and results 38 heart failure patients (NYHA II-III, QRS > 120 ms, LVEF Conclusion There is a significant decrease in the circumferential 2D-strain derived delays after CRT, indicating that resynchronization induces improvement in all three dimensions of myocardial contraction. However, the resulting predictive values of 2D strain delays are not superior to longitudinal and radial 2D-strain or TDI delays.

  8. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats.

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    Takano, Hiroshi; Isogai, Tomomi; Aoki, Takuma; Wakao, Yoshito; Fujii, Yoko

    2015-02-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart. PMID:25373881

  9. 左室径向应变和圆周应变对冠状动脉粥样硬化性心脏病患者心肌缺血的诊断价值%Value of left ventricular radial and circumferential strain for evaluation of myocardial ischemia in patients with coronary heart disease

    Institute of Scientific and Technical Information of China (English)

    黄佳; 周青; 邓倾; 胡波; 贾妍; 吴田; 郭瑞强

    2011-01-01

    目的 应用斑点追踪技术评价室壁运动正常的心肌缺血患者左室径向应变及圆周应变,探讨其检测心肌缺血的临床价值.方法 30例经冠状动脉造影证实的冠状动脉粥样硬化性心脏病(CHD)患者,28例健康者为对照组,应用二维应变软件分析左室短轴二尖瓣水平、乳头肌水平及心尖水平图像,获取左室短轴各节段心肌径向应变和圆周应变均值.结果 CHD组径向应变和圆周应变均较对照组减低(P<0.001);ROC曲线表明径向应变诊断心肌缺血的敏感性为89.3%,特异性为80.0%;圆周应变诊断心肌缺血的敏感性为75.0%,特异性为63.3%;径向应变诊断心肌缺血的敏感性和特异性均较圆周应变增高.结论 二维短轴应变能较敏感地发现心肌缺血,径向应变较圆周应变能更准确地评价心肌缺血.%Objective To assess left ventricular radial strain and circumferential strain in coronary artery disease patients without regional wall motion abnormality by speckle tracking imaging( STI) , and to explore its clinical value in detecting myocardial ischemia. Methods Thirty patients with coronary artery disease ( CAD group) and 28 cases of normal subjects ( control group)were enrolled in this study. The speckle data were obtained in left ventricular short-axis views at the levels of mitral annulus, papillary muscle and apex. The average of peak systolic cireumferential strain and radial strain were analyzed. Results The circumferential strain and radial strain in CAD group were decreased than those in control group( P < 0. 001) , ROC curve showed the sensitivity and specificity of radial strain in diagnosis of myocardial ischemia were 89. 3% and 80. 0% ,while the sensitivity and specificity of radial strain in diagnosis of myocardial ischemia were 75. 0% and 63. 3% . The sensitivity and specificity of radial strain were higher than those of cireumferential strain. Conclusion Two - dimensional regional strain is

  10. Improved myocardial strain measured by strain-encoded magnetic resonance imaging in a patient with cardiac sarcoidosis.

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    Nakano, Shintaro; Kimura, Fumiko; Osman, Nael; Sugi, Keiki; Tanno, Jun; Uchida, Yoshitaka; Shiono, Ayako; Senbonmatsu, Takaaki; Nishimura, Shigeyuki

    2013-11-01

    A woman aged 64 years with cardiac sarcoidosis responded favourably to corticosteroid therapy in terms of recovered longitudinal myocardial strain, as evaluated by strain-encoded magnetic resonance imaging (SENC-MRI). In contrast, circumferential myocardial strain and late gadolinium enhancement demonstrated minimal improvement, suggesting relatively advanced pathology of the myocardial middle layer. We propose SENC-MRI as a marker of disease at an early stage of cardiac sarcoidosis.

  11. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masashi, E-mail: m.nakamura1230@gmail.com [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan); Kido, Tomoyuki [Department of Radiology, Saiseikai Matsuyama Hospital, Ehime 791-0295 (Japan); Kido, Teruhito; Tanabe, Yuki; Matsuda, Takuya; Nishiyama, Yoshiko; Miyagawa, Masao; Mochizuki, Teruhito [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan)

    2015-08-15

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

  12. Echocardiographic assessment of myocardial strain.

    Science.gov (United States)

    Gorcsan, John; Tanaka, Hidekazu

    2011-09-27

    Echocardiographic strain imaging, also known as deformation imaging, has been developed as a means to objectively quantify regional myocardial function. First introduced as post-processing of tissue Doppler imaging velocity converted to strain and strain rate, strain imaging has more recently also been derived from digital speckle tracking analysis. Strain imaging has been used to gain greater understanding into the pathophysiology of cardiac ischemia and infarction, primary diseases of the myocardium, and the effects of valvular disease on myocardial function, and to advance our understanding of diastolic function. Strain imaging has also been used to quantify abnormalities in the timing of mechanical activation for heart failure patients undergoing cardiac resynchronization pacing therapy. Further advances, such as 3-dimensional speckle tracking strain imaging, have emerged to provide even greater insight. Strain imaging has become established as a robust research tool and has great potential to play many roles in routine clinical practice to advance the care of the cardiovascular patient. This perspective reviews the physiology of myocardial strain, the technical features of strain imaging using tissue Doppler imaging and speckle tracking, their strengths and weaknesses, and the state-of-the-art present and potential future clinical applications.

  13. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats

    OpenAIRE

    Takano, Hiroshi; ISOGAI, Tomomi; Aoki, Takuma; WAKAO, Yoshito; Fujii, Yoko

    2014-01-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM...

  14. Assessment of circumferential endocardial extent of myocardial edema and infarction in patients with reperfused acute myocardial infarction: a cardiovascular magnetic resonance study.

    Science.gov (United States)

    Ota, Shingo; Tanimoto, Takashi; Hirata, Kumiko; Orii, Makoto; Shiono, Yasutsugu; Shimamura, Kunihiro; Ishibashi, Kohei; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Imanishi, Toshio; Akasaka, Takashi

    2014-01-01

    T2 weighted (T2W) images on cardiovascular magnetic resonance (CMR) visualizes myocardial edema, which reflects the myocardial area at risk (AAR) in reperfused acute myocardial infarction (AMI). Late gadolinium enhancement (LGE) demonstrates myocardial infarction. LGE images cover the whole left ventricle, but T2W images are obtained from a few slices of the left ventricle due to the long sequence time, so the quantification of AAR of the entire left ventricle is difficult. We hypothesize that we can quantify AAR with only LGE images if there is a strong correlation between the circumferential endocardial extent of myocardial edema and infarction. Thirty patients with first AMI were enrolled. All patients underwent successfully reperfusion therapy and CMR was performed within the first week after the event. We measured the circumferential extent of edema and infarction on short-axis views (T2 angle and LGE angle), respectively. A total of 82 short-axis slices showed transmural edema on T2W images. Corresponding LGE images were analyzed for the circumferential extent of infarction. The median [interquartile range] of T2 angle and DE angle were 147° [116°-219°] and 134° [104°-200°] in patients with LAD culprit lesion, 91° [87°-101°] and 85° [80°-90°] in LCX, and 110° [94°-123°] and 104° [89°-118°] in RCA, respectively. T2 angle was well correlated with LGE angle (r = 0.99, P infarction in reperfused AMI. Thus, T2 weighted imaging can be skipped to quantify the amount of AAR.

  15. In vivo vascular wall shear rate and circumferential strain of renal disease patients.

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    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-02-01

    This study measures the vascular wall shear rate at the vessel edge using decorrelation based ultrasound speckle tracking. Results for nine healthy and eight renal disease subjects are presented. Additionally, the vascular wall shear rate and circumferential strain during physiologic pressure, pressure equalization and hyperemia are compared for five healthy and three renal disease subjects. The mean and maximum wall shear rates were measured during the cardiac cycle at the top and bottom wall edges. The healthy subjects had significantly higher mean and maximum vascular wall shear rate than the renal disease subjects. The key findings of this research were that the mean vascular wall shear rates and circumferential strain changes between physiologic pressure and hyperemia that was significantly different between healthy and renal disease subjects.

  16. Abnormal Myocardial Strain Indices in Children Receiving Anthracycline Chemotherapy.

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    Pignatelli, Ricardo H; Ghazi, Payam; Reddy, S Chandra-Bose; Thompson, Patrick; Cui, Qiqiong; Castro, Jacqueline; Okcu, Mehmet F; Jefferies, John Lynn

    2015-12-01

    Anthracycline chemotherapy (AC) is associated with impaired left ventricular (LV) systolic function. LV ejection fraction (EF %) obtained by two-dimensional echocardiography is the current gold standard for detection and monitoring of LV systolic function. However, dependence on LVEF has been shown to be unreliable due to its inherent limitations. Speckle tracking echocardiography (STE) measures myocardial strain and is a sensitive method to detect LV systolic dysfunction with demonstrated utility in such detection in adult and pediatric cohort studies. Compare myocardial strain indices derived by STE with LVEF to detect ACT-induced LV systolic dysfunction. Prospective, cross-sectional measurements of LV myocardial strain indices derived from STE with LVEF. Pediatric cohort of 25 patients (pts): 17 females, eight males with a mean age 9.8 ± 5.8 years, who received anthracyclines (AC); median cumulative dose ≥150 ± 124.4 mg/m(2), range 60-450 mg/m(2) showing normal LV end-diastolic diameter (mm) and normal LVEF (≥55 %) underwent STE to obtain LV myocardial strain indices: strain and strain rate. The inter- and intraobserver variability for the strain indices was 5 %. Fifteen of 25 pts (60 %) showed abnormal global longitudinal peak systolic strain (GLPSS) and 19/25 pts (76 %) showed abnormal peak circumferential strain (PCS) compared to age-matched controls (p = 0.005). In contrast, no significant differences was observed in either indices with the dose of AC. Likewise, no significant changes in the systolic or diastolic strain rate were noted with the dose of AC (r (2) = 0.0076 for peak E, r (2) = 0.072 for peak A, p = NS). GLPSS and PCS were diminished and, however, correlated poorly with the cumulative dose of AC. These observations indicate an early onset of LV systolic dysfunction by the strain indices in pts who continue to show a normal LVEF implying presence of occult LV systolic dysfunction. These novel strain indices may assist in

  17. Myocardial Strain and Strain Rate Imaging: Comparison between Doppler Derived Strain Imaging and Speckle Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Anita Sadeghpour

    2013-05-01

    Full Text Available Regional myocardial function has been traditionally assessed by visual estimation (1. Echocardiographic strain imaging which is known as deformation imaging, has been emerged as a quantitative technique to accurately estimate regional myocardial function and contractility. Currently, strain imaging has been regarded as a research tool in the most echocardiography laboratories. However, in recent years, strain imaging has gain momentum in daily clinical practice (2. The following two techniques have dominated the research arena of echocardiography: (1 Doppler based tissue velocity measurements, frequently referred to tissue Doppler or myocardial Doppler, and (2 speckle tracking on the basis of displacement measurements (3. Over the past two decades, Tissue Doppler Imaging (TDI and Doppler –derived strain (S and strain rate (SR imaging were introduced to quantify regional myocardial function. However, Doppler–derived strain variables faced criticisms, with regard to the angle dependency, noise interference, and substantial intraobserver and interobserver variability. The angle dependency is the major weakness of Doppler based methodology; however, it has the advantage of online measurements of velocities and time intervals with excellent temporal resolution, which is essential for the assessment of ischemia (4. Speckle-tracking echocardiography (STE or Non Doppler 2D strain echocardiography is a relatively new, largely angle-independent technique that analyzes motion by tracking natural acoustic reflections and interference patterns within an ultrasonic window. The image-processing algorithm tracks elements with approximately 20 to 40 pixels containing stable patterns and are described as ‘‘speckles’’ or ‘‘fingerprints’’. The speckles seen in grayscale B-mode (2D images are tracked consecutively frame to frame (5, 6. Assessment of 2D strain by STE is a semiautomatic method that requires definition of the myocardium

  18. Global and regional left ventricular strain indices in post-myocardial infarction patients with ventricular arrhythmias and moderately abnormal ejection fraction.

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    Nguyen, Bich Lien; Capotosto, Lidia; Persi, Alessandro; Placanica, Attilio; Rafique, Asim; Piccirillo, Gianfranco; Gaudio, Carlo; Gang, Eli S; Siegel, Robert J; Vitarelli, Antonio

    2015-02-01

    The aim of the study described here was to compare myocardial strains in ischemic heart patients with and without sustained ventricular tachycardia (VT) and moderately abnormal left ventricular ejection fraction (LVEF) to investigate which index could better predict VT on the basis of the analysis of global and regional left ventricular (LV) dysfunction. We studied 467 patients with previous myocardial infarction and LVEF >35%. Fifty-one patients had documented VT, and 416 patients presented with no VT. LV volumes and score index were obtained by 2-D echocardiography. Longitudinal, radial and circumferential strains were determined. Strains of the infarct, border and remote zones were also obtained. There were no differences in standard LV 2-D parameters between patients with and those without VT. Receiver operating characteristic values were -12.7% for global longitudinal strain (area under the curve [AUC] = 0.72), -4.8% for posterior-inferior wall circumferential strain (AUC = 0.80), 61 ms for LV mechanical dispersion (AUC = 0.84), -10.1% for longitudinal strain of the border zone (AUC = 0.86) and -9.2% for circumferential strain of the border zone (AUC = 0.89). In patients with previous myocardial infarction and moderately abnormal LVEF, peri-infarct circumferential strain was the strongest predictor of documented ventricular arrhythmias among all strain quantitative indices. Additionally, strain values from posterior-inferior wall infarctions had a higher association with arrhythmic events compared with global strain.

  19. Magnetic resonance imaging detects significant sex differences in human myocardial strain

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    Reynolds Lina M

    2011-08-01

    Full Text Available Abstract Background The pathophysiology responsible for the significant outcome disparities between men and women with cardiac disease is largely unknown. Further investigation into basic cardiac physiological differences between the sexes is needed. This study utilized magnetic resonance imaging (MRI-based multiparametric strain analysis to search for sex-based differences in regional myocardial contractile function. Methods End-systolic strain (circumferential, longitudinal, and radial was interpolated from MRI-based radiofrequency tissue tagging grid point displacements in each of 60 normal adult volunteers (32 females. Results The average global left ventricular (LV strain among normal female volunteers (n = 32 was significantly larger in absolute value (functionally better than in normal male volunteers (n = 28 in both the circumferential direction (Male/Female = -0.19 ± 0.02 vs. -0.21 ± 0.02; p = 0.025 and longitudinal direction (Male/Female = -0.14 ± 0.03 vs. -0.16 ± 0.02; p = 0.007. Conclusions The finding of significantly larger circumferential and longitudinal LV strain among normal female volunteers suggests that baseline contractile differences between the sexes may contribute to the well-recognized divergence in cardiovascular disease outcomes. Further work is needed in order to determine the pathologic changes that occur in LV strain between women and men with the onset of cardiovascular disease.

  20. Alteration in the global and regional myocardial strain patterns in patients with inferior ST-elevation myocardial infarction prior to and after percutaneous coronary intervention.

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    Song, Chen-Fang; Zhou, Qing; Guo, Rui-Qiang

    2014-01-01

    This study was designed to investigate the alteration on regional and global strains of left and right ventricle (LV, RV) in patients with inferior wall ST-elevation myocardial infarction (MI). Patients were examined prior to and 7 days after percutaneous coronary intervention (PCI) using speckle-tracking techniques. Fifty-nine patients (36 males and 23 females) and 60 healthy controls (40 males and 20 females) were enrolled in this study. LV strains were measured from three deformations including radial, longitudinal, and circumferential. RV strains were measured only from the longitudinal. Three types of LV global strains were significantly lower in patients than in controls, and LV global longitudinal and circumferential strains were moderately improved by PCI. The LV regional strains reduced significantly in most of the segments (87%) after inferior wall MI and over half of them (60%) were improved by PCI. The RV global longitudinal strains were significantly lower in patients than in controls, and they were moderately improved by PCI. In conclusion, the regional and global strains of LV and RV were reduced in patients with inferior wall MI, and PCI most markedly improved the global strains and regional strains of the infarct and adjacent myocardium in the apical and middle levels.

  1. Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Oyama-Manabe, Noriko; Sugimori, Hiroyuki; Kamishima, Tamotsu; Tha, Khin Khin; Terae, Satoshi; Shirato, Hiroki [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, Sapporo (Japan); Ishimori, Naoki; Tsutsui, Hiroyuki [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Medicine, Sapporo (Japan); Van Cauteren, Marc; Okuaki, Tomoyuki [Philips Healthcase, MR Clinical Science, Tokyo (Japan); Kudo, Kohsuke [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Manabe, Osamu [Hokkaido University Hospital, Department of Nuclear Medicine, Sapporo (Japan); Ito, Yoichi M. [Hokkaido University Graduate School of Medicine, Hokkaido Organization for Translational Research, Sapporo (Japan)

    2011-11-15

    To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction. (orig.)

  2. Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 tesla

    International Nuclear Information System (INIS)

    To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction. (orig.)

  3. Three-dimensional regional strain analysis in porcine myocardial infarction: a 3T magnetic resonance tagging study

    Directory of Open Access Journals (Sweden)

    Soleimanifard Sahar

    2012-12-01

    Full Text Available Abstract Background Previous studies of mechanical strain anomalies in myocardial infarction (MI have been largely limited to analysis of one-dimensional (1D and two-dimensional (2D strain parameters. Advances in cardiovascular magnetic resonance (CMR methods now permit a complete three-dimensional (3D interrogation of myocardial regional strain. The aim of this study was to investigate the incremental value of CMR-based 3D strain and to test the hypothesis that 3D strain is superior to 1D or 2D strain analysis in the assessment of viability using a porcine model of infarction. Methods Infarction was induced surgically in 20 farm pigs. Cine, late gadolinium enhancement, and CMR tagging images were acquired at 11 days before (baseline, and 11 days (early and 1 month (late after induction of infarct. Harmonic phase analysis was performed to measure circumferential, longitudinal, and radial strains in myocardial segments, which were defined based on the transmurality of delayed enhancement. Univariate, bivariate, and multivariate logistic regression models of strain parameters were created and analyzed to compare the overall diagnostic accuracy of 3D strain analysis with 1D and 2D analyses in identifying the infarct and its adjacent regions from healthy myocardium. Results 3D strain differed significantly in infarct, adjacent, and remote segments (p  Conclusions Cumulative 3D strain information accurately identifies infarcts and their neighboring regions from healthy myocardium. The 3D interrogation of myocardial contractility provides incremental diagnostic accuracy in delineating the dysfunctional and nonviable myocardium in comparison with 1D or 2D quantification of strain. The infarct neighboring regions are the major beneficiaries of the 3D assessment of regional strain.

  4. Preliminary clinical study of left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy by three-dimensional speckle tracking imaging

    Directory of Open Access Journals (Sweden)

    Duan Fengxia

    2012-03-01

    Full Text Available Abstract Background Non-ischemic dilated cardiomyopathy (DCM is the most common cardiomyopathy worldwide, with significant mortality. Correct evaluation of the patient's myocardial function has important clinical significance in the diagnosis, therapeutic effect assessment and prognosis in non-ischemic DCM patients. This study evaluated the feasibility of three-dimensional speckle tracking imaging (3D-STE for assessment of the left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy (DCM. Methods Apical full-volume images were acquired from 65 patients with non-ischemic DCM (DCM group and 59 age-matched normal controls (NC group, respectively. The following parameters were measured by 3D-STE: the peak systolic radial strain (RS, circumferential strain (CS, longitudinal strain (LS of each segment. Then all the parameters were compared between the two groups. Results The peak systolic strain in different planes had certain regularities in normal groups, radial strain (RS was the largest in the mid region, the smallest in the apical region, while circumferential strain (CS and longitudinal strain (LS increased from the basal to the apical region. In contrast, the regularity could not be applied to the DCM group. RS, CS, LS were significantly decreased in DCM group as compared with NC group (P Conclusions 3D-STE is a reliable tool for evaluation of left ventricular myocardial strain in patients with non-ischemic DCM, with huge advantage in clinical application.

  5. Moderate ischemic mitral regurgitation after postero-lateral myocardial infarction in sheep alters left ventricular shear but not normal strain in the infarct and infarct borderzone

    Science.gov (United States)

    Ge, Liang; Wu, Yife; Soleimani, Mehrdad; Khazalpour, Michael; Takaba, Kiyoaki; Tartibi, Mehrzad; Zhang, Zhihong; Acevedo-Bolton, Gabriel; Saloner, David A.; Wallace, Arthur W.; Mishra, Rakesh; Grossi, Eugene A.; Guccione, Julius M.; Ratcliffe, Mark B.

    2016-01-01

    Background Chronic ischemic mitral regurgitation (CIMR: MR) is associated with poor outcome. Left ventricular (LV) strain after postero-lateral myocardial infarction (MI) may drive LV remodeling. Although moderate CIMR has been previously shown to effect LV remodeling, the effect of CIMR on LV strain after postero-lateral MI remains unknown. We tested the hypothesis that moderate CIMR alters LV strain after postero-lateral MI. Methods/Results Postero-lateral MI was created in 10 sheep. Cardiac MRI with tags was performed 2 weeks before and 2, 8 and 16 weeks after MI. LV and right ventricular (RV) volumes were measured and regurgitant volume indexed to body surface area (BSA; RegurgVolume Index) calculated as the difference between LV and RV stroke volumes / BSA. Three-dimensional strain was calculated. Circumferential (Ecc)and longitudinal (Ell) strains were reduced in the infarct proper, MI borderzone (BZ) and remote myocardium 16 weeks after MI. In addition, radial circumferential (Erc) and radial longitudinal (Erl) shear strains were reduced in remote myocardium but increased in the infarct and BZ 16 weeks after MI. Of all strain components, however, only Erc was effected by RegurgVolume Index (p=0.0005). There was no statistically significant effect of RegurgVolume Index on Ecc, Ell, Erl, or circumferential longitudinal shear strain (Ecl). Conclusions Moderate CIMR alters radial circumferential shear strain after postero-lateral MI in the sheep. Further studies are needed to determine the effect of shear strain on myocyte hypertrophy and the effect of mitral repair on myocardial strain. PMID:26857634

  6. Metabolic Syndrome, Strain, and Reduced Myocardial Function: Multi-Ethnic Study of Atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, André Luiz Cerqueira de, E-mail: andrealmeida@cardiol.br [Johns Hopkins University, Baltimore, MD (United States); Universidade Estadual de Feira de Santana, Bahia (Brazil); Teixido-Tura, Gisela; Choi, Eui-Young; Opdahl, Anders; Fernandes, Verônica R. S. [Johns Hopkins University, Baltimore, MD (United States); Wu, Colin O. [National Heart, Lung and Blood Institute, Bethesda, MD (United States); Bluemke, David A. [National Institutes of Health Clinical Center, National Institute for Biomedical Imaging and Bioengineering, Bethesda, MD (United States); Lima, João A. C. [Johns Hopkins University, Baltimore, MD (United States)

    2014-04-15

    Subclinical cardiovascular disease is prevalent in patients with Metabolic Syndrome (MetSyn). Left ventricular (LV) circumferential strain (ε{sub CC}) and longitudinal strain (ε{sub LL}), assessed by Speckle Tracking Echocardiography (STE), are indices of systolic function: shortening is indicated by negative strain, and thus, the more negative the strain, the better the LV systolic function. They have been used to demonstrate subclinical ventricular dysfunction in several clinical disorders. We hypothesized that MetSyn is associated with impaired myocardial function, as assessed by STE. We analyzed Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent STE and were evaluated for all MetSyn components. Among the 133 participants included [women: 63%; age: 65 ± 9 years (mean ± SD)], the prevalence of MetSyn was 31% (41/133). Individuals with MetSyn had lower ε{sub CC} and lower ε{sub LL} than those without MetSyn (-16.3% ± 3.5% vs. -18.4% ± 3.7%, p < 0.01; and -12.1% ± 2.5% vs. -13.9% ± 2.3%, p < 0.01, respectively). The LV ejection fraction (LVEF) was similar in both groups (p = 0.09). In multivariate analysis, MetSyn was associated with less circumferential myocardial shortening as indicated by less negative ε{sub CC} (B = 2.1%, 95%CI:0.6 3.5, p < 0.01) even after adjusting for age, ethnicity, LV mass, and LVEF). Likewise, presence of MetSyn (B = 1.3%, 95%CI:0.3 2.2, p < 0.01) and LV mass (B = 0.02%, 95% CI: 0.01-0.03, p = 0.02) were significantly associated with less longitudinal myocardial shortening as indicated by less negative ε{sub LL} after adjustment for ethnicity, LVEF, and creatinine. Left ventricular ε{sub CC} and ε{sub LL}, markers of subclinical cardiovascular disease, are impaired in asymptomatic individuals with MetSyn and no history of myocardial infarction, heart failure, and/or LVEF < 50%.

  7. Inertial gas pressure and circumferential ridge sheath strains in CANFLEX-ACR fuel

    International Nuclear Information System (INIS)

    'Full text:' ACR-1000® fuel is designed to operate with an average exit burnup of up to 20 MWd/kgU. This average exit burnup is in excess of the burnup in current CANDU® designs. The increased burnup will result in higher fission product inventory. This paper reports the evaluation of fuel sheath strains and internal gas pressures during normal operation. The internal gas pressures and sheath strains are assessed using the ELESTRES computer code. Predicted strains and pressures have adequate margin to the relevant acceptance criteria.

  8. Relation between job strain and myocardial infarction

    DEFF Research Database (Denmark)

    Netterstrøm, B; Nielsen, F E; Kristensen, T S;

    1999-01-01

    OBJECTIVES: To study the influence of different job related and socioeconomic factors for development of myocardial infarction (MI). METHOD: The study was a case-control study of 76 male wage earners who had been admitted to hospital with MI. As a control group 176 male wage earners not admitted...

  9. Myocardial strains from 3D displacement encoded magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Kindberg Katarina

    2012-04-01

    Full Text Available Abstract Background The ability to measure and quantify myocardial motion and deformation provides a useful tool to assist in the diagnosis, prognosis and management of heart disease. The recent development of magnetic resonance imaging methods, such as harmonic phase analysis of tagging and displacement encoding with stimulated echoes (DENSE, make detailed non-invasive 3D kinematic analyses of human myocardium possible in the clinic and for research purposes. A robust analysis method is required, however. Methods We propose to estimate strain using a polynomial function which produces local models of the displacement field obtained with DENSE. Given a specific polynomial order, the model is obtained as the least squares fit of the acquired displacement field. These local models are subsequently used to produce estimates of the full strain tensor. Results The proposed method is evaluated on a numerical phantom as well as in vivo on a healthy human heart. The evaluation showed that the proposed method produced accurate results and showed low sensitivity to noise in the numerical phantom. The method was also demonstrated in vivo by assessment of the full strain tensor and to resolve transmural strain variations. Conclusions Strain estimation within a 3D myocardial volume based on polynomial functions yields accurate and robust results when validated on an analytical model. The polynomial field is capable of resolving the measured material positions from the in vivo data, and the obtained in vivo strains values agree with previously reported myocardial strains in normal human hearts.

  10. Left ventricular global longitudinal strain in acute myocardial infarction

    DEFF Research Database (Denmark)

    Ersbøll, Mads

    Systolic dysfunction, clinical heart failure and elevated levels of neurohormonal peptides are major predictors of adverse outcome after acute myocardial infarction (MI). In the present thesis we evaluated global longitudinal strain (GLS) in patients with acute MI in relation to neurohormonal...

  11. Interobserver, intraobserver and intrapatient reliability scores of myocardial strain imaging with 2-d echocardiography in patients treated with anthracyclines.

    NARCIS (Netherlands)

    Mavinkurve-Groothuis, A.M.C.; Weijers, G.; Groot-Loonen, J.J.; Pourier, M.S.; Feuth, A.B.; Korte, C.L. de; Hoogerbrugge, P.M.; Kapusta, L.

    2009-01-01

    Myocardial strain imaging with 2-D echocardiography is a relatively new noninvasive method to assess myocardial deformation. To determine the interobserver, intraobserver and intrapatient reliability scores, we evaluated myocardial strain measurements of 10 asymptomatic survivors of childhood cancer

  12. Assessment of myocardial strain and strain rate by tissue doppler echocar-diography

    Directory of Open Access Journals (Sweden)

    Ekimova N.A.

    2013-03-01

    Full Text Available The objective of the article is to review the current data on the method of quantitative evaluation of cardiac mechanics — assessment of myocardial strain and strain rate according to the results of the tissue Doppler echocardiography and prospects of its clinical application.

  13. Fast myocardial strain estimation from 3D ultrasound through elastic image registration with analytic regularization

    Science.gov (United States)

    Chakraborty, Bidisha; Heyde, Brecht; Alessandrini, Martino; D'hooge, Jan

    2016-04-01

    Image registration techniques using free-form deformation models have shown promising results for 3D myocardial strain estimation from ultrasound. However, the use of this technique has mostly been limited to research institutes due to the high computational demand, which is primarily due to the computational load of the regularization term ensuring spatially smooth cardiac strain estimates. Indeed, this term typically requires evaluating derivatives of the transformation field numerically in each voxel of the image during every iteration of the optimization process. In this paper, we replace this time-consuming step with a closed-form solution directly associated with the transformation field resulting in a speed up factor of ~10-60,000, for a typical 3D B-mode image of 2503 and 5003 voxels, depending upon the size and the parametrization of the transformation field. The performance of the numeric and the analytic solutions was contrasted by computing tracking and strain accuracy on two realistic synthetic 3D cardiac ultrasound sequences, mimicking two ischemic motion patterns. Mean and standard deviation of the displacement errors over the cardiac cycle for the numeric and analytic solutions were 0.68+/-0.40 mm and 0.75+/-0.43 mm respectively. Correlations for the radial, longitudinal and circumferential strain components at end-systole were 0.89, 0.83 and 0.95 versus 0.90, 0.88 and 0.92 for the numeric and analytic regularization respectively. The analytic solution matched the performance of the numeric solution as no statistically significant differences (p>0.05) were found when expressed in terms of bias or limits-of-agreement.

  14. Strain Echocardiography Improves Risk Prediction of Ventricular Arrhythmias After Myocardial Infarction

    DEFF Research Database (Denmark)

    Haugaa, Kristina H; Grenne, Bjørnar L; Eek, Christian H;

    2013-01-01

    The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI).......The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI)....

  15. A new 2D-based method for myocardial velocity strain and strain rate quantification in a normal adult and paediatric population: assessment of reference values

    Directory of Open Access Journals (Sweden)

    Arcidiacono C

    2009-02-01

    Full Text Available Abstract Background Recent advances in technology have provided the opportunity for off-line analysis of digital video-clips of two-dimensional (2-D echocardiographic images. Commercially available software that follows the motion of cardiac structures during cardiac cycle computes both regional and global velocity, strain, and strain rate (SR. The present study aims to evaluate the clinical applicability of the software based on the tracking algorithm feature (studied for cardiology purposes and to derive the reference values for longitudinal and circumferential strain and SR of the left ventricle in a normal population of children and young adults. Methods 45 healthy volunteers (30 adults: 19 male, 11 female, mean age 37 ± 6 years; 15 children: 8 male, 7 female, mean age 8 ± 2 years underwent transthoracic echocardiographic examination; 2D cine-loops recordings of apical 4-four 4-chamber (4C and 2-chamber (2C views and short axis views were stored for off-line analysis. Computer analyses were performed using specific software relying on the algorithm of optical flow analysis, specifically designed to track the endocardial border, installed on a Windows™ based computer workstation. Inter and intra-observer variability was assessed. Results The feasibility of measurements obtained with tissue tracking system was higher in apical view (100% for systolic events; 64% for diastolic events than in short axis view (70% for systolic events; 52% for diastolic events. Longitudinal systolic velocity decreased from base to apex in all subjects (5.22 ± 1.01 vs. 1.20 ± 0.88; p Values of global systolic SR, both longitudinal and circumferential, were significantly higher in children than in adults (-1.3 ± 0.2, vs. -1.11 ± 0.2, p = 0.006; -1.9 ± 0.6 vs. -1.6 ± 0.5, p = 0.0265, respectively. No significant differences in longitudinal and circumferential systolic velocities were identified for any segment when comparing adults with children. Conclusion

  16. Comparison of cardiovascular magnetic resonance feature tracking and tagging for the assessment of left ventricular systolic strain in acute myocardial infarction

    International Nuclear Information System (INIS)

    Highlights: • We compared feature tracking (FT) and tagging quantification of myocardial strain in acute MI. • This is the first study assessing FT strain assessment in acute MI. • FT was more robust and had better myocardial tracking than tagging. • FT had better interobserver agreement and FT analysis was quicker. • FT has stronger correlation with global and segmental infarct size, area at risk (oedema), myocardial salvage and infarct transmurality. • FT is feasible in acute MI and is likely to become the preferred quantification method. - Abstract: Aims: To assess the feasibility of feature tracking (FT)-measured systolic strain post acute ST-segment elevation myocardial infarction (STEMI) and compare strain values to those obtained with tagging. Methods: Cardiovascular MRI at 1.5 T was performed in 24 patients, 2.2 days post STEMI. Global and segmental circumferential (Ecc) and longitudinal (Ell) strain were assessed using FT and tagging, and correlated with total and segmental infarct size, area at risk and myocardial salvage. Results: All segments tracked satisfactorily with FT (p < 0.001 vs. tagging). Total analysis time per patient was shorter with FT (38.2 ± 3.8 min vs. 63.7 ± 10.3 min, p < 0.001 vs. tagging). Global Ecc and Ell were higher with FT than with tagging, apart from FT Ecc using the average of endocardial and epicardial contours (−13.45 ± 4.1 [FT] vs. −13.85 ± 3.9 [tagging], p = 0.66). Intraobserver and interobserver agreement for global strain were excellent for FT (ICC 0.906–0.990) but interobserver agreement for tagging was lower (ICC < 0.765). Interobserver and intraobserver agreement for segmental strain was good for both techniques (ICC > 0.7) apart from tagging Ell, which was poor (ICC = 0.15). FT-derived Ecc significantly correlated with total infarct size (r = 0.44, p = 0.03) and segmental infarct extent (r = 0.44, p < 0.01), and best distinguished transmurally infarcted segments (AUC 0.77) and infarcted from

  17. Comparison of cardiovascular magnetic resonance feature tracking and tagging for the assessment of left ventricular systolic strain in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Jamal N., E-mail: jk211@le.ac.uk; Singh, Anvesha, E-mail: as707@le.ac.uk; Nazir, Sheraz A., E-mail: sn191@le.ac.uk; Kanagala, Prathap, E-mail: pk214@le.ac.uk; Gershlick, Anthony H., E-mail: agershlick@aol.com; McCann, Gerry P., E-mail: gerry.mccann@uhl-tr.nhs.uk

    2015-05-15

    Highlights: • We compared feature tracking (FT) and tagging quantification of myocardial strain in acute MI. • This is the first study assessing FT strain assessment in acute MI. • FT was more robust and had better myocardial tracking than tagging. • FT had better interobserver agreement and FT analysis was quicker. • FT has stronger correlation with global and segmental infarct size, area at risk (oedema), myocardial salvage and infarct transmurality. • FT is feasible in acute MI and is likely to become the preferred quantification method. - Abstract: Aims: To assess the feasibility of feature tracking (FT)-measured systolic strain post acute ST-segment elevation myocardial infarction (STEMI) and compare strain values to those obtained with tagging. Methods: Cardiovascular MRI at 1.5 T was performed in 24 patients, 2.2 days post STEMI. Global and segmental circumferential (Ecc) and longitudinal (Ell) strain were assessed using FT and tagging, and correlated with total and segmental infarct size, area at risk and myocardial salvage. Results: All segments tracked satisfactorily with FT (p < 0.001 vs. tagging). Total analysis time per patient was shorter with FT (38.2 ± 3.8 min vs. 63.7 ± 10.3 min, p < 0.001 vs. tagging). Global Ecc and Ell were higher with FT than with tagging, apart from FT Ecc using the average of endocardial and epicardial contours (−13.45 ± 4.1 [FT] vs. −13.85 ± 3.9 [tagging], p = 0.66). Intraobserver and interobserver agreement for global strain were excellent for FT (ICC 0.906–0.990) but interobserver agreement for tagging was lower (ICC < 0.765). Interobserver and intraobserver agreement for segmental strain was good for both techniques (ICC > 0.7) apart from tagging Ell, which was poor (ICC = 0.15). FT-derived Ecc significantly correlated with total infarct size (r = 0.44, p = 0.03) and segmental infarct extent (r = 0.44, p < 0.01), and best distinguished transmurally infarcted segments (AUC 0.77) and infarcted from

  18. Effects of steroids and angiotensin converting enzyme inhibition on circumferential strain in boys with Duchenne muscular dystrophy: a cross-sectional and longitudinal study utilizing cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Kinnett Kathi J

    2011-10-01

    Full Text Available Abstract Background Steroid use has prolonged ambulation in Duchenne muscular dystrophy (DMD and combined with advances in respiratory care overall management has improved such that cardiac manifestations have become the major cause of death. Unfortunately, there is no consensus for DMD-associated cardiac disease management. Our purpose was to assess effects of steroid use alone or in combination with angiotensin converting enzyme inhibitors (ACEI or angiotension receptor blocker (ARB on cardiovascular magnetic resonance (CMR derived circumferential strain (εcc. Methods We used CMR to assess effects of corticosteroids alone (Group A or in combination with ACEI or ARB (Group B on heart rate (HR, left ventricular ejection fraction (LVEF, mass (LVM, end diastolic volume (LVEDV and circumferential strain (εcc in a cohort of 171 DMD patients >5 years of age. Treatment decisions were made independently by physicians at both our institution and referral centers and not based on CMR results. Results Patients in Group A (114 studies were younger than those in Group B (92 studies(10 ± 2.4 vs. 12.4 ± 3.2 years, p cc magnitude was lower in Group B than Group A (-13.8 ± 1.9 vs. -12.8 ± 2.0, p = 0.0004, age correction using covariance analysis eliminated this effect. In a subset of patients who underwent serial CMR exams with an inter-study time of ~15 months, εcc worsened regardless of treatment group. Conclusions These results support the need for prospective clinical trials to identify more effective treatment regimens for DMD associated cardiac disease.

  19. Myocardial strain and strain rate in monitoring subclinical heart failure in asymptomatic long-term survivors of childhood cancer.

    NARCIS (Netherlands)

    Mavinkurve-Groothuis, A.M.C.; Groot-Loonen, J.J.; Marcus, K.A.; Bellersen, L.; Feuth, T.; Bokkerink, J.P.M.; Hoogerbrugge, P.M.; Korte, C.L. de; Kapusta, L.

    2010-01-01

    We studied the role of global myocardial strain and strain rate in monitoring subclinical heart failure in a large group of asymptomatic long-term survivors of childhood cancer. Global strain (rate) parameters of survivors were compared with those in healthy controls and were related to conventional

  20. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Andreas, E-mail: andreas_schuster@gmx.net [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Department of Cardiology and Pulmonology and Heart Research Centre, Georg-August-University, Göttingen (Germany); Morton, Geraint, E-mail: geraint.morton@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Hussain, Shazia T., E-mail: shazia.1.hussain@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); and others

    2013-02-15

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell{sub RV} and Ell{sub LV}) and LV long-axis radial strain (Err{sub LAX}) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (Ecc{sub SAX}, Err{sub SAX}) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general Ecc{sub SAX} was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was Ell{sub RV} (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further

  1. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

    International Nuclear Information System (INIS)

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (EllRV and EllLV) and LV long-axis radial strain (ErrLAX) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (EccSAX, ErrSAX) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general EccSAX was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was EllRV (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further refinements are needed before CMR-FT can be fully

  2. Comparison of homogenous strain-analysis with wall thickening for the assessment of regional myocardial function; Homogene Strain-Analyse im Vergleich zur Wanddickenzunahme fuer die MR-tomographische Beurteilung der regionalen Myokardfunktion

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.; Pickup, S.; Zhou, R.; Glickson, J. [Dept. of Radiology, Univ. of Pennsylvania, Philadelphia, PA (United States); Ferrari, V.A. [Dept. of Radiology, Univ. of Pennsylvania, Philadelphia, PA (United States); Dept. of Medicine, Div. of Cardiology, Univ. of Pennsylvania (United States)

    2005-07-01

    Purpose: to compare strain analysis and wall thickening (WT) analysis in differentiating the infarcted, adjacent, and remote zones in a rat model of myocardial infarction (MI). Material and methods: three normal (NL) and ten rats subjected to myocardial infarction were imaged on a 4.7T scanner. Gradient-echo and SPAMM-tagged cine images were acquired at three short axis levels of the left ventricle (LV). A homogenous strain analysis (principal strains {lambda}1 and {lambda}2, displacement D, angle {beta}) and a WT-analysis (mm- and %-thickening) were performed in all slices demonstrating MI. Regional function was compared between infarcted rats (infarcted, adjacent and remote zone) and corresponding regions in the NL rats. Additional segmental analysis was performed in the NL rats for the anterior, lateral, inferior and septal wall. Results: in the NL rats, {lambda}{sub 1} (greatest radial thickening) was greatest in the lateral and anterior wall. WT-analysis showed a pattern of function similar to {lambda}1, however, regional differences using WT-analysis were not significant. {lambda}{sub 2} (greatest circumferential shortening) was most negative in the anterior wall. D was greatest in the lateral and inferior wall. The angle {beta} was radially directed in all segments. In the infarcted rats, both strain and WT-analyses revealed significant impairment in function in the infarcted and adjacent zones as compared to NL (p < 0.001). However, only the strain analysis ({lambda}1, {lambda}2, p < 0.001) detected significant remote myocardial dysfunction. Myocardial function differed significantly between the infarcted and adjacent and between the infarcted and remote regions. Strain analysis ({lambda}2, D, {beta}, p < 0.001) also identified significant functional differences between the adjacent and remote zones, however, no statistically significant differences were found using WT-analysis. (orig.)

  3. Longitudinal strain is a marker of microvascular obstruction and infarct size in patients with acute ST-segment elevation myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Loïc Bière

    Full Text Available OBJECTIVES: We assessed the value of speckle tracking imaging performed early after a first ST-segment elevation myocardial infarction (STEMI in order to predict infarct size and functional recovery at 3-month follow-up. METHODS: 44 patients with STEMI who underwent revascularization within 12 h of symptom onset were prospectively enrolled. Echocardiography was performed 3.9 ± 1.2 days after myocardial reperfusion, assessing circumferential (CGS, radial (RGS, and longitudinal global (GLS strains. Late gadolinium-enhanced cardiac magnetic imaging (CMR, for assessing cardiac function, infarct size, and microvascular obstruction (MVO, was conducted 5.6 ± 2.5 days and 99.4 ± 4.6 days after myocardial reperfusion. RESULTS: GLS was evaluable in 97% of the patients, while CGS and RGS could be assessed in 85%. Infarct size significantly correlated with GLS (R = 0.601, p-6.0% within the infarcted area exhibited 96% specificity and 61% sensitivity for predicting the persistence of akinesia (≥ 3 segments at 3-month follow-up. CONCLUSIONS: Speckle-tracking strain imaging performed early after a STEMI is easy-to-use as a marker for persistent akinetic territories at 3 months. In addition, GLS correlated significantly with MVO and final infarct size, both parameters being relevant post-MI prognostic factors, usually obtained via CMR.

  4. Myocardial strain estimation from CT: towards computer-aided diagnosis on infarction identification

    Science.gov (United States)

    Wong, Ken C. L.; Tee, Michael; Chen, Marcus; Bluemke, David A.; Summers, Ronald M.; Yao, Jianhua

    2015-03-01

    Regional myocardial strains have the potential for early quantification and detection of cardiac dysfunctions. Although image modalities such as tagged and strain-encoded MRI can provide motion information of the myocardium, they are uncommon in clinical routine. In contrary, cardiac CT images are usually available, but they only provide motion information at salient features such as the cardiac boundaries. To estimate myocardial strains from a CT image sequence, we adopted a cardiac biomechanical model with hyperelastic material properties to relate the motion on the cardiac boundaries to the myocardial deformation. The frame-to-frame displacements of the cardiac boundaries are obtained using B-spline deformable image registration based on mutual information, which are enforced as boundary conditions to the biomechanical model. The system equation is solved by the finite element method to provide the dense displacement field of the myocardium, and the regional values of the three principal strains and the six strains in cylindrical coordinates are computed in terms of the American Heart Association nomenclature. To study the potential of the estimated regional strains on identifying myocardial infarction, experiments were performed on cardiac CT image sequences of ten canines with artificially induced myocardial infarctions. The leave-one-subject-out cross validations show that, by using the optimal strain magnitude thresholds computed from ROC curves, the radial strain and the first principal strain have the best performance.

  5. iPSC-derived human mesenchymal stem cells improve myocardial strain of infarcted myocardium.

    Science.gov (United States)

    Miao, Qingfeng; Shim, Winston; Tee, Nicole; Lim, Sze Yun; Chung, Ying Ying; Ja, K P Myu Mia; Ooi, Ting Huay; Tan, Grace; Kong, Geraldine; Wei, Heming; Lim, Chong Hee; Sin, Yoong Kong; Wong, Philip

    2014-08-01

    We investigated global and regional effects of myocardial transplantation of human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) in infarcted myocardium. Acute myocardial infarction (MI) was induced by ligation of left coronary artery of severe combined immunodeficient mice before 2 × 10(5) iMSCs or cell-free saline were injected into peri-infarcted anterior free wall. Sham-operated animals received no injection. Global and regional myocardial function was assessed serially at 1-week and 8-week by segmental strain analysis by using two dimensional (2D) speckle tracking echocardiography. Early myocardial remodelling was observed at 1-week and persisted to 8-week with global contractility of ejection fraction and fractional area change in saline- (32.96 ± 14.23%; 21.50 ± 10.07%) and iMSC-injected (32.95 ± 10.31%; 21.00 ± 7.11%) groups significantly depressed as compared to sham control (51.17 ± 11.69%, P myocardial dilatation was observed in saline-injected animals (4.40 ± 0.62 mm, P strain analysis showed significant improved basal anterior wall strain (28.86 ± 8.16%, P strain only in saline-injected (21.50 ± 5.31%, P myocardial strain coincided with the presence of interconnecting telocytes in interstitial space of the infarcted anterior segment of the heart. Our results show that localized injection of iMSCs alleviates ventricular remodelling, sustains global and regional myocardial strain by paracrine-driven effect on neoangiogenesis and myocardial deformation/compliance via parenchymal and interstitial cell interactions in the infarcted myocardium.

  6. Identifying regional cardiac abnormalities from myocardial strains using nontracking-based strain estimation and spatio-temporal tensor analysis.

    Science.gov (United States)

    Qian, Zhen; Liu, Qingshan; Metaxas, Dimitris N; Axel, Leon

    2011-12-01

    Myocardial strain is a critical indicator of many cardiac diseases and dysfunctions. The goal of this paper is to extract and use the myocardial strain pattern from tagged magnetic resonance imaging (MRI) to identify and localize regional abnormal cardiac function in human subjects. In order to extract the myocardial strains from the tagged images, we developed a novel nontracking-based strain estimation method for tagged MRI. This method is based on the direct extraction of tag deformation, and therefore avoids some limitations of conventional displacement or tracking-based strain estimators. Based on the extracted spatio-temporal strain patterns, we have also developed a novel tensor-based classification framework that better conserves the spatio-temporal structure of the myocardial strain pattern than conventional vector-based classification algorithms. In addition, the tensor-based projection function keeps more of the information of the original feature space, so that abnormal tensors in the subspace can be back-projected to reveal the regional cardiac abnormality in a more physically meaningful way. We have tested our novel methods on 41 human image sequences, and achieved a classification rate of 87.80%. The regional abnormalities recovered from our algorithm agree well with the patient's pathology and clinical image interpretation, and provide a promising avenue for regional cardiac function analysis. PMID:21606022

  7. Evaluation of Regional Myocardial Systolic Function in the Early Stage of Acute Myocardial Infarction by Strain Rate Imaging

    Directory of Open Access Journals (Sweden)

    M Esmaeilzadeh

    2009-12-01

    Full Text Available Background: We sought to evaluate the impact of different therapeutic strategies on longitudinal regional myocardial systolic function in the early phase of acute myocardial infarction using strain rate imaging.Methods: A total of 38 patients (34 males, with first acute myocardial infarction (AMI were evaluated. Our patients were divided into 3 groups according to the kind of therapy. The mean age of the patients was 55 ± 9.4 years (range: 39- 75 years. Mean left ventricular ejection fraction (LVEF in the patients was 41 ± 10.7%. Primary percutaneous coronary intervention (PCI was performed in 10 patients. Sixteen patients were treated by thrombolytic therapy using streptokinase (SK and 12 were followed-up conservatively. All patients underwent a comprehensive echocardiography study including SR imaging within 3- 5 days after AMI. The parameters measured included peak systolic strain (peakε and strain rate (SRs, end-systolic strain (εes, post systolic shortening (PSS, time to peak systolic strain rate (tSRs, time to end of shortening (teSRs, post systolic strain (PSε, post-systolic strain index (PSI, PSS ratio (PSS/ εMax and peak postsystolic strain rate (SRPSS. Results: There was not any association either between WMSI and tå (P=0.4, or MI location and PSS ratio (P=0.13. But there was an inverse relationship between WMSI and mean SRS, especially when WMSI was more pronounced. A significant relationship was found between tε and teSRs with the kind of therapy (shorter in PCI group (P= 0.04. Using a simple linear regression model, no association was found between PSS ratio and SRs (â=0.056, P =0.70, PSI and teSRs (β= -0.772, P=0.12. Simple linear regression model showed a weak but significant relationship between PSI and Median tε (β = -0.851, P =0.04; r =0.33.Conclusion: Our study showed that PCI resulted in early recovery of regional systolic function of infarcted myocardium during the early stage of acute myocardial infarction.

  8. Myocardial strain imaging: how useful is it in clinical decision making?

    Science.gov (United States)

    Smiseth, Otto A; Torp, Hans; Opdahl, Anders; Haugaa, Kristina H; Urheim, Stig

    2016-04-14

    Myocardial strain is a principle for quantification of left ventricular (LV) function which is now feasible with speckle-tracking echocardiography. The best evaluated strain parameter is global longitudinal strain (GLS) which is more sensitive than left ventricular ejection fraction (LVEF) as a measure of systolic function, and may be used to identify sub-clinical LV dysfunction in cardiomyopathies. Furthermore, GLS is recommended as routine measurement in patients undergoing chemotherapy to detect reduction in LV function prior to fall in LVEF. Intersegmental variability in timing of peak myocardial strain has been proposed as predictor of risk of ventricular arrhythmias. Strain imaging may be applied to guide placement of the LV pacing lead in patients receiving cardiac resynchronization therapy. Strain may also be used to diagnose myocardial ischaemia, but the technology is not sufficiently standardized to be recommended as a general tool for this purpose. Peak systolic left atrial strain is a promising supplementary index of LV filling pressure. The strain imaging methodology is still undergoing development, and further clinical trials are needed to determine if clinical decisions based on strain imaging result in better outcome. With this important limitation in mind, strain may be applied clinically as a supplementary diagnostic method.

  9. Noninvasive monitoring of myocardial function after surgical and cytostatic therapy in a peritoneal metastasis rat model: assessment with tissue Doppler and non-Doppler 2D strain echocardiography

    Directory of Open Access Journals (Sweden)

    Wernecke Klaus-Dieter

    2007-07-01

    Full Text Available Abstract Objective We sought to evaluate the impact of different antineoplastic treatment methods on systolic and diastolic myocardial function, and the feasibility estimation of regional deformation parameters with non-Doppler 2D echocardiography in rats. Background The optimal method for quantitative assessment of global and regional ventricular function in rats and the impact of complex oncological multimodal therapy on left- and right-ventricular function in rats remains unclear. Methods 90 rats after subperitoneal implantation of syngenetic colonic carcinoma cells underwent different onclogical treatment methods and were diveded into one control group and five treatment groups (with 15 rats in each group: group 1 = control group (without operation and without medication, group 2 = operation group without additional therapy, group 3 = combination of operation and photodynamic therapy, group 4 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with mitomycine, and group 5 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with gemcitabine, group 6 = operation in combination with taurolidin i.p. instillation. Echocardiographic examination with estimation of wall thickness, diameters, left ventricular fractional shortening, ejection fraction, early and late diastolic transmitral and myocardial velocities, radial and circumferential strain were performed 3–4 days after therapy. Results There was an increase of LVEDD and LVESD in all groups after the follow-up period (P = 0.0037. Other LV dimensions, FS and EF as well as diastolic mitral filling parameters measured by echocardiography were not significantly affected by the different treatments. Values for right ventricular dimensions and function remained unchanged, whereas circumferential 2D strain of the inferior wall was slightly, but significantly reduced under the treatment (-18.1 ± 2.5 before and -16.2 ± 2.9 % after

  10. Myocardial Strain Imaging with High-Performance Adaptive Dynamic Grid Interpolation Method

    Science.gov (United States)

    Shuhui Bu,; Makoto Yamakawa,; Tsuyoshi Shiina,

    2010-07-01

    The accurate assessment of local myocardial strain is important for diagnosing ischemic heart diseases because decreased myocardial motion often appears in the early stage. Calculating the spatial derivation of displacement is a necessary step in the strain calculation, but the numerical calculation is extremely sensitive to noise. Commonly used smoothing methods are the moving-average and median filters; however, these methods have a trade-off between spatial resolution and accuracy. A novel smoothing/fitting method is proposed for overcoming this problem. In this method, the detected displacement vectors are discretized at mesh nodes, and virtual springs are connected between adjacent nodes. By controlling the elasticity of the virtual springs, misdetected displacements are fitted without the above problem. Further improvements can be achieved by applying a Kalman filter for position tracking, and then calculating the strain from the accumulated displacement vectors. From the simulation results, we conclude that the proposed method improves the accuracy and spatial resolution of the strain images.

  11. Assessment of Regional Myocardial Function in Patients with Hypertrophic Cardiomyopathy by Tissue Strain Imaging

    Institute of Scientific and Technical Information of China (English)

    XIONG Runqing; XIE Mingxing; WANG Xinfang; L(U) Qing

    2006-01-01

    The value of tissue strain imaging (SI) in regional myocardial systolic anddiastolic function assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 20 age-matched healthy subjects, regional myocardial longitudinal peak systolic strain in eject time (represented by εet) was measured at basal, mid and apical segments of septal, lateral and posterior walls of the left ventricle (LV) and compared between groups. εet had no significant difference between segments in control group (P>0.05), which displayed a decreasing trend from basal segments to apical ones. εet in the HCM group was significantly decreased (P<0. 05) as compared with that in the healthy group. In the HCM group, εet in the midseptum was significantly less than at the basal and apical septum, and was also less than at the rest LV walls in the same group (P<0.01). The systolic reversed εet was noticed in 35 % of the hypertrophic segments in HCM group. Significantly negative correlation existed between the absolute value of εet and wall thickness in the midseptum (r=- 0.83). The post-systolic strain(PSS) segment number the and amplitudes in healthy group were significantly less than those in HCM group (P<0.05). Both regional myocardial systolic and diastolic functions were impaired in hypertrophic or non-hypertrophic segments in patients with the HCM, especially in hypertrophic segments. Strain imaging technique is a sensitive and accura tool in myocardial dysfunction assessment.

  12. Assessment of Myocardial Perfusion and Systolic Function in Patients with Coronary Artery Disease after Coronary Artery Bypass Surgery by Myocardial Contrast Echocardiography and Two-dimensional Strain Echocardiography

    Institute of Scientific and Technical Information of China (English)

    Rong LIU; Youbin DENG; Xiaojun BI; Yani LIU; Li XIONG; Liuping CHEN

    2009-01-01

    The clinically applied value of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery using real-time myocardial contrast echo-cardiography (RT-MCE) combined with two-dimensional strain echocardiography was assessed.Twenty patients underwent intravenous RT-MCE by intravenous injections of Sono Vue before and after coronary artery bypass surgery. Two-dimensional images were recorded from the left ventricular four-chamber view, two-chamber view and the apical view before, and two weeks and three months af-ter coronary artery bypass surgery, and the peak systolic longitudinal strain was measured. The results showed that myocardial perfusion was significantly increased after coronary artery bypass surgery in about 71.6% segments. In the group that myocardial perfusion was improved, the peak systolic longitu-dinal strain three months after bypass surgery was significantly higher than that before operation [(-15.78±5.91)% vs (-10.45±8.31)%, P0.05]. It was con-cluded that whether or not the improvement of myocardial perfusion can mirror the recovery trend of regional systolic function, two-dimensional strain echocardiography can observe dynamic change of re-gional systolic function. The combination of myocardial perfusion with two-dimensional strain echocar-diography can more accurately assess the curative effectiveness of coronary artery bypass surgery.

  13. Longitudinal Strain Is a Marker of Microvascular Obstruction and Infarct Size in Patients with Acute ST-Segment Elevation Myocardial Infarction

    OpenAIRE

    Loïc Bière; Erwan Donal; Gwenola Terrien; Gaëlle Kervio; Serge Willoteaux; Alain Furber; Fabrice Prunier

    2014-01-01

    International audience Objectives: We assessed the value of speckle tracking imaging performed early after a first ST-segment elevation myocardial infarction (STEMI) in order to predict infarct size and functional recovery at 3-month follow-up. Methods: 44 patients with STEMI who underwent revascularization within 12 h of symptom onset were prospectively enrolled. Echocardiography was performed 3.961.2 days after myocardial reperfusion, assessing circumferential (CGS), radial (RGS), and lo...

  14. Cardiac mechanics in patients with human immunodeficiency virus: a study of systolic myocardial deformation in children and young adults.

    Science.gov (United States)

    Al-Naami, Ghassan; Kiblawi, Fuad; Kest, Helen; Hamdan, Ayman; Myridakis, Dorothy

    2014-08-01

    Human immunodeficiency virus (HIV) infection causes dysfunction of different organ systems. Myocardial diastolic dysfunction has been reported previously in an adult HIV population. Our aim was to study myocardial strain in children and young adults infected by HIV who have apparently normal ejection fraction. Forty HIV-infected patients (mean age 20.6 ± 1.5 years) with normal ejection fraction and 55 matched normal controls (mean age 17 ± 1.5 years) were studied by two-dimensional echocardiogram. The images were stored then exported to velocity vector imaging software for analysis. Measures considered were left-ventricular peak global systolic strain (LV S) and strain rate (LV SR) as well as right-ventricular peak global systolic strain (RV S) and strain rate (RV SR). Circumferential measures of the left ventricle included the following: LV circumferential peak global systolic strain (LV circ S), strain rate (LV circ SR), radial velocity (LV rad vel), and rotational velocity (LV rot vel) at the level of the mitral valve. Statistical significance was set at p strain and strain rate in children and young adults. Normal ejection fraction might be attributed to preserved circumferential myocardial deformation. Strain and strain rate may help identify HIV patients at high risk for cardiac dysfunction and allow early detection of silent myocardial depression.

  15. Evaluation of myocardial strain and artery elasticity using speckle tracking echocardiography and high-resolution ultrasound in patients with bicuspid aortic valve.

    Science.gov (United States)

    Li, Yang; Deng, You-Bin; Bi, Xiao-Jun; Liu, Ya-Ni; Zhang, Jun; Li, Li

    2016-07-01

    Reduced artery elasticity and reduced myocardial strain were present in patients with bicuspid aortic valve (BAV). Their relation to dilation of proximal aorta is unclear. We aimed to study their relation to dilation of proximal aorta. We studied 57 BAV patients categorized into 2 subgroup according to proximal ascending aortic dimensions (nondilated strain, distensibility and stiffness index were derived. Left ventricular myocardial strain were acquired with speckle-tracking echocardiography. BAV patients with dilation of proximal ascending aorta had lower aortic strain (4.1 ± 4.2 % vs. 7.1 ± 3.5 %) and carotid strain (4.8 ± 1.9 % vs. 10.6 ± 4.2 %), lower aortic distensibility (1.4 ± 1.5 cm(2) dyn(-1) 10(-6) vs. 2.5 ± 1.5 cm(2) dyn(-1) 10(-6)) and carotid distensibility (1.6 ± 0.7 cm(2) dyn(-1) 10(-6) vs. 3.9 ± 2.4 cm(2) dyn(-1) 10(-6)), higher aortic stiffness index (19.7 ± 14.1 vs. 8.3 ± 4.9) and carotid stiffness index (12.2 ± 8.5 vs. 5.0 ± 2.2), and lower global circumferential (-15.9 ± 5.8 % vs. -19.1 ± 4.1 %), radial (19.3 ± 11.6 % vs. 29.8 ± 14.9 %) and longitudinal (-15.7 ± 3.4 % vs. -18.4 ± 3.4 %) compared with those without dilation of proximal ascending aorta. All mean values are different to p myocardial strain in BAV patients, supporting the need for detailed and extensive vascular and cardiac surveillance in BAV patients.

  16. Characteristics of myocardial postsystolic shortening in patients with coronary artery disease assessed by strain rate imaging

    Institute of Scientific and Technical Information of China (English)

    YANG Li; QIU Qiong; ZHANG Hui-zhong; XIA Jin-xi

    2007-01-01

    Background Postsystolic shortening (PSS) has been proposed as a marker of myocardial dysfunction. Strain rate imaging (SRI)is a novel ultrasonic technique, allowing reliable and noninvasive measurement of myocardial deformation.The purpose of this study was to investigate the characteristics of myocardial longitudinal PSS by SRI in ischemic and infarct myocardium in patients with coronary artery disease, and to explore its clinical applicability.Methods Eleven patients with angina pectoris, 21 patients with myocardial infarction and 20 healthy subjects were included in the study. Apical four-, three- and two-chamber views were displayed; and septal, lateral, anteroseptal,posterior, anterior and inferior walls of the left ventricle were scanned, respectively. PSS strain (εpss), the ratio of εpss and systolic strain (εpss/εsys), the ratio of εpss and maximum strain (εpss/εmax) and the duration of PSS (Tpss) in ischemic, infarct and normal myocardium were analyzed.Results PSS was found more frequent in the ischemic and infarct segments compared with the normal segments (39%vs 22% and 56% vs 22%, respectively; both P<0.01). It was even more frequent in the infarct segments than in the ischemic segments (56% vs 39%, P<0.01). The absolute magnitude of εpss, εpss/εsys, εpss/εmax were significantly larger and Tpss significantly longer in the ischemic and infarct segments compared with that in the normal myocardium (P<0.01).εpss/εsys, εpss/εmax were even larger and Tpss even longer in the infarct than in the ischemic segments (P<0.01).Conclusions PSS is a common and important feature of the ischemic and infarct myocardium. εpss, εpss/εsys, εpss/εmax and Tpss as measured by SRI may be promising markers for the quantitative assessment of regional myocardial dysfunction in patients with coronary artery disease. εpss/εsys, εpss/εmax and Tpss may be helpful in differentiating infarct from ischemic myocardium.

  17. Strain measurement by cardiovascular magnetic resonance in pediatric cancer survivors: validation of feature tracking against harmonic phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jimmy C. [C.S. Mott Children' s Hospital, University of Michigan Congenital Heart Center, Ann Arbor, MI (United States); University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, Ann Arbor, MI (United States); University of Michigan, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States); Connelly, James A. [University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Hematology-Oncology, Ann Arbor, MI (United States); Zhao, Lili [University of Michigan, Department of Biostatistics, Ann Arbor, MI (United States); Agarwal, Prachi P. [University of Michigan, Department of Radiology, Division of Cardiothoracic Radiology, Ann Arbor, MI (United States); Dorfman, Adam L. [University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, Ann Arbor, MI (United States); University of Michigan, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States)

    2014-09-15

    Left ventricular strain may be a more sensitive marker of left ventricular dysfunction than ejection fraction in pediatric cancer survivors after anthracycline therapy, but there is limited validation of strain measurement by feature tracking on cardiovascular magnetic resonance (MR) images. To compare left ventricular circumferential and radial strain by feature tracking vs. harmonic phase imaging analysis (HARP) in pediatric cancer survivors. Twenty-six patients (20.2 ± 5.6 years old) underwent cardiovascular MR at least 5 years after completing anthracycline therapy. Circumferential and radial strain were measured at the base, midventricle and apex from short-axis myocardial tagged images by HARP, and from steady-state free precession images by feature tracking. Left ventricular ejection fraction more closely correlated with global circumferential strain by feature tracking (r = -0.63, P = 0.0005) than by HARP (r = -0.39, P = 0.05). Midventricular circumferential strain did not significantly differ by feature tracking or HARP (-20.8 ± 3.4 vs. -19.5 ± 2.5, P = 0.07), with acceptable limits of agreement. Midventricular circumferential strain by feature tracking strongly correlated with global circumferential strain by feature tracking (r = 0.87, P < 0.0001). Radial strain by feature tracking had poor agreement with HARP, particularly at higher values of radial strain. Intraobserver and interobserver reproducibility was excellent for feature tracking circumferential strain, but reproducibility was poor for feature tracking radial strain. Midventricular circumferential strain by feature tracking is a reliable and reproducible measure of myocardial deformation in patients status post anthracycline therapy, while radial strain measurements are unreliable. Further studies are necessary to evaluate potential relation to long-term outcomes. (orig.)

  18. Two-dimensional speckle-tracking-derived segmental peak systolic longitudinal strain identifies regional myocardial involvement in patients with myocarditis and normal global left ventricular systolic function.

    Science.gov (United States)

    Uppu, Santosh C; Shah, Amee; Weigand, Justin; Nielsen, James C; Ko, H Helen; Parness, Ira A; Srivastava, Shubhika

    2015-06-01

    The presence of myocardial late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) imaging in concert with electrocardiography and elevated biomarkers helps support the diagnosis of acute myocarditis. Two-dimensional echocardiography is limited to global and qualitative regional function assessment and may not contribute to the diagnosis, especially in the presence of normal LV systolic function. Two-dimensional speckle-tracking (2D-STE)-derived segmental peak systolic (pkS) longitudinal strain (LS) may identify segmental myocardial involvement in myocarditis. We sought to identify an association between segmental pkS, LGE, and troponin levels in patients with myocarditis. Retrospective analysis of myocardial segmental function by 2D-STE segmental strain was compared to the presence of LGE and admission peak troponin levels in patients with acute myocarditis and preserved global LV systolic function. American Heart Association 17-segment model was used for comparison between imaging modalities. Global function was assessed by m-mode-derived shortening fraction (SF). Descriptive statistics and regression analysis were utilized. Forty-four CMRs performed to evaluate for myocarditis were identified. Of the 44, 10 patients, median age 17.5 years (14-18.5 years) and median SF 35 % (28-44 %), had paired CMR and 2D-STE data for analysis, and 161/170 segments could be analyzed by both methods for comparison. PkS LS was decreased in 51 % of segments that were positive for LGE with average pkS of -14.7 %. Segmental pkS LS abnormalities were present in all but one patient who had abnormal pkS circumferential strain. Global pkS LS was decreased in patients with myocarditis. There is a moderate correlation between decreased pkS LS and the presence of LGE by CMR, 2D-STE for myocardial involvement in acute myocarditis can serve as an useful noninvasive adjunct to the existing tests used for the diagnosis of acute myocarditis and might have a role in prognostication.

  19. Myocardial Strain Imaging Based on Two-Dimensional Displacement Vector Measurement

    Science.gov (United States)

    Nitta, Naotaka; Shiina, Tsuyoshi

    2004-05-01

    The abnormalities of myocardial wall motion caused by changes in wall stiffness often appear in the early stage of ischemic heart disease. Since the myocardium exhibits complex and large motion, a two-dimensional (2D) or three-dimensional (3D) assessment of stiffness distribution is required for accurate diagnosis. Although a 3D assessment is ultimately required, as a stepped approach for practical use, we propose novel methods for tracking the 2D motion using a one-dimensional (1D) phased array and for assessing myocardial malfunction by visualizing the invariant of a strain tensor. The feasibilities of the proposed methods were evaluated by numerically simulating the short-axis imaging of a 3D myocardial model. This model includes a hard infarction located between 1 and 3 o’clock, which is difficult to detect by conventional tissue Doppler and strain rate imaging, and the motions of the model were assigned by referring to actual myocardial motion. These results revealed that the proposed imaging methods clearly depicted the hard infarction area which conventional imaging could not detect.

  20. Early detection of myocardial dysfunction in children with mitochondrial disease: An ultrasound and two-dimensional strain echocardiography study

    NARCIS (Netherlands)

    Marcus, K.A.; Barends, M.; Morava, E.; Feuth, T.; Korte, C.L. de; Kapusta, L.

    2011-01-01

    BACKGROUND: Myocardial dysfunction in children diagnosed with mitochondrial disease is an ominous sign and has been associated with substantial increased mortality rates. Early detection of cardiac involvement would therefore be desirable. Two dimensional strain echocardiography (2DSTE) has proven t

  1. Evaluation of myocardial infarction size with three-dimensional speckle tracking echocardiography: a comparison with single photon emission computed tomography.

    Science.gov (United States)

    Wang, Qiushuang; Zhang, Chunhong; Huang, Dangsheng; Zhang, Liwei; Yang, Feifei; An, Xiuzhi; Ouyang, Qiaohong; Zhang, Meiqing; Wang, Shuhua; Guo, Jiarui; Ji, Dongdong

    2015-12-01

    To assess whether global and regional myocardial strains from three-dimensional speckle tracking echocardiography (3D-STE) correlate with myocardial infarction size (MIS) detected by single photon emission computed tomography (SPECT). Fifty-seven patients with a history of ST-segment elevation myocardial infarction (MI) within 3-6 months were enrolled, alongside 24 healthy volunteers. Left ventricular (LV) global area strain, global longitudinal strain (GLS), global radial strain, global circumferential strain, left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) were measured and compared with the corresponding SPECT-detected MISs. Patients were sub-grouped into massive MIS group (MIS ≥ 12%) and small MIS group (MIS Myocardial strains of all the LV segments were compared with the corresponding MIS. Global myocardial strain parameters, LVEF and WMSI of the patients were significantly different from the control group (all P myocardial strain parameters were found between the massive and small MIS groups (all P myocardial strain parameters were observed between segments with and without transmural MIs (P myocardial strain parameters evaluated LV global MIS, 3D GLS had the highest diagnostic value. It also preliminarily gauged the degree of ischemia and necrosis of regional myocardial segments.

  2. Comparison of parallel and spiral tagged MRI geometries in estimation of 3-D myocardial strains

    Science.gov (United States)

    Tustison, Nicholas J.; Amini, Amir A.

    2005-04-01

    Research involving the quantification of left ventricular myocardial strain from cardiac tagged magnetic resonance imaging (MRI) is extensive. Two different imaging geometries are commonly employed by these methodologies to extract longitudinal deformation. We refer to these imaging geometries as either parallel or spiral. In the spiral configuration, four long-axis tagged image slices which intersect along the long-axis of the left ventricle are collected and in the parallel configuration, contiguous tagged long-axis images spanning the width of the left ventricle between the lateral wall and the septum are collected. Despite the number of methodologies using either or both imaging configurations, to date, no comparison has been made to determine which geometry results in more accurate estimation of strains. Using previously published work in which left ventricular myocardial strain is calculated from 4-D anatomical NURBS models, we compare the strain calculated from these two imaging geometries in both simulated tagged MR images for which ground truth strain is available as well as in in vivo data. It is shown that strains calculated using the parallel imaging protocol are more accurate than that calculated using spiral protocol.

  3. Assessment of Left Ventricular Longitudinal Regional Myocardial Systolic Function by Strain Imaging Echocardiography in Patients with Hypertrophic Cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    LIU Yani; DENG Youbin; LI Xiulan; CHANG Qing; LU Yongping; LI Chunlei

    2005-01-01

    To assess the left ventricular longitudinal regional myocardial systolic function by strain imaging (SI) echocardiography and to study the relationship between regional myocardial systolic function and left ventricular structure in patients with hypertrophic cardiomyopathy (HCM). SI echocardiography were performed in 18 patients with HCM and 17 healthy subjects. For each wall,regional myocardial systolic strain was analyzed at the basal, mid, and apical level respectively.And the peak systolic strain was measured. Our results showed that the patients with HCM had reduced peak systolic strain at almost each segment of different walls when compared with healthy subjects. There was significant correlation between the mid-septum peak systolic strain and the thickness of IVS, so was the correlation between the mid-septum peak systolic strain and the IVS to LVPW thickness ratio. This study demonstrated that the left ventricular longitudinal regional myocardial systolic function was abnormal in HCM, and this kind of abnormalities existed extensively in hypertrophic and non-hypertrophic cardiac segments. The degrees of left ventricle hypertrophy and asymmetry are related to the myocardial regional systolic function in HCM.

  4. Quantitative assessment of myocardial strain with displacement encoding with stimulated echoes MRI in patients with coronary artery disease.

    Science.gov (United States)

    Miyagi, Hideki; Nagata, Motonori; Kitagawa, Kakuya; Kato, Shingo; Takase, Shinichi; Sigfridsson, Andreas; Ishida, Masaki; Dohi, Kaoru; Ito, Masaaki; Sakuma, Hajime

    2013-12-01

    To determine the diagnostic performance and reproducibility of strain assessment with displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR) in identifying contractile abnormalities in myocardial segments with late gadolinium enhancement (LGE). DENSE CMR was obtained on short-axis planes of the left ventricle (LV) in 24 patients with suspected coronary artery disease. e1 and e2 strains of LV wall were quantified. Cine MRI was acquired to determine percent systolic wall thickening (%SWT), followed by (LGE) CMR. The diagnostic performance of e1, e2 and %SWT for predicting the presence of LGE was evaluated by receiver operating characteristics (ROC) analysis. Myocardial scar on LGE CMR was observed in 91 (24 %) of 384 segments. The area under ROC curve for predicting the segments with LGE was 0.874 by e1, 0.916 by e2 and 0.828 by %SWT (p = 0.001 between e2 and %SWT). Excellent inter-observer reproducibility was found for strain [Intraclass correlation coefficient (ICC) = 0.962 for e1, 0.955 for e2] as compared with %SWT (ICC = 0.790). DENSE CMR can be performed as a part of routine CMR study and allows for quantification of myocardial strain with high inter-observer reproducibility. Myocardial strain, especially e2 is useful in detecting altered abnormal systolic contraction in the segments with myocardial scar.

  5. Doppler-derived myocardial systolic strain rate is a strong index of left ventricular contractility

    Science.gov (United States)

    Greenberg, Neil L.; Firstenberg, Michael S.; Castro, Peter L.; Main, Michael; Travaglini, Agnese; Odabashian, Jill A.; Drinko, Jeanne K.; Rodriguez, L. Leonardo; Thomas, James D.; Garcia, Mario J.

    2002-01-01

    BACKGROUND: Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. METHODS AND RESULTS: TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance-high-fidelity pressure catheter. Peak elastance (Emax) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (Sm) and peak (epsilon'(p)) and mean (epsilon'(m)) strain rates obtained at the basal septum were compared against Emax by linear regression. Emax as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between Emax and epsilon'(p) (r=0.94, P<0.01, y=0.29x+0.46) and epsilon'(m) (r=0.88, P<0.01) than for Sm (r=0.75, P<0.01). CONCLUSIONS: TDE-derived epsilon'(p) and epsilon'(m) are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S(m), perhaps by eliminating translational artifact.

  6. Myocardial dysfunction in patients with chronic kidney disease evaluated by global 2-dimensional strain imaging%二维超声应变评价慢性肾病心肌损害的价值

    Institute of Scientific and Technical Information of China (English)

    王泓; 曹铁生; 杨斌; 傅宁华; 李娟; 孙晖

    2011-01-01

    Objective To evaluate whether global 2-dimensional strain imaging can offer additional benefit over conventional echocardiography to detect subclinical myocardial damage in patients with chronic kidney disease(CKD). Methods Conventional echocardiography and global 2-dimension strain imaging were performed in 39 patients with CKD [23 men and 16 women,mean age (45.6± 14.6) years] and 29 control subjects. Twenty patients had CKD stage 2 or 3(group 1 ) and nineteen patients had CKD stage 4 or 5(group 2). Left ventricular structure and function were evaluated by conventional echocardiography. Global longitudinal and circumferential strain and strain rate were analyzed. Results There were no differences in ejection fraction and fraction shortening between CKD patients and controls. Compared with controls, CKD groups had significantly decreased value of global longitudinal strain and strain rate. Global longitudinal strain decreased from - (23.8 ± 3.1 ) % in controls to - ( 18. 5 ± 2.4) % in group 1 and to - (15.2 ± 3.2) % in group 2 ( P <0. 001 ). Compared with controls, there was no difference in global circumferential strain and strain rate between group 1 and controls, but global circumferential strain and strain rate of group 2 was reduced [ - (17.1± 3. 0) % vs -(21.2±2.8)%, P<0.05;-(1.0±0.2)% vs -(1.3±0.3)%, P<0.05]. In correlation analyses, global longitudinal strain was positively related to eGFR( r =0. 376, P <0. 001 ) and inversely related to left ventricular mass index( r = - 0. 473, P <0.01). Conclusions Global 2-dimensional strain imaging may represent a useful tool for the assessment of subclinical myocardial dysfunction in patients with CKD.%目的 探讨整体二维超声应变成像评价慢性肾病(CKD)心肌损害的价值.方法 39例CKD患者,其中20例为2~3期CKD患者(组1),19例为4~5期CKD患者(组2),设29例正常对照.使用常规超声心动图评价左室结构和功能,使用二维超声应变成像评价心肌整

  7. Relationship between acute strain pattern and recovery in tako-tsubo cardiomyopathy and acute anterior myocardial infarction: a comparative study using two-dimensional longitudinal strain.

    Science.gov (United States)

    Meimoun, Patrick; Abouth, Shirley; Boulanger, Jacques; Luycx-Bore, Anne; Martis, Sonia; Clerc, Jérome

    2014-12-01

    After acute-anterior myocardial infarction (AMI), left ventricular (LV) viable myocardial segments show some degree of active deformation (longitudinal shortening) despite wall motion abnormalities (WMA). Tako-tsubo cardiomyopathy (TTC) is characterized by myocardial stunning; however, it is unclear whether in TTC the strain pattern mimics AMI. To compare the strain-pattern in TTC and AMI using the 2D-longitudinal strain by speckle-tracking in segments with WMA, and its relationship with recovery of function at follow-up. 21 consecutive patients with typical TTC and 21 age-matched AMI patients treated by primary angioplasty had an analysis of LV-longitudinal strain at the acute-phase and at follow-up (1 and 6 months later for TTC and AMI respectively). The recovery of a segment was defined as normal wall motion at follow-up. Among the 706 analyzable LV-segments at the acute-phase, 406 had WMA (TTC 229, AMI 177). At follow-up, total recovery was observed for 45 % segments in AMI and 100 % in TTC, (p strain at follow-up (all, p ≤ 0.01). Furthermore, among the 57 % of segments exhibiting any systolic lengthening duration in AMI, only ¼ recovered, versus 62 % of such segments in TTC with 100 % recovery (p myocardial stunning in TTC and AMI is different according to longitudinal strain.

  8. Myocardial steatosis as a possible mechanistic link between diastolic dysfunction and coronary microvascular dysfunction in women.

    Science.gov (United States)

    Wei, Janet; Nelson, Michael D; Szczepaniak, Edward W; Smith, Laura; Mehta, Puja K; Thomson, Louise E J; Berman, Daniel S; Li, Debiao; Bairey Merz, C Noel; Szczepaniak, Lidia S

    2016-01-01

    Women with coronary microvascular dysfunction (CMD) and no obstructive coronary artery disease (CAD) have increased rates of heart failure with preserved ejection fraction (HFpEF). The mechanisms of HFpEF are not well understood. Ectopic fat deposition in the myocardium, termed myocardial steatosis, is frequently associated with diastolic dysfunction in other metabolic diseases. We investigated the prevalence of myocardial steatosis and diastolic dysfunction in women with CMD and subclinical HFpEF. In 13 women, including eight reference controls and five women with CMD and evidence of subclinical HFpEF (left ventricular end-diastolic pressure >12 mmHg), we measured myocardial triglyceride content (TG) and diastolic function, by proton magnetic resonance spectroscopy and magnetic resonance tissue tagging, respectively. When compared with reference controls, women with CMD had higher myocardial TG content (0.83 ± 0.12% vs. 0.43 ± 0.06%; P = 0.025) and lower diastolic circumferential strain rate (168 ± 12 vs. 217 ± 15%/s; P = 0.012), with myocardial TG content correlating inversely with diastolic circumferential strain rate (r = -0.779; P = 0.002). This study provides proof-of-concept that myocardial steatosis may play an important mechanistic role in the development of diastolic dysfunction in women with CMD and no obstructive CAD. Detailed longitudinal studies are warranted to explore specific treatment strategies targeting myocardial steatosis and its effect on diastolic function.

  9. Fast 3-Breath-Hold 3-Dimensional Tagging Cardiac Magnetic Resonance in Patients with Hypertrophic Myocardial Diseases: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Yasuo Amano

    2016-01-01

    Full Text Available Tagging CMR has been established as the standard reference for measurement of myocardial strain. The current 2D tagging technique requires multiple breath-holds to cover the whole heart and cannot show the 3D motions of the left ventricle. We performed fast 3-breath-hold 3D tagging with localized tagging preparation and complementary spatial modulation of magnetization in 10 patients with hypertrophic myocardial diseases and 6 normal volunteers. The left wall motion was observed at any view angle, which allowed for the identification of regional and global hypokinesis using the fast 3D tagging. Although a decrease in the circumferential strain and LGE were observed at the basal septum in hypertrophic cardiomyopathy, they were not located together in each patient. In hypertensive heart disease, the decrease in circumferential strain was observed more widely than LGE, and the summed strain of all segments was significantly decreased. The decrease in strain and LGE were observed diffusely in cardiac amyloidosis. In conclusion, fast 3-breath-hold 3D tagging is feasible for the regional and global strain analysis. The location of reduced circumferential strain is not necessarily the same as that of LGE and is related to the global cardiac function in patients with hypertrophic myocardial diseases.

  10. Analyses of axial, lateral and circumferential deformations of rock specimen in triaxial compression

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-bin

    2008-01-01

    The axial, lateral and circumferential strains were analyzed for a rock specimen subjected to shear failure in the form of a shear band bisecting the specimen in triaxial compression. Plastic deformation of the specimen stemmed from shear strain localization initiated at the peak shear stress. Beyond the onset of strain localization, the axial, lateral and circumferential strains were decomposed into two parts, respectively. One is the elas-tic strain described by general Hooke's law. The other is attributable to the plastic shear slips along shear band with a certain thickness dependent on the internal length of rock.The post-peak circumferential strain-axial strain curve of longer specimen is steeper than that of shorter specimen, as is consistent with the previous experiments. In elastic stage,the circumferential strain-axial strain curve exhibits nonlinear characteristic, as is in agreement with the previous experiment since confining pressure is loaded progressively until a certain value is reached. When the confining pressure is loaded completely, the circumferential strain-axial strain curve is linear in elastic and strain-softening stages. The predicted circumferential strain-axial strain curve in elastic and strain- softening stages agrees with the previous experiment.

  11. Reference values for myocardial two-dimensional strain echocardiography in a healthy pediatric and young adult cohort

    NARCIS (Netherlands)

    Marcus, K.A.; Mavinkurve-Groothuis, A.M.C.; Barends, M.; Dijk, A.P.J. van; Feuth, T.; Korte, C.L. de; Kapusta, L.

    2011-01-01

    BACKGROUND: The accurate evaluation of intrinsic myocardial contractility in children with or without congenital heart disease (CHD) has turned out to be a challenge. Two-dimensional strain echocardiographic (2DSTE) imaging or two-dimensional speckle-tracking echocardiographic imaging appears to hol

  12. Acrolein inhalation causes myocardial strain delay and decreased cardiac performance as detected by high-frequency echocardiography in mice

    Science.gov (United States)

    Acrolein, an unsaturated aldehyde found in air pollution, impairs Ca2+ flux and contraction in cardiomyocytes in vitro. To better define direct and delayed functional cardiac effects, we hypothesized that a single exposure to acrolein would modify myocardial strain and performanc...

  13. A novel, view-independent method for strain mapping in myocardial elastography: eliminating angle and centroid dependence

    Energy Technology Data Exchange (ETDEWEB)

    Zervantonakis, I K; Fung-Kee-Fung, S D; Lee, W-N; Konofagou, E E [Department of Biomedical Engineering, Columbia University, New York, NY (United States)

    2007-07-21

    Robust indices of regional and global cardiac function are a key factor in detection and treatment of heart disease as well as understanding of the fundamental mechanisms of a healthy heart. Myocardial elastography provides a noninvasive method for imaging and measuring displacement and strain of the myocardium for the early detection of cardiovascular disease. However, two-dimensional in-plane axial and lateral strains measured depend on the sonographic view used. This becomes especially critical in a clinical setting and may induce large variations in the measured strains, potentially leading to false diagnoses. A novel method in myocardial elastography is proposed for eliminating this view dependence by deriving the polar, principal and classified principal strains. The performance of the proposed methodology is assessed by employing 3D finite-element left-ventricular models of a control and an ischemic canine heart. Although polar strains are angle-independent, they are sensitive to the selected reference coordinate system, which requires the definition of a centroid of the left ventricle (LV). In contrast, principal strains derived through eigenvalue decomposition exhibit the inherent characteristic of coordinate system independence, offering view (i.e., angle and centroid)-independent strain measurements. Classified principal strains are obtained by assigning the principal components in the physical ventricular coordinate system. An extensive strain analysis illustrates the improvement in interpretation and visualization of the full-field myocardial deformation by using the classified principal strains, clearly depicting the ischemic and non-ischemic regions. Strain maps, independent of sonographic views and imaging planes, that can be used to accurately detect regional contractile dysfunction are demonstrated.

  14. A novel, view-independent method for strain mapping in myocardial elastography: eliminating angle and centroid dependence

    Science.gov (United States)

    Zervantonakis, I. K.; Fung-Kee-Fung, S. D.; Lee, W.-N.; Konofagou, E. E.

    2007-07-01

    Robust indices of regional and global cardiac function are a key factor in detection and treatment of heart disease as well as understanding of the fundamental mechanisms of a healthy heart. Myocardial elastography provides a noninvasive method for imaging and measuring displacement and strain of the myocardium for the early detection of cardiovascular disease. However, two-dimensional in-plane axial and lateral strains measured depend on the sonographic view used. This becomes especially critical in a clinical setting and may induce large variations in the measured strains, potentially leading to false diagnoses. A novel method in myocardial elastography is proposed for eliminating this view dependence by deriving the polar, principal and classified principal strains. The performance of the proposed methodology is assessed by employing 3D finite-element left-ventricular models of a control and an ischemic canine heart. Although polar strains are angle-independent, they are sensitive to the selected reference coordinate system, which requires the definition of a centroid of the left ventricle (LV). In contrast, principal strains derived through eigenvalue decomposition exhibit the inherent characteristic of coordinate system independence, offering view (i.e., angle and centroid)-independent strain measurements. Classified principal strains are obtained by assigning the principal components in the physical ventricular coordinate system. An extensive strain analysis illustrates the improvement in interpretation and visualization of the full-field myocardial deformation by using the classified principal strains, clearly depicting the ischemic and non-ischemic regions. Strain maps, independent of sonographic views and imaging planes, that can be used to accurately detect regional contractile dysfunction are demonstrated.

  15. Correlation of CT-based regional cardiac function (SQUEEZ) with myocardial strain calculated from tagged MRI: an experimental study.

    Science.gov (United States)

    Pourmorteza, Amir; Chen, Marcus Y; van der Pals, Jesper; Arai, Andrew E; McVeigh, Elliot R

    2016-05-01

    The objective of this study was to investigate the correlation between local myocardial function estimates from CT and myocardial strain from tagged MRI in the same heart. Accurate detection of regional myocardial dysfunction can be an important finding in the diagnosis of functionally significant coronary artery disease. Tagged MRI is currently a reference standard for noninvasive regional myocardial function analysis; however, it has practical drawbacks. We have developed a CT imaging protocol and automated image analysis algorithm for estimating regional cardiac function from a few heartbeats. This method tracks the motion of the left ventricular (LV) endocardial surface to produce local function maps: we call the method Stretch Quantification of Endocardial Engraved Zones (SQUEEZ). Myocardial infarction was created by ligation of the left anterior descending coronary artery for 2 h followed by reperfusion in canine models. Tagged and cine MRI scans were performed during the reperfusion phase and first-pass contrast enhanced CT scans were acquired. The average delay between the CT and MRI scans was myocardial strain (Ecc) was calculated from the tagged MRI data. The agreement between peak systolic Ecc and SQUEEZ was investigated in 162 segments in the 9 hearts. Linear regression and Bland-Altman analysis was used to assess the correlation between the two metrics of local LV function. The results show good agreement between SQUEEZ and Ecc: (r = 0.71, slope = 0.78, p function. The good agreement between the estimates of local myocardial function obtained from CT SQUEEZ and tagged MRI provides encouragement to investigate the use of SQUEEZ for measuring regional cardiac function at a low clinical dose in humans.

  16. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

    Science.gov (United States)

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-01

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  17. Acute myocardial infarction in mice: assessment of transmurality by strain rate imaging.

    Science.gov (United States)

    Thibault, Hélène; Gomez, Ludovic; Donal, Erwan; Pontier, Gerard; Scherrer-Crosbie, Marielle; Ovize, Michel; Derumeaux, Geneviève

    2007-07-01

    In vivo evaluation of the transmural extension of myocardial infarction (TEI) is crucial to prediction of viability and prognosis. With the rise of transgenic technology, murine myocardial infarction (MI) models are increasingly used. Our study aimed to evaluate systolic strain rate (SR), a new parameter of regional function, to quantify TEI in a murine model of acute MI induced by various durations of ischemia followed by 24 h of reperfusion. Global and regional left ventricular (LV) function were assessed by echocardiography (13 MHz, Vivid 7, GE) in 4 groups of wild-type mice (C57BL/6, 2 mo old): a sham-treated group (n = 10) and three MI groups [30 (n = 11), 60 (n = 10), and 90 (n = 9) min of left coronary artery occlusion]. Conventional LV dimensions, anterior wall (AW) thickening, and peak systolic SR were measured before and 24 h after reperfusion. Area at risk (AR) was measured by blue dye and infarct size (area of necrosis, AN) and TEI by triphenyltetrazolium chloride staining. AN increased with ischemia duration (25 +/- 2%, 56 +/- 5%, 71 +/- 6% of AR for 30, 60, and 90 min, respectively; P AW thickening decrease was not influenced by ischemia duration. Conversely, systolic SR decreased with ischemia duration (13 +/- 5, 4 +/- 3, -2 +/- 6 s(-1); P < 0.05) and was significantly correlated with TEI (r = 0.89, P < 0.01). Receiver operating characteristic (ROC) curves identified systolic SR as the most accurate parameter to predict TEI. In conclusion, in a murine model of MI, SR imaging is superior to conventional echocardiography to predict TEI early after MI. PMID:17384134

  18. Early Detection of Regional and Global Left Ventricular Myocardial Function Using Strain and Strain-rate Imaging in Patients with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Qin Wang

    2015-01-01

    Full Text Available Background: Strain and strain-rate imaging (SRI have been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. The aim of this study was to evaluate the regional and global left ventricular (LV myocardial function in metabolic syndrome (MS with SRI so that we can provide more myocardial small lesions in patients with MS, which is robust and reliable basis for early detection of LV function. Methods: Thirty-nine adults with MS were enrolled in the study. There was a control group of 39 healthy adults. In addition to classic echocardiographic assessment of LV global functional changes, SRI was used to evaluate regional and global LV function. Including: Peak systolic strain (S, peak systolic strain-rate (SR-s, peak diastolic strain-rate (SR-e. Results: There were no statistically significant differences between MS and controls in all traditional parameters of LV systolic function. On the other hand, significant differences were observed between MS and the control group in most of the parameters of S, SR-s, SR-e in regional LV function. Multiple stepwise regression analyses revealed that S and SR significantly were negatively correlated with blood pressure, waist circumference, fasting plasma glucose, uric acid, suggesting that risk factories were relevant to regional systolic dysfunction. Conclusion: In MS with normal LV ejection fraction, there was regional myocardial dysfunction, risk factors contributed to the impairment of systolic and diastolic function of the regional myocardium. Assessment of myocardial function using SRI could be more accurate in MS patient evaluation than conventional echocardiography alone.

  19. Early Detection of Regional and Global Left Ventricular Myocardial Function Using Strain and Strain-rate Imaging in Patients with Metabolic Syndrome

    Institute of Scientific and Technical Information of China (English)

    Qin Wang; Qi-Wei Sun; Dan Wu; Ming-Wu Yang; Rong-Juan Li; Bo Jiang; Jiao Yang

    2015-01-01

    Background:Strain and strain-rate imaging (SRI) have been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies,and identifying early subclinical changes in various pathologies.The aim of this study was to evaluate the regional and global left ventricular (LV) myocardial function in metabolic syndrome (MS) with SRI so that we can provide more myocardial small lesions in patients with MS,which is robust and reliable basis for early detection of LV function.Methods:Thirty-nine adults with MS were enrolled in the study.There was a control group of 39 healthy adults.In addition to classic echocardiographic assessment of LV global functional changes,SRI was used to evaluate regional and global LV function.Including:Peak systolic strain (S),peak systolic strain-rate (SR-s),peak diastolic strain-rate (SR-e).Results:There were no statistically significant differences between MS and controls in all traditional parameters of LV systolic function.On the other hand,significant differences were observed between MS and the control group in most of the parameters of S,SR-s,SR-e in regional LV function.Multiple stepwise regression analyses revealed that S and SR significantly were negatively correlated with blood pressure,waist circumference,fasting plasma glucose,uric acid,suggesting that risk factories were relevant to regional systolic dysfunction.Conclusion:In MS with normal LV ejection fraction,there was regional myocardial dysfunction,risk factors contributed to the impairment of systolic and diastolic function of the regional myocardium.Assessment of myocardial function using SRI could be more accurate in MS patient evaluation than conventional echocardiography alone.

  20. Utility of strain-echocardiography in current clinical practice.

    Science.gov (United States)

    Dohi, Kaoru; Sugiura, Emiyo; Ito, Masaaki

    2016-06-01

    Myocardial strain measurement with two-dimensional speckle-tracking echocardiography (2D-STE) is of paramount importance in the early detection of subclinical left ventricular (LV) systolic dysfunction and the prediction of patient outcomes in various types of heart disease, especially when assessed with global longitudinal strain (GLS). The routine application of myocardial strain parameters requires the definition of normal values and an understanding of their reliabilities. One of the most important potential limitations to widespread clinical application of this technique is inter-vendor differences in normal strain values. Recent clinical reports indicate that the smallest differences were noted in GLS measurements among three orthogonal directions. Because the contribution of circumferential fibers to LV myocardial thickening is greater than that of longitudinal fibers, patients who have a reduced LV ejection fraction can have impaired global circumferential strain (GCS), which reflects more advanced intrinsic myocardial systolic dysfunction and is thus closely related to a poor prognosis. Since STE-derived strain analysis allows us to define the timing of the regional myocardial peak systolic deformation, it permits the assessment of LV mechanical dyssynchrony. The severity of LV mechanical dyssynchrony in the short axis plane, i.e., radial and/or circumferential strain imaging, is favorable for predicting the clinical response to cardiac resynchronization therapy. GLS in the right ventricular (RV) four-chamber view has recently been used as a surrogate for global RV function because longitudinal shortening is the major contributor to overall RV performance. Finally, 2D-STE can be used to quantify and characterize RV mechanical dyssynchrony in various diseases including acute pulmonary thromboembolism and chronic pulmonary hypertension. PMID:26936263

  1. Novel cardiac nuclear magnetic resonance method for noninvasive assessment of myocardial fibrosis in hemodialysis patients.

    Science.gov (United States)

    Graham-Brown, Matthew P M; March, Daniel S; Churchward, Darren R; Stensel, David J; Singh, Anvesha; Arnold, Ranjit; Burton, James O; McCann, Gerry P

    2016-10-01

    Left ventricular hypertrophy and myocardial fibrosis frequently occur in patients with end-stage renal disease receiving hemodialysis therapy and are associated with poor prognosis. Native T1 mapping is a novel cardiac magnetic resonance imaging technique that measures native myocardial T1 relaxation, a surrogate of myocardial fibrosis. Here we compared global and segmental native myocardial T1 time and global longitudinal, circumferential and segmental strain, and cardiac function of 35 hemodialysis patients and 22 control individuals. The median native global T1 time was significantly higher in the hemodialysis than the control group (1270 vs. 1085 ms), with the septal regions of hemodialysis patients having significantly higher median T1 times than nonseptal regions (1293 vs. 1252 ms). The mean peak global circumferential strain and global longitudinal strain were both significantly reduced in hemodialysis patients compared with controls (-18.3 vs. -21.7 and -16.1 vs. -20.4, respectively). Systolic strain was also significantly reduced in the septum compared with the nonseptal myocardium in hemodialysis patients (-16.2 vs. -21.9) but not in control subjects. Global circumferential strain and longitudinal strain significantly correlated with global native T1 values (r = 0.41 and 0.55, respectively), and the septal native T1 significantly correlated with the septal systolic strain (r = 0.46). Thus, myocardial fibrosis may be assessed noninvasively with native T1 mapping; the interventricular septum appears to be particularly prone to the development of fibrosis in hemodialysis patients.

  2. Evaluation of left ventricular strain by real-time three-dimensional speckle tracking echocardiography in patients with hypertension and myocardial hypertrophy%实时三维超声心动图斑点追踪技术测量高血压心肌肥厚患者收缩期左室心肌应变

    Institute of Scientific and Technical Information of China (English)

    汤乔颖; 邓又斌; 黄润青; 刘琨; 孙杰; 邓琪

    2013-01-01

    Objective To investigate left ventricular (LV) strain in patients with hypertension (HT)and myocardial hypertrophy using three-dimensional speckle tracking echocardiography.Methods Myocardial movement was analyzed in 37 primary HT patients with myocardial hypertrophy and 27 healthy volunteers.LV longitudinal,circumferential,radial and area strains were measured.The correlation between each global strain parameter and LV ejection fraction (LVEF) was analyzed.Results LV global longitudinal strain(GSL),global radial strain (GSR) and global area strain (GSA) of HT patients with myocardial hypertrophy were significantly lower than the contrast group,whereas global circumferential strain(GSC) showed no significant difference between the two groups.Longitudinal,radial and area strains were decreased in LV basal and middle levels,while decreased circumferential strain was detected only in basal level.There were significant correlations between LVEF and GSL,GSC,GSR,GSA.Conclusions Impairment of LV regional myocardial contractility can be detected by three-dimensional speckle tracking echocardiography.%目的 采用实时三维超声心动图斑点追踪技术研究原发性高血压心肌肥厚患者的收缩期左室心肌应变特点.方法 采用三维超声心动图斑点追踪技术对37例原发性高血压心肌肥厚患者及27例健康志愿者进行了室壁运动分析,测量左室纵向、圆周向、径向、面积应变,比较两组间各应变参数的差异,并分析各项整体应变参数与左室射血分数(LVEF)的相关性.结果 高血压心肌肥厚患者的左室整体纵向、径向和面积应变较正常对照组明显减低,左室整体圆周向应变与对照组间无明显差异.纵向、径向、圆周向应变在左室基底段、中段明显减低,圆周向应变减低仅见于基底段.左室整体纵向、圆周向、径向、面积应变与LVEF具有相关性.结论 实时三维超声心动图斑点追踪技术可检测到高血压心

  3. Comparative Myocardial Deformation in 3 Myocardial Layers in Mice by Speckle Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Nicole Tee

    2015-01-01

    Full Text Available Background. Speckle tracking echocardiography (STE using dedicated high-resolution ultrasound is a relatively new technique that is useful in assessing myocardial deformation in 3 myocardial layers in small animals. However, comparative studies of STE parameters acquired from murine are limited. Methods. A high-resolution rodent ultrasound machine (VSI Vevo 2100 and a clinically validated ultrasound machine (GE Vivid 7 were used to consecutively acquire echocardiography images from standardized parasternal long axis and short axis at midpapillary muscle level from 13 BALB/c mice. Speckle tracking strain (longitudinal, circumferential, and radial from endocardial, myocardial, and epicardial layers was analyzed using vendor-specific offline analysis software. Results. Intersystem differences were not statistically significant in the global peak longitudinal strain (−16.8 ± 1.7% versus −18.7 ± 3.1% and radial strain (46.8 ± 14.2% versus 41.0 ± 9.5%, except in the global peak circumferential strain (−16.9 ± 3.1% versus 27.0 ± 5.2%, P<0.05. This was corroborated by Bland Altman analysis that revealed a weak agreement in circumferential strain (mean bias ± 1.96 SD of −10.12 ± 6.06% between endocardium and midmyocardium. However, a good agreement was observed in longitudinal strain between midmyocardium/endocardium (mean bias ± 1.96 SD of −1.88 ± 3.93% and between midmyocardium/epicardium (mean bias ± 1.96 SD of 3.63 ± 3.91%. Radial strain (mean bias ± 1.96 SD of −5.84 ± 17.70% had wide limits of agreement between the two systems that indicated an increased variability. Conclusions. Our study shows that there is good reproducibility and agreement in longitudinal deformation of the 3 myocardial layers between the two ultrasound systems. Directional deformation gradients at endocardium, myocardium, and epicardium observed in mice were consistent to those reported in human subjects, thus attesting the clinical relevance of STE

  4. Prediction of all-cause mortality and heart failure admissions from global left ventricular longitudinal strain in patients with acute myocardial infarction and preserved left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Valeur, Nana; Mogensen, Ulrik Madvig;

    2013-01-01

    This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%....

  5. Total Removal of Unwanted Harmonic Peaks (TruHARP) MRI for Single Breath-Hold High-Resolution Myocardial Motion and Strain Quantification

    OpenAIRE

    Agarwal, Harsh K.; Prince, Jerry L.; Abd-Elmoniem, Khaled Z.

    2010-01-01

    Current MRI methods for myocardial motion and strain quantification have limited resolution because of Fourier space spectral peak interference. Methods have been proposed to remove this interference in order to improve resolution; however, these methods are clinically impractical due to the prolonged imaging times. In this paper, we propose total removal of unwanted harmonic peaks (TruHARP); a myocardial motion and strain quantification methodology that uses a novel single breath-hold MR ima...

  6. Correlation between Left Ventricular Global and Regional Longitudinal Systolic Strain and Impaired Microcirculation in Patients with Acute Myocardial Infarction

    DEFF Research Database (Denmark)

    Løgstrup, Brian B; Høfsten, Dan Eik; Christophersen, Thomas Brøcher;

    2012-01-01

    Objectives: We investigated the correlation between left ventricular global and regional longitudinal systolic strain (GLS and LRS) and coronary flow reserve (CFR) assessed by transthoracic echocardiography (TTE) in patients with a recent acute myocardial infarction (AMI). Furthermore, we...... investigated if LRS and GLS imaging is superior to conventional measures of left ventricle (LV) function. Methods: In a consecutive population of first time AMI patients, who underwent successful revascularization, we performed comprehensive TTE. GLS and LRS were obtained from the three standard apical views....... Assessment of CFR by TTE was performed in a modified apical view using color Doppler guidance. Results: The study population consisted of 183 patients (51 females) with a median age of 63 [54;70] years. Eighty-nine (49%) patients had a non-ST elevation myocardial infarction and 94 (51%) patients had a ST...

  7. Early diastolic strain rate in relation to systolic and diastolic function and prognosis in acute myocardial infarction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Andersen, Mads J; Valeur, Nana;

    2014-01-01

    AIMS: Diastolic dysfunction in acute myocardial infarction (MI) is associated with adverse outcome. Recently, the ratio of early mitral inflow velocity (E) to global diastolic strain rate (e'sr) has been proposed as a marker of elevated LV filling pressure. However, the prognostic value...... of this measure has not been demonstrated in a large-scale setting when existing parameters of diastolic function are known. We hypothesized that the E/e'sr ratio would be independently associated with an adverse outcome in patients with MI. METHODS AND RESULTS: We prospectively included patients with MI.......0001). CONCLUSION: Deformation-based E/e'sr contributes important information about global myocardial relaxation superior to velocity-based analysis and is independently associated with the outcome in acute MI....

  8. Longitudinal peak strain detects a smaller risk area than visual assessment of wall motion in acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Brudin Lars

    2010-01-01

    Full Text Available Abstract Background Opening of an occluded infarct related artery reduces infarct size and improves survival in acute ST-elevation myocardial infarction (STEMI. In this study we performed tissue Doppler analysis (peak strain, displacement, mitral annular movement (MAM and compared with visual assessment for the study of the correlation of measurements of global, regional and segmental function with final infarct size and transmurality. In addition, myocardial risk area was determined and a prediction sought for the development of infarct transmurality ≥50%. Methods Twenty six patients with STEMI submitted for primary percutaneous coronary intervention (PCI were examined with echocardiography on the catheterization table. Four to eight weeks later repeat echocardiography was performed for reassessment of function and magnetic resonance imaging for the determination of final infarct size and transmurality. Results On a global level, wall motion score index (WMSI, ejection fraction (EF, strain, and displacement all showed significant differences (p ≤ 0.001, p ≤ 0.001, p ≤ 0.001 and p = 0.03 between the two study visits, but MAM did not (p = 0.17. On all levels (global, regional and segmental and both pre- and post PCI, WMSI showed a higher correlation with scar transmurality compared to strain. We found that both strain and WMSI predicted the development of scar transmurality ≥50%, but strain added no significant information to that obtained with WMSI in a logistic regression analysis. Conclusions In patients with acute STEMI, WMSI, EF, strain, and displacement showed significant changes between the pre- and post PCI exam. In a ROC-analysis, strain had 64% sensitivity at 80% specificity and WMSI around 90% sensitivity at 80% specificity for the detection of scar with transmurality ≥50% at follow-up.

  9. Evaluation of strain and strain rate imaging on myocardial ischemia in patients with myocardial bridge%应变及应变率成像评估心肌桥患者局部心肌缺血的价值

    Institute of Scientific and Technical Information of China (English)

    蔡伟; 董彦; 李学文; 周瑞娟; 赵季红; 姜铁民

    2012-01-01

    目的 探讨定量组织速度成像和应变及应变率评估冠状动脉心肌桥引起局部心肌缺血的临床价值.方法 冠状动脉前降支心肌桥患者47例(心肌桥组)与冠状动脉正常者40例(对照组),测量前降支支配区域9个节段的收缩期峰值速度、峰值应变及应变率、舒张早、晚期峰值速度、舒张早、晚期峰值应变及相应的应变率.结果 与对照组比较,心肌桥组前间隔各节段、前壁基底段及中间段、后间隔中间段收缩期峰值速度及峰值应变率明显减低(P<0.05);前间隔基底段和中间段舒张早期、晚期峰值速度及舒张早期峰值应变率明显减低(P<0.05);前壁基底段、前间隔各节段收缩期峰值应变,前壁、前间隔舒张晚期峰值应变明显减低、侧壁心尖段明显升高(P<0.05).结论 定量组织速度成像和应变及应变率可定量检测冠状动脉心肌桥引起的心肌缺血.%Objective To study the clinical value of quantitative tissue velocity imaging (QTVD, strain (S) and strain rate imaging (SR) to the evaluation of myocardial ischemia in patients with myocardial bridge. Methods A total of 47 patients with myocardial bridge and 40 normal controls were measured peak systolic velocity (Vs), peak velocity in early diastole (Ve), peak velocity in late diastole (Va), peak systolic strain rate (SRs) , peak systolic strain (Ss), peak early diastolic strain rate (SRe), peak early diastolic strain (Se), peak late diastolic strain rate (SRa), and peak late diastolie strain (Sa) of nine segments supplied by the anterior descending with echocardiography. Results Compared with control group, Vs and SRs of segments on the anteroseptal, posterior septal and anterior wall decreased significantly (P<0. 05) , and Ve, Va and SRe of basal and middle segments on anteroseptal wall decreased significantly (P<0. 05). Ss of each segments of anteroseptal and basal segment of anterior wall decreased significantly (P<0. 05

  10. Segment-orientated analysis of two-dimensional strain and strain rate as assessed by velocity vector imaging in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Thomas Butz, Corinna N. Lang, Marc van Bracht, Magnus W. Prull, Hakan Yeni, Petra Maagh, Gunnar Plehn, Axel Meissner, Hans-Joachim Trappe

    2011-01-01

    Full Text Available Aims: Strain rate imaging techniques have been proposed for the detection of ischemic or viable myocardium in coronary artery disease, which is still a challenge in clinical cardiology. This retrospective comparative study analyzed regional left ventricular function and scaring with two-dimensional strain (2DS in the first 4 to 10 days after acute anterior myocardial infarction (AMI.Methods and results: The study population consisted of 32 AMI patients with an LAD occlusion and successful reperfusion. The assessment of peak systolic 2DS and peak systolic strain rate (SR was performed segment-oriented with the angle-independent speckle tracking algorithm Velocity Vector Imaging (VVI. The infarcted, adjacent and non-infarcted segments were revealed by late enhancement MRI (LE-MRI, which was used as reference for the comparison with 2DS. The infarcted segments showed a significant decrease of tissue velocities, 2DS and SR in comparison to the non-affected segments.Conclusion: 2DS and SR as assessed by VVI seem to be a suitable approach for echocardiographic quantification of global and regional myocardial function as well as a promising tool for multimodal risk stratification after anterior AMI.

  11. Left Ventricular Systolic Function Changes in Primary Hypertension Patients Detected by the Strain of Different Myocardium Layers.

    Science.gov (United States)

    Huang, Jun; Yan, Zi-Ning; Rui, Yi-Fei; Fan, Li; Shen, Dan; Chen, Dong-Liang

    2016-01-01

    This study investigated left ventricular (LV) systolic dysfunction associated with differential strain among myocardial layers in primary hypertension (PH) patients with or without LV hypertrophy (LVH), and normal patients.In 63 PH and 42 healthy patients, two-dimensional speckle tracking echocardiography was used to measure the peak systolic longitudinal and circumferential strain of the myocardial subendocardial, middle and subepicardial layers, and the peak systolic radial strain. To assess LV systolic function, the apical long axis, 4- and 2-chamber views, and parasternal short axis at the basal, middle, and apical levels were acquired by cardiovascular ultrasound (Vivid E9, GE Healthcare, USA).Overall, the pattern in peak systolic longitudinal strain among myocardial layers was subendocardial > middle > subepicardial. In the peak systolic circumferential strain, this was middle > subepicardial > subendocardial. The peak systolic longitudinal strain was normal > NLVH > LVH. Among the groups, the peak systolic circumferential strain at the basal parasternal short-axis level was statistically similar, but at the middle and the apical parasternal short-axis levels were NLVH > normal > LVH. In normal and NLVH patients, the peak radial strain was middle > apical > basal, and in LVH patients was apical > middle > basal. The peak averages of the longitudinal and subendocardial circumferential strains differed significantly when LVH compared with NLVH and normal patients.The systolic function of PH patients was damaged in comparison with normal individuals, which could be detected conveniently and accurately using two-dimensional speckle tracking echocardiography.

  12. In vivo study of myocardial elastography under graded ischemia conditions

    Science.gov (United States)

    Lee, Wei-Ning; Provost, Jean; Fujikura, Kana; Wang, Jie; Konofagou, Elisa E.

    2011-02-01

    The capability of currently available echocardiography-based strain estimation techniques to fully map myocardial abnormality at early stages of myocardial ischemia is yet to be investigated. In this study, myocardial elastography (ME), a radio-frequency (RF)-based strain imaging technique that maps the full 2D transmural angle-independent strain tensor in standard echocardiographic views at both high spatial and temporal resolution is presented. The objectives were to (1) evaluate the performance of ME on mapping the onset, extent and progression of myocardial ischemia at graded coronary constriction levels (from partial to complete coronary flow reduction), and (2) validate the accuracy of the strain estimates against sonomicrometry (SM) measurements. A non-survival canine ischemic model (n = 5) was performed by gradually constricting the left anterior descending (LAD) coronary blood flow from 0% (baseline blood flow) to 100% (zero blood flow) at 20% increments. An open-architecture ultrasound system was used to acquire RF echocardiograms in a standard full short-axis view at the frame rate of 211 fps, at least twice higher than what is typically used in conventional echocardiographic systems, using a previously developed, fully automated composite technique. Myocardial deformation was estimated by ME and validated against sonomicrometry. ME estimates and maps transmural (1) 2D displacements using RF cross-correlation and recorrelation; and (2) 2D polar (radial and circumferential) strains, derived from 2D (i.e. both lateral and axial) displacement components, at high accuracy. Full-view strain images were shown and found to reliably depict decreased myocardial function in the region at risk at increased levels of coronary flow reduction. The ME radial strain was deemed to be a more sensitive, quantitative, regional measure of myocardial ischemia as a result of coronary flow reduction when compared to the conventional wall motion score index and ejection fraction

  13. In vivo study of myocardial elastography under graded ischemia conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wei-Ning; Provost, Jean; Konofagou, Elisa E [Department of Biomedical Engineering, Columbia University, New York, NY (United States); Fujikura, Kana [Department of Radiology, Columbia University, New York, NY (United States); Wang Jie, E-mail: ek2191@columbia.edu [Department of Medicine, Columbia University, New York, NY (United States)

    2011-02-21

    The capability of currently available echocardiography-based strain estimation techniques to fully map myocardial abnormality at early stages of myocardial ischemia is yet to be investigated. In this study, myocardial elastography (ME), a radio-frequency (RF)-based strain imaging technique that maps the full 2D transmural angle-independent strain tensor in standard echocardiographic views at both high spatial and temporal resolution is presented. The objectives were to (1) evaluate the performance of ME on mapping the onset, extent and progression of myocardial ischemia at graded coronary constriction levels (from partial to complete coronary flow reduction), and (2) validate the accuracy of the strain estimates against sonomicrometry (SM) measurements. A non-survival canine ischemic model (n = 5) was performed by gradually constricting the left anterior descending (LAD) coronary blood flow from 0% (baseline blood flow) to 100% (zero blood flow) at 20% increments. An open-architecture ultrasound system was used to acquire RF echocardiograms in a standard full short-axis view at the frame rate of 211 fps, at least twice higher than what is typically used in conventional echocardiographic systems, using a previously developed, fully automated composite technique. Myocardial deformation was estimated by ME and validated against sonomicrometry. ME estimates and maps transmural (1) 2D displacements using RF cross-correlation and recorrelation; and (2) 2D polar (radial and circumferential) strains, derived from 2D (i.e. both lateral and axial) displacement components, at high accuracy. Full-view strain images were shown and found to reliably depict decreased myocardial function in the region at risk at increased levels of coronary flow reduction. The ME radial strain was deemed to be a more sensitive, quantitative, regional measure of myocardial ischemia as a result of coronary flow reduction when compared to the conventional wall motion score index and ejection fraction

  14. Electro-mechanical characteristics of myocardial infarction border zones and ventricular arrhythmic risk: novel insights from grid-tagged cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Dennis T.L.; Weightman, Michael J.; Baumert, Mathias; Tayeb, Hussam; Richardson, James D.; Puri, Rishi; Bertaso, Angela G.; Roberts-Thomson, Kurt C.; Sanders, Prashanthan; Worthley, Matthew I. [University of Adelaide, Cardiovascular Research Centre, Royal Adelaide Hospital and Discipline of Medicine, SA (Australia); Worthley, Stephen G. [University of Adelaide, Cardiovascular Research Centre, Royal Adelaide Hospital and Discipline of Medicine, SA (Australia); Royal Adelaide Hospital, Cardiovascular Investigational Unit, SA (Australia)

    2012-08-15

    To investigate whether grid-tag myocardial strain evaluation can characterise 'border-zone' peri-infarct region and identify patients at risk of ventricular arrhythmia as the peri-infarct myocardial zone may represent an important contributor to ventricular arrhythmia following ST-segment elevation myocardial infarction (STEMI). Forty-five patients with STEMI underwent cardiac magnetic resonance (CMR) imaging on days 3 and 90 following primary percutaneous coronary intervention (PCI). Circumferential peak circumferential systolic strain (CS) and strain rate (CSR) were calculated from grid-tagged images. Myocardial segments were classified into 'infarct', 'border-zone', 'adjacent' and 'remote' regions by late-gadolinium enhancement distribution. The relationship between CS and CSR and these distinct myocardial regions was assessed. Ambulatory Holter monitoring was performed 14 days post myocardial infarction (MI) to estimate ventricular arrhythmia risk via evaluation of heart-rate variability (HRV). We analysed 1,222 myocardial segments. Remote and adjacent regions had near-normal parameters of CS and CSR. Border-zone regions had intermediate CS (-9.0 {+-} 4.6 vs -5.9 {+-} 7.4, P < 0.001) and CSR (-86.4 {+-} 33.3 vs -73.5 {+-} 51.4, P < 0.001) severity compared with infarct regions. Patients with 'border-zone' peri-infarct regions had reduced very-low-frequency power on HRV analysis, which is a surrogate for ventricular arrhythmia risk (P = 0.03). Grid-tagged CMR-derived myocardial strain accurately characterises the mechanical characteristics of 'border-zone' peri-infarct region. Presence of 'border-zone' peri-infarct region correlated with a surrogate marker of heightened arrhythmia risk following STEMI. (orig.)

  15. Electro-mechanical characteristics of myocardial infarction border zones and ventricular arrhythmic risk: novel insights from grid-tagged cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    To investigate whether grid-tag myocardial strain evaluation can characterise 'border-zone' peri-infarct region and identify patients at risk of ventricular arrhythmia as the peri-infarct myocardial zone may represent an important contributor to ventricular arrhythmia following ST-segment elevation myocardial infarction (STEMI). Forty-five patients with STEMI underwent cardiac magnetic resonance (CMR) imaging on days 3 and 90 following primary percutaneous coronary intervention (PCI). Circumferential peak circumferential systolic strain (CS) and strain rate (CSR) were calculated from grid-tagged images. Myocardial segments were classified into 'infarct', 'border-zone', 'adjacent' and 'remote' regions by late-gadolinium enhancement distribution. The relationship between CS and CSR and these distinct myocardial regions was assessed. Ambulatory Holter monitoring was performed 14 days post myocardial infarction (MI) to estimate ventricular arrhythmia risk via evaluation of heart-rate variability (HRV). We analysed 1,222 myocardial segments. Remote and adjacent regions had near-normal parameters of CS and CSR. Border-zone regions had intermediate CS (-9.0 ± 4.6 vs -5.9 ± 7.4, P < 0.001) and CSR (-86.4 ± 33.3 vs -73.5 ± 51.4, P < 0.001) severity compared with infarct regions. Patients with 'border-zone' peri-infarct regions had reduced very-low-frequency power on HRV analysis, which is a surrogate for ventricular arrhythmia risk (P = 0.03). Grid-tagged CMR-derived myocardial strain accurately characterises the mechanical characteristics of 'border-zone' peri-infarct region. Presence of 'border-zone' peri-infarct region correlated with a surrogate marker of heightened arrhythmia risk following STEMI. (orig.)

  16. Evaluation of Global and Regional Strain in Patients with Acute Coronary Syndrome without Previous Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Alireza Moaref

    2016-03-01

    Full Text Available Speckle Tracking Echocardiography (STE is a new non-invasive method, which has been recently used as an alternative technique to assess regional and global myocardial function, especially left ventricular function. It is also considered to be a valid technique to evaluate the patients with Acute Coronary Syndrome (ACS.

  17. Quantitative analysis of left ventricular strain using cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buss, Sebastian J., E-mail: sebastian.buss@med.uni-heidelberg.de [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Schulz, Felix; Mereles, Derliz [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Hosch, Waldemar [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Galuschky, Christian; Schummers, Georg; Stapf, Daniel [TomTec Imaging Systems GmbH, Munich (Germany); Hofmann, Nina; Giannitsis, Evangelos; Hardt, Stefan E. [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Katus, Hugo A.; Korosoglou, Grigorios [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany)

    2014-03-15

    Objectives: To investigate whether cardiac computed tomography (CCT) can determine left ventricular (LV) radial, circumferential and longitudinal myocardial deformation in comparison to two-dimensional echocardiography in patients with congestive heart failure. Background: Echocardiography allows for accurate assessment of strain with high temporal resolution. A reduced strain is associated with a poor prognosis in cardiomyopathies. However, strain imaging is limited in patients with poor echogenic windows, so that, in selected cases, tomographic imaging techniques may be preferable for the evaluation of myocardial deformation. Methods: Consecutive patients (n = 27) with congestive heart failure who underwent a clinically indicated ECG-gated contrast-enhanced 64-slice dual-source CCT for the evaluation of the cardiac veins prior to cardiac resynchronization therapy (CRT) were included. All patients underwent additional echocardiography. LV radial, circumferential and longitudinal strain and strain rates were analyzed in identical midventricular short axis, 4-, 2- and 3-chamber views for both modalities using the same prototype software algorithm (feature tracking). Time for analysis was assessed for both modalities. Results: Close correlations were observed for both techniques regarding global strain (r = 0.93, r = 0.87 and r = 0.84 for radial, circumferential and longitudinal strain, respectively, p < 0.001 for all). Similar trends were observed for regional radial, longitudinal and circumferential strain (r = 0.88, r = 0.84 and r = 0.94, respectively, p < 0.001 for all). The number of non-diagnostic myocardial segments was significantly higher with echocardiography than with CCT (9.6% versus 1.9%, p < 0.001). In addition, the required time for complete quantitative strain analysis was significantly shorter for CCT compared to echocardiography (877 ± 119 s per patient versus 1105 ± 258 s per patient, p < 0.001). Conclusion: Quantitative assessment of LV strain

  18. Two-dimensional longitudinal strains and torsion analysis to assess the protective effects of ischemic postconditioning on myocardial function: a speckle tracking echocardiography study in rabbits.

    Science.gov (United States)

    Liu, Y J; Leng, X P; Du, G Q; Wang, X D; Tian, J W; Ren, M

    2015-02-01

    The reperfusion injury that occurs in the early reperfusion often results in myocardial dysfunction. This study evaluated global and regional left ventricular (LV) function using speckle tracking echocardiography (STE) in a rabbit ischemia-reperfusion (I/R) model with and without ischemic postconditioning (I-PostC). The aim is to investigate the potential benefit of I-PostC for myocardial function and validate whether regional longitudinal strain is an appropriate index to indicate myocardial dysfunction. Forty rabbits were divided into an ischemia-reperfusion group (group I) and an I-PostC group (group II). After the coronary arteries were ligated, LV systolic strain and twist parameters decreased, and absolute value of strain rate of isovolumetric relaxation period (SRivr) and post-systolic strain index (PSI) increased significantly in both groups (all pstrain rate (SRsys), systolic strain (Ssys), LV twist and untwisting rate increased, and SRivr and PSI decreased in group II. These changes were not seen in group I. All STE parameters were correlated with area of necrosis (AN)/area at risk (AR) (all p0.8 or 0.6. The sensitivities of GSRsys, GSsys, SRsys, Ssys, and LV twist to detect the myocardial infarction were 81.3%, 62.5%, 87.5%, 93.8% and 81.3%, respectively. And the specificities of those parameters were 75.0%, 81.2%, 75.0%, 87.5% and 68.7%. These results indicate that STE is useful for quantitative detection on myocardial function improvement induced by I-PostC in a rabbit I/R model. The regional index-Ssys is an appropriate parameter to indicate myocardial dysfunction because of its sensitivity, specificity, and repeatability.

  19. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.

  20. Myocardial 2D strain echocardiography and cardiac biomarkers in children during and shortly after anthracycline therapy for acute lymphoblastic leukaemia (ALL): a prospective study

    NARCIS (Netherlands)

    Mavinkurve-Groothuis, A.M.C.; Marcus, K.A.; Pourier, M.; Loonen, J.; Feuth, T.; Hoogerbrugge, P.M.; Korte, C.L. de; Kapusta, L.

    2013-01-01

    AIMS: The aim of this study was to investigate myocardial 2D strain echocardiography and cardiac biomarkers in the assessment of cardiac function in children with acute lymphoblastic leukaemia (ALL) during and shortly after treatment with anthracyclines. METHODS AND RESULTS: Cardiac function of 60 c

  1. Influence of Positive End-Expiratory Pressure on Myocardial Strain Assessed by Speckle Tracking Echocardiography in Mechanically Ventilated Patients

    Directory of Open Access Journals (Sweden)

    Federico Franchi

    2013-01-01

    Full Text Available Purpose. The effects of mechanical ventilation (MV on speckle tracking echocardiography- (STE-derived variables are not elucidated. The aim of the study was to evaluate the effects of positive end-expiratory pressure (PEEP ventilation on 4-chamber longitudinal strain (LS analysis by STE. Methods. We studied 20 patients admitted to a mixed intensive care unit who required intubation for MV and PEEP titration due to hypoxia. STE was performed at three times: (T1 PEEP = 5 cmH2O; (T2 PEEP = 10 cmH2O; and (T3 PEEP = 15 cmH2O. STE analysis was performed offline using a dedicated software (XStrain MyLab 70 Xvision, Esaote. Results. Left peak atrial-longitudinal strain (LS was significantly reduced from T1 to T2 and from T2 to T3 (. Right peak atrial-LS and right ventricular-LS showed a significant reduction only at T3 (. Left ventricular-LS did not change significantly during titration of PEEP. Cardiac chambers’ volumes showed a significant reduction at higher levels of PEEP (. Conclusions. We demonstrated for the first time that incremental PEEP affects myocardial strain values obtained with STE in intubated critically ill patients. Whenever performing STE in mechanically ventilated patients, care must be taken when PEEP is higher than 10 cmH2O to avoid misinterpreting data and making erroneous decisions.

  2. Myocardial Integrated Backscatter in Obese Adolescents: Associations with Measures of Adiposity and Left Ventricular Deformation.

    Directory of Open Access Journals (Sweden)

    Lijian Xie

    Full Text Available Myocardial fibrosis has been proposed to play an important pathogenetic role in left ventricular (LV dysfunction in obesity. This study tested the hypothesis that calibrated integrated backscatter (cIB as a marker of myocardial fibrosis is altered in obese adolescents and explored its associations with adiposity, LV myocardial deformation, and metabolic parameters.Fifty-two obese adolescents and 38 non-obese controls were studied with conventional and speckle tracking echocardiography. The average cIB of ventricular septum and LV posterior wall was measured. In obese subjects, insulin resistance as estimated by homeostasis model assessment (HOMA-IR and glucose tolerance were determined. Compared with controls, obese subjects had significantly greater cIB of ventricular septum (-16.8±7.8 dB vs -23.2±7.8 dB, p<0.001, LV posterior wall (-20.5±5.6 dBvs -25.0±5.1 dB, p<0.001 and their average (-18.7±5.7 dB vs -24.1±5.0 dB, p<0.001. For myocardial deformation, obese subjects had significantly reduced LV longitudinal systolic strain rate (SR (p = 0.045 and early diastolic SR (p = 0.015, and LV circumferential systolic strain (p = 0.008, but greater LV longitudinal late diastolic SR (p<0.001, and radial early (p = 0.037 and late (p = 0.002 diastolic SR than controls. For the entire cohort, myocardial cIB correlated positively with body mass index (r = 0.45, p<0.001 and waist circumference (r = 0.45, p<0.001, but negatively with LV circumferential systolic strain (r = -0.23, p = 0.03 and systolic SR (r = -0.25, p = 0.016. Among obese subjects, cIB tended to correlate with HOMA-IR (r = 0.26, p = 0.07.Obese adolescents already exhibit evidence of increased myocardial fibrosis, which is associated with measures of adiposity and impaired LV circumferential myocardial deformation.

  3. [The features of myocardial deformation of left ventricle in patients with ischemic heart disease defined by the two dimensional strain method].

    Science.gov (United States)

    Galimskaia, V A; Donchenko, I A; Romanovskaia, E M; Oleĭnikov, V É

    2014-01-01

    Aim of this study was to assess qualitative and quantitative features of deformation parameters of left ventricular myocardium in patients with ischemic heart disease (IHD) with and without history of myocardial infarction (MI) using two-dimensional strain imaging. We examined 30 patients with clinical IHD with (group 1, n = 15) and without (group 2, n = 15) history of MI and 20 healthy volunteers. Compared with healthy subjects IHD patients of both groups had reduced longitudinal and circular myocardial deformation. There were no significant differences between patients with IHD and controls in parameters of radial, global, and regional deformation.

  4. The influence of real-time blood glucose levels on left ventricular myocardial strain and strain rate in pediatric patients with type 1 diabetes mellitus - a speckle tracking echocardiography study

    OpenAIRE

    Hensel, Kai O.; Grimmer, Franziska; Jenke, Andreas C.; Wirth, Stefan; Heusch, Andreas

    2015-01-01

    Background Echocardiographic myocardial performance parameters such as strain and strain rate are increasingly used to assess systolic and diastolic function in patients with diabetes mellitus and several other clinical and scientific scenarios. While long-term metabolic marks such as HbA1C are inherently assessed in diabetic patients, the actual blood glucose level at the very moment of the echocardiographic study has not yet been taken into account for the assessment of cardiac mechanics. T...

  5. Does global longitudinal speckle-tracking strain predict left ventricular remodeling in patients with myocardial infarction? a systematic review

    Directory of Open Access Journals (Sweden)

    Afsoon Fazlinejad

    2016-07-01

    Full Text Available Introduction: Left ventricular remodeling is a relatively prevalent complication of acute myocardial infarction (AMI, and it is associated with higher rates of medical issues and mortality. Left ventricle ejection fraction (LVEF and wall motion score index (WMSI are unable to detect accurately minor lesions following AMI. Global longitudinal strain (GLS, which is obtained through 2D-speckle tracking echocardiography (2D-STE, provides an angle-dependent measurement by which the infarcted area can be assessed as a means of identifying potential dysfunction. The main objective of this study was to evaluate whether GLS could adequately predict LV remodeling in AMI patients. Methods: The MEDLINE database from database inception to May 6th, 2015, was searched for relevant keywords and the reference lists of systematic reviews and eligible studies were also screened. All studies involving patients with their first reported case of AMI were examined for GLS by 2D-STE and were evaluated for LV remodeling at a three-month follow-up point.  Four English-language prospective cohort studies were eligible for inclusion in this study.Result: A total of 291 AMI patients (mean age=57.92 years were investigated across four different studies. The main finding of this study was that the most reliable and consistent measurement for the purposes of predicting LV remodeling in AMI patients is GLS obtained at the time of discharge, especially in STEMI patients.Discussion: In addition to their poor reproducibility, inability to stratify risks, and inter-observer variability, compensatory hyperkinesis of intact myocytes and myocardial stunning after an AMI are among the main reasons why LVEF and WMSI may not be the most effective predictors of LV remodeling in AMI.Conclusion: GLS obtained by 2D-STE at the time of discharge could be used as a reliable predictor of LV remodeling in AMI patients.

  6. Evaluation of Myocardial Systolic Function by Strain and Strain Rate Imaging in Post-Myocardial inFarction Rats%心梗后大鼠应变、应变率成像及心室重塑研究

    Institute of Scientific and Technical Information of China (English)

    赵永锋; 朱文晖; 唐水娟; 段星星; 刘稳刚

    2011-01-01

    目的 应用应变及应变率成像评价心肌梗死后心力衰竭大鼠局部心肌收缩功能,探讨心肌收缩功能与心室重塑的关系.方法 雄性SD大鼠70只随机分为手术4周组(25)、4周对照组(10)、手术8周组(25)、8周对照组(10).结扎大鼠左冠脉前降支造模成功后,分别于4周末、8周末行应变及应变率成像,胶原容积分数(CVF)测定.结果 各手术组前壁基底段、中间段,侧壁基底段的收缩期峰值应变(Ssys)、收缩期峰值应变率(SRsys)较相应对照组显著降低(P<0.01).手术8周组较手术4周组显著下降(P<0.01).手术4周组CVF与平均收缩期峰值应变(mSsys)(r=0.76,P<0.01)及平均收缩期峰值应变率(mSRsys)(r=0.60,P<0.05)密切相关,手术8周组CVF与mSsys(r=0.74,P<0.01)、mSRsys(r=0.73,P<0.01)密切相关.结论 SI及SRI可定量评价心肌梗死后心力衰竭大鼠局部收缩功能改变,其收缩功能下降程度与心室重塑程度密切相关.%Objective To evaluate left ventricular segmental systolic function in post-myocardial infarction rats by strain imaging (SI) and strain rate imaging (SRI). Explore the relationship between systolic function and ventricular remodeling. Methods 70 male Sprague-Dawley rats were randomly divided into 4 groups: 4 weeks operation group (25), 4 weeks sham operation group ( 10), 8 weeks operation group (25), 8 weeks sham operation group (10). Postinfarction rat model was induced by left anterior descending ligature. SI and SRI were applied at 4 weeks and 8 weeks after operation. Measurement of collagen volume fraction (CVF) was carried out afterward. Results Compared with corresponding sham operation groups, peak systolic strain (Ssys) and peak systolic strain rate (SRsys) in middle anterior wall, basal anterior wall and basal lateral wall were significantly decreased in two operation groups(P<0. 01).Compared with 4 weeks operation group, Ssys and SRsys in these segments in 8 weeks operation group were significantly

  7. Direct calculation of 2D components of myocardial strain using sinusoidal MR tagging

    Science.gov (United States)

    Osman, Nael F.; Prince, Jerry L.

    1998-07-01

    A new technique to measure local planar strain in left ventricular myocardium using two-dimensional tagged MR images is presented. This new technique is computationally fast, is fully automated, and generates dense motion estimates. It is based on using a 1-1 SPAMM tag pattern which comprise several one-dimensional sinusoidal tag patterns at different frequencies. A local deformation of the myocardium produces a variation in the local frequencies of these patterns, which can be used to compute strain components in the image plane. Local frequency is measured by scanning certain spectral peaks to create complex images, for which the local frequency is the gradient of the angle associated with their complex data points. The method is demonstrated using both simulations and real tagged MR images, and a discussion of these results and of directions for future research is provided.

  8. Development of a Cyclic Strain Bioreactor for Mechanical Enhancement and Assessment of Bioengineered Myocardial Constructs.

    Science.gov (United States)

    Salazar, Betsy H; Cashion, Avery T; Dennis, Robert G; Birla, Ravi K

    2015-12-01

    The purpose of this study was to develop enabling bioreactor technologies using a novel voice coil actuator system for investigating the effects of periodic strain on cardiac patches fabricated with rat cardiomyocytes. The bioengineered muscle constructs used in this study were formed by culturing rat neonatal primary cardiac cells on a fibrin gel. The physical design of the bioreactor was initially conceived using Solidworks to test clearances and perform structural strain analysis. Once the software design phase was completed the bioreactor was assembled using a combination of commercially available, custom machined, and 3-D printed parts. We utilized the bioreactor to evaluate the effect of a 4-h stretch protocol on the contractile properties of the tissue after which immunohistological assessment of the tissue was also performed. An increase in contractile force was observed after the strain protocol of 10% stretch at 1 Hz, with no significant increase observed in the control group. Additionally, an increase in cardiac myofibril alignment, connexin 43 expression, and collagen type I distribution were noted. In this study we demonstrated the effectiveness of a new bioreactor design to improve contractility of engineered cardiac muscle tissue.

  9. 纵向、径向及周向二维应变评价冠心病患者左心室局部收缩功能异常%Longitudinal, radial and circumferential 2-dimensional strain for quantitative analysis of regional left ventricular systolic dysfunction in patients with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    李燕; 胡莉君; 李薇玢; 吕清; 王新房; 谢明星; 张静; 丁尚伟; 陈明; 王静; 贺林

    2009-01-01

    Objective To assess longitudinal, radial and circumferential systolic strain of regional myocardium in patients with coronary artery disease by 2-dimensional strain echocardiography, and to explore stenosis of coronary artery impacting on regional left ventricular systolic dysfunction in quietscent condition. Methods Twenty-six patients with coronary artery disease were entrolled into this study and 26 healthy volenteers in the control group. The two-dimensional loop-einec were obtained in apical 4-chamber view,apical 2-chamber view and long axis view of left venricular, and three levels of the short axis views (mitral valve,papillary muscle and cardiac apex). According to left ventricle 18 segments divla, there were 194 affected myocardiums in 26 cases. According to stenosis degrees of coronary artery, the affected myocardiums were divided into two groups: group A (coronary stenosis degree≤70%) and group B (coronary stenosis degree>70%). Longitudinal, radial and circumferential systolic strain (SL, SR, SC) from regional myocardium were analyzed. Results Group A had 90 segments. Compared with control group,SL was decreased significantly from control group (P 0.05). Group B had 104 segments. Compared with control group, SL, SC and SR were decreased significantly in group B(P 70%供血的心肌.结果 A组共90个节段.其纵向收缩期峰值应变(SL)明显低于对照组(P0.05);B组共104个节段,其SL、SR和SC均明显低于对照组(P<0.05),A组和B组之间SL、SC和SR的差异有统计学意义(P<0.05).结论 二维应变超声心动图能准确评价冠心病患者左室局部收缩功能异常,局部心肌SL、SR和SC的变化町反映冠脉狭窄严重程度.

  10. Circumferential profiles for region-based analysis of dynamic SPECT data

    International Nuclear Information System (INIS)

    Kinetic parameters (washin, washout) of dynamic SPECT teboroxime data sets may provide a more sensitive measure of coronary artery disease than conventional (Tl, MIBI) static myocardial perfusion studies. A time-consuming and subjective step of the data analysis is drawing regions of interest to delineate blood pool and myocardial tissue regions. The time-activity curves for the regions are then used to estimate local kinetic parameters. In this work, the appropriate time-activity curves are found automatically, in a manner similar to that used for calculating circumferential profiles in conventional static cardiac studies. The drawbacks to applying standard static circumferential profile methods are the high noise level and high liver uptake common in dynamic studies. Searching along each ray for maxima to locate the myocardium does not always provide useful information. Here we propose an iterative scheme in which constraints are imposed on the radii searched. The constraints are based on the shape of the time-activity curve of the circumferential profile members and on an assumption that the short axis slices are approximately circular. The constraints eliminate outliers and help to reduce the effects of the noise and the liver activity. Kinetic parameter estimates from the automatically generated regions were comparable to estimates from manually selected regions in canine dynamic teboroxime studies

  11. Left ventricular myocardial function in hemodialysis and nondialysis uremia patients: a three-dimensional speckle-tracking echocardiography study.

    Directory of Open Access Journals (Sweden)

    Ran Chen

    Full Text Available BACKGROUND: Several studies have demonstrated that uremic patients who have preserved left ventricular ejection fraction (LVEF could still have the potential for systolic dysfunction. The aim of this study was to assess the differences between the left ventricular (LV myocardial function in hemodialysis and nondialysis uremic patients based on three-dimensional speckle-tracking echocardiography. METHODS: The study population consisted of 35 maintenance hemodialysis patients (the hemodialysis group, 30 uremic patients who were hospitalized for the creation of a primary arteriovenous fistula (the nondialysis group, and 32 healthy volunteers. All of the patients had normal left ventricular ejection fractions (i.e., 55% or greater. Three-dimensional speckle tracking echocardiography was performed to assess the left ventricle's global three-dimensional strain, regional longitudinal strain, circumferential strain, and radial strain. RESULTS: The left ventricular regional longitudinal strain, radial strain, circumferential strain, and global three-dimensional strain were significantly decreased in the nondialysis patients compared with the other two groups (all, P<0.001. However, the three-dimensional strain and the regional longitudinal strain were lower in the hemodialysis patients than in the controls (P<0.01. In the hemodialysis patients and the control group, the longitudinal strain, circumferential strain, and radial strain were higher at the apical level than they were at the basal level and midlevels. A multivariate linear regression analysis showed that the blood urea nitrogen and creatinine levels were independently associated with the values of the global three-dimensional strain (β = -0.217, P = 0.000; β = -0.243, P = 0.011, respectively and the longitudinal strain (β = -0.154, P = 0.032; β = -0.188, P = 0.029, respectively. CONCLUSIONS: Three-dimensional speckle-tracking echocardiography may detect

  12. Assessment of myocardial viability in patients with acute myocardial infarction by two-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography.

    Science.gov (United States)

    Gong, Lei; Li, Dongye; Chen, Junhong; Wang, Xiaoping; Xu, Tongda; Li, Wenhua; Ren, Shaoyang; Wang, Cheng

    2013-06-01

    It is clinically important to determine the myocardial viability of regional wall motion abnormality segments in patients with acute myocardial infarction (AMI). The purpose of this study was to ascertain the ability and value of a combination of speckle tracking echocardiography (STE) and low dose dobutamine stress echocardiography (LDDSE) for the evaluation of viable myocardium in patients with AMI. Forty-two hospitalized patients with AMI and left ventricular systolic dysfunction (left ventricular ejection fraction <50%) were underwent STE in conjunction with LDDSE and dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT). Percutaneous coronary intervention (PCI) was performed subsequently in all patients. STE was used to measure radial, circumferential, and longitudinal end-systolic strain and peak systolic strain rate. The movement of each segment was observed by routine echocardiography 1, 3, and 6 months after PCI, and its improvement over time was the criterion of viable myocardium. The sensitivity, specificity and accuracy of DISA-SPECT for the assessment of viable myocardium were 83.6, 74.4, and 80.7%, respectively. Among the radial, circumferential, and longitudinal strain and strain rate parameters, only longitudinal strain (LS) and longitudinal strain rate (LSr) at rest and LDDSE emerged as independent predictors of viable myocardium, When combining LS and LSr at LDDSE, the sensitivity, specificity and accuracy for the assessment of viable myocardium rose to 89.8, 90.2 and 89.9%, respectively. The sensitivity of STE in conjunction with LDDSE was similar to DISA-SPECT for detecting viable myocardium in patients with AMI, but the specificity and accuracy of STE performed with LDDSE were higher than DISA-SPECT.

  13. 49 CFR 178.345-7 - Circumferential reinforcements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Circumferential reinforcements. 178.345-7 Section... reinforcements. (a) A cargo tank with a shell thickness of less than 3/8 inch must be circumferentially... tank heads. (1) Circumferential reinforcement must be located so that the thickness and...

  14. Circumferential cracking of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  15. Circumferential TIG welding of zircaloy flow tubes

    International Nuclear Information System (INIS)

    Reactivity control mechanism consists of 10 mtr. long zircaloy flow tubes (inner and outer) with components welded to hold the absorber elements. These components were welded by the plug welding process and supplied to Madras Atomic Power Station (MAPS) and Narora Atomic Power Station (NAPS). In view of the in-service problem faced in Rajasthan Atomic Power Station (RAPS), the spot welds were modified to circumferential TIG welding with additional reinforcement. Development work was taken up for additional reinforcement with screws and circumferential TIG welding of these assemblies. The additional reinforcement with screws and spot welds were critically examined and the job was taken up and successfully completed at Narora site for Narora Atomic Power Projects (NAPP-II). Several trials were conducted for circumferential TIG welding of zircaloy. Since zircaloy is highly reactive in nature, good shielding with inert gas should be ensured to avoid weld contamination due to oxygen and nitrogen. The strength, microstructural and radiographical requirements were examined with different parameters of welding such as weld current, feed, inert gas flow and weld configuration. The strength and other requirements were achieved meeting stringent specifications and assemblies for KAPP-I were successfully completed and despatched. (author). 7 figs

  16. 速度向量成像对不伴心肌梗死的冠心病患者左室收缩应变的研究%Assessments of Left Ventricular Peak Systolic Strain with Velocity Vector Imaging in the Patients with Coronary Disease without Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    李华; 陈斌; 胡元平; 田新桥; 徐峰

    2011-01-01

    目的 探讨速度向量成像技术(velocity vector imaging,VVI)对不伴心肌梗死的冠心病患者的诊断价值.方法对72例冠心病患者进行超声心动图检查,并追踪造影结果,应用VVI软件测量心肌纵向、径向、圆周左室峰值收缩期应变,根据冠脉造影结果分为3组,A组:冠造阴性及狭窄程度<50%,B组:50%≤狭窄程度<75%,C组:狭窄程度≥75%,比较组间差异.结果 C组与A、B组之间纵向峰值收缩应变差异有统计学意义(P<0.05),截断值-18.28%,诊断狭窄程度≥75%的特异度为80%,敏感度为76%;C组与A、B组之间径向峰值收缩应变差异有统计学意义(P<0.05),截断值25.88%,诊断狭窄程度≥75%的特异度为71%,敏感度为70%;而C组与A、B组之间圆周峰值收缩应变差异无统计学意义(P >0.05);A组与B组之间纵向、径向及圆周峰值收缩应变差异均无统计学意义(均P >0.05).结论 VVI能帮助检测出不伴心肌梗死而有重度冠脉狭窄患者的左室心肌收缩功能异常.%Objective To evaluate the diagnostic values by using velocity vector imaging in patients with coronary disease without myocardial infarction. Methods On conventional two- dimensional echocardiography, 72 patients were examed and underwent coronary angiography within one week. The myocardial longitudinal, radial and circumferential strain were measured. The patients were classified into three groups according to the result of coronary angiography (A:0.05). There were no significant differences in longitudinal, radial and circumferential strain between the intermediate group and the control group (P >0.05). Conclusion WI can help to identify left ventricular myocardial systolic function abnormalities in patients with severe coronary stenosis but without myocardial infarction.

  17. Myocardial strain and torsion quantified by cardiovascular magnetic resonance tissue tagging - Studies in normal and impaired left ventricular function

    NARCIS (Netherlands)

    Gotte, Marco J. W.; Germans, Tjeerd; Russel, Iris K.; Zwanenburg, Jaco J. M.; Marcus, J. Tim; van Rossum, Albert C.; van Veldhuisen, Dirk J.

    2006-01-01

    Accurate quantification and timing of regional myocardial function allows early identification of dysfunction, and therefore becomes increasingly important for clinical risk assessment, patient management, and evaluation of therapeutic efficacy. For this purpose, the application of tissue Doppler ec

  18. On the correlation between myocardial mechanics and cardiac function after acute myocardial infarction%急性心肌梗死后心肌力学与心功能变化的相关性研究

    Institute of Scientific and Technical Information of China (English)

    张爱红; 张建刚; 景江新; 玛依努尔·买买提明; 宋鹏远; 吴山; 王霞; 李君; 塔娜

    2014-01-01

    目的:探讨急性心肌梗死后各节段心肌圆周应变率(SrC)、径向应变率(SrR)及心肌扭转角度变化与左室射血分数(LVEF)的相关性。方法选取51例经冠脉造影证实的急性心肌梗死患者作为心肌梗死组,40例正常健康者作为对照组,使用二维超声斑点追踪技术分别测量心尖水平与瓣环水平左室短轴各节段心肌的圆周应变率、径向应变率、心肌扭转及 LVEF 指标,并分析急性心肌梗死后心肌应变率及左室扭转角度与左室射血分数的相关性。结果(1)急性心肌梗死组患者左室容积较对照组增大,但差异无统计学意义(P >0.05);LVEF 较对照组下降,差异有统计学意义(P <0.05)。(2)急性心肌梗死组患者各节段心肌 SrC、SrR 较对照组均明显下降,差异有统计学意义(P <0.05)。(3)急性心肌梗死组患者各节段心肌扭转角度较对照组明显下降,差异有统计学意义(P <0.05)。(4)直线相关方程显示,急性心梗组患者各节段 SrC、SrR 及扭转角度均与 LVEF 具有相关性,其中左室整体扭转角度与 LVEF 相关性较好(P <0.05)。结论急性心肌梗死后心肌力学发生了严重改变,其中心肌扭转较应变率对心功能的影响更为明显。%Objective To investigate the correlation between left ventricular ejection fraction (LVEF)and myocardial circumferential strain,radial strain rate,myocardial torsion angle after acute myocardial infarc-tion.Methods 51 cases suffered from acute myocardial infarction and confirmed by coronary angiography were chosen as myocardial infarction group,40 healthy patients as control group.Each segment of the my-ocardial circumferential strain rate,radial strain rate,left ventricular torsion and LVEF were measured by two - dimensional ultrasound speckle tracking technology at apical level and annulus level in left ventricular short axis view

  19. Myocardial deformation imaging by two-dimensional speckle-tracking echocardiography in comparison to late gadolinium enhancement cardiac magnetic resonance for analysis of myocardial fibrosis in severe aortic stenosis.

    Science.gov (United States)

    Hoffmann, Rainer; Altiok, Ertunc; Friedman, Zvi; Becker, Michael; Frick, Michael

    2014-10-01

    Myocardial deformation analysis by speckle-tracking echocardiography (STE) has been used for analysis of myocardial viability and myocardial fibrosis. Patients with severe aortic stenosis are known to develop myocardial fibrosis. This study evaluated the association between myocardial fibrosis determined by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) and 2-dimensional STE in patients with severe aortic stenosis. In 30 patients (78±7 years) with severe aortic stenosis (mean gradient 53±21 mm Hg), peak systolic circumferential strain based on 2-dimensional echocardiographic parasternal short-axis views and peak systolic longitudinal strain based on apical views were determined for analysis of regional function. LGE CMR was performed to define the amount of fibrosis in each segment within 24 hours of echocardiography. Relative amount of fibrosis was determined based on LGE CMR as gray-scale threshold 6 SDs above the mean signal intensity of the normal remote myocardium. There was a decrease in LGE from base to apex (14.4±8.7% for basal segments, 3.4±3.0% for midventricular segments, and 2.1±3.0% for apical segments; pmyocardial deformation expressed as peak systolic longitudinal strain from base to apex (-11.6±7.0% for basal segments, -16.9±6.5% for midventricular segments, and -17.4±7.7% for apical segments; p=0.001). There was a negative correlation between the amount of myocardial fibrosis determined by LGE CMR and peak systolic longitudinal strain for the total left ventricle (r=-0.538, p=0.007). Myocardial fibrosis defined as LGE>10% could be identified by peak systolic longitudinal strain less than -11.6%, with a sensitivity of 65% and a specificity of 75% (area under the receiver operating characteristic curve 0.69). In conclusion, myocardial fibrosis increases from apical to basal left ventricular segments in patients with severe aortic stenosis. There is an association between severity of myocardial fibrosis defined by LGE CMR

  20. SRI对急性前壁STEMI患者心肌存活的早期预测价值%Early prediction of myocardial viability by strain rate imaging in patients with anterior wall ST elevation myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    钟新波; 赵有生; 王小庆; 王涓; 陈文斌; 李涯

    2012-01-01

    目的 探讨应变率成像(SRI)对急性前壁ST段抬高心肌梗死(STEMI)患者心肌存活的早期预测价值.方法 行急诊经皮冠状动脉介入术(PCI)的前壁STEMI患者在术后测量室间隔心尖段的SRI指标,当收缩末期应变(SES)≥-7%时则纳入研究,并于6个月后复查,评价急性期SRI指标对心肌存活的预测价值.结果 46例前壁STEMI患者纳入研究,其中25例在6个月时SES<-7%,我们定义为存活心肌;21例随访时SES≥-7%,我们定义为失活心肌.存活心肌组SES、收缩后应变(SPS)、收缩期应变率(SRS)及舒张早期应变率(SRE)等指标明显优于失活心肌组(P<0.01),而收缩后应变率、舒张晚期应变率两组间无明显差异(P>0.05).SRS、SRE、SPS、SES均能预测心肌的存活,其中SRS曲线下面积最大(0.803,P<0.01),当临界值取-0.31 s-1时,其预测存活心肌的敏感性、特异性、阳性预测值、阴性预测值分别为83%、68%、76%、71%.结论 在行急诊PCI的前壁STEMI患者中,SRI技术能早期预测受累心肌的存活性.%Objective To investigate the predictive value of strain rate imaging (SRI) on myocardial viability in patients with anterior wall ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods SRI parameters of apical septal segments were determined in patients with anterior wall STEMI. The patients with their acute end-systolic strain values (SES)≥-7% were included and reassess wall motion at 6-month followed-up. Results Forty-six anterior wall STEMI patients were enrolled. At the end of the followed-up, twenty-five segments improved their SES to <-7% and were defined as viable, twenty-one failed to do so defined as non-viable. Compared to the non-viable group, viable segments had significantly better SES, post-systolic strain, systolic and early diastolic strain rate values. All the above-mentioned parameters could predict myocardial viability in

  1. 一种心肌应变图的快速绘制方法%A Fast Mapping Method of Myocardial Strain Image

    Institute of Scientific and Technical Information of China (English)

    单志蕊; 李璇; 王青; 黄庆华; 冯前进; 陈武凡

    2016-01-01

    灰度B超图显示心脏的解剖结构,应变图可反映心肌的力学信息。心肌应变图与心脏灰度B超图混叠显示,有助于观察各阶段心肌组织的形态学及力学上的变化。提出一种心肌彩色应变图覆盖到心脏灰度B超图的快速绘制方法,即整体映射方法。采用Sonix RP超声系统扫描正常成年男性心脏6 s,保存左心室长轴的超声射频信号,经过重建灰度B超图像、计算位移图及应变图、勾画心肌的区域、彩色编码应变值等处理步骤,将心肌应变图整体映射到心脏灰度B超图上相应的位置,完成灰度B超图与彩色应变图混叠显示。实验结果:该方法绘制时间短,心肌勾画区域为1×106个像素点时,彩色应变图的绘制时间约为0.24 s,心肌勾画区域为4×106个像素点时,彩色应变图的绘制时间约为2.4 s。说明提出的心肌应变图的整体映射绘制方法,费时少,可以用于实现实时观察心肌的形状和弹性信息。%The grayscale B-mode ultrasound image displays the anatomic structure of the heart, while the strain map reflects the mechanical information of the myocardium.The combination of the myocardial color-coded strain map with the grayscale B-mode image benefits the detection of alterations in the myocardium.Objective:This study proposed a fast mapping method of myocardial strain image superimposed onto the grayscale B-mode ultrasound im-age, i.e.the overall mapping method.Methods:The heart of a health adult male was scanned using Sonix RP ul-trasound system for 6 seconds.The ultrasonic RF signals of the left ventricular long-axis view of the heart were re-corded for reconstruction of the B-mode image.The displacement and strain maps of the myocardium were obtained respectively using the method of dynamic estimation and analytic minimization and the polynomial linear regression. Then, the color-coded strain map of the myocardium was overall superimposed on the

  2. Sensitive cardiac troponins and N-terminal pro-B-type natriuretic peptide in stable coronary artery disease: correlation with left ventricular function as assessed by myocardial strain.

    Science.gov (United States)

    Smedsrud, Marit Kristine; Gravning, Jørgen; Omland, Torbjørn; Eek, Christian; Mørkrid, Lars; Skulstad, Helge; Aaberge, Lars; Bendz, Bjørn; Kjekshus, John; Edvardsen, Thor

    2015-06-01

    N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponins (cTns) measured with sensitive assays provide strong prognostic information in patients with stable coronary artery disease. However, the relationship between these biomarkers and myocardial contractile function, as well as infarct size, in this patient group, remains to be defined. The study population consisted of 160 patients referred to a follow-up echocardiography scheduled 1 year after coronary revascularization. Concentrations of NT-proBNP, high-sensitive cTnT (hs-cTnT) and sensitive cTnI assays were assessed. Left ventricular function was measured as global peak systolic longitudinal strain by speckle tracking echocardiography and infarct size was assessed by late-enhancement MRI. NT-proBNP and sensitive cTnI levels were significantly associated with left ventricular function by peak systolic strain (R-values 0.243 and 0.228, p = 0.002 and 0.004) as well as infarct size (R-values 0.343 and 0.366, p = 0.014 and p = 0.008). In contrast, hs-cTnT did not correlate with left ventricular function (R = 0.095, p = 0.231) and only marginally with infarct size (R = 0.237, p = 0.094). NT-proBNP and sensitive cTnI levels correlate with left ventricular function and infarct size in patients with stable coronary artery disease after revascularization. As opposed to hs-cTnT, NT-proBNP and cTnI seem to be indicators of incipient myocardial dysfunction and the extent of myocardial necrosis.

  3. Left ventricular myocardial function in congenital valvar aortic stenosis assessed by ultrasound tissue-velocity and strain-rate techniques.

    NARCIS (Netherlands)

    Kiraly, P.; Kapusta, L.; Thijssen, J.M.; Daniëls, O.

    2003-01-01

    A pilot study was performed to reveal the potentials of new echo Doppler techniques for the detection of myocardial changes due to congenital valvar aortic stenosis. A total of 24 patients, (age range 0.1 to 17 years), with various degrees of aortic stenosis, and 24 age- and gender-matched, healthy

  4. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

    Directory of Open Access Journals (Sweden)

    Nagao Michinobu

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV using tagged cardiovascular magnetic resonance (CMR and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. Methods 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix. The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. Results The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6% than non-stenotic segment (-18.8 ± 10.2%, p Conclusions Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

  5. Consideration on evaluation of internal pressure creep rupture for tube with circumferential joint

    International Nuclear Information System (INIS)

    The behavior of internal pressure creep rupture of the thin-walled cylinders with circumferential joints is affected by the combination of creep characteristics of parent materials and weld metals. In particular, the compatibility of the creep strain rate of parent materials and weld metals becomes an important controlling factor. The behavior of internal pressure creep of the welded parts in circumferential joint cylinders can be evaluated simply with the uniaxial creep data of parent materials and weld metals, considering it by approximately substituting with the creep behavior of a uniaxial longitudinal joint. The method of evaluation is, first, to analyze the breaking behavior of uniaxial longitudinal joints using the uniaxial creep characteristic values of parent materials and weld metals, and next, by combining the equation for the relation between the rupture times of uniaxial creep and internal pressure creep with the analyzed breaking behavior of uniaxial joints, the internal pressure creep rupture behavior of the cylinders with circumferential joints can be evaluated. The internal pressure creep behavior of the thin-walled cylinders with circumferential joints, their rupture life and the uniaxial creep rupture life of longitudinal joints, and the examination of Hastelloy X cylinders are reported. (Kako, I.)

  6. Left ventricle short axis two-dimensional strain in pigs with myocardial contusion measured by speckle tracking imaging echocardiography%超声斑点追踪技术对猪心肌挫伤前、后左室短轴二维应变的研究

    Institute of Scientific and Technical Information of China (English)

    袁彬彬; 张卫达; 张雪花; 王晓武

    2012-01-01

    目的:运用斑点追踪技术(STI)测量猪闭合性心肌挫伤前、后左心室短轴各节段的二维应变值,观察正常人室壁二维应变的规律,探讨斑点追踪技术对节段性心肌缺血的临床应用价值.方法:采用小型撞击器对9只贵州小型巴马猪进行撞击建立闭合性心肌损伤模型,记录猪撞击前及撞伤后左室短轴观3个水平的高帧频图像,应用二维应变分析软件测量各节段的径向应变(RS)、圆周应变(CS).结果:闭合性心肌挫伤前Rs在同一水平各节段间差异无统计学意义,乳头肌水平显著高于心尖水平(P<0.05);Cs在同一水平不同节段间差异有统计学意义(P<0.05).闭合性心肌挫伤后的挫伤节段的Rs和Cs显著低于正常组相应节段(均为P<0.01、P<0.05).结论:STI能够准确测量左室短轴各节段的二维应变值、敏感评价心肌缺血程度.%Objective:To evaluate the clinical value of speckle tracking echocardiography for the measurement of two dimensional strain echocardiography (2D-SE) technique in pigs with close myocardial contusion and to estimate the left ventricle function of close myocardial contusion. Methods:9 small Guizhou-Panama pigs were used. The close myocardial contusion animal mode, was snccessfully set up using the small impactor. High frame rate two-dimensional images were recorded from the left ventricular short-axis views at three different levels before and after the MC. Radial strain (RS) and circumferential strain (CS) were measured in the left ventricular short-axis views using 2DS strain analysis software. Results: 2DS analysis software showed that there was no significant difference ( P >0. 05) of the RS at the same levels mentioned above in left ventricle before the MC. RS and CS after the strike were significantly decreased compared with pre-my-ocardial contusion ( P <0. 05. P<0. 01) at the same levels mentioned above in left ventricle. Conclusion: Speckle tracking imaging

  7. The relationship between biventricular myocardial performance and metabolic parameters during incremental exercise and recovery in healthy adolescents.

    Science.gov (United States)

    Pieles, Guido E; Gowing, Lucy; Forsey, Jonathan; Ramanujam, Paramanantham; Miller, Felicity; Stuart, A Graham; Williams, Craig A

    2015-12-15

    Background left ventricular (LV) and right ventricular (RV) myocardial reserve during exercise in adolescents has not been directly characterized. The aim of this study was to quantify myocardial performance response to exercise by using two-dimensional (2-D) speckle tracking echocardiography and describe the relationship between myocardial reserve, respiratory, and metabolic exercise parameters. A total of 23 healthy boys and girls (mean age 13.2 ± 2.7 yr; stature 159.1 ± 16.4 cm; body mass 49.5 ± 16.6 kg; BSA 1.47 ± 0.33 m(2)) completed an incremental cardiopulmonary exercise test (25 W · 3 min increments) with simultaneous acquisition of 2-D transthoracic echocardiography at rest, each exercise stage up to 100 W, and in recovery at 2 min and 10 min. Two-dimensional LV (LV Sl) and RV (RV Sl) longitudinal strain and LV circumferential strain (LV Sc) were analyzed to define the relationship between myocardial performance reserve and metabolic exercise parameters. Participants achieved a peak oxygen uptake (V̇o 2peak) of 40.6 ± 8.9 ml · kg(-1) · min(-1) and a work rate of 154 ± 42 W. LV Sl and LV Sc and RV Sl increased significantly across work rates (P strain, V̇o 2peak, oxygen pulse, and work rate (0.530 ≤ r ≤ 0.784, P myocardial performance and metabolic parameters during exercise by using a novel methodology. Relationships detected present novel data directly describing myocardial adaptation at different stages of exercise and recovery that in the future can help directly assess cardiac reserve in patients with cardiac pathology.

  8. Cardiac biplane strain imaging: initial in vivo experience

    Energy Technology Data Exchange (ETDEWEB)

    Lopata, R G P; Nillesen, M M; Thijssen, J M; De Korte, C L [Clinical Physics Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Verrijp, C N; Lammens, M M Y; Van der Laak, J A W M [Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Singh, S K; Van Wetten, H B [Department of Cardiothoracic Surgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kapusta, L [Pediatric Cardiology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: R.Lopata@cukz.umcn.nl

    2010-02-21

    In this study, first we propose a biplane strain imaging method using a commercial ultrasound system, yielding estimation of the strain in three orthogonal directions. Secondly, an animal model of a child's heart was introduced that is suitable to simulate congenital heart disease and was used to test the method in vivo. The proposed approach can serve as a framework to monitor the development of cardiac hypertrophy and fibrosis. A 2D strain estimation technique using radio frequency (RF) ultrasound data was applied. Biplane image acquisition was performed at a relatively low frame rate (<100 Hz) using a commercial platform with an RF interface. For testing the method in vivo, biplane image sequences of the heart were recorded during the cardiac cycle in four dogs with an aortic stenosis. Initial results reveal the feasibility of measuring large radial, circumferential and longitudinal cumulative strain (up to 70%) at a frame rate of 100 Hz. Mean radial strain curves of a manually segmented region-of-interest in the infero-lateral wall show excellent correlation between the measured strain curves acquired in two perpendicular planes. Furthermore, the results show the feasibility and reproducibility of assessing radial, circumferential and longitudinal strains simultaneously. In this preliminary study, three beagles developed an elevated pressure gradient over the aortic valve ({delta}p: 100-200 mmHg) and myocardial hypertrophy. One dog did not develop any sign of hypertrophy ({delta}p = 20 mmHg). Initial strain (rate) results showed that the maximum strain (rate) decreased with increasing valvular stenosis (-50%), which is in accordance with previous studies. Histological findings corroborated these results and showed an increase in fibrotic tissue for the hearts with larger pressure gradients (100, 200 mmHg), as well as lower strain and strain rate values.

  9. Cardiac biplane strain imaging: initial in vivo experience

    Science.gov (United States)

    Lopata, R. G. P.; Nillesen, M. M.; Verrijp, C. N.; Singh, S. K.; Lammens, M. M. Y.; van der Laak, J. A. W. M.; van Wetten, H. B.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2010-02-01

    In this study, first we propose a biplane strain imaging method using a commercial ultrasound system, yielding estimation of the strain in three orthogonal directions. Secondly, an animal model of a child's heart was introduced that is suitable to simulate congenital heart disease and was used to test the method in vivo. The proposed approach can serve as a framework to monitor the development of cardiac hypertrophy and fibrosis. A 2D strain estimation technique using radio frequency (RF) ultrasound data was applied. Biplane image acquisition was performed at a relatively low frame rate (cardiac cycle in four dogs with an aortic stenosis. Initial results reveal the feasibility of measuring large radial, circumferential and longitudinal cumulative strain (up to 70%) at a frame rate of 100 Hz. Mean radial strain curves of a manually segmented region-of-interest in the infero-lateral wall show excellent correlation between the measured strain curves acquired in two perpendicular planes. Furthermore, the results show the feasibility and reproducibility of assessing radial, circumferential and longitudinal strains simultaneously. In this preliminary study, three beagles developed an elevated pressure gradient over the aortic valve (Δp: 100-200 mmHg) and myocardial hypertrophy. One dog did not develop any sign of hypertrophy (Δp = 20 mmHg). Initial strain (rate) results showed that the maximum strain (rate) decreased with increasing valvular stenosis (-50%), which is in accordance with previous studies. Histological findings corroborated these results and showed an increase in fibrotic tissue for the hearts with larger pressure gradients (100, 200 mmHg), as well as lower strain and strain rate values.

  10. 斑点追踪应变成像评价类风湿关节炎左心室收缩功能早期损伤%Assessment on Early Impairment of Left Ventricular Myocardial Systolic Function in Patients With Rheumatoid Arthritis by Speckle Tracking Strain Imaging

    Institute of Scientific and Technical Information of China (English)

    丁茜; 刘栩; 周慧青; 朱天刚

    2013-01-01

    目的:应用斑点追踪应变成像评价类风湿关节炎患者左心室收缩功能早期损伤.方法:选取常规超声心动图检查的类风湿关节炎患者25例(类风湿组)及健康查体者25例(正常组),常规应用M型超声测量左心室舒张末内径、室间隔厚度、左心室后壁厚度;改良辛普森式法测定左心室射血分数;脉冲组织多普勒测量二尖瓣环收缩期峰值速度;斑点追踪成像测定左心室心尖四腔、两腔、三腔切面长轴方向心肌收缩期峰值应变(Strain)及应变率(strain rate,SRs)和二尖瓣水平、乳头肌水平、心尖水平左心室短轴周径方向Strain及SRs.结果:两组左心室舒张末内径、室间隔厚度、左心室后壁厚度、左心室射血分数、二尖瓣环收缩期峰值速度均无统计学差异;类风湿组心尖四腔、两腔长轴Strain降低(P<0.05),而各短轴周径Strain、SRs均增大(P<0.01);心尖四腔、两腔长轴Strain与病程呈正相关(相关系数分别为0.372及0.308,P<0.05),心尖短轴周径Strain与病程呈负相关(r=-0.435,P<0.01).结论:常规超声检查正常的类风湿患者可出现亚临床左心室收缩功能异常,累及心内膜下心肌,表现为长轴Strain降低.斑点追踪应变是研究左心室收缩功能早期损伤的有效工具.%Objective:To assess the early impairment of left ventricular (LV) myocardial systolic function in patients with rheumatoid arthritis (RA) by speckle tracking strain imaging.Methods:Our work included two groups,RA group,n=25 patients,and Control group,n=25 healthy subjects from normal physical examination.Standard echo and speckle tracking strain imaging were conducted to analyze and compare the LV systolic peak longitudinal strain with strain rate from apical 4-chamber,2-chamber and 3-chamber views and LV systolic peak circumferential strain with strain rate from short axis views at mitral valve,papillary and apical levels between two groups

  11. Assessment of Myocardial Strain Transmural Gradient by 2-Dimension Strain Imaging in Essential Hypertension Patients%二维应变显像评价高血压病患者左室收缩应变的跨壁阶差

    Institute of Scientific and Technical Information of China (English)

    牛海燕; 黄小玲; 张江霞; 高宇; 张轻; 简文豪

    2012-01-01

    目的 应用组织二维应变成像技术检测高血压患者左室心肌内外膜层组织应变特征,评价左心室收缩功能的改变,为早期诊断及治疗高血压心肌病变提供依据.方法 高血压病患者82例(LVN组:左室质量正常,无左室肥厚45例;LVH组:左室肥厚组37例)及健康对照组30例.常规超声心动图检测左心室收缩、舒张功能及左心室心肌质量指数(LVMI).取左心室乳头肌水平将室壁平均分为两层,即心内膜层和心外膜层.获取各节段心肌的纵向应变(SSL)和圆周应变(SSC)的峰值.结果 各组各室壁节段心内膜层心肌收缩期峰值应变均高于心外膜层心肌(P<0.05).高血压病患者的心内膜层SSL峰值减低,LVH组较LVN组低(P<0.05).高血压LVN组内膜层SSC较对照组高,LVH组较LVN组和对照组低(P<0.05).高血压病组患者的心内外膜层应变峰值的比值(跨壁阶差)减低(P<0.05).结论 二维应变显像技术可早期检测出高血压患者内外膜层心肌应变跨壁阶差的变化,评价心肌局部收缩功能异常具有重要意义.%Objective To explore the characteristics of 2-dimension(2D) strain echocardiography of myocardial strain transmural gradient to assess left ventricle( LV) systolic dysfunction in patients with essential hypertension. Methods 82 hypertension patients were divided into two groups: group LVN(patients with left ventricular normal geometric LVN, n = 45),group LVH (patients with left ventricular hypertrophy LVH, n - 37), as well as 30 age and gender matched healthy volunteers as the control group. M-mode,2-D echocardialgraphy were used to measure the thickness of LV wall, inner diameter of LV, get EF,and calculate LV mass index(LVMI). 2-D strain analysis was carried out by defining the wall as a 2-layer structure with suitable regions of interest, subendocardial(endo) and sub-epicardial(epi) myocardium layers. Systolic longitudinal strain(SSL) and circumferential strain(SSC) were

  12. Regional ejection fraction and regional area strain for left ventricular function assessment in male patients after first-time myocardial infarction.

    Science.gov (United States)

    Teo, Soo-Kng; Vos, F J A; Tan, Ru-San; Zhong, Liang; Su, Yi

    2015-04-01

    In this work, we present a method to assess left ventricle (LV) regional function from cardiac magnetic resonance (CMR) imaging based on the regional ejection fraction (REF) and regional area strain (RAS). CMR scans were performed for 30 patients after first-time myocardial infarction (MI) and nine age- and sex-matched healthy volunteers. The CMR images were processed to reconstruct three-dimensional LV geometry, and the REF and RAS in a 16-segment model were computed using our proposed methodology. The method of computing the REF was tested and shown to be robust against variation in user input. Furthermore, analysis of data was feasible in all patients and healthy volunteers without any exclusions. The REF correlated well with the RAS in a nonlinear manner (quadratic fit-R(2) = 0.88). In patients after first-time MI, the REF and RAS were significantly reduced across all 16 segments (REF: p function in the patients with preserved global ejection fraction with reasonable accuracy (more than 78%). These preliminary results confirmed the validity of our approach for accurate analysis of LV regional function. Our approach potentially offers physicians new insights into the local characteristics of the myocardial mechanics after a MI.

  13. Preliminary Validation of Angle-Independent Myocardial Elastography Using MR Tagging in a Clinical Setting

    Science.gov (United States)

    Lee, Wei-Ning; Qian, Zhen; Tosti, Christina L.; Brown, Truman R.; Metaxas, Dimitris N.; Konofagou, Elisa E.

    2014-01-01

    Myocardial Elastography (ME), a radio-frequency (RF) based speckle tracking technique, was employed in order to image the entire two-dimensional (2D) transmural deformation field in full view, and validated against tagged Magnetic Resonance Imaging (tMRI) in normal as well as reperfused (i.e., treated myocardial infarction (MI)) human left ventricles. RF ultrasound and tMRI frames were acquired at the papillary muscle level in 2D short-axis (SA) views at nominal frame rates of 136 (fps; real time) and 33 fps (electrocardiogram (ECG)-gated), respectively. In ultrasound, in-plane, 2D (lateral and axial) incremental displacements were iteratively estimated using one-dimensional (1D) cross-correlation and recorrelation techniques in a 2D search with a 1D matching kernel. In tMRI, cardiac motion was estimated by a template-matching algorithm on a 2D grid-shaped mesh. In both ME and tMRI, cumulative 2D displacements were estimated and then used to estimate 2D Lagrangian finite systolic strains, from which polar (i.e., radial and circumferential) strains, namely angle-independent measures, were further obtained through coordinate transformation. Principal strains, which are angle-independent and less centroid-dependent than polar strains, were also computed and imaged based on the 2D finite strains with a previously established strategy. Both qualitatively and quantitatively, angle-independent ME is shown to be capable of 1) estimating myocardial deformation in good agreement with tMRI estimates in a clinical setting and of 2) differentiating abnormal from normal myocardium in a full left-ventricular view. Finally, the principal strains are suggested to be an alternative diagnostic tool of detecting cardiac disease with the characteristics of their reduced centroid dependence. PMID:18952364

  14. Reduction of longitudinal axial residual stresses in near-root region of circumferential joint of steam pipeline in technological way

    Directory of Open Access Journals (Sweden)

    V. M. Prokhorenko

    2013-10-01

    Full Text Available The paper proposes a variant for solving the problem of reduction of longitudinal residual stresses in near-root region of a circumferential welded joint of section of steam pipeline by FEM simulation of the stress-strain state of repaired section of a circumferential weld in the zone of lack of root penetration on a thin-wall shell of 89 mm diameter and 6 mm wall thickness from steel 20. The result of solving the problem is total distribution of stresses and residual plastic deformations in the repaired zone.

  15. Acute regional improvement of myocardial function after interventional transfemoral aortic valve replacement in aortic stenosis: A speckle tracking echocardiography study

    Directory of Open Access Journals (Sweden)

    Schattke Sebastian

    2012-03-01

    Full Text Available Abstract Background Transcatheter aortic valve implantation (TAVI is a promising therapy for patients with severe aortic stenosis (AS and high perioperative risk. New echocardiographic methods, including 2D Strain analysis, allow the more accurate measurement of left ventricular (LV systolic function. The goal of this study was to describe the course of LV reverse remodelling immediately after TAVI in a broad spectrum of patients with symptomatic severe aortic valve stenosis. Methods Thirty consecutive patients with symptomatic aortic valve stenosis and preserved LVEF underwent transfemoral aortic valve implantation. We performed echocardiography at baseline and one week after TAVI. Echocardiography included standard 2D and Doppler analysis of global systolic and diastolic function as well as 2D Strain measurements of longitudinal, radial and circumferential LV motion and Tissue Doppler echocardiography. Results The baseline biplane LVEF was 57 ± 8.2%, the mean pressure gradient was 46.8 ± 17.2 mmHg and the mean valve area was 0.73 ± 0.27 cm2. The average global longitudinal 2D strain of the left ventricle improved significantly from -15.1 (± 3.0 to -17.5 (± 2.4 % (p Conclusion There is an acute improvement of myocardial longitudinal systolic function of the basal and medial segments measured by 2D Strain analysis immediately after TAVI. The radial, circumferential strain and LVEF does not change significantly in all patients acutely after TAVI. These data suggest that sensitive new echo methods can reliably detect early regional changes of myocardial function after TAVI before benefits in LVEF are detectable.

  16. 超声二维应变成像观察冠心病患者缺血心肌收缩功能异常%Investigation of ischemic myocardial systolic dysfunction incoronary artery disease patients withtwo-dimensional strain imaging

    Institute of Scientific and Technical Information of China (English)

    杨莉; 吴灵敏; 邱琼

    2011-01-01

    Objective To observe ischemic myocardial systolic dysfunction with two-dimensional strain imaging in different directions of the left ventricular in patients with coronary artery disease.Methods Fifty-two patients with coronary artery disease proved with coronary angiography and 31 control subjects were enrolled.High frame rate two-dimensional dynamic images were recorded from the left ventricular short-axis views at the level of mitral annulus, papillary muscle and apex, as well as the four-chamber, two-chamber and long-axis views of the left ventricular from the apex.Using two-dimensional strain software, peak systolic longitudinal strain (LS), radial strain (RS), circumferential strain (CS) and rotation angle (RA) from different segments of the left ventricular were measured.Results Totally 95.26% (402/422) of ischemic myocardium were successfully measured with two-dimensional strain imaging in patients with coronary artery disease.LS and RS significantly reduced in ischemic myocardium than those in normal myocardium (P<0.05), while CS and RA were not significantly different between the two groups (P>0.05) with the exception of RA in anterior and posterior walls at the level of papillary muscle.Conclusion Measured with two-dimensional strain imaging, LS and RS, rather than CS and RA, are sensitive markers of ischemic myocardial systolic dysfunction in patients with coronary artery disease.%目的 应用超声二维应变成像技术检测冠心病患者左心室缺血心肌在不同方向上收缩运动的变化特点.方法 收集接受冠状动脉造影检查患者83例,其中52例造影证实为冠心病(冠心病组),31例造影未见异常(对照组).超声采集左心室短轴及心尖长轴切面的高频二维动态图像,应用二维应变分析软件测量左心室各节段心肌的收缩期纵向应变(LS)、径向应变(RS)、圆周应变(CS)和旋转角度(RA).结果 二维应变技术对冠心病组缺血心肌的测量成功率为95

  17. Value of 4D-strain imaging echocardiography in detecting left ventricular systolic dysfunction in patients with aortic stenosis

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhi-chao; LI He-zhi; LI Chang-mao; CHEN Ou-di; FEI Hong-wen; LIN Qiong-wen

    2016-01-01

    Background The myocyte dysfunction may be present in aortic stenosis (AS) patients with preserved left ventricular ejection fraction (LVEF).Early aortic valve replacement (AVR) can reverse the LV hypertrophy and improve LV systolic performance and clinical outcome.Strain imaging has demonstrated to be the most appropriate method to evaluate LV myocardial contractility.However,4D-strain imaging echocardiography for the detection of subclinical left ventricular dysfunction in AS patients with preserved LVEF is seldom studied.Methods We prospectively enrolled 30 consecutive moderate to severe AS patients with preserved LVEF,and 30 healthy controls.Conventional echocardiography and 4D-strain imaging echocardiography were undergone in two groups.The 4D strain echocardiographic analyses were undertaken by using 4D Auto LVQ software.Results Compared with the healthy controls,the moderate to severe AS patients with preserved LVEF had significantly decreased global radial strain (GRS),global longitudinal strain (GLS),global area strain (GAS) and 4D strain (P < 0.05),had significantly increased left ventricular end-diastolic volume index (LVEDVI) and left ventricular mass index (LVMI) (P < 0.05),and had lower global circumferential strain (GCS) (P > 0.05).Conclusions Impaired LV myocardial contractility exists in moderate to severe AS patients,although LVEF is preserved.4D-strain imaging echocardiography can detect early left ventricular dysfunction in AS patients with preserved LVEF.

  18. Three-dimensional speckle tracking imaging for reviewing myocardial strain parameter changes in patients with different severity coronary artery stenosis%三维斑点追踪成像评价冠脉不同程度狭窄心肌整体应变参数变化

    Institute of Scientific and Technical Information of China (English)

    李丹; 刘梅; 牛海燕; 段雅琦; 黄晓玲; 王建华

    2016-01-01

    Objective To review the global myocardial strain by applying three-dimensional speckle tracking imaging (3D-STI) in patients with different severity coronary artery stenosis.Methods The patients with suspected coronary heart disease (CHD,n=63) were chosen from Dec. 2013 to May. 2014. According to the outcomes of coronary angiography (CAG), the patients were divided into control group (without coronary artery stenosis,n=10), mild stenosis group (mild group, stenosis rate ≤50%,n=9), moderate stenosis group (moderate group, 50%75%,n=34). The global myocardial strain parameters were obtained by applying 3D-STI, including global long axis strain (GLS), global radial strain (GRS), global circumferential strain (GCS) and global area strain (GAS) of left ventricular systolic peak. The difference in global myocardial strain parameters of different severity coronary artery stenosis was compared.Results All myocardial strain parameters decreased significantly in severe group compared with other groups. GLS, GRS and GAS decreased significantly in moderate group compared with control group, and GAS decreased significantly in moderate group compared with mild group. GAS decreased significantly in mild group compared with control group (P<0.05).Conclusion 3D-STI can be taken as an effective detective method for reviewing global left ventricular systolic function in CHD patients without ventricular wall motion. GAS is a parameter with the highest sensitivity and repeatability. As the increase of coronary artery stenosis severity, the damage of myocardial strain will become heavier and GAS damage is the most significant.%目的:应用三维斑点追踪成像(three-dimensional speckle tracking imaging,3D-STI)技术评价冠脉不同程度狭窄心肌整体应变。方法收集2013年12月至2014年5月于北京军区总医院心内科住院,临床诊断疑似为冠心病患者共计63例,根据患者冠状动脉造影结果,按三支冠脉不同

  19. Longitudinal Strain and Strain Rate Abnormalities Precede Invasive Diagnosis of Transplant Coronary Artery Vasculopathy in Pediatric Cardiac Transplant Patients.

    Science.gov (United States)

    Zoeller, Bridget B; Miyamoto, Shelley D; Younoszai, Adel K; Landeck, Bruce F

    2016-04-01

    Transplant coronary artery vasculopathy (TCAV) is the primary cause of late graft loss in pediatric heart transplant recipients. TCAV is diagnosed using angiography or intravascular ultrasound; however, noninvasive methods remain elusive. We sought to define patterns of myocardial mechanics in patients with TCAV and to determine whether this can detect TCAV before invasive methods. In this retrospective study, we queried our heart transplant database to identify all recipients with TCAV since 2006 (n = 41). Echoes were reviewed from the last normal catheterization and at TCAV diagnosis, and from time-matched transplant controls (n = 33) without TCAV. Peak global circumferential and longitudinal strain and systolic and diastolic strain rate (SSR and DSR) of the left ventricle were derived using velocity vector imaging. T tests were used to compare both groups longitudinally and between groups at both time points. Longitudinal strain, SSR, and DSR were diminished in the TCAV group compared to the transplant control group at both time points. No differences were found across time points in either group. Retrospective modeling using a longitudinal strain cutoff of 15 % on echoes 2 years prior to TCAV diagnosis predicted development or exclusion of TCAV with sensitivity of 53 %, specificity of 89 % with an area under the curve of 0.8. Decreases in longitudinal strain measurements demonstrate that alterations in myocardial mechanics occur in patients with TCAV at least 2 years prior to invasive diagnosis. These early changes may be due to microvascular disease. This modality could aid in earlier treatment and intervention for this challenging problem .

  20. Assessment of the relationships between myocardial contractility and infarct tissue revealed by serial magnetic resonance imaging in patients with acute myocardial infarction.

    Science.gov (United States)

    McComb, Christie; Carrick, David; McClure, John D; Woodward, Rosemary; Radjenovic, Aleksandra; Foster, John E; Berry, Colin

    2015-08-01

    Imaging changes in left ventricular (LV) volumes during the cardiac cycle and LV ejection fraction do not provide information on regional contractility. Displacement ENcoding with Stimulated Echoes (DENSE) is a strain-encoded cardiac magnetic resonance (CMR) technique that measures strain directly. We investigated the relationships between strain revealed by DENSE and the presence and extent of infarction in patients with recent myocardial infarction (MI). 50 male subjects were invited to undergo serial CMR within 7 days of MI (baseline) and after 6 months (follow-up; n = 47). DENSE and late gadolinium enhancement (LGE) images were acquired to enable localised regional quantification of peak circumferential strain (Ecc) and the extent of infarction, respectively. We assessed: (1) receiver operating characteristic (ROC) analysis for the classification of LGE, (2) strain differences according to LGE status (remote, adjacent, infarcted) and (3) changes in strain revealed between baseline and follow-up. 300 and 258 myocardial segments were available for analysis at baseline and follow-up respectively. LGE was present in 130/300 (43%) and 97/258 (38%) segments, respectively. ROC analysis revealed moderately high values for peak Ecc at baseline [threshold 12.8%; area-under-curve (AUC) 0.88, sensitivity 84%, specificity 78%] and at follow-up (threshold 15.8%; AUC 0.76, sensitivity 85%, specificity 64%). Differences were observed between remote, adjacent and infarcted segments. Between baseline and follow-up, increases in peak Ecc were observed in infarcted segments (median difference of 5.6%) and in adjacent segments (1.5%). Peak Ecc at baseline was indicative of the change in LGE status between baseline and follow-up. Strain-encoded CMR with DENSE has the potential to provide clinically useful information on contractility and its recovery over time in patients with MI.

  1. Two-dimentional speckle tracking strain imaging in the assessment of myocardial diastolic function in patients with stable angina pectoris

    Directory of Open Access Journals (Sweden)

    Somaye Farokhnejad

    2015-06-01

    Full Text Available Introduction: Ischemic heart disease is caused mainly by obstruction of coronary arteries. The ischemic assessment through echocardiography is dependent on wall motion abnormality detection during systole. In patients with ischemic heart disease the diastolic function is impaired before systolic function and measurement of regional diastolic dysfunction if possible will be most sensitive for assessment of obstructed coronary artery region. This study was designed to determine whether regional left ventricular delayed relaxation diagnosis could be detected with strain imaging derived from two-dimensional speckle-tracking echocardiography in patients with coronary artery disease.Methods: All the articles reviewed were obtained using MEDLINE & ScienceDirect (up to October 2014. All data extracted by speckle tracking echocardiography. The index which is used is strain imaging diastolic index which is calculated as: (A-B A×100  . A is the amount of strain at the time Aortic value closure and B is the amount of strain in first one-third point of diastolic duration.Result: Four articles were reviewed. Three articles assessed patients with echocardiography at rest and one with stress echocardiography. All articles showed the coronary artery tracking with significant stenosis is possible by regional deformation analysis through two-dimensional strain.Discussion: The usage of strain images obtained through two-dimensional speckle tracking has been validated for the quantitation assessment of regional dysfunction in ischemic heart disease. Regional LV delayed relaxation diagnosis with strain imaging is a reliable method after treadmill stress test.Conclusion:  Strain imaging is reasonable for evaluation of ischemia as a low cost noninvasive test with high accuracy.

  2. Effect of circumferential wave number on stability of suspension flow

    Directory of Open Access Journals (Sweden)

    Wang Feng-Hui

    2014-01-01

    Full Text Available The linear stability analysis is carried out for the suspension flow of spherical particles between a rotating inner cylinder and a stationary concentric outer cylinder. The mass conservation equation and Navier-Stokes equation are applied to the continuous fluid phase and the particle phase. Results of stability analysis show that the increase of wave number in the circumferential direction attenuates the effect of the axial wave number on the amplification factor. The ratio of particle density to fluid density increasing above 0.1 amplifies the flow instability, while it can be weakened with higher circumferential direction wave number. Effect of the critical Taylor number on the amplification factor is reduced by increasing the circumferential direction wave number. The flow stability is affected by the geometry of flow field (the radius ratio at non-zero circumferential direction wave numbers.

  3. Myocardial Strain Analysis by 2-Dimensional Speckle Tracking Echocardiography Improves Diagnostics of Coronary Artery Stenosis in Stable Angina Pectoris

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Hoffmann, Soren; Mogelvang, Rasmus;

    2014-01-01

    an independent predictor of CAD after multivariable adjustment for baseline data, exercise test, and conventional echocardiography (odds ratio, 1.25 [P=0.016] per 1% decrease). Area under receiver operating characteristic curve for exercise test and global longitudinal peak systolic strain in combination...... is an independent predictor of significant CAD and significantly improves the diagnostic performance of exercise test. Furthermore, 2-dimensional strain echocardiography seems capable of identifying high-risk patients....... of the exercise test. Patients with an area stenosis≥70% in ≥1 epicardial coronary artery were categorized as having significant CAD (n=107). Global longitudinal peak systolic strain was significantly lower in patients with CAD compared with patients without (17.1±2.5% versus 18.8±2.6%; P

  4. Assessment of left ventricular segmental function after autologous bone marrow stem cells transplantation in patients with acute myocardial infarction by tissue tracking and strain imaging

    Institute of Scientific and Technical Information of China (English)

    RUAN Wen; PAN Cui-zhen; HUANG Guo-qian; LI Yan-lin; GE Jun-bo; SHU Xian-hong

    2005-01-01

    Background Emerging evidence suggests that stem cells can be used to improve cardiac function in patients after acute myocardial infarction. In this randomized trial, we aimed to use Doppler tissue tracking and strain imaging to assess left ventricular segmental function after intracoronary transfer of autologous bone-marrow stem cells (BMCs) for 6 months' follow up. Methods Twenty patients with acute myocardial infarction and anterior descending coronary artery occlusion proven by angiography were double-blindedly randomized into intracoronary injection of bone-marrow cell (treated, n=9) or diluted serum (control, n=11) groups. GE vivid 7 and Q-analyze software were used to perform echocardiogram in both groups 1 week, 3 months and 6 months after treatment. Three apical views of tissue Doppler imaging were acquired to measure peak systolic displacement (Ds) and peak systolic strain (εpeak) from 12 segments of LV walls. Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were obtained by Simposon's biplane method. Results (1) 3 months later, Ds and εpeak over the infract-related region clearly increased in the BMCs group [Ds: (4.49±2.71) mm vs (7.56±2.95) mm, P0.05; εpeak : (-13.84±6.05)% vs (-15.04±6.75)%, P>0.05]. At the same time, Ds over the normal region also increased, but the Ds enhancement was markedly higher in the BMCs group than that in the control group [(3.21±3.17) mm vs (0.76±1.94) mm, P0.05). (2) LVEF in treated and control groups were almost the same at baseline (1st week after PCI) [(53.37±8.92)% vs (53.51±5.84)%, P>0.05]. But 6 months later, LVEF in the BMCs group were clearly higher than that in the control group [(59.33±12.91)% vs (50.30±8.30)%, P0.05; ESV: (57.12±18.66) ml vs (62.09±17.68) ml, P>0.05]. Three months later, EDV and ESV in the control group were markedly greater than those in the BMCs group [EDV: (154.89±46.34) ml vs (104.85±33.21) ml, P0.05). Conclusions Emergency

  5. Application of two-dimensional ultrasound imaging in the evaluation of left entricular function of patients with acute myocardial infarction%二维超声成像在急性心肌梗死患者左室功能评估中的应用

    Institute of Scientific and Technical Information of China (English)

    胡桂珍; 肖永芳

    2012-01-01

    Objective To study the changes of two-dimensional ultrasound imaging in the evaluation of left entricular function of patients with acute myocardial infarction. Methods The clinical data of 40 patients with acute myocardial infarction in our hospital from October 2009 to May 2011 were analyzed retrospectively. All patients were divided into two groups, anterior wall myocardial infarction group (20 cases) and inferior myocardial infarction group (20 cases) according to different parts of obstruction. Each segment of circumferential strain of patients with left ventricular myocardial infarction of the two groups was detected by two-dimensional ultrasound spots tracking imaging (STI). Results In the conventional ultrasound examination, the LVDD, LVDS of anterior wall myocardial infarction group were significantly greater than the inferior myocardial infarction group, LVEF was obviously less than the inferior myocardial infarction group. Each segment of circumferential strain of anterior wall, interventricular septum and cardiac apex in the anterior wall myocardial infarction group was significantly less than the inferior myocardial infarction group, while each segment of circumferential strain of posterior wall and inferior wall was less than the inferior myocardial infarction group (P < 0.05); and GCS of the anterior wall myocardial infarction group was less than the inferior myocardial infarction group (P < 0.01). Conclusion The two-dimensional ultrasound imaging can quantitative evaluate the changes of left ventricular function of patients with acute myocardial infarction, and provide an effective, non-inasie method for evaluating the changes of left ventricular function in clinic.%目的 探讨二维超声成像在评估急性心肌梗死患者左室功能变化情况.方法 回顾性分析我院2009年10月~2011年5月收治入院的40例急性心梗患者临床资料,根据梗阻部位不同分为两组,前壁心梗组(20例)和下壁心梗组(20例),两组

  6. Evaluation of the myocardial systolic function and ventricular remodeling of rats with experimental myocardial infarction by strain/strain rate imaging and MMP-9%应变/应变率成像结合基质金属蛋白酶-9评价心力衰竭大鼠心肌收缩功能及心室重构

    Institute of Scientific and Technical Information of China (English)

    朱文晖; 段星星; 张梦玺; 唐水娟; 刘稳刚

    2010-01-01

    Objective To evaluate the myocardial systolic function and ventricular remodeling in heart failure rat induced by myocardial infarction (MI) with S/SRI and MMP-9. Methods A total of 70 male SD rats were randomly assigned to 4 groups: 4 weeks and 8 weeks MI ( anterior descending branch of left coronary artery were ligated ) , sham operation (thoracotomy without ligation of coronary artery ) and nonoperated control group. The regional myocardial systolic function of rats was quantified with S/SRI. The myocardial MMP-9 expression was detected by Western blot Results In the 4 weeks MI group, all segment's Ssys, SRsys, the strain of end-systole were reduced while PSI was increased compared to sham and nomoperated group with the exception of the inferior wall. These changes were more significant in 8 weeks MI group compared to the 4 weeks MI group. In the 4 weeks MI group, the expression of MMP-9 was significantly upregulated than the sham operation group and this upregulation was more significant at 8 weeks post MI. Conclusions S/SRI can quantitative evaluate the regional systolic function of heart failure rat induced by myocardial infarction. Progressive upregulation of myocardial MMP-9 expression paralleled the deterioration of regional systolic function in this heart failure rat model.%目的 应用应变/应变率成像(S/SRI)及基质金属蛋白酶-9(MMP-9)蛋白表达评价心肌梗死后心力衰竭(心衰)大鼠心肌收缩功能及心室重构.方法 70只雄性SD大鼠随机分为4组:手术4周组及手术8周组,开胸结扎左冠状动脉前降支;假手术组,同样开胸,但不结扎;正常组作为对照.应用S/SRI定量评价心肌局部收缩功能,用Western blot法检测各组实验大鼠心肌MMP-9蛋白表达.结果 (1)除下壁中间段及基底段外,手术4周组各节段收缩期峰值应变、收缩期峰值应变率、收缩末期应变均明显下降(P<0.05),收缩后应变指数升高(P<0.05);手术8周组各指标值较手术4

  7. Structural and leakage integrity of tubes affected by circumferential cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hernalsteen, P. [TRACTEBEL, Brussels (Belgium)

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  8. Circumferential gap propagation in an anisotropic elastic bacterial sacculus

    CERN Document Server

    Taneja, Swadhin; Rutenberg, Andrew D

    2013-01-01

    We have modelled stress concentration around small gaps in anisotropic elastic sheets, corresponding to the peptidoglycan sacculus of bacterial cells, under loading corresponding to the effects of turgor pressure in rod-shaped bacteria. We find that under normal conditions the stress concentration is insufficient to mechanically rupture bacteria, even for gaps up to a micron in length. We then explored the effects of stress-dependent smart-autolysins, as hypothesised by Arthur L Koch [Advances in Microbial Physiology 24, 301 (1983); Research in Microbiology 141, 529 (1990)]. We show that the measured anisotropic elasticity of the PG sacculus can lead to stable circumferential propagation of small gaps in the sacculus. This is consistent with the recent observation of circumferential propagation of PG-associated MreB patches in rod-shaped bacteria. We also find a bistable regime of both circumferential and axial gap propagation, which agrees with behavior reported in cytoskeletal mutants of B. subtilis. We con...

  9. Circumferential fusion improves outcome in comparison with instrumented posterolateral fusion

    DEFF Research Database (Denmark)

    Videbaek, Tina S; Christensen, Finn B; Soegaard, Rikke;

    2006-01-01

    -36 instrument, and the Low Back Pain Rating Scale. All measures assessed the endpoint outcomes at 5 to 9 years after surgery. RESULTS: The available response rate was 93%. The circumferential group showed a significantly better improvement (P ...STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion...... fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were the Oswestry Disability Index, the SF...

  10. GUIDED CIRCUMFERENTIAL WAVES IN DOUBLE-WALLED CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A model of guided circumferential waves propagating in double-walled carbon nanotubes is built by the theory of wave propagation in continuum mechanics, while the van der Waals force between the inner and outer nanotube has been taken into account in the model. The dispersion curves of the guided circumferential wave propagation are studied, and some dispersion characteristics are illustrated by comparing with those of single-walled carbon nanotubes. It is found that in double-walled carbon nanotubes, the guided circumferential waves will propagate in more dispersive ways. More interactions between neighboring wave modes may take place. In particular, it has been found that a couple of wave modes may disappear at a certain frequency and that, while a couple of wave modes disappear, another new couple of wave modes are excited at the same wave number.

  11. Global left ventricular longitudinal strain is closely associated with increased neurohormonal activation after acute myocardial infarction in patients with both reduced and preserved ejection fraction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Valeur, Nana; Mogensen, Ulrik Madvig;

    2012-01-01

    N-terminal pro brain natriuretic peptide (NT-proBNP) is released in response to increased myocardial wall stress and is associated with adverse outcome in acute myocardial infarction. However, little is known about the relationship between longitudinal deformation indices and NT-proBNP....

  12. The Effect on Strain Rate Imaging in Quantitative Evaluation of Nicorandil on Myocardial Ischemia Function%应变率成像定量评价尼可地尔对缺血心肌功能的影响

    Institute of Scientific and Technical Information of China (English)

    刘一; 陈作元

    2015-01-01

    目的:采用应变率成像定量,对尼可地尔在治疗缺血心肌时对其功能的影响加以评价。方法选取36例心肌缺血疾病患者作为对象,对其给予尼可地尔进行治疗,并且采取应变率成像技术,评定该药物对缺血心肌功能的影响。结果0级组SRs在治疗后1个月较治疗前增高,P<0.05,差异具有统计学意义;3级组与治疗前比较,术后1个月Ve/Va增高,P<0.05,差异具有统计学意义。结论应变率定量技术及速度等指标在评价缺血心肌局部舒缩功能方面有应用价值。%Objective To evaluate the effects on function in nicorandil treatment of myocardial ischemia adopt strain rate imaging in quantitative. Methods Selected 36 cases with myocardial ischemia disease as the object, treatmented with nicorandil, adopt strain rate imaging technique and evaluated effects on the drug on ischemic myocardial function. Results SRs in the one months after treatment than before treatment increased, P<0.05, had difference statistically significance, the 3 groups compared with that before treatment, after one months of Ve/Va increased, P<0.05, had difference statistically signiifcance. Conclusion The quantitative technique of strain rate and speed indicators has application value in the evaluation of ischemic myocardial regional systolic and diastolic function.

  13. Inter-study reproducibility of cardiovascular magnetic resonance myocardial feature tracking

    Directory of Open Access Journals (Sweden)

    Morton Geraint

    2012-06-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT is a recently described method of post processing routine cine acquisitions which aims to provide quantitative measurements of circumferentially and radially directed ventricular wall strain. Inter-study reproducibility is important for serial assessments however has not been defined for CMR-FT. Methods 16 healthy volunteers were imaged 3 times within a single day. The first examination was performed at 0900 after fasting and was immediately followed by the second. The third, non-fasting scan, was performed at 1400. CMR-FT measures of segmental and global strain parameters were calculated. Left ventricular (LV circumferential and radial strain were determined in the short axis orientation (EccSAX and ErrSAX respectively. LV and right ventricular longitudinal strain and LV radial strain were determined from the 4-chamber orientation (EllLV, EllRV, and ErrLAX respectively. LV volumes and function were also analysed. Inter-study reproducibility and study sample sizes required to demonstrate 5% changes in absolute strain were determined by comparison of the first and second exams. The third exam was used to determine whether diurnal variation affected reproducibility. Results CMR-FT strain analysis inter-study reproducibility was variable. Global strain assessment was more reproducible than segmental analysis. Overall EccSAX was the most reproducible measure of strain: coefficient of variation (CV 38% and 20.3% and intraclass correlation coefficient (ICC 0.68 (0.55-0.78 and 0.7 (0.32-0.89 for segmental and global analysis respectively. The least reproducible segmental measure was EllRV: CV 60% and ICC 0.56 (0.41-0.69 whilst the least reproducible global measure was ErrLAX: CV 33.3% and ICC 0.44 (0–0.77. Variable reproducibility was also reflected in the calculated sample sizes, which ranged from 11 (global EccSAX to 156 subjects (segmental EllRV. The

  14. Myocardial dysfunction in patients with type 2 diabetes mellitus: role of endothelial progenitor cells and oxidative stress

    Directory of Open Access Journals (Sweden)

    Zhao Chun

    2012-12-01

    Full Text Available Abstract Background Endothelial progenitor cells (EPCs are responsible for angiogenesis and maintenance of microvascular integrity, the number of EPCs is correlated with oxidative stress. Their relation to myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM is nonetheless unknown. Methods Eighty-seven patients with T2DM and no history of coronary artery disease were recruited. Transthoracic echocardiography and detailed evaluation of left ventricular (LV systolic function by 2-dimensional (2D speckle tracking derived strain analysis in 3 orthogonal directions was performed. Four subpopulations of EPCs, including CD34+, CD133+, CD34+/kinase insert domain-containing receptor (KDR + and CD133+/KDR + EPCs, were measured by flow cytometry. Oxidative stress was assessed by superoxide dismutase (SOD. Results The mean age of the patients was 62 ± 9 years and 39.6% were male. Those with an impaired longitudinal strain had a lower number of CD34+ EPCs (2.82 ± 1.87% vs. 3.74 ± 2.12%, P  Conclusions LV global circumferential strain was independently associated with number of CD34+ EPCs and SOD. These findings suggest that myocardial dysfunction in patients with T2DM is related to depletion of EPCs and increased oxidative stress.

  15. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  16. Myocardial Bridge

    Science.gov (United States)

    ... Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic ... Related terms: myocardium, coronary arteries, myocardial ischemia Your heart is made of muscle, called the myocardium. The ...

  17. A Critical Appraisal of Circumferential Resection Margins in Esophageal Carcinoma

    NARCIS (Netherlands)

    Pultrum, Bareld B.; Honing, Judith; Smit, Justin K.; van Dullemen, Hendrik M.; van Dam, Gooitzen M.; Groen, Henk; Hollema, Harry; Plukker, John Th. M.

    2010-01-01

    In esophageal cancer, circumferential resection margins (CRMs) are considered to be of relevant prognostic value, but a reliable definition of tumor-free CRM is still unclear. The aim of this study was to appraise the clinical prognostic value of microscopic CRM involvement and to determine the opti

  18. Ultransonic circumferential waves in empty and water- filled tubes

    Science.gov (United States)

    Li, Xing

    Ultrasonic waves propagating in the circumference of elastic isotropic cylindrical shells are theoretically and experimentally studied. Dispersion relations of different circumferential modes, including the SH-type and Lamb-type families, are obtained by solving the wave equations numerically. Asymptotic solutions are also given for the SH-like modes. Various technologies are applied for generating and detecting the circumferential waves. In particular, a new approach is developed for experimental determination of the dispersion of the circumferential waves in cylindrical shells. With a chirp interdigital transducer (IDT) as a broadband transmitter and receiver made on a stainless steel tube coated with piezoelectric film, both the group and phase velocities of the circumferential waves are obtained over a wide frequency range, which covers the most sensitive region of the lowest flexural mode. Other transduction approaches are also used as complementary tools in the experiments. Experiments are carried out on both empty and fluid- loaded cylindrical shells at different frequencies. With the specially developed experimental configuration, propagation of a new flexural wave type in a water-filled tube is observed. Mode conversions are also observed between the A 0 mode in the shell and the compressional waves in the water. The results show good application potentials in liquid level sensing.

  19. How do hypertrophic cardiomyopathy mutations affect myocardial function in carriers with normal wall thickness? Assessment with cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Pinto Yigal M

    2010-03-01

    Full Text Available Abstract Background Clinical data on myocardial function in HCM mutation carriers (carriers is sparse but suggests that subtle functional abnormalities can be measured with tissue Doppler imaging before the development of overt hypertrophy. We aimed to confirm the presence of functional abnormalities using cardiovascular magnetic resonance (CMR, and to investigate if sensitive functional assessment could be employed to identify carriers. Results 28 carriers and 28 controls were studied. Global left atrial (LA and left ventricular (LV dimensions, segmental peak systolic circumferential strain (SCS and peak diastolic circumferential strain rate (DCSR, as well as the presence of late Gadolinium enhancement (LGE were determined with CMR. Septal and lateral myocardial velocities were measured with echocardiographic tissue Doppler imaging. lv mass and volumes were comparable between groups. Maximal septal to lateral wall thickness ratio (SL ratio was larger in carriers than in controls (1.3 ± 0.2 versus 1.1 ± 0.1, p 1.2 and a peak DCSR -1 was present in 45% of carriers and in none of the controls, yielding a positive predictive value of 100%. Two carriers and 18 controls had a SL ratio 105%.s-1, yielding a negative predictive value of 90%. With multivariate analysis, HCM mutation carriership was an independent determinant of reduced peak SCS and peak DCSR. Conclusions HCM mutation carriership is an independent determinant of reduced peak SCS and peak DCSR when LV wall thickness is within normal limits, and is associated with increased LA volumes and SL ratio. Using SL ratio and peak DCSR has a high accuracy to identify carriers. However, since carriers also display structural abnormalities and focal LGE, we advocate to also evaluate morphology and presence of LGE when screening for carriers.

  20. Peri-infarct dysfunction in post-myocardial infarction: assessment of 3-T tagged and late enhancement MRI

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yuma; Nagao, Michinobu; Higashino, Hiroshi; Hosokawa, Kohei; Kido, Teruhito; Kurata, Akira; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Diagnostic and Therapeutic Radiology, Toon-city, Ehime (Japan); Yang, Xiaomei [Sichuan University, College of Electrical Engineering and Information Technology, Sichuan (China); Okayama, Hideki; Higaki, Jitsuo [Ehime University Graduate School of Medicine, Department of Integrated Medicine and Informatics, Matsuyama City (Japan); Murase, Kenya [Osaka University Medical School, Department of Medical Engineering Division of Allied Health Sciences, Osaka (Japan)

    2010-05-15

    To determine LV function at different distances from myocardial infarction (MI) by using 3-T tagged MRI and late gadolinium enhancement (LGE). Cardiac MR images were acquired from 21 patients with previous MI. The harmonic phase (HARP) method was used to calculate radial and circumferential strain (RS, CS). The two strains were synchronised by subtracting the CS from the RS at the same time, and this was defined as the efficient strain (ES). Peak strain (P-RS, P-CS, P-ES) and time to peak strain (T-RS, T-CS, T-ES) were used as estimates of contractile function. Based on the presence of LGE, myocardium was classified into infarct, border zone, adjacent and remote areas. P-RS and P-ES were significantly greater for remote than for adjacent and infarct areas. P-CS values were significantly greater for remote and border zone than for infarct areas. T-RS and T-ES were significantly shorter for remote and border zone than for infarct areas. T-CS was significantly shorter for border zone than for infarct areas. Contractile dysfunction demonstrated by peak strain was correlated with location at different distances from the infarct. In the border zone, contractile deformation was characterised as earlier T-RS, T-CS and T-ES and greater P-CS than in the infarct area. (orig.)

  1. 急性心肌缺血状态下左心室心肌的力学研究%Mechanics study on Left Ventricular myocardial During Acute Myocardial Ischemia

    Institute of Scientific and Technical Information of China (English)

    刘会若; 张瑞芳; 滑少华; 董刚; 高珂; 候苏芸; 许建威; 孙梦娇

    2016-01-01

    Objective To investigate segmental subendocardial mechanical pattern of left ventricle (LV) during acute myocardial ischemia using ultrasonic velocity vector imaging(VVI),and to demonstrate LV subendocardial mechanicals changs for the precise quantitative evaluation of early ischemic myocardial function.MethodsNine mongrel dogs after thoracotomy and the heart was exposed by ligation of the left anterior descending branch of the induced acute myocardial ischemia were collected before ischemia, after different left ventricular short axis two-dimensional dynamic grey scale of image plane, by off-line velocity vector imaging were left ventricular endocardium myocardial 16 segments of radial strain and the variation of circumferential strain.Results Beforeischemia,the myocardial circumferential strain of the left ventricle was increased from the basal level to the apical level in the same wall, thechanges disappear after ischemia, andthecircumferential strain of all segments decreased.Before ischemia with one compartment wall radial strain basal segment level were lower than those of the papillary muscle level segments and apical level segments, all room wall papillary myotome segments and apical section radial stress appeared as homogeneous change, after ischemia, part of segmental radial strain increases and the corresponding segment of strain is reduced.Conclusion Demonstrates that abnormal mechanical pattern of LV subendocardium induced by acute myocardial ischemia is the important pathophysiological mechanism of LV functional and anatomical remodeling.%目的:通过构建动物急性心肌缺血模型,运用速度向量成像技术观察急性心肌缺血前、后左心室心肌的径向应变、周向应变的变化,探讨急性心肌缺血状态下左心室心肌部分力学变化规律。方法9只杂种犬经开胸暴露心脏后,通过结扎左前降支造成急性心肌缺血,分别采集缺血前、后左心室不同的短轴二维动态灰阶切

  2. Detection of Left Ventricular Regional Dysfunction and Myocardial Abnormalities Using Complementary Cardiac Magnetic Resonance Imaging in Patients with Systemic Sclerosis without Cardiac Symptoms: A Pilot Study.

    Science.gov (United States)

    Kobayashi, Yasuyuki; Kobayashi, Hitomi; T Giles, Jon; Yokoe, Isamu; Hirano, Masaharu; Nakajima, Yasuo; Takei, Masami

    2016-01-01

    Objective We sought to detect the presence of left ventricular regional dysfunction and myocardial abnormalities in systemic sclerosis (SSc) patients without cardiac symptoms using a complementary cardiac magnetic resonance (CMR) imaging approach. Methods Consecutive patients with SSc without cardiac symptoms and healthy controls underwent CMR on a 1.5 T scanner. The peak systolic regional function in the circumferential and radial strain (Ecc, % and Err, %) were calculated using a feature tracking analysis on the mid-left ventricular slices obtained with cine MRI. In addition, we investigated the myocardial characteristics by contrast MRI. Pharmacological stress and rest perfusion scans were performed to assess perfusion defect (PD) due to micro- or macrovascular impairment, and late gadolinium enhancement (LGE) images were obtained for the assessment of myocarditis and/or fibrosis. Results We compared 15 SSc patients with 10 healthy controls. No statistically significant differences were observed in the baseline characteristics between the patients and healthy controls. The mean peak Err and Ecc of all segments was significantly lower in the patients than the controls (p=0.011 and p=0.003, respectively). Four patients with LGE (28.6%) and seven patients with PD (50.0%) were observed. PD was significantly associated with digital ulcers (p=0.005). Utilizing a linear regression model, the presence of myocardial LGE was significantly associated with the peak Ecc (p=0.024). After adjusting for age, the association between myocardial LGE and the peak Ecc was strengthened. Conclusion A subclinical myocardial involvement, as detected by CMR, was prevalent in the SSc patients without cardiac symptoms. Regional dysfunction might predict the myocardial abnormalities observed in SSc patients without cardiac symptoms.

  3. Correlation of Global Strain Rate and Left Ventricular Filling Pressure in Patients with Coronary Artery Disease: A 2-D Speckle-Tracking Study.

    Science.gov (United States)

    Ma, Hong; Wu, Wei-Chun; Xie, Rong-Ai; Gao, Li-Jian; Wang, Hao

    2016-02-01

    The aim of the present study was to evaluate the role of 2-D speckle-tracking imaging in the prediction of left ventricular filling pressure in patients with coronary artery disease (CAD) and normal left ventricular ejection fraction (LVEF). Eighty-four patients with CAD and 30 healthy controls were recruited prospectively. The longitudinal strain rate (SR) curves were determined in three apical views of the left ventricle long axis. Circumferential and radial SR curves were determined in three short-axis views. Left ventricular end-diastolic pressure (LVEDP) was invasively obtained by left heart catheterization. Compared with the 30 controls, the patients with CAD had significantly lower global SR during early diastole (SRe) and higher E/SRe in three directions of myocardial deformation. CAD patients with elevated LVEDP had significantly lower SRe and higher E/SRe of three deformations. Pearson's correlation analysis revealed that LVEDP correlated positively with E/E' ratio, radial SRe and longitudinal and circumferential E/SRe. LVEDP correlated negatively with longitudinal and circumferential SRe and radial E/SRe. Receiver operating characteristic curve analysis revealed that these SR indexes predicted elevated LVEDP (areas under the curve: longitudinal E/SRe = 0.74, circumferential E/SRe = 0.74, circumferential SRe = 0.70, longitudinal SRe = 0.69, radial E/SRe = 0.68, radial SRe = 0.65), but neither was superior to the tissue Doppler imaging index E/E' (area under the curve = 0.84). The present study indicates that 2-D speckle-tracking imaging is a practical method for evaluating LV filling pressure, but it might not provide additional advantages compared with E/E' in CAD patients.

  4. Circumferential wires as a supplement to intramedullary nailing in unstable trochanteric hip fractures

    DEFF Research Database (Denmark)

    Ban, Ilija; Birkelund, Lasse; Palm, Henrik;

    2012-01-01

    Fixation of unstable trochanteric fractures is challenging. Application of a circumferential wire may facilitate bone contact and avoid postoperative fracture displacement. However, the use of circumferential wires remains controversial due to possible disturbance of the blood supply to the under...

  5. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf Strain e strain rate por meio de ecocardiogratia speckle traking bidimensional em um lobo-guará

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.A obtenção de parâmetros cardiovasculares em animais selvagens são importantes de serem avaliados, assim como em animais de companhia, para a obtenção da função miocárdica e determinação precoce de alterações cardíacas que poderiam evoluir para insuficiência cardíaca . A ecocardiografia speckle tracking (2D STE é uma ferramenta nova que tem sido utilizada em medicina veterinária, a qual tem demonstrado várias vantagens quanto ao seu uso, como a independência do ângulo de insonação e a possibilidade de se obter o diagnóstico precoce de altera

  6. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.

    2011-03-01

    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  7. Quantitative assessment of left ventricular myocardial function by two dimensional strain echocardiography%二维应变成像评价冠心病患者左心室局部功能的价值

    Institute of Scientific and Technical Information of China (English)

    王健; 康春松; 董建红; 薛继平

    2009-01-01

    Objective To probe into the value of the evaluation of left ventricular myocardial function by two dimensional strain(2DS) for coronary artery disease(CAD) patients with different degrees of left anterior descending(LAD) branch stenosis. Methods Fifty-five eases without myocardial infarction among a total of 72 patients with CAD were divided in to 3 groups based on the extent of LAD stenosis,that was group A(stenosis75%, n = 12). Another 17 eases of CAD with myocardial infarction were selected as group D. Strain and strain rate of the whole 11 segments that blood supplied by LAD of all cases were measured with 2DS. Results The 2DS ultrasound showed that the peak strain(S), the peak systolic strain rate(SRs) and the peak early diastolic strain rate (SRE) in all the 11 segments of group A were high and sharp. The above mentioned parameters of group B decreased compared with that of group A, however, there was no statistical significant difference (P >0.05). The S, SRs and SRE of group C cases decreased in some segments compared with that of group A and group B (P0.05). While in group D cases, the SRA decreased markedly. The SRE/SRA was more than 1 in group A. However, in group B, C and D cases, the SRE/SRA were all less than 1. Conclusions 2DS can sensitively reflect the decrease of regional myocardial systolic and diastolic function caused by the reduction of perfusion,and it may be beneficial to find myocardial ischemia for patients as early as possible.%目的 探讨二维应变成像评价冠心病患者左前降支(LAD)不同程度狭窄时局部心功能改变的价值.方法 72例冠心病患者中非心肌梗死患者55例,根据LAD狭窄程度分组:A组(狭窄75%)12例;17例心肌梗死患者为D组.应用二维应变成像检测LAD参与供血的11个节段应变和应变率参数的变化.结果 A组各节段峰值应变(S)、收缩期峰值应变率(SRS)与舒张早期峰值应变牢(SRE)较高尖.B组与A组比较有所下降,

  8. 斑点追踪成像技术在心肌梗死左室心肌应变能力中的应用%Application of Speckle Tracking Imaging in Left Ventricular Strain Capacity of Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    喻丽华; 赵季红; 蔡伟; 李学文

    2012-01-01

    目的:探讨超声斑点追踪成像(speckle tracking imaging,STI)技术评价心肌梗死患者左室心肌整体和局部应变的价值.方法:收集医院60例确诊为前壁心肌梗死患者,将同期体检健康志愿者60例作为正常对照.分别收集2组心尖位左室长轴3个切面高帧频二维动态图像,以自动功能成像软件(automated functional imaging,AFI)测量左室18节段峰值收缩期应变(S)、切面峰值收缩应变(GLS)及左室长轴平均总应变(GLS-Avg),分析GLS-Avg与左室射血分数(left ventricular ejection fraction,LVEF)的相关性;比较2组患者GLS-Avg.结果:前壁心肌梗死患者左室18节段S值自基底段向心尖段逐渐增加,各壁间差异无统计学意义(P>0.05);前壁心肌梗死患者各节段壁应变绝对值低于正常对照组(P<0.05).GLS-Avg与LVEF具有良好相关性(r=0.93,P<0.05).结论:斑点追踪成像技术能定量测定心肌梗死患者左室和整体心肌的变化.%Objective To study the application of speckle tracking imaging(STI) technology in myocardial infarction patients with left ventricular global and local strain. Methods Sixty cases of myocardial infarction patients were selected, and another sixty healthy patients were in control group. Left ventricular apical long-axis positions were recorded in three two-dimensional slices of high frame rate dynamic images. Left ventricular peak systolic strain in paragraph 18(S), the section peak systolic strain(GLS) and left ventricular long axis of the average total strain(GLS-Avg) of all cases were measured by automated functional imaging(AFI). The relationship of GLS-Avg and left ventricular ejection fraction(LVEF) was analyzed. Results Paragraph 18(S) values of left ventricle from the basal to apical segments gradually increased in control group. The intramural difference was not statistically significant(P>0.05), and strain of the wall segment in myocardial infarction group was lower than that of the control

  9. Myocardial feature tracking reduces observer-dependence in low-dose dobutamine stress cardiovascular magnetic resonance.

    Directory of Open Access Journals (Sweden)

    Andreas Schuster

    Full Text Available To determine whether quantitative wall motion assessment by CMR myocardial feature tracking (CMR-FT would reduce the impact of observer experience as compared to visual analysis in patients with ischemic cardiomyopathy (ICM.15 consecutive patients with ICM referred for assessment of hibernating myocardium were studied at 3 Tesla using SSFP cine images at rest and during low dose dobutamine stress (5 and 10 μg/kg/min of dobutamine. Conventional visual, qualitative analysis was performed independently and blinded by an experienced and an inexperienced reader, followed by post-processing of the same images by CMR-FT to quantify subendocardial and subepicardial circumferential (Eccendo and Eccepi and radial (Err strain. Receiver operator characteristics (ROC were assessed for each strain parameter and operator to detect the presence of inotropic reserve as visually defined by the experienced observer.141 segments with wall motion abnormalities at rest were eligible for the analysis. Visual scoring of wall motion at rest and during dobutamine was significantly different between the experienced and the inexperienced observer (p0.05. Eccendo was the most accurate (AUC of 0.76, 10 μg/kg/min of dobutamine parameter. Diagnostic accuracy was worse for resting strain with differences between operators for Eccendo and Eccepi (p0.05.Whilst visual analysis remains highly dependent on operator experience, quantitative CMR-FT analysis of myocardial wall mechanics during DS-CMR provides diagnostic accuracy for the detection of inotropic reserve regardless of operator experience and hence may improve diagnostic robustness of low-dose DS-CMR in clinical practice.

  10. 超声二维心肌应变的变化与心肌梗死范围的相关性研究%Relation between myocardial strain and infarction size detected by two-dimensional echocardiography

    Institute of Scientific and Technical Information of China (English)

    张梅青; 王秋霜; 黄党生; 张丽伟; 欧阳巧红; 王宇玫; 安秀芝

    2013-01-01

    目的 评价心肌梗死患者超声二维心肌应变的变化与心肌梗死范围的相关性.方法 选择71例急性心肌梗死患者,于心肌梗死后3~6个月行超声心动图和单光子发射计算机断层摄影(SPECT)检查,根据心肌梗死面积将患者分为A组28例(心肌梗死面积<12%),B组43例(心肌梗死面积≥12%).所有患者行超声二维斑点追踪分析,测量心肌收缩期整体纵向应变(GLS)、收缩期整体径向应变(GRS)、收缩期整体圆周应变(GCS),对心肌应变与SPECT检测的左心室壁缺血坏死心肌的面积占左心室壁的百分比(Extent)进行相关分析,并应用ROC曲线评价3种心肌应变检测心肌梗死范围的价值.结果 B组的GLS、GCS及GRS均低于A组(P<0.05).GLS、GCS与Extent均相关(r=0.721、r=0.504,P<0.01),GLS、GCS及GRS的ROC曲线下面积分别为0.818、0.749、0.678,诊断心肌梗死面积≥12%对应的界值分别为-13.83%、-11.65%、26.64%,敏感性和特异性分别为72.7%、88.9%,63.6%、88.9%,81.8%、55.6%.结论 超声二维心肌应变的变化能够反映心肌梗死范围的改变,其中GLS能够较好地评价心肌梗死范围.%Objective To assess the relation between myocardial strain and infarction size detected by two-dimensional echocardiography in patients with myocardial infarction .Methods Seventy-one acute myocardial infarction patients ,who underwent echocardiography and single photon e-mission computed tomography (SPECT ) 3 -6 months after onset of the disease ,were divided into group A with its myocardial infarction size<12% (n=28)and group B with its myocardial infarction size≥l2% (n=43).Their cardiac global longitudinal strain (GLS ),global radial strain (GRS) and global circumference strain (GCS ) were detected by two-dimensional echocardiography and compared with the left ventricular ischemic size detected by SPECT .ROC curves were plotted for the GLS ,GCS and GRS .Results The incidence of GLS ,GCS and GRS was significantly

  11. Sensitivity and specificity of strain imaging in evaluating myocardial viability among patients with ST-segment elevation acute myocardial infarction%应变显像评价ST段抬高急性心肌梗死患者存活心肌的敏感性与特异性

    Institute of Scientific and Technical Information of China (English)

    阮雯; 舒先红; 石洪成; 潘翠珍; 周易; 陈灏珠

    2008-01-01

    目的 比较应变显像(SI)与静息-再分布201Tl心肌灌注显像(RR-201Tl-SPECT)预测ST段抬高的急性心肌梗死(AMI)患者存活心肌的敏感性与特异性.方法 对26例AMI患者进行介入治疗1周后行超声心动图和RR-201Tl-SPECT检查,并随访治疗≥3个月后的超声心动图.测量左室长轴16节段的应变及RR-201 Tl-SPECT心肌灌注评分,以1周和≥3个月的室壁运动评分(WMS)对比作为判定存活心肌的"金标准".结果 ①共研究260个缺血节段.随访(5±2)月,据WMS判定存活节段201个,梗死节段59个.RR-201 Tl-SPECT预测存活心肌的敏感性和特异性为87%(175/201)和58%(34/59).②以收缩期应变(Set)<-6%为最佳截止点预测存活心肌的敏感性和特异性分别为81%(161/201)和66%(39/59).③Set与RR-201 Tl-SPECT总符合率77%(199/260),具有中等一致性(Kappa=0.40).结论 S1评价ST段抬高AMI患者的存活心肌是可行的,其与RR-201 Tl-SPECT显像诊断效力相似,是更简便、无创、低成本的替代选择.%Obiective To compare the sensitivity and specificity of strain imaging(SI)and restredistribution Tl-201(RR-201 TI)SPECT imaging in evaluating myocardial viability among patients with STelevation acute myocardial infarction(AMI).Methods Twenty-six AMI patients underwent echocardiography and RR-201 Tl-SPECT imaging a week(baseline)after percutaneous coronary intervention(PCI)therapy.At baseline,wall motion score(WMS)and systolic strain were assessed,SPECT scoring were performed on 16 segments of left ventricle(LV).WMS was repeated more than 3 months later to assess myocardial viability,which is deemed as reference.Results ①Two hundred and sixty segments in the"at risk"regions were followed up for(5±2)months,among which 201 were identified as viable and 59 were not,according to the WMS.②In comparison to the reference standard,the sensitivity and specificity of RR-201 Tl-SPECT to predict myocardial viability were 87%(175/201)and 58%(34/59)respectively

  12. Relation Between Parameters of Myocardial Mechanics and Ventricular Arterial Coupling: A Three-Dimensional Speckle-Tracking Study in Healthy Adults

    Directory of Open Access Journals (Sweden)

    Esmaeilzadeh

    2015-08-01

    Full Text Available Background Understanding the relation between ventricular-arterial coupling (VAC and myocardial mechanical parameters could offer an adjunctive perspective on left ventricular function. Objectives Our aim was to study the relation between VAC and the parameters of myocardial mechanics using three-dimensional speckle-tracking echocardiography (3DSTE. Patients and Methods We studied 68 normal participants (mean age, 35 ± 12.2 y; 36 [53%] males. VAC was measured by the ratio of arterial elastance (Ea to ventricular elastance (Ees. The peak systolic value of longitudinal strain (LS, circumferential strain (CS, radial strain, three-dimensional global strain (3DGS, apical rotation, torsion, and twist and their time to peak were calculated. Results Almost all deformation indices were higher in the women than in the men. LS (r = -0.41, P < 0.01, twist (r = 0.26, P < 0.03, rotation (r = 0.41, P < 0.01, and 3DGS (r = - 0.39, P < 0.01 were associated with age. Although significant associations were found between VAC and Ea or Ees in the men and women, no relation was found between Ea and Ees in both sexes (r = 0.07 in men and r = 0.08 in women. Indeed, VAC had a stronger association with Ea than with Ees (r = 0.708 vs. r = -0.537. Ees and VAC were related to torsion (r = 0.30 vs. r = -0.37; both P < 0.05; and Ea, Ees, and VAC were also associated with CS (r = 0.64, r = -0.45, and r = 0.79; all P < 0.05 and 3DGS (r = -0.55, r = 0.38, and r = -0.64; all P < 0.01. Conclusions Amongst all myocardial mechanical parameters, VAC was related to CS and 3DGS as well as torsion.

  13. Evaluation of myocardial function in patients with essential hypertension with left ventricular normal geometry using two dimensional strain imaging%二维应变成像技术评价左心室构型正常高血压患者的心肌功能

    Institute of Scientific and Technical Information of China (English)

    李真真; 王志斌; 孙品; 聂晶; 李艳; 付秀秀; 张金慧

    2013-01-01

    ,normal filling group and abnormal relaxation group respectively .There were significant differences among the groups (F=3.96,P=0.02).In detail,the significant differences were identified in following comparisons:group normal control/normal filling with abnormal relaxation group (q=3.69,3.07,both P<0.05).Conclusions LV myocardial contraction and relaxation were first impaired in the longitudinal direction among the 3 directions in EH patients with normal left ventricular geometry .However,LV pump function and LV filling were compensated by circumferential shortening at ventricular systole and 3 directional lengthenings at atrial systole,respectively.Two-dimension strain imaging can quantify left ventricular myocardium strain and assess early alteration of left ventricular function correctly in patients with EH .%  目的应用二维应变成像检测原发性高血压左心室构型正常患者心肌应变,并探讨其临床意义.方法选择左心室构型正常的原发性高血压患者70例和健康志愿者30例(健康对照组),原发性高血压患者中左心室舒张充盈正常者(左心室舒张充盈正常组)35例,松弛性减低者(左心室松弛性减低组)35例.采集心尖四腔心切面、二腔心切面、左心室长轴切面及胸骨旁乳头肌水平左心室短轴切面的二维灰阶动态图像.应用二维应变成像测量左心室纵向、圆周、径向应变率.结果健康对照组、左心室舒张充盈正常组、左心室松弛性减低组收缩期纵向峰值应变率分别为(-1.4±0.2)s-1、(-1.4±0.2)s-1、(-1.2±0.2) s-1,组间比较差异有统计学意义(F=11.38,P=0.00),且左心室松弛性减低组与健康对照组、左心室舒张充盈正常组比较,差异均有统计学意义(q=5.68、5.92,P均<0.01).健康对照组、左心室舒张充盈正常组、左心室松弛性减低组舒张早期纵向峰值应变率分别为(2.9±0.4)s-1、(2.6±0.3)s-1、(2.3±0.4)s-1,组间比较差异有统计学意义(F=21.51,P=0.00),且左

  14. Left ventricular layer function in hypertension assessed by myocardial strain rate using novel one-beat real-time three-dimensional speckle tracking echocardiography with high volume rates.

    Science.gov (United States)

    Saeki, Maki; Sato, Noriaki; Kawasaki, Masanori; Tanaka, Ryuhei; Nagaya, Maki; Watanabe, Takatomo; Ono, Koji; Noda, Toshiyuki; Zile, Michael R; Minatoguchi, Shinya

    2015-08-01

    We recently developed novel software to measure phasic strain rate (SR) using automated one-beat real-time three-dimensional speckle tracking echocardiography (3D-STE) with high volume rates. We tested the hypothesis that left ventricular (LV) systolic function and relaxation analyzed by SR with the novel 3D-STE in hypertension (HTN) with hypertrophy may be impaired in the endocardium before there is LV systolic dysfunction. We measured LV longitudinal, radial and circumferential SR in patients with HTN (n=80, 69±7 years) and age-matched normotensive controls (n= 60, 69±10 years) using 3D-STE. HTN patients were divided into four groups according to LV geometry: normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. We measured SR during systole as an index of systolic function, SR during isovolumic relaxation (IVR) as an index of relaxation and E/e' as an index of filling pressure. Endocardial SR during systole in HTN with concentric and eccentric hypertrophy decreased compared with that in controls despite no reduction in ejection fraction or epicardial SR. Endocardial radial SR during IVR decreased even in normal geometry, and it was further reduced in concentric remodeling and hypertrophy despite no reduction in epicardial SR. LV phasic SR assessed by 3D-STE with high volume rates is a useful index to detect early decreases in LV systolic function and to predict subclinical LV layer dysfunction in patients with HTN.

  15. Strain dyssynchrony index determined by three-dimensional speckle area tracking can predict response to cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Onishi Tetsuari

    2011-04-01

    Full Text Available Abstract Background We have previously reported strain dyssynchrony index assessed by two-dimensional speckle tracking strain, and a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT. A newly developed three-dimensional (3-D speckle tracking system can quantify endocardial area change ratio (area strain, which coupled with the factors of both longitudinal and circumferential strain, from all 16 standard left ventricular (LV segments using complete 3-D pyramidal datasets. Our objective was to test the hypothesis that strain dyssynchrony index using area tracking (ASDI can quantify dyssynchrony and predict response to CRT. Methods We studied 14 heart failure patients with ejection fraction of 27 ± 7% (all≤35% and QRS duration of 172 ± 30 ms (all≥120 ms who underwent CRT. Echocardiography was performed before and 6-month after CRT. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained from 3-D speckle tracking imaging using 16 segments. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, Yu Index, and two-dimensional radial dyssynchrony by speckle-tracking strain. Response was defined as a ≥15% decrease in LV end-systolic volume 6-month after CRT. Results ASDI ≥ 3.8% was the best predictor of response to CRT with a sensitivity of 78%, specificity of 100% and area under the curve (AUC of 0.93 (p Conclusions ASDI can predict responders and LV reverse remodeling following CRT. This novel index using the 3-D speckle tracking system, which shows circumferential and longitudinal LV dyssynchrony and residual endocardial contractility, may thus have clinical significance for CRT patients.

  16. Estimation of circumferential fiber shortening velocity by echocardiography.

    Science.gov (United States)

    Ruschhaupt, D G; Sodt, P C; Hutcheon, N A; Arcilla, R A

    1983-07-01

    The M-mode and two-dimensional echocardiograms of 40 young patients were analyzed to compare the mean circumferential fiber shortening velocity (Vcf) of the left ventricle calculated separately by two methods. The mean circumferential fiber shortening velocity was derived from the M-mode echocardiogram as minor axis shortening/ejection time and derived from the two-dimensional echocardiogram as actual circumference change/ejection time. With computer assistance, circumference was determined from the short-axis two-dimensional echocardiographic images during end-diastole and end-systole. Good correlations were obtained between the left ventricular diameter derived by M-mode echocardiography and the vertical axis during end-diastole (r = 0.79) and end-systole (r = 0.88) derived by two-dimensional echocardiography. Likewise, high correlations were noted between diameter and circumference in end-diastole (r = 0.89) and end-systole (r = 0.88). However, comparison of Vcf obtained by M-mode echocardiography with that obtained by two-dimensional echocardiography showed only fair correlation (r = 0.68). Moreover, the diameter/circumference ratio determined in end-diastole and end-systole differed significantly (p less than 0.001), possibly owing to the change in geometry of the ventricular sector image during systole. Although Vcf derived by M-mode echocardiography is a useful index of left ventricular performance, it does not truly reflect the circumference change during systole.

  17. Evaluation of the kinetics of myocardial during isovolumic relaxation in normal subjects combined with exercise stress testing using speckle-tracking imaging%斑点追踪显像结合运动负荷试验研究正常人等容舒张期心肌应变的特点

    Institute of Scientific and Technical Information of China (English)

    陈晓燕; 康春松; 李朝军; 张燕霞; 宋倩; 赵哲黠

    2013-01-01

    Objective To observe the kinetics of myocardial during isovolumic relaxation (IVR) in normal subjects during exercise stress testing,and evaluate the relationship between the recovery rate of circumferential strain during IVR and the diastolic function of the heart.Methods Echocardiography was performed in 43 healthy students at rest,at peak stress and at recovery of the exercise test.The ratio of peak early-diastolic mitral orifice flow velocity and peak early-diastolic mitral annular velocity in left ventricular posterior wall (E/e) was measured.The records of the movement in the basal,papillary muscle and apical short-axis views of the left ventricular were stored.The circumferential strain during the end systolic (ES) and the end isovolumetric relaxation (IRA) of the subendocardial and subepicardial layers in the three short axis were analyzed using X-strain software.The circumferential strain recovery rate of the subendocardial and subepicardial layers during the IVR (ENCSrec,EPCSrec) were calculated.The circumferential strain of the subendocardial and subepicardial layers in the three short-axis during ES and IRA phases in different status were compared.The relationship between the circumferential strain recovery rate during IVR and E/e were analyzed.Results The circumferential strain of the basal,papillary level in short axis during ES and IRA phases decreases at the beginning and then increased along with the exercise intensity (P <0.05).The circumferential strain of the subendocardial layer is greater than the subepicardial layer in the three shortaxis during ES and IRA in different exercise status (P <0.01).The ENCSrec and EPCSrec of the three short-axis increases at the beginning and then decreased along with the exercise intensity (P <0.05).The ENCSrec and EPCSrec of 3 short axis are correlated with E/e in different exercise phases (P <0.05).Conclusions In normal subjects,the kinetics of circumferential strain during IVR is consisted with the

  18. The Prognostic Value of Left Atrial Peak Reservoir Strain in Acute Myocardial Infarction Is Dependent on Left Ventricular Longitudinal Function and Left Atrial Size

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Andersen, Mads J; Valeur, Nana;

    2013-01-01

    Peak atrial longitudinal strain (PALS) during the reservoir phase has been proposed as a measure of left atrium function in a range of cardiac conditions, with the potential for added pathophysiological insight and prognostic value. However, no studies have assessed the interrelation of PALS...... and left ventricular longitudinal strain (global longitudinal strain) in large-scale populations in regard to prognosis....

  19. Detection of a longitudinal defect in a pipe based on guided circumferential waves techniques

    Institute of Scientific and Technical Information of China (English)

    LI Longtao; HE Cunfu; WU Bin

    2005-01-01

    Based on elasticity theory, the multi-modes and disperse characteristics of guided circumferential waves in a pipe were investigated theoretically and experimentally, the disperse curves of guided circumferential waves were gotten by numerical calculations. The relationships between the angle of beam transducer, frequency and guided circumferential modes were analyzed by our guided wave experiment system. Then single guided circumferential mode was excited in the pipe (O.D 88.8 mm, I.D 80.8 mm). An artificial longitudinal defect (25 × 1 × 0.7 mm)on the surface of the pipe was detected by use of the single guided circumferential wave. The results show that single guided circumferential mode can be excited in the pipe by choosing special frequency and special angle beam transducer, similar to the excitation of Lamb wave in a plate, and it can be used to find the longitudinal defect on a pipe surface.

  20. Systolic and diastolic myocardial mechanics in hypertrophic cardiomyopathy and their link to the extent of hypertrophy, replacement fibrosis and interstitial fibrosis.

    Science.gov (United States)

    Nucifora, Gaetano; Muser, Daniele; Gianfagna, Pasquale; Morocutti, Giorgio; Proclemer, Alessandro

    2015-12-01

    Aim of the present study was to investigate the relations between myocardial mechanics and the extent of hypertrophy and fibrosis in hypertrophic cardiomyopathy (HCM). Forty-five consecutive patients with HCM and 15 subjects without structural heart disease were included. Cardiac magnetic resonance with late gadolinium enhancement (LGE) imaging was performed to evaluate biventricular function, LV mass index and presence/extent of LGE, expression of replacement fibrosis. Myocardial T1 relaxation, a surrogate of interstitial fibrosis, was measured from Look-Locker sequence. Feature-tracking analysis was applied to LV basal, mid and apical short-axis images to assess systolic and diastolic global LV circumferential strain (CS) and strain rate (CSr). Peak systolic CS and CSr were significantly higher among HCM patients as compared to control subjects (p = 0.015 and p = 0.007, respectively). The ratio of peak CSr during early filling to peak systolic CSr was significantly lower among HCM patients (p = 0.002). At multivariate linear regression analysis, LV mass index (p mechanics are enhanced and LV diastolic mechanics are impaired in HCM. Extent of hypertrophy and replacement fibrosis influence the LV systolic mechanics while extent of replacement fibrosis and interstitial fibrosis influence the LV diastolic mechanics.

  1. 二维应变超声心动图评价干细胞移植对心肌梗死大鼠左心室局部收缩功能的影响%Assessment of Regional Myocardial Function Following Mesenchymal Stem Cells Transportation in A Rat Model of Myocardial Infarction by 2 -dimensional Strain Echocardiography

    Institute of Scientific and Technical Information of China (English)

    廖书生; 阮琴韵; 林美燕; 鄢磊; 苏津自; 林茂海

    2012-01-01

    Objective To investigate the value of 2 -dimensional strain echocardiography (2DSE) in a research of mesenchymal stem cells ( MSCs) transplantation therapy in a ral model of myocardial infarction. Methods Forty Sprague - Dawley rats were divided into myocardial infarct (Ml) group (n = 14) , MSCs treatment group ( n = 16) , and control group(ra = 10). Rat model of myocardial infarction was established following ligation of the proximal left anterior descending coronary artery for MI - group and MSCs group, and control group with sham - operation. The MSCs labeled by DAP1 was implanted into the acute infarct site for the MSCs group. Myocardial strain and strain rate of left ventricular mid - anterior segment were detected by 2DSE pre - procedurally at baseline, 1 - week and 4 -week after procedures. Fluorescence microscope was used to identify the DAPI - labeled cells, and immunohistochemistry staining of Tro-ponin I was used to evaluate the differentiation and expression of engrafted MSCs. Results In the end of 4 weeks, when compared with MI group, increased strain parameters were found in MSCs group (P<0.01). The labeled cells were viable in the host myocardium and immunochemical staining revealed that the engrafted stem cells expressed Troponin I. Conclusion 2DSE may detect the improved regional systolic function after transplantation of MSCs on a post - MI of rat model noninvasively.%目的 应用二维应变超声心动图(2 -dimensional strain echocardiography,2DSE)观察心肌梗死大鼠在骨髓间充质干细胞(mesenchymal stem ceils,MSCs)移植后局部心肌功能改善情况,探讨2DSE在心肌梗死大鼠干细胞移植研究中心功能评价的价值.方法40只SD大鼠随机分为心肌梗死组(n=14)、MSCs治疗组(n=16)和对照组(n=10),心肌梗死组与MSCs组建立心肌梗死模型,对照组只进行假手术.MSCs组在梗死区心肌局部注射DAPI标记的MSCs,心肌梗死组和对照组只注射DMEM培养基.分别于术前1天和术后1

  2. Characterization of mechanical and geometrical properties of a tube with axial and circumferential guided waves.

    Science.gov (United States)

    Yeh, Cheng-Hung; Yang, Che-Hua

    2011-05-01

    Guided waves propagating in cylindrical tubes are frequently applied for the characterization of material or geometrical properties of tubes. In a tube, guided waves can propagate in the axial direction and called axial guided waves, or in the circumferential direction called circumferential guided waves. Dispersion spectra for the axial and circumferential guided waves share some common behaviors and however exhibit some particular behaviors of their own. This study provides an investigation with theoretical modeling, experimental measurements, and a simplex-based inversion procedure to explore the similarity and difference between the axial guided waves and circumferential guided waves, aiming at providing useful information while axial and circumferential guided waves are applied in the area of material characterization. The sensitivity to the radius curvature for the circumferential guided waves dispersion spectra is a major point that makes circumferential guided waves different from axial guided waves. For the purpose of material characterization, both axial and circumferential guided waves are able to extract an elastic moduli and wall-thickness information from the dispersion spectra, however, radius information can only be extracted from the circumferential guided waves spectra. PMID:21211810

  3. Effect of strain rate imaging on the assessment of left ventricular regional systolic myocardial function before and after intravenous thrombolytic therapy in patients with acute myocardial infarction%应变率成像评价急性心肌梗死患者溶栓前后左室局部收缩功能48例分析

    Institute of Scientific and Technical Information of China (English)

    魏天辉

    2010-01-01

    @@ 治疗急性心肌梗死(acute myocardial infarction,AMI)的治疗关键是及早开通梗死相关血管,而紧急溶栓是目前治疗AMI的重要方法,但部分患者于血管再通后心肌再灌注障碍,影响心脏功能及临床预后.应变率显像技术(strain rate imaging,SRI)是新近发展起来的一种无创、可定量评价局部室壁运动的超声心动图新方法[1].我们采用SRI技术观察心肌梗死溶栓治疗前后左室局部收缩功能的变化,探讨其临床价值.

  4. Transverse shear effect in a circumferentially cracked cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1979-01-01

    The objectives of the paper are to solve the problem of a circumferentially-cracked cylindrical shell by taking into account the effect of transverse shear, and to obtain the stress intensity factors for the bending moment as well as the membrane force as the external load. The formulation of the problem is given for a specially orthotropic material within the framework of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions as to moment and stress resultants on the crack surface. The effect of Poisson's ratio on the stress intensity factors and the nature of the out-of-plane displacement along the edges of the crack, i.e., bulging, are also studied.

  5. Transient thermal stress problem for a circumferentially cracked hollow cylinder

    Science.gov (United States)

    Nied, H. F.; Erdogan, F.

    1982-01-01

    The transient thermal stress problem for a hollow elasticity cylinder containing an internal circumferential edge crack is considered. It is assumed that the problem is axisymmetric with regard to the crack geometry and the loading, and that the inertia effects are negligible. The problem is solved for a cylinder which is suddenly cooled from inside. First the transient temperature and stress distributions in an uncracked cylinder are calculated. By using the equal and opposite of this thermal stress as the crack surface traction in the isothermal cylinder the crack problem is then solved and the stress intensity factor is calculated. The numerical results are obtained as a function of the Fourier number tD/b(2) representing the time for various inner-to-outer radius ratios and relative crack depths, where D and b are respectively the coefficient of diffusivity and the outer radius of the cylinder.

  6. Accurate wall thickness measurement using autointerference of circumferential Lamb wave

    International Nuclear Information System (INIS)

    In this paper, a method of accurately measuring the pipe wall thickness by using noncontact air-coupled ultrasonic transducer (NAUT) was presented. In this method, accurate measurement of angular wave number (AWN) is a key technique because the AWN is changes minutely with the wall thickness. An autointerference of the circumferential (C-) Lamb wave was used for accurate measurements of the AWN. Principle of the method was first explained. Modified method for measuring the wall thickness near a butt weld line was also proposed and its accuracy was evaluated within 6 μm error. It was also shown in the paper that wall thickness measurement was accurately carried out beyond the difference among the sensors by calibrating the frequency response of the sensors. (author)

  7. Tensile and Fracture Properties of Circumferentially Notched Tensile Specimens of Stainless Steel Weldments

    International Nuclear Information System (INIS)

    The tensile and fracture properties of different types of austenitic stainless steel weldments were determined using round notched tensile specimens. These included 304L, 316L and 6%Mo super austenitic stainless steels and their weld metals. The triaxial state of stress, the plastic constraint and the plane strain conditions developed ahead of the notch root make notched specimens eligible for the evaluation of fracture toughness. This was achieved through the testing procedure: J-evaluation on tensile test (JETT) using circumferentially notched round bar specimens. The JETT index was taken as a measure of the relevant elastic-plastic fracture toughness of the tested materials. In the case of austenitic stainless steels being too ductile at room temperature the resulted JETT were of relatively higher values than the fracture toughness values determined from the standard fracture mechanics test methods. This could be related to the difference in the stress state ahead of the sharp crack of the standard fracture mechanics specimen and that of the blunt notch of the tensile specimen. The results showed that the 6% Mo weld metal ranked highest while the 316L weld metal ranked lowest regarding JETT fracture toughness values. The deformation mechanisms pertinent to austenitic stainless steels (generation of stacking faults and formation of strain induced martensite) were employed for the interpretation of the experimental results.

  8. Proprieties of quantitative evaluation of defect size by myocardial SPECT. Evaluation using myocardial phantom

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Jiro; Nakatsuka, Teruo; Fujioka, Tadao; Kashima, Kenji; Matsumura, Yasushi; Yamamoto, Kazuhiro

    1987-09-01

    The accuracy to quantify the size and the extent of Thallium-201 (Tl) uptake of defect zone by Tl single photon emission computed tomogram (SPECT) was evaluated, using myocardial phantom. Long-axis SPECT image was devided into 6 slices from apex to base, and radians were projected from the center to define 32 myocardial secters, 11.25 degrees each. Then the maximum count in each secter was plotted on each radian (maximum count circumferential profile analysis:mcCPA), and was normalized to the maximum count for the whole heart (%Tl-uptake). In this way, circumferential profile curve was obtained, and normal value in each secter of myocardial phantom with defects was analysed and the ratio of segments, %Tl-uptake of which was below the normal value, was defined as % defect volume (%DV). The difference between the value of %Tl-uptake of defect zone and the normal value was difined as defect severity, and the average of defect severity was defined as mean defect severity (mDS). We prepared myocardial phantoms with a variety of area of defect, and with a variety of thickness of defect, and acquired these SPECT images. %DV and mDS were calculated from those images and compared with real area and thickess of defect. In the phantom with given thickness of defect, %DV was closely correlated to area of defect (r > 0.976), but also correlated to thickness of defect. In the phantom with given area of defect, mDS was closely correlated to thickness of defect (r = 0.988), and also correlated to area of defect. In conclusion, %DV and mDS were good indices of the defect size and the extent of Tl-uptake respectively, but it is necessary to consider their influence on each other.

  9. Visualizing myocardial function using HARP MRI

    Energy Technology Data Exchange (ETDEWEB)

    Osman, N.F. [Center for Imaging Science, Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218 (United States); Prince, J.L. [Center for Imaging Science, Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218 (United States). E-mail: prince at jhu.edu

    2000-06-01

    Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application. (author)

  10. Visualizing myocardial function using HARP MRI

    Science.gov (United States)

    Osman, Nael F.; Prince, Jerry L.

    2000-06-01

    Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application.

  11. The use of circumferentially varying stagger guide vanes in an axial flow pump or compressor

    Science.gov (United States)

    Horlock, J. H.

    1990-04-01

    An actuator disk analysis is given of the flow through a guide vane and rotor combination. It is shown that changes in total pressure across the rotor are, in general, related to circumferential variations in guide vane outlet angle. In particular, known variations in inlet total pressure may be eliminated by suitable circumferential changes in guide vane stagger.

  12. Influence of circumferential flaw length on internal burst pressure of a wall-thinned pipe

    International Nuclear Information System (INIS)

    Highlights: ► The effect of θ on pf was examined by experimental analysis and FEA. ► Here θ is the circumferential angle of a flaw, pf is the internal burst pressure. ► pf decreased as θ increased in some cases. ► The effect of θ on pf should be taken into consideration in evaluating pf. -- Abstract: This paper examines the effect of the circumferential angle of a flaw θ on the internal burst pressure pf of pipes with artificial wall-thinned flaws. The effect of θ has conventionally been regarded as unimportant in the evaluation of the pf of wall-thinned straight pipes. Therefore, a burst pressure equation for an axial crack inside a cylinder (Fig. 1, left), such as Kiefner's equation (Kiefner et al., 1973), has been widely applied (ANSI/ASME B31.G., 1991; Hasegawa et al., 2011). However, the following implicit assumptions notably exist when applying the equation to planar flaws in situations with non-planar flaws. 1)The fracture mode of the non-planar flaw under consideration is identical to that of the crack. 2)The effect of θ on pf, which is not considered for an axial crack, is small or negligible. However, the experimental results from the systematic burst tests for carbon steel pipes with artificial wall-thinned flaws examined in this paper showed that these implicit assumptions may be incorrect. In this paper the experimental results are evaluated in further detail. The purpose of the evaluation was to clarify the effect of θ on pf. Specifically, the significance of the flaw configuration (axial length δz and wall-thinning ratio t1/t) was studied for its effects on θ and pf. In addition, a simulation of this effect was conducted using a large strain elastic-plastic Finite Element Analysis (FEA) model. As observed from the experimental results, θ tended to affect pf in cases with large δz, and t1/t was also correlated with a decrease in pf with an increase in θ. These tendencies were successfully simulated by the large strain elastic

  13. Analysis of circumferential waves on a water-filled cylindrical shell

    Institute of Scientific and Technical Information of China (English)

    FAN Wei; ZHENG Guoyin; FAN Jun

    2012-01-01

    The formation of scattering field from a water-filled cylindrical shell was studied. The analytic solutions of scattering field are derived using elastic thin shell theory and Sommerfeld-Watson Transformation (SWT) method. Complex wave-number poles of circumferential waves are found numerically, the phase speed and attenuation of circumferential waves between the situation of a hollow cylindrical shell and a water-filled cylindrical shell are compared. The synthesis of backscattering form functions which are sum of specular reflection component and circumferential waves is consistent with normal mode result. The calculated echo sequences of additional fluid circumferential waves are compared with experimental results. The results show that richer resonance peaks appeared in the backscattering form functions of a water-filled cylindrical shell and the formation of echo's structure are due to re-radiation effects of additional fluid circumferential waves.

  14. Assessment of Retrograde Coronary Venous Infusion of Mesenchymal Stem Cells Combined with Basic Fibroblast Growth Factor in Canine Myocardial Infarction Using Strain Values Derived from Speckle-Tracking Echocardiography.

    Science.gov (United States)

    Sun, Qi-Wei; Zhen, Lei; Wang, Qin; Sun, Yan; Yang, Jiao; Li, Yi-Jia; Li, Rong-Juan; Ma, Ning; Li, Zhi-An; Wang, Lu-Ya; Nie, Shao-Ping; Yang, Ya

    2016-01-01

    Speckle-tracking echocardiography was used to assess retrograde coronary venous infusion of mesenchymal stem cells (MSCs) combined with basic fibroblast growth factor (bFGF) in a canine model of acute myocardial infarction (AMI). AMI was induced by ligation of the left anterior descending coronary artery. Coronary venous retroperfusion was performed at 1 wk after AMI. Twenty-eight animals were randomized into four groups: saline, bFGF+saline, saline+MSCs and bFGF+MSCs. Echocardiography was performed before AMI, at 7 d post-AMI and 40 d after retroperfusion. Apoptotic cardiomyocytes in the border zone of the ischemic region were evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling. Vascular endothelial growth factor and factor VIII concentrations were measured by western blotting. The left ventricular end-systolic volume increased significantly, whereas the left ventricular ejection fraction and global and segmental strain values decreased significantly after AMI. After retroperfusion, the strain values of the infarct zone, but not conventional echocardiographic parameters, were significantly different between control and bFGF+MSC groups. Cardiomyocyte apoptosis decreased, whereas vascular endothelial growth factor and factor VIII concentrations were higher in the bFGF+MSC, bFGF and MSC groups. Cardiomyocyte apoptosis was well correlated with the strain values. Although retrograde coronary venous infusion of bFGF and MSCs promoted neo-vascularization of the infarcted myocardium and inhibited apoptosis, there was only a slight strain improvement without a substantial increase in global cardiac functions.

  15. Is the effect of job strain on myocardial infarction risk due to interaction between high psychological demands and low decision latitude?

    DEFF Research Database (Denmark)

    Hallqvist, J; Diderichsen, Finn; Theorell, T;

    1998-01-01

    referents were included in the analysis. Exposure categories of job strain were formed from self reported questionnaire information. The results show that high demands and low decision latitude interact with a synergy index of 7.5 (95% C.I.: 1.8-30.6) providing empirical support for the core mechanism...... of the job strain model. Manual workers are more susceptible when exposed to job strain and its components and this increased susceptibility explains about 25-50% of the relative excess risk among manual workers. Low decision latitude may also, as a causal link, explain about 30% of the socioeconomic...

  16. 彩色M型应变及应变率技术检测尿毒症右室心肌功能异常%Detection of Right Ventricular Myocardial Dysfunction in Uremia using Colour M-mode Strain and Strain Rate

    Institute of Scientific and Technical Information of China (English)

    卢西梅; 高晓军; 贾莉; 宋喜焕; 卢茗

    2011-01-01

    Objective To detect regional myocardial systolic and diastolic functions of right ventricular myocardium in uremia patients. Methods Control group contained 30 healthy individuals,called group A. 34 patients with uremia were divided into two groups according to whether left ventricle was hypertrophic, 18 patients in group without hypertrophic left ventricle called group B and 16 patients in group with hypertrophic left ventricle called group C. The colour M-mode strain and strain rate images were acquired in basal and middle segments of right ventricular free wall and septum,and maximum systolic strain(ε)、peak systolic strain rate(SRs),early diastolic strain rate(SRe) and late diastolic strain rate(SRa) were measured. Results The colour of colour M-mode strain and strain rate was lighter in group B and group C of right ventricular free wall and septum than in group A, especially in group C whose lightness was with significance,and ε in partial segments of group C delayed. ε、SRs and SRe in each segment of right ventricular free wall and septum were lower in group B and group C than in group A(P<0. 05). In subtotal segments they were higher in group B than in group C. SRa was the lowest in group A and highest in group C in free wall,and in septum it was lower in group C than in group A and group B. Conclusions Colour M-mode strain and strain rate could evaluate regional myocardial systolic and diastolic functions of right ventricular myocardium in uremia patients sensitively and direct-viewingly.%目的 应用彩色M型应变及应变率技术检测尿毒症患者右室心肌局部收缩与舒张功能.方法 对照组A组30例健康人.34例尿毒症患者根据左心室肥厚与否分为左心室非肥厚组B组18例,左心室肥厚组C组16例.获取右室游离壁、室间隔的基底段及中间段的应变及应变率的彩色M型图像,并测量收缩期最大应变(maximum systolic strain,ε)、收缩期峰值应变率(peak systolic strain rate,SRs

  17. Left Ventricular Myocardial Strain in Patients with Cardiac Amyloidosis Using Speckle Tracking Imaging%斑点追踪成像评价心脏淀粉样变性患者左心室心肌分层应变

    Institute of Scientific and Technical Information of China (English)

    张晶; 肖杨杰; 任卫东; 刘爽; 孙菲菲; 乔伟

    2013-01-01

    Purpose To evaluate the systolic function of left ventricular subendocardial and subepicardial myocardium using speckle tracking imaging (STI) in patients with cardiac amyloidosis. Materials and Methods Twenty patients with cardiac amyloidosis (CA group ) and thirty healthy subjects (control group) were examined using two-dimensional echocardiography. High frame rate two-dimensional images were recorded at left ventricular short-axis views during three consecutive cardiac cycles on basal, papillary muscle and apical planes. Peak systolic circumferential strain (CS) and radial strain (RS) were measured in subendocardial, subepicardial and transmural myocardium. The mean CS and RS were calculated in subendocardial and subepicardial myocardium. Results Compared with control group, IVSd, LVPWDd, LAESd, E/A and E/e of CA group were significantly increased (P0.05). In three short-axis and global views, CS of subendocardial myocardium was higher than that of subepicardial myocardium in both CA group and control group (P0.05)。CA组和对照组左心室短轴二尖瓣水平、乳头肌水平、心尖水平及左心室整体内膜下心肌收缩期CS峰值高于外膜下心肌(P<0.001)。对照组内膜下心肌收缩期RS峰值高于外膜下心肌(P<0.001),CA组内膜下心肌收缩期RS值均低于外膜下心肌(P<0.05)。与对照组比较,CA组左心室二尖瓣水平、乳头肌水平、心尖水平内膜下、外膜下及平面整体心肌收缩期CS峰值和RS峰值均减低(P<0.001),左心室整体内膜下、外膜下心肌收缩期CS峰值和RS峰值均减低(P<0.001),且内膜下心肌减低更明显。结论STI可以评价CA患者左心室圆周及径向心肌收缩功能,可作为临床早期诊断CA和评价病变程度的无创性检查方法。

  18. Fracture behavior of short circumferentially surface-cracked pipe

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswamy, P.; Scott, P.; Mohan, R. [Battelle, Columbus, OH (United States)] [and others

    1995-11-01

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission`s (NRC) research program entitled ``Short Cracks in Piping and Piping Welds`` that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC`s PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria.

  19. Exoscope Update: Automated Laser Welding Of Circumferential Tissue Anastomoses

    Science.gov (United States)

    Sauer, Jude S.; McGuire, Kevin P.; Hinshaw, J. Raymond

    1989-09-01

    The speed, accuracy and efficiency of using laser energy to fuse together or weld living tissue makes laser tissue welding one of the most exciting areas of medical research today. Numerous investigators using animal models and several surgeons conducting clinical studies have demonstrated many promising potential applications of laser tissue welding. Accurate tissue positioning and well controlled delivery of laser energy during laser welding are essential for consistently successful laser tissue repairs. Many surgical procedures involve the creation of functional anastomoses, which are patent connections between hollow, tubular tissue structures, like bowel, blood vessels or fallopian tubes. We are developing the Exoscope SystemTM to automate and simplify the production of laser welded end-to-end and end-to-side anastomoses. Any laser light that can be passed through an optical fiber can be used in this system. The Exoscope SystemTM employs a fiber optic Exoscope Device,TM which provides for the precise placement of laser energy onto the abutted tissue seam, and a biocompatible, dissolvable intraluminal PolySurgeTM stent, which holds the tissue in circumferential apposition during lasing. The feasibility of employing the Exoscope SystemTM technique for the construction of rabbit small bowel anastomoses was successfully demonstrated in a Phase I study comparing 30 Exoscope SystemTM laser welded anastomoses to 30 conventional sutured anastomoses.

  20. Three-dimensional circumferential strain in evaluating changes of left ventricular myocardial contractional function in early chronic kidney disease patients%三维圆周应变评价早期慢性肾病患者左心室心肌收缩功能变化

    Institute of Scientific and Technical Information of China (English)

    刘开薇; 任卫东; 孙璐; 宋光; 刘慧

    2016-01-01

    目的 采用三维整体圆周应变(GCS)评价早期慢性肾病(CKD)患者左心室心肌收缩功能.方法 选取26例CKD2期患者(CKD2期组)、20例CKD3期(CKD3期组)患者及30名健康志愿者(对照组).对所有受检者行常规二维超声心动图和三维斑点追踪成像(3D-STE),测量并比较常规超声心动图指标,包括左心室舒张末期间间隔厚度(IVSTd)、左心室舒张末期内径(LVEDd)、左心室舒张末期后壁厚度(LVPWTd)、左心室舒张末期容积(EDV)和收缩末期容积(ESV),以及3D-STE指标,包括三维左心室射血分数(3D-LVEF)、三维左心室心肌质量指数(3D-LVMi)及左心室GCS.结果 与对照组比较,CKD2期组的IVSTd增大,LVEDd、GCS减小;CKD3期组的IVSTd、LVESV、3D-LVMi增大,LVEDd、3D-LVEF、GCS减小;与CKD2期组比较,CKD3期组的IVSTd、3D-LVMi增大,LVEDd、GCS减小,以上差异均有统计学意义(P均<0.05).结论 早期CKD患者左心室心肌收缩功能已减低,可通过GCS进行评价.

  1. 心肌弹性新参数的价值探讨%Preliminary study on new parameter of myocardial elasticity

    Institute of Scientific and Technical Information of China (English)

    罗向红; 李朝军; 杨娅

    2013-01-01

    Objective To discuss the value of the new parameter of myocardial elasticity derived from circumferential strain.Methods Right ventrieular apical pacing was established on the beagle dogs.Before and after pacing,the peak of early diastolic flow velocity (E peak),peak of atrial flow velocity (A peak),and the ratio of A/E were measured.The peak pressure-rise rate (+ dp/dtmax),peak pressure-fall rate (-dp/dt max),left ventricular systolic pressure(LVSP),LV diastolic pressure(LVDP)were measured by cardiac catheterization.The circumferential strain at the levels of base (CSRA),papillary (CSPM) and cardiac apex (CSAP) were measured,and the parameter of myocardial clasticity at the levels of base (EBA),papillary (EPM) and cardiac apex (EAP) were measured and calculated,respectively.Results ①After pacing,the + dp/dt and LVDP were increased,but the-dp/dtmax was decreased (P <0.05).② After pacing,the CSPM and CSAP were all decreased,but EBA,EPM,EA were all increased(P <0.05).③ The areas under the receiver operating characteristic curves (ROC) of CSAP,CSPM,EAP,EPM and EBA were all 1,and the area under the curve of CSBA was 0.687.EAB,EPM and EAP were significant negative correlation with CSPM and CSAP,but are positive correlated with A/E and LVDP (P < 0.05).Conclusions The parameter of myocardial elasticity derived from circumferential strain includes useful information about myocardial deformation and function.The new parameter can be applied to assess the diastolic function of left ventricle.%目的 初步探讨基于心肌环向应变推演的心肌弹性新参数的价值.方法 对比格犬右室心尖起搏,测量起搏前、后犬二尖瓣舒张早、晚期血流速度峰值(E峰、A峰),计算A/E;心导管检测左室内压最大上升速率(+dp/dtmax)、最大下降速率(-dp/dtmax)、心室收缩峰压(LVSP)和舒张压(LVDP).分别获取左室基底(BA)、乳头肌(PM)和心尖(AP)水平的环向应变(CSBA,CSPM,CSAP);计算左室基底(BA)、乳头

  2. Myocardial contractility

    Energy Technology Data Exchange (ETDEWEB)

    Comet, M.; Machecourt, J.

    1988-01-01

    The myocardial contractility characterizes the intensity of the activation representing the globality of the processes which lead to the formation of the sites where the strength is generated. Some parameters allowing a quantification of the contractility are measured during the isovolumic phase of the ventricular contraction: they are essentially dP/dt/sub max/, and eventually V/sub max/. For the measurement of these parameters, a pressure detector needs to be introduced into the left ventricle. Other parameters are measured during the systolic ejection phase: they are the ejection fraction, which is easy to measure and is very load dependant, and the maximal elastance. This last parameter is not easy to measure, but seems load independant. With the radioisotopes, it is possible to measure the ejection fraction and the maximal elastance. Contractility measurements are of interest in the study of ischemic cardiopathies and of valvular desease.

  3. Effect of strength matching on the reliability of welded pipe with circumferential surface crack

    Institute of Scientific and Technical Information of China (English)

    何柏林; 于影霞; 霍立兴; 张玉凤

    2004-01-01

    For different strength matching, the reliability index and failure probability of welded pressure pipe with circumferential surface crack were calculated using three dimensional stochastic finite element method. This method has overcome the shortcomings of conservative results in safety assessment with deterministic fracture mechanics method. The effects of external moment and the depth of the circumferential surface crack (a) on the reliability of pressure pipe were also calculated and discussed. The calculation results indicate that the strength matching has certain effect on the reliability of the welded pressure pipe with circumferential surface crack. The failure probability of welded pressure pipe with high strength matching is lower than that with low strength matching at the same conditions. The effects of strength matching on the failure probability and reliability index increased by adding external moment (M) and the depth of the circumferential surface crack (a).

  4. ISSLS prize winner: cost-effectiveness of two forms of circumferential lumbar fusion

    DEFF Research Database (Denmark)

    Freeman, Brian J C; Steele, Nicholas A; Sach, Tracey H;

    2007-01-01

    STUDY DESIGN: Economic evaluation alongside a prospective, randomized controlled trial from a secondary care National Health Service (NHS) perspective. OBJECTIVE: To determine the cost-effectiveness of titanium cages (TC) compared with femoral ring allografts (FRA) in circumferential lumbar spina...

  5. Circumferential Propagation of Tip Leakage Flow Unsteadiness for a Low-Speed Axial Compressor

    Institute of Scientific and Technical Information of China (English)

    Shaojuan Geng; Feng Lin; Jingyi Chen; Hongwu Zhang; Lei He

    2009-01-01

    ase shift propagating at about half of rotor rotation speed. Features of the short and long length-scale circum-ferential waves are similar to those of rotating instability and modal wave, respectively.

  6. Variation in circumferential resection margin: Reporting and involvement in the South-Netherlands

    NARCIS (Netherlands)

    Homan, J.; Bokkerink, G.M.J.; Aarts, M.J.; Lemmens, V.E.; Lijnschoten, G. van; Rutten, H.J.; Wijsman, J.H.; Nagtegaal, I.D.; Wilt, J.H.W. de

    2015-01-01

    BACKGROUND: Since the introduction of total mesorectal surgery the outcome of rectal cancer patients has improved significantly. Involvement of the circumferential resection margin (CRM) is an important predictor of increased local recurrence, distant metastases and decreased overall survival. Abdom

  7. Reduced Circumferential Resection Margin Involvement in Rectal Cancer Surgery: Results of the Dutch Surgical Colorectal Audit

    NARCIS (Netherlands)

    Gietelink, L.; Wouters, M.W.; Tanis, P.J.; Deken, M.M.; Berge, M.G. Ten; Tollenaar, R.A.; Krieken, J.H.J.M. van; Noo, M.E. de

    2015-01-01

    BACKGROUND: The circumferential resection margin (CRM) is a significant prognostic factor for local recurrence, distant metastasis, and survival after rectal cancer surgery. Therefore, availability of this parameter is essential. Although the Dutch total mesorectal excision trial raised awareness ab

  8. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  9. 应变及应变率成像技术对中老年Ⅱ型糖尿病患者心肌功能评价的研究%Strain and strain rate imaging techniques in older patients with type II diabetes myocardial function evaluation

    Institute of Scientific and Technical Information of China (English)

    丁岩; 王丽; 赵明; 胡忠春

    2015-01-01

    Objective:Explore the strain and strain rate imaging of myocardial function in elderly patients with Type II diabetes affects the situation.Methods: Select the third quarter of 2013 to the second quarter of 2014 in 52 elderly patients with diabetes type II in our hospital, and in accordance with the duration of disease were divided into Group A(≤10 years, 25 people) and B(≥15 years 27),respectively, according to the apex of two, three, four chamber facets derived tissue velocity imaging image (Tvl),after application of strain rate imaging (Strain Rate Imaging, SRI) method of left ventricular basal segments of the heart as well as the central cardiac get the strain rate curve analysis, calculated the size of the strain rate values.Results: Group A and group B comparison with the results, group A early and late diastole, peak systolic strain rate was significantly higher than that of group B. Conclusion: The strain and strain rate imaging can be more accurate evaluation of cardiac function in elderly patients with type II diabetes.%目的:探究应变及应变率成像(SRI)技术对中老年Ⅱ型糖尿病患者心肌功能的影响情况。方法:选取52例住院治疗的中老年Ⅱ型糖尿病患者,按病程长短将其分为观察组(25例)与对照组(27例),依据心尖二腔、三腔和四腔的切面得出组织速度成像图像(Tvl),运用SRI技术方法对左室基底以及心脏中部各节段心肌得到的应变率曲线进行分析,计算得出应变率值的大小。结果:观察组舒张早期和晚期、收缩期的峰值应变率明显高于对照组,两组比较具有显著差异。结论:应变及SRI可以较为准确的评价中老年Ⅱ型糖尿病患者的心肌功能。

  10. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    OpenAIRE

    Qing Wei Li; Gui Huan Yao

    2015-01-01

    A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by t...

  11. Understanding the link between circumferential dikes and eruptive fissures around calderas based on numerical and analog models

    Science.gov (United States)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-06-01

    Active calderas are seldom associated with circumferential eruptive fissures, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential fissure development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential fissures.

  12. Subclinical Cardiac Dysfunction Detected by Strain Imaging During Breast Irradiation With Persistent Changes 6 Weeks After Treatment

    International Nuclear Information System (INIS)

    Purpose: To evaluate 2-dimensional strain imaging (SI) for the detection of subclinical myocardial dysfunction during and after radiation therapy (RT). Methods and Materials: Forty women with left-sided breast cancer, undergoing only adjuvant RT to the left chest, were prospectively recruited. Standard echocardiography and SI were performed at baseline, during RT, and 6 weeks after RT. Strain (S) and strain rate (Sr) parameters were measured in the longitudinal, circumferential, and radial planes. Correlation of change in global longitudinal strain (GLS % and Δ change) and the volume of heart receiving 30 Gy (V30) and mean heart dose (MHD) were examined. Results: Left ventricular ejection fraction was unchanged; however, longitudinal systolic S and Sr and radial S were significantly reduced during RT and remained reduced at 6 weeks after treatment [longitudinal S (%) −20.44 ± 2.66 baseline vs −18.60 ± 2.70* during RT vs −18.34 ± 2.86* at 6 weeks after RT; longitudinal Sr (s−1) −1.19 ± 0.21 vs −1.06 ± 0.18* vs −1.06 ± 0.16*; radial S (%) 56.66 ± 18.57 vs 46.93 ± 14.56* vs 49.22 ± 15.81*; *P<.05 vs baseline]. Diastolic Sr were only reduced 6 weeks after RT [longitudinal E Sr (s−1) 1.47 ± 0.32 vs 1.29 ± 0.27*; longitudinal A Sr (s−1) 1.19 ± 0.31 vs 1.03 ± 0.24*; *P<.05 vs baseline], whereas circumferential strain was preserved throughout. A modest correlation between S and Sr and V30 and MHD was observed (GLS Δ change and V30 ρ = 0.314, P=.05; GLS % change and V30 ρ = 0.288, P=.076; GLS Δ change and MHD ρ = 0.348, P=.03; GLS % change and MHD ρ = 0.346, P=.031). Conclusions: Subclinical myocardial dysfunction was detected by 2-dimensional SI during RT, with changes persisting 6 weeks after treatment, though long-term effects remain unknown. Additionally, a modest correlation between strain reduction and radiation dose was observed

  13. Subclinical Cardiac Dysfunction Detected by Strain Imaging During Breast Irradiation With Persistent Changes 6 Weeks After Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Queenie [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Sydney, NSW (Australia); Hee, Leia; Batumalai, Vikneswary [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Sydney, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Allman, Christine [Liverpool Hospital, Sydney, NSW (Australia); MacDonald, Peter [University of New South Wales, Sydney, NSW (Australia); St. Vincent' s Hospital, Sydney, NSW (Australia); Delaney, Geoff P. [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Sydney, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Lonergan, Denise [Liverpool Hospital, Sydney, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Thomas, Liza, E-mail: l.thomas@unsw.edu.au [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Sydney, NSW (Australia)

    2015-06-01

    Purpose: To evaluate 2-dimensional strain imaging (SI) for the detection of subclinical myocardial dysfunction during and after radiation therapy (RT). Methods and Materials: Forty women with left-sided breast cancer, undergoing only adjuvant RT to the left chest, were prospectively recruited. Standard echocardiography and SI were performed at baseline, during RT, and 6 weeks after RT. Strain (S) and strain rate (Sr) parameters were measured in the longitudinal, circumferential, and radial planes. Correlation of change in global longitudinal strain (GLS % and Δ change) and the volume of heart receiving 30 Gy (V30) and mean heart dose (MHD) were examined. Results: Left ventricular ejection fraction was unchanged; however, longitudinal systolic S and Sr and radial S were significantly reduced during RT and remained reduced at 6 weeks after treatment [longitudinal S (%) −20.44 ± 2.66 baseline vs −18.60 ± 2.70* during RT vs −18.34 ± 2.86* at 6 weeks after RT; longitudinal Sr (s{sup −1}) −1.19 ± 0.21 vs −1.06 ± 0.18* vs −1.06 ± 0.16*; radial S (%) 56.66 ± 18.57 vs 46.93 ± 14.56* vs 49.22 ± 15.81*; *P<.05 vs baseline]. Diastolic Sr were only reduced 6 weeks after RT [longitudinal E Sr (s{sup −1}) 1.47 ± 0.32 vs 1.29 ± 0.27*; longitudinal A Sr (s{sup −1}) 1.19 ± 0.31 vs 1.03 ± 0.24*; *P<.05 vs baseline], whereas circumferential strain was preserved throughout. A modest correlation between S and Sr and V30 and MHD was observed (GLS Δ change and V30 ρ = 0.314, P=.05; GLS % change and V30 ρ = 0.288, P=.076; GLS Δ change and MHD ρ = 0.348, P=.03; GLS % change and MHD ρ = 0.346, P=.031). Conclusions: Subclinical myocardial dysfunction was detected by 2-dimensional SI during RT, with changes persisting 6 weeks after treatment, though long-term effects remain unknown. Additionally, a modest correlation between strain reduction and radiation dose was observed.

  14. Two-Dimensional Strain in the Diagnosis of Myocardial Ischemia with Normal Ventricular Wall Motion%二维应变对室壁运动正常冠心病的应用研究

    Institute of Scientific and Technical Information of China (English)

    沈燕华; 贺声; 高云华; 张云山; 李馨

    2009-01-01

    目的 应用二维应变超声心动图(2DSE)定量分析常规方法 显示室壁运动正常冠心病患者的左室收缩运动,探讨其临床应用意义.方法 采集经冠脉造影证实的38例冠心病和31例对照组患者的心尖长轴、四腔和二腔观的二维灰阶动态图像,应用二维应变软件测量左室壁各节段的收缩应变、应变率及整体长轴应变(GLS),心尖双平面Simpson 法测量左室射血分数(LVEF),比较两组参数值及分析LVEF与GLS的相关性.结果 组间比较,各项常规超声指标均无统计学差异(P>0.05),部分节段的应变、应变率及GLS有统计学差异(P0.05).Strain and strain rate have significant differences at several segments(P<0.05 or P<0.01).GLS has good correlations with LVEF (P<0.05).Conclusions 2DSE has higher sensitivity than conventional echocardiography in the diagnosis of myocardial ischemia.

  15. Change of regional myocardial function after cardiac resynchronization therapy valued by speckle tracking imaging%应用斑点追踪成像技术评价心脏再同步化治疗后局部心肌功能变化

    Institute of Scientific and Technical Information of China (English)

    张音佳; 陈悦; 王海尔; 钟春燕; 陈璐

    2012-01-01

    目的:研究慢性心力衰竭患者心脏再同步化治疗(CRT)术后局部心肌纵向、径向、圆周方向心肌收缩运动及旋转角度随时间的动态变化规律,并评估CRT术后左心室各方向收缩同步性.方法:应用斑点追踪成像技术分析15例接受CRT治疗的慢性心力衰竭患者术前、术后1周、术后3月局部心肌纵向应变、径向应变、圆周应变及旋转角度,观察纵向应变、径向应变、圆周应变及旋转角度达峰时间,获得不同方向达峰时间标准差.结果:CRT术后1周心肌纵向应变达峰时间标准差减小(P<0.05),径向、圆周、应变及旋转角度达峰时间标准差较术前无明显差异;术后3月径向应变、圆周应变、旋转角度达峰时间标准差均减小(P<0.05).术后1周心肌纵向应变及圆周应变较术前增大,径向应变及旋转角度较术前无明显差异,术后3月心肌纵向、径向、圆周应变及旋转角度均较术前明显增高(P<0.05).结论:应用斑点追踪成像技术能评价CRT术后心肌局部功能,CRT治疗有效者术后心肌局部功能恢复在心肌不同收缩方向存在动态变化过程.%Objective: To find the dynamic regional myocardial function and its systolic synchronization in patients of chronic heart failure who were treated with cardiac resynchronization therapy (CRT),The longitudinal strain radial strain,cir-cumferential strain and rotation were observed. Methods: Fifteen patients suffering from heart failure,who received CRT,were select. Speckle tracking imaging in addition to standard echocardiography were performed prior to CRT,one week and 3 months after CRT. We observed the longitudinal strain,radial strain,circumferential strain and rotation,as well as time to peak strain and peak rotation. The standard deviation of time to each peak systolic strain and rotation (Ts-sl-SD,Ts-Sr-SD,Ts-sc-SD,Ts-srot-SD)were calculated. Results: One week after CRT,the Ts-sl-SD shortened(P<0.05),but

  16. Assessment of myocardial elastography performance in phantoms under combined physiologic motion configurations with preliminary in vivo feasibility

    Science.gov (United States)

    Okrasinski, S. J.; Ramachandran, B.; Konofagou, E. E.

    2012-09-01

    Myocardial elastography (ME) is a non-invasive, ultrasound-based strain imaging technique, which can detect and localize abnormalities in myocardial function. By acquiring radio-frequency (RF) frames at high frame rates, the deformation of the myocardium can be estimated, and used to identify regions of abnormal deformation indicative of cardiovascular disease. In this study, the primary objective is to evaluate the effect of torsion on the performance of ME, while the secondary objective is to image inclusions during different motion schemes. Finally, the phantom findings are validated with an in vivo human case. Phantoms of homogeneous stiffness, or containing harder inclusions, were fixed to a pump and motors, and imaged. Incremental displacements were estimated from the RF signals, and accumulated over a motion cycle, and rotation angle, radial strain and circumferential strain were estimated. Phantoms were subjected to four motion schemes: rotation, torsion, deformation, and a combination of torsion and deformation. Sonomicrometry was used as a gold standard during deformation and combined motion schemes. In the rotation scheme, the input and estimated rotation angle agree in both the homogeneous and inclusion phantoms. In the torsion scheme, the estimated rotation angle was found to be highest, closest to the source of torsion and lowest farthest from the source of torsion. In the deformation scheme, if an inclusion was not present, the estimated strain patterns accurately depicted homogeneity, while if an inclusion was present, abnormalities were observed which enabled detection of the inclusion. In addition, no significant rotation was detected. In the combined scheme, if an inclusion was not present, the estimated strain patterns accurately depicted homogeneity, while, if an inclusion was present, abnormalities were observed which enabled detection of the inclusion. Also, torsion was separated from the combined scheme and was found to be similar to the

  17. Classification of myocardial infarction

    DEFF Research Database (Denmark)

    Saaby, Lotte; Poulsen, Tina Svenstrup; Hosbond, Susanne Elisabeth;

    2013-01-01

    The classification of myocardial infarction into 5 types was introduced in 2007 as an important component of the universal definition. In contrast to the plaque rupture-related type 1 myocardial infarction, type 2 myocardial infarction is considered to be caused by an imbalance between demand...... and supply of oxygen in the myocardium. However, no specific criteria for type 2 myocardial infarction have been established....

  18. Evaluation of regional left ventricular systolic dysfunction in patients with infarct and ischemia myocardial by speckle tracking imaging%斑点追踪成像技术评价梗死心肌和缺血心肌对左心室局部收缩功能的影响

    Institute of Scientific and Technical Information of China (English)

    覃琴; 周青; 邓倾; 朱丽敏; 郭瑞强

    2011-01-01

    Objective To assess the longitudinal, radial and circumferential systolic strain ( LS , RS , CS ) and strain rate ( LSR, RSR, CSR ) from regional myocardial in patients with myocardial infarction and ischemia by speckle tracking imaging STI ) and to evaluate regional left ventricular systolic dysfunction. Methods The high frame rate two-dimensional echocardiography were performed in the 30 patients of the myocardial infarction and 25 patients of the ischemia myocardial group and 25healthy subjects. The longitudinal and radial and circumferential systolic strain ( LS,RS , CS ) and strain rate ( LSR , RSR , CSR ) from 18 regional myocardial were measured in the apical 2-chamber view.apical 4-chamber view and three level of short-axis views mitral valve, papillary muscle and cardial apex ) by STI. Results Compared with normal segments , the LS , RS, CS and LSR, RSR, CSR of ischemia segments were decreased. LS and LSR were significantly decreased from control group ( P<0.05 ),while there were no significant differences in CS, CSR and RS, RSR ( P> 0.05 ).Compared with normal segments , LS , RS, CS and LSR, RSR, CSR of infarct segments were significantly decreased ( P<0.01 ). Conclusions Regional left ventricular systolic dysfunction could be accurately analyzed by LS, RS, CS and LSR , RSR, CSR from regional myocardial in patients with infarction and ischemia myocardial by STI. LS and LSR are more sensitive than other indices in myocardial ischemia.%目的 应用超声斑点追踪成像(STI)技术分析梗死心肌及缺血心肌节段心肌纵向、径向及周向的收缩期峰值应变及应变率,评价其对左心室局部心肌收缩功能的影响.方法 35例心肌梗死患者(梗死组)、25例心肌缺血患者(缺血组)和25例正常体检者(正常组),接受超声检查,采集左心室长轴观、心尖四腔观,心尖二腔观及左心室短轴观(二尖瓣环水平、乳头肌水平和心尖水平)二维灰阶图像,按左心室18节段划分法,

  19. Left ventricular twist and circumferential strain in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Zois, Nora Elisabeth; Olsen, N. T.; Moesgaard, S. G.;

    2013-01-01

    During the cardiac cycle, the ventricle undergoes a twisting motion because of the oblique orientation of the left ventricular (LV) myofibers. This can be quantified by speckle-tracking echocardiography (STE). In mitral regurgitation (MR) in humans, the short axis deformation has been suggested...

  20. Transient myocardial ischemia after myocardial infarction

    DEFF Research Database (Denmark)

    Mickley, H

    1995-01-01

    Ambulatory ST-segment monitoring is a relatively new device in the evaluation of myocardial ischemia. The method is unique in allowing us to continuously examine the patient over an extended period of time in a changing environmental milieu. In survivors of acute myocardial infarction...... the prevalence of ambulatory or transient myocardial ischemia is lower than in patients with chronic, stable coronary artery disease. A greater proportion of ischemic episodes, however, are silent than in other subgroups with ischemic heart disease. Early after the infarction, transient myocardial ischemia...... exhibits a circadian variation with a peak activity occurring in the late evening hours. Patients with non-Q wave infarction have more transient myocardial ischemia, whereas thrombolytic therapy seems to result in less residual ischemia. Exercise testing is more sensitive than ambulatory monitoring...

  1. 实时三维超声心动图斑点追踪技术评价正常人左心室心肌应变%Evaluation of left ventricular strain by real-time three-dimensional speckle tracking imaging in healthy adults

    Institute of Scientific and Technical Information of China (English)

    汤乔颖; 邓又斌; 黄润青; 杨好意; 王婷

    2012-01-01

    目的 评价三维超声斑点追踪技术测量正常人左室心肌应变的能力,并对心肌总应变矢量的大小和角度进行初步研究.方法 使用三维超声斑点追踪和二维超声斑点追踪技术对31例健康志愿者进行了心肌运动分析,测量左室的纵向、圆周向及径向应变,并通过纵向及圆周向应变计算心肌总应变矢量的大小及角度.结果 三维斑点追踪测得的纵向及圆周向应变在左室整体及各短轴水平均小于二维应变,而径向应变则相反.三维斑点追踪测得的心肌应变在左室不同水平间存在差异,左室中部水平的纵向、圆周向及径向应变均大于基底部及心尖部水平,而二维应变在不同水平间的差异未显示出明显规律.通过测量的纵向及圆周向应变计算得到心肌总应变矢量大小和角度,应用三维应变计算出的心肌总应变矢量绝对值在左室中部水平最大,而总应变矢量角度在不同水平间无明显差异.结论 三维斑点追踪可通过测量心肌应变对左室局部功能进行准确评价且重复性良好,具有潜在的临床应用价值.%Objective To investigate the ability of three-dimensional(3D) speckle tracking imaging (STI) for assessing left ventricular (LV) strain,and measure the value and angle of myocardial main strain vector.Methoods Longitudinal,circumferential and radial strain of LV were measured in 31 healthy adults by 3D-STI and two-dimensional(2D) STI.The main strain vector and the angle between main strain vector and the LV short-axis plane were calculated from longitudinal and circumferential strains.Results The global longitudinal,circumferential strains and strains at basal,middle,apical level of LV by 3D-STI were significantly smaller than those by 2D-STI,whereas radial strain showed an opposite trend.The 3D strains presented significant difference between different levels of LV,longitudinal,circumferential and radial 3D strains were greater at

  2. 应变及应变率的速度向量成像定量分析诊断猪心肌挫伤%Diagnosis of Early Myocardial Contusion in Pigs by Velocity Vector Imaging and Quantitative Analysis of Strain and Strain Rate

    Institute of Scientific and Technical Information of China (English)

    王小燕; 王莎莎; 李叶阔; 朱贤胜; 程琦; 罗国新

    2010-01-01

    目的 探讨应变(strain,ε)、应变率(strain rate,SR)的速度向量成像(velocity vector imaging,VVI)定量分析对猪心肌挫伤(myocardial contusion,MC)的早期诊断价值.方法 建立8只猪MC模型.分别于撞击前及撞击后0.5、2、4、8 h,采集左室二尖瓣、乳头肌、心尖水平短轴切面VVI动态图像,利用VVI脱机分析软件获得左室短轴各节段径向峰值ε、SR.结果 撞击后MC节段左室径向峰值ε及SR测值低于撞击前(P<0.05),损伤节段的径向峰值ε及SR测值低于非损伤节段(P<0.05).结论 VVI技术能够定量评价MC后室壁运动异常,为MC早期诊断提供了新方法.

  3. Acute myocardial infarct imaging

    International Nuclear Information System (INIS)

    A brief review is presented of radiopharmaceuticals used for imaging acute myocardial infarction and instrumentation using the rectilinear scanner and the scintillation camera. Clinical experience indicates that myocardial imaging with /sup 99 m/Tc pyrophosphate is a useful adjunct to the electrocardiogram and serum enzyme activity in managing patients with myocardial infarction. The technique allows rapid diagnosis, accurate localization, and an estimate of the size of acute infarcts. It can also be used to document infarct extension and in association with myocardial perfusion imaging can help differentiate fresh from old myocardial infarction

  4. Numerical investigation of a centrifugal compressor with circumferential grooves in vane diffuser

    Science.gov (United States)

    Chen, X. F.; Qin, G. L.; Ai, Z. J.

    2015-08-01

    Enhancing stall and surge margin has a great importance for the development of turbo compressors. The application of casing treatment is an effective measure to expand the stall margin and stable operation range. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with circumferential groove casing treatment in vane diffuser. Numerical cases with different radial location, radial width and axial depth of a circumferential single groove and different numbers of circumferential grooves were carried out to compare the results. The CFD analyses results show that the centrifugal compressor with circumferential grooves in diffuser can extend stable range by about 9% while the efficiency over the whole operating range decreases by 0.2 to 1.7%. The evaluation based on stall margin improvement showed the optimal position for the groove to be located was indicated to exist near the leading edge of the diffuser, and a combination of position, width, depth and numbers of circumferential grooves that will maximize both surge margin range and efficiency.

  5. Speckle tracking imaging in evaluation of myocardial middle strain in hypertension patients%二维斑点追踪成像评价高血压患者心肌中层应变

    Institute of Scientific and Technical Information of China (English)

    程辉; 王欢

    2015-01-01

    目的 应用二维超声斑点追踪成像(STI)技术检测高血压患者左室心肌内、中、外层组织应变特征,探讨心肌中层应变在高血压患者左室收缩功能评价中的价值,为早期诊断及治疗高血压心肌病变提供依据.方法 78例原发性高血压患者,根据左室肥厚诊断标准分为A组(无左室肥厚组,41例)、B组(左室肥厚组,37例),30例健康志愿者作为对照组.取左室短轴乳头肌水平切面,将室壁平均分为三层,即内膜层、中间心肌层、外膜层.获取各组各层心肌圆周应变(SSC)峰值.结果 各组心肌收缩期峰值应变内膜层>中间心肌层>外膜层(P middle myocardium > epicardial layer (P<0.05). Group A had higher middle myocardium SSC peak value than control group (P<0.05), and group B had lower endocardial layer than group A and control group (P<0.05).Conclusion Myocardial middle strain contains important clinical significance for diagnosis of early left ventricular systolic dysfunction in hypertension patients.

  6. Heart deformation analysis: measuring regional myocardial velocity with MR imaging.

    Science.gov (United States)

    Lin, Kai; Collins, Jeremy D; Chowdhary, Varun; Markl, Michael; Carr, James C

    2016-07-01

    The aim of the present study was to test the hypothesis that heart deformation analysis (HDA) may serve as an alternative for the quantification of regional myocardial velocity. Nineteen healthy volunteers (14 male and 5 female) without documented cardiovascular diseases were recruited following the approval of the institutional review board (IRB). For each participant, cine images (at base, mid and apex levels of the left ventricle [LV]) and tissue phase mapping (TPM, at same short-axis slices of the LV) were acquired within a single magnetic resonance (MR) scan. Regional myocardial velocities in radial and circumferential directions acquired with HDA (Vrr and Vcc) and TPM (Vr and VФ) were measured during the cardiac cycle. HDA required shorter processing time compared to TPM (2.3 ± 1.1 min/case vs. 9.5 ± 3.7 min/case, p TPM could be found on multiple myocardial segments (r = 0.460-0.774) and slices (r = 0.409-0.814) with statistical significance (p TPM were also noticed. By providing comparable velocity measures as TPM does, HDA may serve as an alternative for measuring regional myocardial velocity with a faster image processing procedure. PMID:27076222

  7. A study on nondestructive evaluation techniques for composite motors cases using circumferential waves

    International Nuclear Information System (INIS)

    For structural integrity evaluation of composite rocket motor cases, acoustic emission (AE) during hydroproof test is currently used. For the suitable performance of this test, it is very important to determine the optimal component of elastic waves to be monitored. In this study, the optimal component of circumferential wave that propagate in the circumferential direction of the composite motor case has been determined experimentally. Then its potential to be served as a robust tool for nondestructive evaluation of composite motor cases was demonstrated by investigating the initial performances for flaw detection and AE source location.

  8. An analysis of the Circumferential Grooves Casing Treatment for transonic compressor flow

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.

  9. Molecular Modeling of the Axial and Circumferential Elastic Moduli of Tubulin

    OpenAIRE

    Zeiger, A. S.; Layton, B. E.

    2008-01-01

    Microtubules play a number of important mechanical roles in almost all cell types in nearly all major phylogenetic trees. We have used a molecular mechanics approach to perform tensile tests on individual tubulin monomers and determined values for the axial and circumferential moduli for all currently known complete sequences. The axial elastic moduli, in vacuo, were found to be 1.25 GPa and 1.34 GPa for α- and β-bovine tubulin monomers. In the circumferential direction, these moduli were 378...

  10. 二维斑点追踪成像评价新生猪缺氧缺血性脑病模型受损心肌圆周运动%Assessing Circumferential Motion of Damaged Myocardium in Newborn Pigs with Hypoxic-ischemic Encephalopathy Using Speckle Tracking Imaging

    Institute of Scientific and Technical Information of China (English)

    乔伟; 任卫东; 肖杨杰; 毕文静; 李红; 王晓明

    2013-01-01

    . After 24 hours, the peak value of circumferential strain (SC) and circumferential strain rate (SrC S, SrC E, SrC A) at each level were measured using STI, and the heart rate (HR), LVEF, Tei index were also measured. The pathological slices of the myocardium and brain were analyzed. Results Cyanosis, convulsions and neck stiffness were observed in experimental group; no abnormality was seen in the control group. Brain neurons cells were intact in control group while degeneration and necrosis were found in the experimental group to confirm successful modeling. Compared with the control group, SC, SrC S, SrC E, SrC A of each level and LVEF were decreased, while HR and Tei index were increased in the experimental group (P<0.05). In the experimental group, degeneration, necrosis and apoptosis were found in some myocardial cells but intact and well defined in the control group. Conclusion Decreased circumferential motion and heart function in the early stage of HIE model is consistent with pathology. It is a reliable method to evaluate the newborn pigs' with HIE and myocardial damage, and it can provide experimental study for researching HIE combined with myocardial damage in newborns.

  11. 超声二维斑点追踪技术定量评价尿毒症患者心肌功能%Quantitative evaluation of myocardial function in patients with uremia by two-dimensional speckle tracking echocardiography

    Institute of Scientific and Technical Information of China (English)

    张梅青; 王秋霜; 黄党生; 安秀芝; 姬冬冬; 王淑华; 郭家瑞

    2011-01-01

    目的:探讨应用超声二维斑点追踪技术(STI)定量评价尿毒症患者心肌功能的价值.方法:尿毒症组(n=45)和健康对照组(n=38)分别行超声心动图,据左室射血分数(LVEF)将尿毒症组分为心功能正常组(n=29,LVEF≥50%)和心功能减退组(n=16,LVEFG50%),应用STI技术测量左室心肌各节段收缩期峰值应变,并计算出心肌整体纵向应变(LS)、径向应变(RS)及圆周应变(CS).结果:与健康对照组相比,心功能正常组及心功能减退组室间隔、左室后壁明显增厚,左房内径增大(P<0.01);心肌应变比较,心功能正常组与健康对照组相比,心肌整体LS、CS均明显减低(P<0.01).心功能减退组较心功能正常组应变进一步降低(P<0.05).结论:超声二维纵向、径向及圆周应变能够早期准确评价尿毒症患者心肌功能,其中纵向、径向应变较LVEF更早的发现心肌功能的减低.%Objective: To evaluate the accuracy and value of the two-dimensional speckle tracking imaging Echocardiography (STI) quantirative measurement of global systolic function in cardiac patients with uremia. Methods: Rourine parameters were determined by echocardiography in 45 uremic patients and 38 healthy controls. According to the left ejection fraction (LVEF) , the uremic group was divided into normal cardiac uremia group (n= 29 , LVEF ≥50% ) and cardiac dysfunction group (n= 16, LVEF <50%). We measured left ventricular myocardial sections of peak systolic strain by STI.and calculated the cardiac global longitudinal strain, radial strain and circumferential strain. Results: Compared with healthy control group, ventricular wall thickness, left atrium diameter were significantly different in Normal cardiac group and cardiac dysfunction group; Compared with healthy control group, the global longitudinal myocardial strain, circumferential strain were significantly lower ( P <0.01) , cardiac dysfunction group compared with normal cardiac function

  12. Determination of the minimum number exposures in radiographic examination of circumferential welds

    International Nuclear Information System (INIS)

    Certain specifications require that, in the radiography of circumferential welds, the penetrated thickness at the side of the beam should not exceed the wall thickness by more than a given percentage. A mathematical solution is presented, which shows the minimum number of exposures in accurate and easy-to-read diagrams suitable for use by field radiographers. (orig.)

  13. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Science.gov (United States)

    2010-10-01

    ..., tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel Code... 46 Shipping 2 2010-10-01 2010-10-01 false Circumferential joints in pipes, tubes and headers...) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding §...

  14. Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter.

    Science.gov (United States)

    Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Liang, Kaicheng; Wang, Zhao; Cleveland, Cody; Booth, Lucas; Potsaid, Benjamin; Jayaraman, Vijaysekhar; Cable, Alex E; Mashimo, Hiroshi; Langer, Robert; Traverso, Giovanni; Fujimoto, James G

    2016-08-01

    We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec. Volumetric data consisting of 4200 circumferential images of 5,000 A-scans each over a 2.6 cm length, covering a ~13 cm(2) area is acquired in <18 seconds. A non-rigid image registration algorithm is used to suppress motion artifacts from non-uniform rotational distortion (NURD), cardiac motion or respiration. En face OCT images at various depths can be generated. OCT angiography (OCTA) is computed using intensity decorrelation between sequential pairs of circumferential scans and enables three-dimensional visualization of vasculature. Wide area volumetric OCT and OCTA imaging of the swine esophagus in vivo is demonstrated.

  15. Optimization of the axial compressor flow passage to reduce the circumferential distortion

    Science.gov (United States)

    Popov, G.; Kolmakova, D.; Shklovets, A.; Ermakov, A.

    2015-08-01

    This work is motivated by the necessity to reduce the effects of the flow circumferential distortion in the flow passage of the aircraft gas turbine engine (GTE). In previous research, the authors have proposed the approaches to decrease of the flow circumferential distortion arising from the mid-support racks of GTE compressor and having a negative impact on the blade rows, located upstream. In particular, the idea of introducing the circumferentially non-uniform blade pitch and profile stagger angle of guide vanes located in front of the support was contributed in order to redistribute the flow and decrease the dynamic stresses in the rotor wheel of the same stage. During the research presented in this paper, another principal of reduction of the flow circumferential distortion was chosen. Firstly, the variants of upgrading the existing support racks were found. Secondly, the new design of support was offered. Both the first and the second version of the support design variation took into account the availability of technological and structural limitations associated with the location of oil pipes, springs and others elements in the support racks. Investigations of modified design showed that the support with altered racks provides a reduction of dynamic stresses by 20% at resonance with the most dangerous harmonic, and the new design of support can give the decrease of 30%.

  16. Conventional CT for the prediction of an involved circumferential resection margin in primary rectal cancer

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; Span, Mark M.; van de Jagt, Eric J.; van de Velde, Cornelis J. H.; Wiggers, Theo

    2007-01-01

    Purpose: To determine the accuracy of conventional computed tomography (CT) scan in the preoperative prediction of an involved circumferential resection margin (CRM) in primary rectal cancer. Methods: 125 patients with biopsy-proven adenocarcinoma of the rectum underwent CT of the abdomen before und

  17. Modification of the ASME code z-factor for circumferential surface crack in nuclear ferritic pipings

    International Nuclear Information System (INIS)

    The purpose of this paper is to modify the ASME Code Z-Factor, which is used in the evaluation of circumferential surface crack in nuclear ferritic pipings. The ASME Code Z-Factor is a load multiplier to compensate plastic load with elasto-plastic load. The current ASME Code Z-Factor underestimates pipe maximum load. In this study, the original SC. TNP method is modified first because the original SC. TNP method has a problem that the maximum allowable load predicted from the original SC. TNP method is slightly higher than that measured from the experiment. Then the new Z-Factor is developed using the modified SC. TNP method. The desirability of both the modified SC. TNP method and the new Z-Factor is examined using the experimental results for the circumferential surface crack in pipings. The results show that (1) the modified SC. TNP method is good for predicting the circumferential surface crack behavior in pipings, and (2) the Z-Factor obtained from the modified SC. TNP method well predicts the behavior of circumferential surface crack in ferritic pipings. 30 refs., 13 figs., 4 tabs. (author)

  18. Impact of different graded coronary stenosis on myocardial perfnsion and function by two-dimensional strain echocardiography combined with myocardial contrast echocardiography%二维应变超声心动图结合实时心肌超声造影评价冠状动脉不同狭窄程度对心肌灌注和心功能的影响

    Institute of Scientific and Technical Information of China (English)

    李燕; 吕清; 王静; 张艳容; 陈明; 张静; 方凌云

    2009-01-01

    目的 应用二维应变超声心动图(2D-Strain)结合实时心肌超声造影(MCE)评价静息状态下冠状动脉(冠脉)不同程度狭窄患者局部心肌血流灌注和应变的变化及两者之间的关系.方法 对25例冠心病患者及15例健康志愿者行MCE和2D-Strain检查.血供异常的心肌节段按供血冠狭窄程度分为轻度狭窄组(50%~75%)、中度狭窄组(76%~89%)和重度狭窄组(≥90%).从MCE再灌注允盈曲线获得A值和β值分析心肌灌注;应用2D-Strain测量心肌纵向收缩期峰值应变(SL)分析心功能.结果 在异常冠脉供血区,随着冠脉狭窄程度的加重;各组的A值与对照组相比呈递减趋势,但差异无统计意义(P>0.05);而中度狭窄组和重度狭窄组的β值和SL值均显著低于对照组(β值:0.75±0.67和0.67±0.53对0.97±0.65;SL值:11.60±5.89和9.58±6.51对19.46±6.17,均P75%的冠脉狭窄引起的心肌缺血,且两者具有较好的相关性.%Objective To estimate the impact of various extent of coronary stenosis at rest on myocardial perfusion and functional indices from myocardial contrast echocardiography(MCE) and two-dimensional strain echocardiography(2D-Strain) and characterize the relationship between them. Methods Three levels of coronary stenosis:mild (50%~75%),moderate (76%~89%),severe (≥90%) in 25 patients with coronary artery stenosis and 15 healthy subjects in the control group were examined. Plateau videointensity (value A) and time to plateau (value β) of the replenishment curve from MCE were calculated for perfusion analysis,and longitudinal peak systolic strain(SL) from 2D-Strain were measured for functional analysis. Results Value A tended to decrease with increasing severity of stenosis,ahhough these differences did not reach the level of statistical significance, β and SL were significantly increased in the context of moderate and severe coronary stenosis when compared with control group (β, moderate 0.75±0.67 and severe 0.67±0

  19. A method for measuring mean circumferential fiber shortening rate from gated blood pool scans

    International Nuclear Information System (INIS)

    Ejection fraction and ejection rate are easily obtained from gated cardiac images, but no method is available for calculating mean circumferential fiber shortening rate. We assumed that the cube root of left ventricular end-diastolic volume or counts is proportional to the minor axis of the left ventricle at end-diastole or end-systole. Mean circumferential fiber shortening rate is then equal to the [cube root of the end-diastolic volume (count) minus cube root of end-systolic volume (count)] divided by [cube root of end-diastolic volume (count) multiplied by the ejection time]. In 250 contrast ventriculograms, the standard mean circumferential fiber shortening rate (MCFSR) and that derived by the cube root method correlated well (r = 0.94). The mean value of MCFSR (0.85 +- 0.35) was greater than the cube root value (0.75 +- 0.35) (P < 0.001). The regression equation was y = 0.86x + 0.02. Similar correlations were obtained from gated radionuclide images using a semiautomated program (r = 0.93) in 24 subjects or completely automated program (r = 0.85) in 28 patients. The regression equation between MCFSR and that derived from the cube root of counts for the semiautomated program was y = 0.82x + 0.04 and for the automated program was y = 0.84x + 0.004. Similar correlations, slopes, and intercepts were seen using circumferential fractional shortening for angiographic data when correlated with both the semiautomated and automated gated blood pool scan programs. These data indicate that MCFSR and circumferential fractional shortening may be obtained from gated blood pool images using cube root estimates of end-diastolic and end-systolic radii with a high degree of correlation with the standard contrast ventriculographic technique. (orig.)

  20. PERIOPERATIVE MYOCARDIAL INFRACTION

    Directory of Open Access Journals (Sweden)

    Ravindra S

    2015-10-01

    Full Text Available Perioperative myocardial ischaemia and infarction (PMI is a major cause of short and long term morbidity and mortality in the surgical population. It is estimated that more than one half of postoperative deaths are caused by cardiac events, most of which are ischaemic in origin. Over 50,000 patients each year sustain a perioperative MI . Thus prevention of a PMI is important to improve overall postoperative outcome. Myocardial ischaemia is a dual state composed of inadequate myocardial oxygenation and accu mulation of anaerobic metabolites and occurs when myocardial oxygen demand exceeds the supply. Myocardial infarction is defined as the death of myocardial myocytes due to prolonged ischaemia. In patients with, or at risk of coronary artery disease (CAD, t he reported incidence of perioperative myocardial ischaemia is 20 - 63%. Various studies have shown that postoperative myocardial ischaemia was consistently found to occur considerably more often than preoperative and intraoperative ischaemia ( R atio approxim ately 3:1 and 5:1 respectively. As more and more patients coming for non - cardiac surgeries who have already undergone coronary intervention such as balloon angioplasty, stenting or CABG, we as anaesthesiologists should have thorough knowledge of the perio perative implications of the same in a day to day practice. Secondly, as the geriatric population is increasing there are more chances of encountering patients with known or unknown ischaemic heart disease both on an emergency and elective basis.

  1. Estimation of infarct size by three-dimensional surface display method of myocardial single photon emission CT with /sup 201/Tl

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Masahiro; Tsuda, Takatoshi; Akiba, Hidenari; Morita, Kazuo; Hosoba, Minoru; Ban, Ryuichi; Hirano, Takako

    1987-11-01

    To estimate infarct size, we devised three-dimensional (3D) surface display method of /sup 201/Tl myocardial single photon emission CT (SPECT). The method was performed with maximum-count circumferential profiles (CPs) of short axis views of /sup 201/Tl myocardial SPECT. The counts of maximum-count CP were put into a pixel line with the calculated left ventricular circumferential length on each short axis slice. A 3D-surface display map was created by arrangement of these pixel lines from apex to base of left ventricle in order. The sizes of defects in myocardial phantom were calculated by this method. There was a high correlation between the real defect sizes and the calculated defect sizes. In 6 patients with anterior myocardial infarction, the infarct sizes were calculated by this method. The extent of abnormality was identified by automatic computer comparison of each patient's profiles with corresponding lower limits of normal profiles. The infarct sizes calculated by 3D-surface display method were closely correlated not only with the infarct sizes calculated by summation of defect sizes in short axis views, but also with left ventricular ejection fractions. We concluded that the 3D-surface display method of /sup 201/Tl myocardial SPECT is effective for noninvasive assessment of the extent of myocardial infarction.

  2. Angle-independent myocardial elastography: theoretical analysis and clinical validation

    Science.gov (United States)

    Konofagou, Elisa E.; Lee, Wei-Ning; Fung-kee-Fung, Simon D.

    2007-03-01

    Several methods have been introduced in the past few years to quantify left-ventricular strain in order to detect myocardial ischemia and infarction. Myocardial Elastography is one of these methods, which is based on ultrasound Radio-Frequency (RF) signal processing at high frame rates for the highest precision and resolution of strain estimation. Myocardial elastography estimates displacement and strain during the natural contraction of the myocardium using cross-correlation techniques. We have previously shown that imaging of the myocardial strain at high precision allows the correct assessment of the contractility of the cardiac muscle and thus measurement of the extent of ischemia or infarct. In this paper, for the first time in echocardiography, we show how angle-independent techniques can be used to estimate and image the mechanics of normal and pathological myocardia, both in simulations and in vivo. First, the fundamental limits of 2D normal and principal strain component estimation are determined using an ultrasound image formation model and a 2D short-axis view of a 3D left-ventricular, finite-element model, in normal and ischemic configurations. Two-dimensional (i.e., lateral and axial) cumulative displacement and strain components were iteratively estimated and imaged using 1D cross-correlation and recorrelation techniques in a 2D search. Validation of these elastographic findings in one normal human subject was performed. Principal strains were also imaged for the characterization of normal myocardium. In conclusion, the feasibility of angle-independent, 2D myocardial elastography technique was shown through the calculation of the in-plane principal strains, which was proven essential in the reliable depiction of strains independent of the beam-tissue angle or the type of sonographic view used.

  3. The myocardial ischemia evaluated by real-time contrast echocardiography may predict the response to cardiac resynchronization therapy: a large animal study.

    Directory of Open Access Journals (Sweden)

    Yongle Chen

    Full Text Available Evidence-based criteria for applying cardiac resynchronization therapy (CRT in patients with ischemic cardiomyopathy are still scarce. The aim of the present study was to evaluate the predictive value of real-time myocardial contrast echocardiography (RT-MCE in a preclinical canine model of ischemic cardiomyopathy who received CRT. Ischemic cardiomyopathy was produced by ligating the first diagonal branch in 20 beagles. Dogs were subsequently divided into two groups that were either treated with bi-ventricular pacing (CRT group or left untreated (control group. RT-MCE was performed at baseline, before CRT, and 4 weeks after CRT. Two-dimensional speckle tracking imaging was used to evaluate the standard deviation of circumferential (Cir12SD, radial (R12SD, and longitudinal (L12SD strains of left ventricular segments at basal as well as middle levels. Four weeks later, the Cir12SD, R12SD, and myocardial blood flow (MBF of the treated group were significantly improved compared to their non-CRT counterparts. Furthermore, MBF values measured before CRT were significantly higher in responders than in non-responders to bi-ventricular pacing. Meanwhile, no significant differences were observed between the responder and non-responder groups in terms of Cir12SD, R12SD, and L12SD. A high degree of correlation was found between MBF values before CRT and LVEF after CRT. When MBF value>24.9 dB/s was defined as a cut-off point before CRT, the sensitivity and specificity of RT-MCE in predicting the response to CRT were 83.3% and 100%, respectively. Besides, MBF values increased significantly in the CRT group compared with the control group after 4 weeks of pacing (49.8±15.5 dB/s vs. 28.5±4.6 dB/s, p<0.05. Therefore, we considered that myocardial perfusion may be superior to standard metrics of LV synchrony in selecting appropriate candidates for CRT. In addition, CRT can improve myocardial perfusion in addition to cardiac synchrony, especially in the setting

  4. Acute myocardial infarction:myocardial salvage assessment

    Institute of Scientific and Technical Information of China (English)

    NSENGIYUMVA Pierre; CHEN Li-juan; MA Gen-shan

    2015-01-01

    Primary coronary revascularization by means of percutaneous coronary intervention ( PCI) is a highly ef-fective treatment of acute myocardial infarction re-establishing coronary perfusion and stopping the ongoing necrosis in the dependent myocardium .Single-photon emission computed tomography ( SPECT) is the most widely used mo-dality assessing myocardial salvage as the difference between the acute perfusion defect before intervention and the remaining scar size measured in a second scan several days after the event .SPECT allows quantification of area at risk( AAR) and final infarct size ( FIS) by tracer injection prior to revascularization and after 1 month, respective-ly.SPECT provides the most validated measure of myocardial salvage and has been utilized in multiple randomized clinical trials.However, SPECT is logistically challenging , expensive, and includes radiation exposure .More re-cently, a large number of studies have suggested that cardiac magnetic resonance ( CMR) can determine salvage in a single examination by combining measures of myocardial oedema in the AAR exposed to ischaemia reperfusion with FIS quantification by late gadolinium enhancement .

  5. Analysis of dispersion characteristics of circumferential guided waves and detection of axial cracks in pipe

    International Nuclear Information System (INIS)

    A circumferential guided wave method was developed to detect the axial crack on the but feeder pipe. Dispersion curves of circumferential guided waves were calculated as a function of curvature of the pipe. In the case of thin plate, i. e. infinite curvature, as the frequency increases, the S0 and A0 become to be coincided and eventually Rayleigh wave mode. In the case of pipe, however, as the curvature increases, the lowest modes do not coincide even in the high frequencies. Based on the analysis, a rocking technique using angle beam transducer was applied to detect axial defect in the bent region of PHWR feeder pipe. After review of the experimental data on the artificial notches, the vibration modes of each signal were identified. It was found that the notches with the depth of 10% of wall thickness be detected with the method.

  6. Circumferential-wave phase velocities for empty, fluid-immersed spherical metal shells

    DEFF Research Database (Denmark)

    Überall, Herbert; Ahyi, A. C.; Raju, P. K.;

    2002-01-01

    In earlier studies of acoustic scattering resonances and of the dispersive phase velocities of surface waves that generate them [see, e.g., Talmant et al., J. Acoust. Soc. Am. 86, 278–289 (1989) for spherical aluminum shells] we have demonstrated the effectiveness and accuracy of obtaining phase...... results with those calculated from three-dimensional elasticity theory whenever the latter are available. The present investigation is based on the mentioned resonance frequency/elasticity theory connection, and we obtain comparative circumferential-wave dispersion-curve results for water......-loaded, evacuated spherical metal shells of aluminum, stainless steel, and tungsten carbide. In particular, the characteristic upturn of the dispersion curves of low-order shell-borne circumferential waves (A or A0 waves) which takes place on spherical shells when the frequency tends towards very low values, is...

  7. Guided waves based diagnostic imaging of circumferential cracks in small-diameter pipe.

    Science.gov (United States)

    Liu, Kehai; Wu, Zhanjun; Jiang, Youqiang; Wang, Yishou; Zhou, Kai; Chen, Yingpu

    2016-02-01

    To improve the safety and reliability of pipeline structures, much work has been done using ultrasonic guided waves methods for pipe inspection. Though good for evaluating the defects in the pipes, most of the methods lack the capability to precisely identify the defects in the pipe features like welds or supports. Therefore, a novel guided wave based cross-sectional diagnostic imaging algorithm was developed to improve the ability of circumferential cracks identification in the pipe features. To ensure the accuracy of the imaging, an angular profile-based frequency selection method is presented. As validation, the approach was employed to identify the presence and location of a small circumferential crack with 1.13% cross sectional area (CSA) in the welding zone of a 48 mm diameter type 304 stainless steel pipe. Accurate identification results have demonstrated the effectiveness of the developed approach. PMID:26548527

  8. Low cycle fatigue of pressurized pipes with circumferential flaws under cyclic bending moment

    International Nuclear Information System (INIS)

    Pipes of 706 mm inner diameter, 47 mm wall thickness and about 5,000 mm in length were provided with circumferential surface cracks and loaded by internal pressure of 15 MPa whilst being simultaneously subjected to an alternating external bending moment. Usually a load ratio R of -1 (Mmin/Mmax), in one case R = 0.1, was applied. The pipes were fabricated of two types of ferritic steel: one, grade 20 MnMoNi 5 5, with a high upper shelf impact energy of about 200 J and one, MnMoNiV-special melt, with a low upper shelf impact energy of about 60 J. Deformation and crack growth in the wall thickness and circumferential direction were determined and compared with calculated values. 9 refs., 13 figs

  9. Crack resistance of austenitic pipes with circumferential through-wall cracks

    International Nuclear Information System (INIS)

    For monotonously increasing load the correct evaluation of the crack resistance properties of a structure is essential for safety analyses. Considerable attention has been given to the through-wall case, since this is generally believed to be the controlling case with regard to complete pipe failure. The maximum load conditions for circumferential crack growth in pipes under displacement-controlled loadings has been determined. The need for crack resistance curves, measured on circumferentially through-wall cracked straight pipes of austenitic stainless steel 316L under bending, is emphasized by the limitation in the data range on small specimens and by the differences in the procedures. To answer open questions and to improve calculational methods a joint fracture mechanics program is being performed by Electricite de France, Novatome and Siemens-Interatom. The working program contains experimental and theoretical investigations on the applicability of small-specimen data to real structures. 10 refs., 10 figs., 4 tabs

  10. Circumferential mucosal dissection and esophageal perforation in a patient with eosinophilic esophagitis

    Institute of Scientific and Technical Information of China (English)

    Gennaro Liguori; Maurizio Cortale; Fabrizio Cimino; Michele Sozzi

    2008-01-01

    A young man with a previous history of episodes of mild solid food dysphagia was admitted with a total dysphagia.The esophagogastroduodenoscopy (EGDS) showed an extensive disruption of mucosal layer with a cul-de-sac in the lower part of the esophagus.Soon after the procedure,the patient suffered from an acute chest pain and subsequent CT scan demonstrated an intramural circumferential dissection of thoracic esophagus,and a mediastinal emphysema.An emergency right thoracotomy was performed,followed by a total esophagectomy with esophagogastroplasty and jejunostomy.The histopathology confirmed that mucosal and submucosal layers were circumferentially detached from muscular wall and showed an eosinophilic infiltration of the whole organ with necrosis and erosions of mucosal,submucosal and muscular layers.The diagnosis was esophageal perforation in eosinophilic esophagitis.

  11. Is Circumferential Minimally Invasive Surgery Effective in the Treatment of Moderate Adult Idiopathic Scoliosis?

    OpenAIRE

    Anand, Neel; Baron, Eli M.; Khandehroo, Babak

    2014-01-01

    Background Outcomes for minimally invasive scoliosis correction surgery have been reported for mild adult scoliosis. Larger curves historically have been treated with open surgical procedures including facet resections or posterior column osteotomies, which have been associated with high-volume blood loss. Further, minimally invasive techniques have been largely reported in the setting of degenerative scoliosis. Questions/purposes We describe the effects of circumferential minimally invasive ...

  12. Numerical Investigation of Inlet Distortion on an Axial Flow Compressor Rotor with Circumferential Groove Casing Treatment

    Institute of Scientific and Technical Information of China (English)

    Huang Jian; Wu Hu

    2008-01-01

    On the base of an assumed steady inlet circumferential total pressure distortion, three-dimensional time-dependent numerical simulations are conducted on an axial flow subsonic compressor rotor. The performances and flow fields of a compressor rotor, either casing treated or untreated, are investigated in detail either with or without inlet pressure distortion. Results show that the circumferential groove casing treatment can expand the operating range of the compressor rotor either with or without inlet pressure distortion at the expense of a drop in peak isentropic efficiency. The casing treatment is capable of weakening or even removing the tip leakage vortex effectively either with or without inlet distortion. In clean inlet circumstances, the enhancement and forward movement of tip leakage vortex cause the untreated compressor rotor to stall. By contrast, with circumferential groove casing, the serious flow separation on the suction surface leads to aerodynamic stalling eventually. In the presence of inlet pressure distortion, the blade loading changes from passage to passage as the distorted inflow sector is traversed. Similar to the clean inlet circumstances, with a smooth wall casing, the enhancement and forward movement of tip leakage vortex are still the main factors which lead to the compressor rotor stalling eventu-ally. When the rotor works under near stall conditions, the blockage resulting from the tip leakage vortex in all the passages is very seri-ous. Especially in several passages, flow-spillage is observed. Compared to the clean inlet circumstances, circumferential groove casing treatment can also eliminate the low energy zone in the outer end wall region effectively.

  13. Selective radiofrequency therapy as a non-invasive approach for contactless body contouring and circumferential reduction.

    Science.gov (United States)

    Fajkošová, Kateřina; Machovcová, Alena; Onder, Meltem; Fritz, Klaus

    2014-03-01

    In this study, the efficacy of non-contact, selective radiofrequency (RF) were evaluated for body contouring as non-invasive fat and circumferential reduction of the abdomen. 40 healthy (36 female, 4 male) subjects showing significant volume of subcutaneous fat tissue on the abdomen and waistline were included. Once a week for 30 minutes, 4 sessions were performed. The applicator was placed on a supplied spacer covering the treatment area. Maximum power was 200W, which induced heat in the fat and connective tissue layer. The homogeneity of heat distribution and temperature of the skin surface were controlled. The circumferential reduction was measured at the baseline and after the last treatment. The photographs and adverse effects were recorded. Participants completed the self-evaluation questionnaires and rated their level of satisfaction. All subjects tolerated the treatments well. The only side effect was mild to moderate erythema. 35 subjects finished the protocol as planned and 5 subjects dropped off due to events not related to the study. 32 subjects had a 1-13 cm decrease in abdominal circumference and 3 subjects did not show significant response (0-1 cm). Most likely, a very thin fat layer was the reason for lack of response (the non-responding group was the thinnest patient group). No significant differences were found between men and women. The average decrease of 4.93 cm was calculated as a result of circumferential reduction statistical evidence. This study demonstrates that the selective RF system designed for contactless deep tissue heating is a painless, safe, and effective treatment for non-surgical body contouring and circumferential fat reduction.

  14. Evaluation of right ventricular systolic function in patients with right ventricular myocardial infarction by ultrasound tissue tracking and strain rate imaging%组织追踪和应变率显像技术评价右室心肌梗死患者右室收缩功能

    Institute of Scientific and Technical Information of China (English)

    卢永昭; 谭深; 闫丽娟; 赵君智; 张景峰; 麦兴盛; 左鹏飞; 张耀仁

    2011-01-01

    Objective To explore the clinical application value of ultrasound tissue tracking( TTI) and strain rate imaging( SRI) in diagnosis of right ventricular myocardial infarction and evaluating right ventricular systolic function. Methods Twenty patients with acute right ventricular myocardial infarction and 24 healthy controls were enrolled in this study, Their right ventricular apical two chamber view and apical four chamher view were examined by TTI and SRI. The peak systolic displacement( PDS) of right ventricular anterior, inferior wall, lateral wall and the maximum systolic strain rate ( SSR) were detected. Results The PDS and SSR in patients with right ventricular myocardial infarction were lower than those in control group (P <0. 05 ) , and the diagnostic sensitivity of SSR was higher than PDS( P <0. 05 ) . Conclusion TTI and SRI can accurately diagnose right ventricular myocardial infarction,and can quantitatively evaluate the right ventricular systolic function.%目的 探讨超声组织追踪(TTI)和应变率显像(SRI)技术在诊断右室壁心肌梗死和评价右室局部收缩功能中的临床应用价值.方法 采用TTI和SRI技术对20例急性右室梗死患者和24例健康对照者的右室心尖两腔心切面和四腔心切面进行扫查,检测分析右室前壁、下壁、侧壁收缩期峰值位移值(PDS)、收缩期最大应变率(SSR).结果 右室心肌梗死患者的PDS和SSR均较对照组降低(P<0.05),而SSR较PDS显示结果更敏感(P<0.01).结论 TTI和SRI技术能够准确地诊断右室壁心肌梗死,并能对右室局部收缩功能进行定量评价.

  15. Nonlinear vibrations and energy exchange of single-walled carbon nanotubes. Circumferential flexural modes

    Science.gov (United States)

    Strozzi, Matteo; Smirnov, Valeri V.; Manevitch, Leonid I.; Milani, Massimo; Pellicano, Francesco

    2016-10-01

    In this paper, the nonlinear vibrations and energy exchange of single-walled carbon nanotubes (SWNTs) are studied. The Sanders-Koiter theory is applied to model the nonlinear dynamics of the system in the case of finite amplitude of vibration. The SWNT deformation is described in terms of longitudinal, circumferential and radial displacement fields. Simply supported, clamped and free boundary conditions are considered. The circumferential flexural modes (CFMs) are investigated. Two different approaches based on numerical and analytical models are compared. In the numerical model, an energy method based on the Lagrange equations is used to reduce the nonlinear partial differential equations of motion to a set of nonlinear ordinary differential equations, which is solved by using the implicit Runge-Kutta numerical method. In the analytical model, a reduced form of the Sanders-Koiter theory assuming small circumferential and tangential shear deformations is used to get the nonlinear ordinary differential equations of motion, which are solved by using the multiple scales analytical method. The transition from energy beating to energy localization in the nonlinear field is studied. The effect of the aspect ratio on the analytical and numerical values of the nonlinear energy localization threshold for different boundary conditions is investigated. Time evolution of the total energy distribution along the axis of a simply supported SWNT

  16. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    Directory of Open Access Journals (Sweden)

    Qing Wei Li

    2015-01-01

    Full Text Available A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by the finite element method. At last, the oxide scale thickness and stress sensors are established on support vector machine (SMV optimized by particle swarm optimization (PSO with time and circumferential angles as inputs and oxide scale thickness and stress as outputs. Temperature and stress calculation methods are validated by the operation data and experimental data, respectively. The soft sensor is applied to the superheater tubes of some power plant. Results show that the soft sensor can give enough accurate results for oxide scale thickness and stress in reasonable time. The forecasting model provides a convenient way for the research of the oxide scale failure.

  17. Myocardial systolic function of local left ventricle in patients with hypertrophic cardiomyopathy evaluated bystrain and strain rate imaging%超声应变和应变率显像技术对肥厚型心肌病患者左室收缩功能的评价

    Institute of Scientific and Technical Information of China (English)

    刘磊; 刘源; 吴美龄

    2011-01-01

    目的 应用超声应变及应变率显像技术评价肥厚型心肌病(HCM)患者左室局部心肌收缩功能。方法 选取38例HCM患者作为观察组,选取健康志愿者36例作为对照组,分别进行组织多普勒超声检查,应用应变和应变率显像技术对局部心肌进行定量分析和评价。结果 观察组患者左房内径、左室内径、左室收缩期末内径、室间隔厚度、左室后壁厚度均明显增加,左室射血分数明显减少(均P<0.05)。观察组患者左室下壁、侧壁、后壁、前壁及室间隔心肌收缩期峰值应变、应变率均明显低于对照组(均P<0.05)。结论 应变和应变率显像技术能准确反映HCM患者左心室局部心肌收缩功能减退及特性的改变。%Objective To evaluate regional myocardial systolic function in patients with hypertrophic cardiomyopathy(HCM) by strain and strain rate imaging.Methods 38 patients with HCM(observe group) and 36 healthy volunteers(control group) were involved in this study.All subjects were received conventional 2D-Color Doppler echocardiography and Color Doppler myocardial image(CDMI) ,then analyzed the regional myocardial function by strain and strain rate imaging.Results Comparwed with the control group, left atrial diameters (LAD), left ventricular diameters (LVD), left ventricular end-systolic dimension (LVDs), interventricular ventricular septal (IVS) and left ventricular posterior wall(LVPW) were significantly increased in patients of observe group (all P < 0.05), but left ventricular ejection fraction(LVEF) was decreased(P <0.05).Patients with HCM showed regional longitudinal peak systolic myocardial deformation properties lower than those of counterparts at inferior, lateral, posterior, frontal and septum waLl of left ventricular(all P < 0.05).Conclusion Hypertrophic cardiomyopathy was associated with significant reduction in systolic function of left ventricle and strain and strain rote imaging was

  18. Strain imaging diastolic index in assessment of left ventricular delayed relaxation after stent implantation in patients with acute myocardial infarction%应变显像舒张指数评价急性心肌梗死患者经皮冠状动脉介入治疗术后左心室舒张功能延迟恢复

    Institute of Scientific and Technical Information of China (English)

    门翠伟; 李玉宏

    2013-01-01

    Objective To detect the changes of the left ventricular strain indicators in patients with acute myocardial infarction (AMI) after sent implantation by two-dimensional speckle tracking imaging (2D-STI), and to assess the clinical value of strain imaging diastolic index (SI-DI) in evaluation on regional myocardial delayed relaxation after reperfusion. Methods Totally 40 patients with AMI underwent echocardiography before, 1 day, 7 days and 1 month after percutaneous coronary intervention (PCI). Transverse peak strain (Speak), delayed time to peak strain (TPS) and strain imaging diastolic index (SI-DI) with strain imaging in both nonischemic segments and ischemic segments were measured and compared. Results Acute coronary artery occlusion would result in significant deterioration in regional myocardial systolic and diastolic function. Compared to nonischemic myocardium, Speak of ischemic myocardium significantly reduced, TPS significantly prolonged, and SI-DI significantly decreased (all P<0. 05). Speak of ischemic myocardial significantly increased, TPS significantly shorten, and SI-DI increased 7 days and 1 month after PCI (all P<0. 05). Though systolic deformation parameters Speak and TPS returned to normal after 7 days, the diastolic deformation parameter SI-DI of ischemic myocardium returned to normal after 1 month. No significant difference of the parameters in non-ischemic myocardium was found. Conclusion SI-DI can be used to evaluate the left ventricular delayed relaxation or diastolic stunning in patients with AMI after PCI.%目的 应用二维超声斑点追踪显像(STI)技术检测急性心肌梗死(AMI)患者经皮冠状动脉介入治疗术(PCI)后不同时期的左心室心肌应变指标的变化,探讨应变显像舒张指数(SI-DI)对定量评价再灌注后局部心肌舒张功能延迟恢复的临床应用价值.方法 选择40例AMI患者,分别在PCI术前、术后1天、7天及1个月接受超声心动图检查,应用二维应变显像技术

  19. Left ventricular strain and strain rate by 2D speckle tracking in chronic thromboembolic pulmonary hypertension before and after pulmonary thromboendarterectomy

    Directory of Open Access Journals (Sweden)

    Waltman Thomas J

    2010-09-01

    Full Text Available Abstract Background Echocardiographic evaluation of left ventricular (LV strain and strain rate (SR by 2D speckle tracking may be useful tools to assess chronic thromboembolic pulmonary hypertension (CTEPH severity as well as response to successful pulmonary thromboendarterectomy (PTE. Methods We evaluated 30 patients with CTEPH before and after PTE using 2D speckle tracking measurements of LV radial and circumferential strain and SR in the short axis, and correlated the data with right heart catheterization (RHC. Results PTE resulted in a decrease in mean PA pressure (44 ± 15 to 29 ± 9 mmHg, decrease in PVR (950 ± 550 to 31 ± 160 [dyne-sec]/cm5, and an increase in cardiac output (3.9 ± 1.0 to 5.0 ± 1.0 L/min, p change in circumferential strain and change in posterior wall radial strain correlated moderately well with changes in PVR, mean PA pressure and cardiac output (r = 0.69, 0.76, and 0.51 for circumferential strain [p Conclusions LV circumferential and posterior wall radial strain change after relief of pulmonary arterial obstruction in patients with CTEPH, and these improvements occur rapidly. These changes in LV strain may reflect effects from improved LV diastolic filling, and may be useful non-invasive markers of successful PTE.

  20. Numerical Simulation for Three-Dimensional (3D) Unsteady State Temperature Field in Circumferential Laser Oxygen Cutting of Pipes

    Institute of Scientific and Technical Information of China (English)

    Kaijin HUANG; Dawen ZENG; Changsheng XIE; Desheng XU

    2003-01-01

    A 3D unsteady state numerical model of heat transfer in the circumferential laser oxygen cutting of pipes wasdeveloped. In order to minimize the computing time required for solving the finite difference equations as much aspossible, the alternating direct

  1. Scalp ulceration from a circumferential head dressing after craniotomy: Case report of an uncommon complication due to human error

    OpenAIRE

    Singhal, Ashutosh; Bray, Peter W.; Bernstein, Mark

    2004-01-01

    The present paper describes a previously unpublished complication of the application of a circumferential head dressing after cranial neuro-surgery. A 34-year-old woman developed a large area of skin necrosis on her forehead from a circumferential head dressing applied after the surgical removal of a colloid cyst. Neurological recovery was excellent but plastic surgical repair of her iatrogenic cosmetic injury was required.

  2. 心肌超声造影评价肥厚型心肌病患者局部心肌收缩功能与灌注的关系%Evaluation of correlation between regional myocardial function and perfusion in patients with hypertrophic cardiomyopathy by myocardial contrast echocardiography

    Institute of Scientific and Technical Information of China (English)

    王婷; 邓又斌; 朱英; 王纯; 杨好意; 毕小军; 刘红云

    2011-01-01

    , left ventricle short-axis apical view)and the 3 left ventricle long-axis apical views( two-chamber view,four-chamber view,left ventricle long-axis apical view ). Twenty volunteers of the thirty-five patients with hypertrophic cardiomyopathy were examined by myocardial contrast echocardiography after they did it randomized as the order of the time registered. A and K of the exponential function Y = A( 1 - e-Kt )fitted by the curves and made by the myocardial signal intensity to time were obtained automatically. Results The global longitudinal strain, global circumferential strain and global radial strain of patients with hypertrophic cardiomyopathy were all significantly lower than controls, The difference was significant 23.48 ±1.86 vs 15. 76 ± 3. 63 ,24. 22 ± 3. 95 vs20.03 ±4.24,41.05 ±10.28 vs 30. 83 ± 11. 28 ,t = -7.775, -3.167, -2.913, all P <0. 01 ). The absolute value of circumferential strain were related to A and K ( R=0. 610, t =3. 079, P <0. 01 ;R =0. 550, t = - 2. 632, P < 0. 05 ); and the absolute value of longitudinal strain were related to K( R = 0. 469 , t = - 2. 252, P < 0.05 ). Conclusions The regional myocardial function in patients with hypertrophic cardiomyopathy were impaired compared with control group, and perfusion defects were related to the impairment. Myocardial contrast echocardiography is a reliable and effective way to study and diagnose the hypertrophic cardiomyopathy.

  3. 组织多普勒应变成像评价无心肌梗死的冠心病患者左心室收缩功能变化%Evaluation of Left Ventricular Function in Patients with Coronary Artery Diseases and without Myocardial Infarction by Strain Imaging Based on Tissue Doppler Imaging

    Institute of Scientific and Technical Information of China (English)

    李伟霞; 周宇

    2012-01-01

    Objective: To assess left ventricular function in patients with coronary artery diseases who had no myocardial infarc-tion history by strain imaging based on tissue Doppler imaging (TDD. Methods: Color-coded tissue Doppler echocardiography was performed in 25 healthy subjects and 26 patients with coronary artery diseases and without myocardial infarction. The short-axis views at basal,middle and apical levels were recorded. The mean peak values of strain were measured using Philips Q-Lab 7. 1 workshop. Results; The mean peak value in the group of coronary artery disease was significantly lower than that in the control group[(-42. 3 ± 9. 3) % vs. (-28. 8 ± 10. 3) %,P<0. 01],while other conventional echocardiographic parameters showed no significant difference. Conclusions: Strain imaging based on TDI can be used to assess myocardial function even when there is no obvious change in left ventricular ejection fraction in patients with coronary artery diseases.%目的:应用组织多普勒(tissue Doppler imaging,TDI)应变成像技术评价无心肌梗死史的冠心病患者左心室收缩功能的变化.方法:对既往均无心肌梗死史的25例健康志愿者(对照组)和26例经冠状动脉造影证实冠心痛的患者(冠心病组)进行TDI应变分析.分别得出每例研究对象的平均左心室应变峰值.结果:冠心病组和对照组的年龄、心率以及经常规超声心动图Simpson法测量的左室射血分数(left ventricular ejection fraction,LVEF)的差异均无统计意义(P>0.05),但冠心病组的平均左心室应变峰值显著低于对照组[(-42.3±9.3)%比(-28.8±10.3)%,P<0.01].结论:TDI应变峰值能敏感地反映左室功能不全的亚临床信息,有助于心血管疾病的早期诊断.

  4. Cardiac mechanics and ventricular twist by three-dimensional strain analysis in relation to B-type natriuretic peptide as a clinical prognosticator for heart failure patients.

    Directory of Open Access Journals (Sweden)

    Sheng-Nan Chang

    Full Text Available BACKGROUND: Three dimensional (3D echocardiography-derived measurements of myocardial deformation and twist have recently advanced as novel clinical tools. However, with the exception of left ventricular ejection fraction and mass quantifications in hypertension and heart failure populations, the prognostic value of such imaging techniques remains largely unexplored. METHODS: We studied 200 subjects (mean age: 60.2±16 years, 54% female, female n = 107 with known hypertension (n = 51, diastolic heart failure (n = 61, or systolic heart failure (n = 30, recruited from heart failure outpatient clinics. Fifty-eight healthy volunteers were used as a control group. All participants underwent 3D-based myocardial deformation and twist analysis (Artida, Toshiba Medical Systems, Tokyo, Japan. We further investigated associations between these measures and brain natriuretic peptide levels and clinical outcomes. RESULTS: The global 3D strain measurements of the healthy, hypertension, diastolic heart failure, and systolic heart failure groups were 28.03%, 24.43%, 19.70%, and 11.95%, respectively (all p<0.001. Global twist measurements were estimated to be 9.49°, 9.77°, 8.32°, and 4.56°, respectively. We observed significant differences regarding 3D-derived longitudinal, radial, and global 3D strains between the different disease categories (p<0.05, even when age, gender, BMI and heart rate were matched. In addition, 3D-derived longitudinal, circumferential, and 3D strains were all highly correlated with brain natriuretic peptide levels (p<0.001. At a mean 567.7 days follow-up (25th-75th IQR: 197-909 days, poorer 3D-derived longitudinal, radial, and global 3D strain measurements remained independently associated with a higher risk of cardiovascular related death or hospitalization due to heart failure, after adjusting for age, gender, and left ventricular ejection fraction (all p<0.05. CONCLUSIONS: 3D-based strain analysis may be a

  5. Evaluation of Myocardial Viability after Myocardial Infarction with Intravenous Real-time Myocardial Contrast Echocardiography

    Institute of Scientific and Technical Information of China (English)

    Weihui SHENTU; Yuhan WU; Youbin DENG; Runqing HUANG; Peng LI; Xiang WEI; Haoyi YANG; Yun ZHANG; Li XIONG; Fen YU

    2008-01-01

    The myocardial viability after myocardial infarction was evaluated by intravenous myocardial contrast echocardiography. Intravenous real-time myocardial contrast echocardiography was performed on 18 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Viable myocardium was defined by evident improvement of segmental wall motion 3 months after coronary revascularization. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions: homogeneous opacification; partial or reduced opaciflcation or subendocardial contrast defect; contrast defect. The former two conditions were used as the standard to define the viable myocardium. The results showed that 109 abnormal wall motion segments were detected among 18 patients with myocardial infarction, including 47 segments of hypokinesis, 56 segments of akinesis and 6 segments of dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascularization which showed homogeneous opacification, 14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronary revascularization which showed partial or reduced opaciflcation or subendocardial contrast defect was improved 3 months after coronary revascularization. In our study, the sensitivity and specificity of evaluation of myocardial viability after myocardial infarction by intravenous real-time myocardial contrast echocardiography were 94.7% and 78.9%, respectively. It was concluded that intravenous real-time myocardial contrast echocardiography could accurately evaluate myocardial viability after myocardial infarction.

  6. Heroin Abuse and Myocardial Infarction

    OpenAIRE

    Tatli, Ersan; Aktoz, Meryem

    2010-01-01

    Information concerning acute myocardial infarction after heroin usage is limited and the actual mechanism of heroin-induced myocardial infarction is not well known. Only one report has been described noting the association between usage heroin and acute myocardial infarction in a young man with normal coronary arteries. We also reported a patient with normal coronary arteries and acute myocardial infarction after heroin abuse. Eroin kullanımı sonrası akut miyokard inf...

  7. Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis.

    Science.gov (United States)

    Skovrlj, Branko; Guzman, Javier Z; Caridi, John; Cho, Samuel K

    2016-02-01

    Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach. PMID:26835214

  8. 二维斑点追踪技术评价心肌缺血患者左室心肌纵向应变%Evaluation of the left ventricular longitudinal strain in patients with myocardial ischemia by two-dimensional speckle tracking imaging

    Institute of Scientific and Technical Information of China (English)

    邓倾; 周青; 黄佳; 陈金玲; 胡波; 贾妍; 吴田; 郭瑞强

    2011-01-01

    目的 应用斑点追踪技术评价室壁运动正常的心肌缺血患者左室心肌纵向应变,探讨二维纵向应变检测心肌缺血的临床价值。方法 44例经冠状动脉造影证实的冠心病患者和28例对照者接受二维超声检查,用二维应变软件分析心尖长轴观、心尖两腔和四腔观的图像,获取左室各节段心肌纵向应变、18节段心肌纵向应变均值(SL18)和12节段(除外6个心尖节段)纵向应变均值(SL12)。结果 冠心病组缺血节段的纵向应变及整体纵向应变均较正常对照组明显减低;无论正常组还是冠心病组,心尖节段纵向应变均明显高于基底段和中间段,SL18与SL12之间差异有统计学意义;ROC曲线表明SL18诊断心肌缺血的截断值为-18.8%,敏感性为80.2%,特异性为74.1%;SL12诊断心肌缺血的截断值为-17.8%,敏感性为81.7%,特异性为85.6%。SL12诊断心肌缺血的敏感性与SL18接近,但特异性较SL18明显增高。结论 二维纵向应变均值能较敏感地发现心肌缺血,12节段的二维纵向应变均值较18节段能更准确地评价心肌缺血。%Objective To assess left ventricular(LV) longitudinal strain in patients with coronary heart disease by two-dimensional speckle tracking imaging (2DSTI),and to explore the clinical value of 2D longitudinal strain in detecting myocardial ischemia. Methods Forty-four patients with coronary heart disease (CHD group) and 28 age-matched subjects (control group) were enrolled into this study. The two-dimensional data were obtained in apical 4-chamble, 2-chamber and long axis view. And the longitudinal strains of every segments, the average longitudinal strain of LV 18 segments (SL18), the average longitudinal strain of 12 segments (SL12,excluded the 6 apical segments) were analyzed. Results In the patients with CHD, the longitudinal strain of ischemia segments and the global LV longitudinal strain were significantly decreased

  9. Investigations on an Axial Flow Fan Stage subjected to Circumferential Inlet Flow Distortion and Swirl

    Institute of Scientific and Technical Information of China (English)

    M.Govardhan; K.Viswanath

    1997-01-01

    The combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage are reported in this paper,The study involves measurements at the inlet of the rotor and exit of the rotor and stator atdesign and off design flow conditions.The study indicated that at the design flow condition,swirl had caused deterioration of the performance in addition to that caused by distortion.Pressure rise imparted in the distortion zone is hogher than in the free zone.The attenuation of distortion is high in the presence of swirl.

  10. Inner wall inspection of steam generator tubes with circumferential welds using ultrasonic crack detection

    International Nuclear Information System (INIS)

    Cracks in the neighbourhood of circumferential welds at the inside of generator tubes to the weld seam can be detected with an ultrasonic probe system using Rayleigh's surface waves. A reference reflector with about 0.5 mm in depth and 1.5 mm in length is used. The ultrasonic inspection system is using a rotating mirror with two faces which can detect cracks on both sides of the weld and which can clearly separate crown or root indications from real defects. The signal-to-noise ratio is better than 12 dB. The system and results on tubes with artificial and real test reflectors are described

  11. Inner wall inspection of steam generator tubes with circumferential welds using ultrasonic crack detection

    International Nuclear Information System (INIS)

    Cracks in the neighbourhood of circumferential welds at the inside of generator tubes to the weld seam can be detected with an ultrasonic probe system using Rayleigh's surface waves. A reference reflector with about 0.5 mm in depth and 1.5 mm in length is used. The ultrasonic inspection system is using a rotating mirror with two faces which can detect cracks on both sides of the weld and which can clearly separate crown or root indications from real defects. The signal-to-noise ratio is better than 12 dB. The system and results on tubes with artificial and real test reflectors are described. 8 refs

  12. Geometric characterization of a circumferential seam by automatic segmentation of digitized radioscopic images

    International Nuclear Information System (INIS)

    The present study deals with the nondestructive control of a circumferential seam by digital radioscopy. A series of images for one complete revolution of the welded component is available. We first resort to a joint approach by simulation and experimentation. This approach allows the detection of the molten zone limits for an initial image. We then develop a segmentation method that permits automatic extraction of the geometric characteristics of the set of images representative of the weld. These measures supply fast and automatic control of the weld quality. Results are shown for real components. (author)

  13. Changes in myocardial perfusion due to physical exercise in patients with stable coronary artery disease

    International Nuclear Information System (INIS)

    Percutaneous transluminal coronary angioplasty (PTCA) is one of the main therapy options for patients with coronary artery disease (CAD), resulting in an improvement in myocardial perfusion and exercise capacity. Nevertheless, studies have also demonstrated a positive effect of regular exercise training on myocardial perfusion and maximum exercise capacity. The aim of this study was to evaluate changes in myocardial stress perfusion after 1 year of exercise training in comparison with the effects of PTCA in patients with CAD. In 66 male patients with angiographically confirmed significant coronary artery stenosis in one target vessel, myocardial perfusion scintigraphy was performed at baseline and 12 months after randomisation into either a physical exercise group or a PTCA group. Circumferential count rate profiles in 16 wall segments were classified according to their relative count rate and localisation within or outside the area supplied by the stenosed vessel. Ischaemic segments showed a significant improvement in myocardial count rate within the target area after 12 months in both the PTCA and the training group (PTCA group: from 76.8±4.9% to 86.6±10.9%, p=0.03; training group: from 74.0±7.3% to 83.7±10.8%, p<0.01). Outside the target area only the training group showed a significant improvement (from 77.7±4.4% to 91.7±4.8%, p<0.01). Our data indicate a significant improvement in stress myocardial perfusion in the training group after 12 months. The ischaemia is reduced not only in the target region of the leading stenosis but also in other ischaemic myocardial areas. In contrast, after PTCA stress perfusion improves only in the initially ischaemic parts of the target area. (orig.)

  14. Regional Longitudinal Myocardial Deformation Provides Incremental Prognostic Information in Patients with ST-Segment Elevation Myocardial Infarction

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Jensen, Jan Skov; Pedersen, Sune H;

    2016-01-01

    BACKGROUND: Global longitudinal systolic strain (GLS) has recently been demonstrated to be a superior prognosticator to conventional echocardiographic measures in patients after myocardial infarction (MI). The aim of this study was to evaluate the prognostic value of regional longitudinal...... myocardial deformation in comparison to GLS, conventional echocardiography and clinical information. METHOD: In total 391 patients were admitted with ST-Segment elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention and subsequently examined by echocardiography. All...... patients were examined by tissue Doppler imaging (TDI) and two-dimensional strain echocardiography (2DSE). RESULTS: During a median-follow-up of 5.3 (IQR 2.5-6.1) years the primary endpoint (death, heart failure or a new MI) was reached by 145 (38.9%) patients. After adjustment for significant confounders...

  15. 应变率成像评价高血压合并阵发性心房颤动患者左心房心肌功能%Evaluation of left atrial myocardial function in hypertensive patients with paroxysmal atrial fibrillation using strain rate imaging

    Institute of Scientific and Technical Information of China (English)

    尹卫华; 王志斌; 聂晶; 李艳

    2011-01-01

    目的:应用实时三平面应变率成像检测高血压合并阵发性心房颤动患者左心房心肌功能的变化,探讨其临床意义.方法:选取单纯高血压患者35例、高血压合并阵发性心房颤动患者32例、正常人33例,应用实时三平面应变率成像检测左心房心肌收缩期平均峰值应变率(MSRs)、舒张早期平均峰值应变率(MSRe)和心房收缩期平均峰值应变率(MSRa).结果:MSRs在正常人、单纯高血压患者和高血压合并阵发性心房颤动患者中呈逐渐减低的变化(P0.05);MSRa在单纯高血压患者中显著增高(P<0.01),在高血压合并阵发性心房颤动患者中显著减低(P<0.05).结论:高血压患者左心房心肌功能受损,合并阵发性心房颤动时受损程度加重,实时三平面应变率成像对高血压患者左心房心肌功能的全面评估具有重要应用价值.%Objective: To evaluate the alteration of left atrial myocardial function in hypertensive patients with paroxysmal atrial fibrillation using real-time triplane strain rate imaging and to investigate its clinical significance.Methods: Thirty-five solitary hypertensive patients, 32 hypertensive patients with paroxysmal atrial fibrillation and 33 healthy subjects were enrolled.Mean systolic peak strain rate, mean early diastolic peak strain rate and mean late diastolic peak strain rate(MSRs, MSRe and MSRa) were measured using real-time triplane strain rate imaging.Results: There was a significantly step-down change among control group, hypertensive group and hypertensive with paroxysmal atrial fibrillation group in MSRs(P<0.0001), MSRe was significantly decreased in hypertensive group (P<0.01), MSRe had no significant difference in hypertension with paroxysmal atrial fibrillation group (P>0.05), MSRa was significantly increased in hypertensive group (P<0.01), while MSRa was decreased in hypertension with paroxysmal atrial fibrillation group(P<0.05).Conclusions: The left atrial myocardial

  16. Fracture Toughness (K1C evaluation for dual phase medium carbon low alloy steels using circumferential notched tensile (CNT specimens

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2011-01-01

    Full Text Available The fracture behavior of dual phase medium carbon low alloy steels produced using two different chemical compositions (A - 0.34C, 0.75Mn, 0.12Cr, 0.13Ni steel and B - 0.3C, 0.97Mn, 0.15Cr steel was investigated using circumferential notched tensile (CNT specimens. Intercritical treatments were performed on samples with composition A by 1 austenitizing at 860 °C for 1 hour cooling in air, then treating at 770 °C for 30 minutes before oil quenching; 2 austenitizing at 860 °C for 1 hour quenching in oil, then treating at 770 °C for 30 minutes before quenching in oil; and 3 austenitizing at 860 °C for 1 hour, super-cooling to 770 °C and then quenching in oil. Samples of composition B were subjected to intercritical treatment at temperatures of 740, 760, and 780 °C for 30 minutes, followed by quenching rapidly in oil. Tensile testing was then performed on specimens without notches and the CNT specimens. It was observed that the dual phase steel produced from procedure (2 yielded a fine distribution of ferrite and martensite which gave the best combination of tensile properties and fracture toughness for composition A while the dual phase structure produced by treating at 760 °C yielded the best combination of tensile properties and fracture toughness for composition B. The fracture toughness results evaluated from the test were found to be valid (in plain strain condition and a high correlation between the fracture toughness and notch tensile strength was observed. The fracture toughness values were also found to be in close agreement with data available in literature.

  17. Early myocardial deformation abnormalities in breast cancer survivors

    NARCIS (Netherlands)

    Bulten, B.F.; Mavinkurve-Groothuis, A.M.C.; Geus-Oei, L.F. de; Haan, A.F.J. de; Korte, C.L. de; Bellersen, L.; Laarhoven, H.W.M. van; Kapusta, L.

    2014-01-01

    To evaluate the role of 2D myocardial strain (rate) imaging in the detection of early subclinical cardiotoxicity in breast cancer survivors treated with an anthracycline-based chemotherapeutic regimen. 57 adult breast cancer survivors were analyzed 1 year after therapy. All patients underwent biomar

  18. 应变率成像对急性前壁心肌梗死患者右室功能的评价%Evaluation of right ventricular function in patients with acute left ventricular anterior myocardial infarction by strain rate imaging

    Institute of Scientific and Technical Information of China (English)

    苏军芳; 张军; 张海滨; 王晶明; 郑烨; 田新桥; 贺建国

    2011-01-01

    Objective To evaluate the clinical value of strain rate imaging ( SRI) in quantitative assessment of right ventricular( RV) regional myocardial function. Methods Twenty patients with acute myocardial infarction( AMI) and thirty control subjects were enrolled in the study. Longitudinal peak strain rate of posterior interventricular septum ( PS) and RV walls during systole, early diastole and atrium contraction ( SRS, SRE and SRA) were measured at different levels ( basal middle and apical) . SRI data were compared with coronary angiography results. Results SRS in all levels of PS ( basal. middle and apical)and base RV wall was significantly decreased in AMI group (P <0. 05 ) , SRE in all levels of PS and base and middle level of RV in AMI group was significantly lower than that of control group (P < 0. 05) , SRA in middle and apex level of PS in AMI group was significantly decreased compared with control group ( P < 0. 05 ) . Conclusion SRI is sensitive and feasible in evaluating RV function of acute LV anterior wall myocardial infarction.%目的 探讨应变率成像(SRI)定量评价急性前壁心肌梗死(AMI)患者右室局部心肌功能的临床价值.方法 AMI组20例,健康者30例为对照组,SRI测量其后间隔及右室侧壁不同水平的纵向收缩期、舒张早期及心房收缩期的峰值应变率(SRS、SRE、SRA),并以冠状动脉造影结果为参照进行对比分析.结果 AMI组后间隔基底段、中段、心尖段及右室侧壁基底段的SRS较对照组减低(P<0.05);AMI组后间隔基底段、中段、心尖段及右室侧壁基底段、中段的SRE较对照组减低(P<0.05);AMI组后间隔中段、心尖段的SRA较对照组减低(P<0.05).结论 SRI技术是临床无创、定量评价AMI患者右室局部心肌功能的有效方法.

  19. 定量组织速度成像与应变率成像在急诊心肌缺血中的应用价值%Value of Quantitative Tissue Velocity and Strain Rate Imaging in the Acute Myocardial Ischemia of Emegency

    Institute of Scientific and Technical Information of China (English)

    彭继红

    2016-01-01

    Objective To observe myocardial velocity and strain rate characteristics in patients with acute myocardial ischemia(AMI) of emergency,and to evaluate the clinical value of quantitative tissue velocity imaging(QTVI)and strain rate imaging(SRI)in quanti-tative assessment of left ventricular(LV)region infarction myocardial function.Methods Thirty two patients with AMI of coronary heart disease(CHD),30 control subjects were enrol ed in the study.Longitudinal peak velocity,strain rate of LV anterior wal (AW) and anterior interventricular septum(AS)during systole,early diastole and atrium contraction(VS,VE,VA),(SRS,SRE,SRA) were measured at different levels(basal,middle and apical).QTVI and SRI data were compared with coronary angiography results. Results VS:different levels of LV infarction wal significantly decreased in CHD group.VE:al levels of LV infarction wal ,except for apex levels of AS,were significantly lower than those in control group.VA:different levels of AW and apex level of AS in CHD group were significantly lower than those in control group.SRS and SRE:al levels of LV infarction wal in CHD group were significantly low-er than those in control group.SRA:different levels of AW and base level of AS in CHD group were significantly lower than those in control group (P<0.05,P<0.01 respectively).Conclusion QTVI and SRI are sensitive and feasible in evaluating functions of congestive heart failure of myocardial ischemia of emergency.%目的:探讨定量组织速度成像(QTVI)及应变率成像(SRI)在急诊心肌缺血中的临床应用价值。方法应用QTVI及SRI对32例急诊心肌缺血病人和30例正常人节段纵向收缩期(S)、舒张早期(E)及收缩期(A)的峰值速度(VS、VE、VA)、峰值应变率(SRS、SRE、SRA)进行测定。结果 VS:心肌缺血组室壁的不同水平均较正常对照组显著性减低;VE:除前间隔的心尖水平外,室壁较正常对照组显著性减低;VA:前壁的不同水平及前间隔的心尖

  20. Quantitative tissue velocity and strain rate imaging in assessment of left ventricular functions in acute left ventricular anterior myocardial infarc0tion%定量组织速度成像与应变率成像评价急性前壁心肌梗死患者心功能的应用价值

    Institute of Scientific and Technical Information of China (English)

    苏军芳; 张军; 张海滨; 王晶明; 徐晖; 郑烨; 郑敏娟

    2012-01-01

    AIM; To observe myocardial velocity and strain rate characteristics in patients with acute anterior wall myocardial infarction ( MI) and to evaluate the clinical value of quantitative tissue velocity imaging ( QTVI) and strain rate imaging ( SRI) in quantitative assessment of left ventricular ( LV) region infarction myocardial function. METHODS: Twenty patients with acute anterior wall MI and 30 control subjects were enrolled in the study. Longitudinal peak velocity, strain rate of LV anterior wall ( AW) and anterior interventricular septum ( AS) during systole, early diastole and atrium contraction ( VS, VE, VA) , (SRS, SRK, SRA) were measured at different levels (basal, middle and apical). QTVI and SRI data were compared with coronary angiography results. RESULTS: VS: different levels of LV infarction wall significantly decreased in acute MI (AMI) group; VE ; all levels of LV infarction wall, except for apex levels of AS, were significantly lower than those in control group; VA : different levels of AW andapex level of AS in AMI group were significantly lower than those in control group; SRS and SRE; all levels of LV infarction wall in AMI group were significantly lower than those in control group; SRA : different levels of AW and base level of AS in AMI group were significantly lower than those in control group (P <0. 05 , P <0. 01 respectively). CONCLUSION; QTVI and SRI are sensitive and feasible in evaluating functions of acute LV anterior wall myocardial infarction.%目的:观察急性前壁心肌梗死患者心肌速度(V)、应变率(SR)的变化特点,探讨定量组织速度成像(QTVI)及应变率成像(SRI)技术定量评价急性心肌梗死(AMI)患者的左室局部梗死心肌功能的临床应用价值.方法:应用QTVI及SRI对20例AMI患者和30例正常人左室前壁及前间壁节段纵向收缩期(S)、舒张早期(E)及房缩期(A)的峰值速度( Vs、VE、VA)、峰值应变率(SRs、SRE、SRA)进行测定,并以冠脉造影结果为标准

  1. Effects of inlet circumferential fluctuation on the sweep aerodynamic performance of axial fans/compressors

    Science.gov (United States)

    Gui, Xingmin; Zhu, Fang; Wan, Ke; Jin, Donghai

    2013-10-01

    Swept blades have been widely used in the transonic fan/compressor of aircraft engines with the aids of 3D CFD simulation since the design concept of controlling the shock structure was firstly proposed and successfully tested by Dr. Wennerstrom in the 1980s. However, some disadvantage phenomenon has also been induced by excessively 3D blade geometries on the structure stress insufficiency, vibration and reliability. Much confusion in the procedure of design practice leading us to recognize a new view on the flow mechanism of sweep aerodynamical induction: the new radial equilibrium established by the influence of inlet circumferential fluctuation (CF) changes the inlet flows of blading and induces the performance modification of axial fans/compressors blade. The view is verified by simplified models through numerical simulation and circumferentially averaged analysis in the present paper. The results show that the CF source items which originate from design parameters, such as the spanwise distributions of the loading and blading geometries, contribute to the changing of averaged incidence spanwise distribution, and further more affect the performance of axial fans/compressors with swept blades.

  2. COMPUTATIONAL AND EXPERIMENTAL STUDY ON TIP LEAKAGE VORTEX OF CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    LI Yang; OUYANG Hua; DU Zhaohui

    2007-01-01

    In the steady operation condition, the experiments and the numerical simulations are used to investigate the tip leakage flow fields in three low pressure axial flow fans with three kinds of circumferential skewed rotors, including the radial rotor, the forward-skewed rotor and the backward-skewed rotor. The three-dimensional viscous flow fields of the fans are computed. In the experiments, the two-dimensional plane particle image velocimetry (PIV) system is used to measure the flow fields in the tip region of three different pitchwise positions of each fan. The results show that the computational results agree well with the experimental data in the flow field of the tip region of each fan. The tip leakage vortex core segments based on method of the eigenmode analysis can display clearly some characteristics of the tip leakage vortex, such as the origination position of tip leakage vortex, the development of vortex strength, and so on. Compared with the radial rotor, the other two skewed rotors can increase the stability of the tip leakage vortex and the increment in the forward-skewed rotor is more than that in the backward-skewed one. Among the tip leakage vortices of the three rotors, the velocity of the vortex in the forward-skewed rotor is the highest in the circumferential direction and the lowest in the axial direction.

  3. Recent evaluations of crack-opening-area in circumferentially cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

    1997-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

  4. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    Directory of Open Access Journals (Sweden)

    Amy Y Hsiao

    Full Text Available The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  5. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    International Nuclear Information System (INIS)

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed

  6. Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

    Science.gov (United States)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

  7. Effects of circumferential rigid wrist orthoses in rehabilitation of patients with radius fracture at typical site

    Directory of Open Access Journals (Sweden)

    Đurović Aleksandar

    2005-01-01

    Full Text Available Background. The use of orthoses is a questionable rehabilitation method for patients with the distal radius fracture at typical site. The aim of this study was to compare the effects of the rehabilitation on patients with radius fracture at the typical site, who wore circumferential static wrist orthoses, with those who did not wear them. Methods. Thirty patients were divided into 3 equal groups, 2 experimental groups, and 1 control group. The patients in the experimental groups were given the rehabilitation program of wearing serially manufactured (off-the-shelf, as well as custom-fit orthoses. Those in the control group did not wear wrist orthoses. Evaluation parameters were pain, edema, the range of the wrist motion, the quality of cylindrical, spherical, and pinch-spherical grasp, the strength of pinch and hand grasp, and patient's assessment of the effects of rehabilitation. Results. No significant difference in the effects of rehabilitation on the patients in experimental groups as opposed to control group was found. Patients in the first experimental group, and in control group were more satisfied with the effects of rehabilitation, as opposed to the patients in the second experimental group (p<0,05. Conclusion. The effects of circumferential static wrist orthoses in the rehabilitation of patients with distal radius fracture at the typical site were not clinically significant. There was no significant difference between the custom and off-the-shelf orthoses.

  8. Status of the steam generator tube circumferential ODSCC degradation experienced at the Doel 4 plant

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, G. [AIB-Vincotte Nuclear, Brussels (Belgium)

    1997-02-01

    Since the 1991 outage, the Doel Unit 4 nuclear power plant is known to be affected by circumferential outside diameter intergranular stress corrosion cracking at the hot leg tube expansion transition. Extensive non destructive examination inspections have shown the number of tubes affected by this problem as well as the size of the cracks to have been increasing for the three cycles up to 1993. As a result of the high percentage of tubes found non acceptable for continued service after the 1993 in-service inspection, about 1,700 mechanical sleeves were installed in the steam generators. During the 1994 outage, all the tubes sleeved during the 1993 outage were considered as potentially cracked to some extent at the upper hydraulic transition and were therefore not acceptable for continued service. They were subsequently repaired by laser welding. Furthermore all the tubes not sleeved during the 1993 outage were considered as not acceptable for continued service and were repaired by installing laser welded sleeves. During the 1995 outage, some unexpected degradation phenomena were evidenced in the sleeved tubes. This paper summarizes the status of the circumferential ODSCC experienced in the SG tubes of the Doel 4 plant as well as the other connected degradation phenomena.

  9. Experimental investigation on circumferential and axial temperature gradient over fuel channel under LOCA

    Science.gov (United States)

    Yadav, Ashwini Kumar; kumar, Ravi; Gupta, Akhilesh; Chatterjee, Barun; Mukhopadhyay, Deb; Lele, H. G.

    2014-06-01

    In a nuclear reactor temperature rises drastically in fuel channels under loss of coolant accident due to failure of primary heat transportation system. Present investigation has been carried out to capture circumferential and axial temperature gradients during fully and partially voiding conditions in a fuel channel using 19 pin fuel element simulator. A series of experiments were carried out by supplying power to outer, middle and center rods of 19 pin fuel simulator in ratio of 1.4:1.1:1. The temperature at upper periphery of pressure tube (PT) was slightly higher than at bottom due to increase in local equivalent thermal conductivity from top to bottom of PT. To simulate fully voided conditions PT was pressurized at 2.0 MPa pressure with 17.5 kW power injection. Ballooning initiated from center and then propagates towards the ends and hence axial temperature difference has been observed along the length of PT. For asymmetric heating, upper eight rods of fuel simulator were activated and temperature difference up-to 250 °C has been observed from top to bottom periphery of PT. Such situation creates steep circumferential temperature gradient over PT and could lead to breaching of PT under high pressure.

  10. Transmit-receive eddy current probes for circumferential cracks in heat exchanger tubes

    International Nuclear Information System (INIS)

    Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without leaks. This paper describes the basic features of T/R surface probes. Two-dimensional voltage diagrams showing computer-derived probe response to frequency, lift-off, carbon steel supports, magnetite deposits and copper deposits are presented and compared with corresponding signals from impedance coils. Theoretical and experimental results show that T/R probes are able to detect defects in the presence of variable lift-off (due to tube-wall deformation) with ten times the signal-to-noise ratio as that exhibited by comparable pancake-type impedance probes. In addition, T/R probes are less sensitive to magnetite deposits, and possess good phase discrimination to internal defects

  11. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M. [and others

    1996-12-01

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

  12. Speckle tracking imaging in evaluation of radial strain of subendocardial and epicardial myocardium in canine acute myocardial ischemia and reperfusion%斑点追踪技术评价犬急性心肌缺血及再灌注心内膜下心肌和心外膜下心肌径向应变

    Institute of Scientific and Technical Information of China (English)

    宋平梅; 任卫东; 马春燕; 王秀芹; 乔伟

    2013-01-01

    Objective To evaluate the radial strain function of subendocardial and epicardial myocardium in acute myocardial ischemia and reperfusion canine with speckle tracking imaging. Methods The first diagonal branch of left coronary artery of 20 adult healthy hybrid dogs were ligated. Radial strain of subendocardial and epicardial myocardium at basal, apical and papillary muscle level were compared by speckle tracking imaging before ligation, ligation immediately, 60,120, 180 min after ligation, reperfusion immediately, and 60, 120 min after reperfusion, respectively. Results Radial strain of basal level elevated by compensatory role in canine acute ischemic process. Radial strain of apical and papillary muscle level decreased obviously. Myocardial reverse movement was even found at apical level. In acute ischemia and reperfusion process, subendocardial myocardium was more sensitive to ischemia. After reperfusion, radial strain of subendocardial and epicardial myocardium at apical and papillary muscle level were still lower than that in basic status. Conclusion Speckle tracking imaging can objectively quantify regional and overall heart function and transmural extent of myocardial infarction in canine.%目的 应用斑点追踪技术检测犬急性心肌缺血及再灌注不同时间点心内膜下心肌和心外膜下心肌的径向应变.方法 选取20只健康成年杂种犬,结扎左冠状动脉第一对角支,分别对结扎前、结扎即刻、60、120和180 min及再灌注即刻、60和120 min基底水平、乳头肌水平和心尖水平心内膜下和心外膜下心肌的径向应变进行比较.结果 在急性缺血过程中,基底水平心肌起代偿作用,其径向应变上升;乳头肌水平和心尖水平心肌下降明显,心尖水平心肌甚至出现反向运动.在急性缺血及再灌注过程中,心内膜下心肌对缺血更加敏感.再灌注后,乳头肌水平和心尖水平心内膜下和心外膜下心肌及跨壁的径向应变

  13. Depression following myocardial infarction

    DEFF Research Database (Denmark)

    Larsen, Karen Kjær

    2013-01-01

    Myocardial infarction (MI) is a severe life event that is accompanied by an increased risk of depression. Mounting evidence suggests that post-MI depression is associated with adverse outcomes, but the underlying mechanisms of this association remain unclear, and no previous studies have examined...

  14. Depression after myocardial infarction.

    Science.gov (United States)

    Ziegelstein, R C

    2001-01-01

    Depression is an independent risk factor for increased postmyocardial infarction morbidity and mortality, even after controlling for the extent of coronary artery disease, infarct size, and the severity of left ventricular dysfunction. This risk factor takes on added significance when one considers that almost half of patients recovering from a myocardial infarction have major or minor depression and that major depression alone occurs in about one in five of these individuals. Despite the well-documented risk of depression, questions remain about the mechanism of the relationship between mood disturbance and adverse outcome. The link may be explained by an association with lower levels of social support, poor adherence to recommended medical therapy and lifestyle changes intended to reduce the risk of subsequent cardiac events, disturbances in autonomic tone, enhanced platelet activation and aggregation, and systemic immune activation. Unfortunately, questions about the pathophysiologic mechanism of depression in this setting are paralleled by uncertainties about the optimal treatment of depression for patients recovering from a myocardial infarction and by a lack of knowledge about whether treating depression lowers the associated increased mortality risk. Ongoing research studies will help to determine the benefits of psychosocial interventions and of antidepressant therapy for patients soon after myocardial infarction. Although the identification of depression as a risk factor may by itself be a reason to incorporate a comprehensive psychological evaluation into the routine care of patients with myocardial infarction, this practice should certainly become standard if studies show that treating depression reduces the increased mortality risk of these patients.

  15. High-resolution three-dimensional 19F-magnetic resonance imaging of rat lung in situ: evaluation of airway strain in the perfluorocarbon-filled lung

    International Nuclear Information System (INIS)

    Perfluorocarbons (PFC) are biologically and chemically inert fluids with high oxygen and CO2 carrying capacities. Their use as liquid intrapulmonary gas carriers during liquid ventilation has been investigated. We established a method of high resolution 3D-19F-MRI of the totally PFC-filled lung. The goal of this study was to investigate longitudinal and circumferential airway strain in the setting of increasing airway pressures on 3D-19F-MR images of the PFC-filled lung. Sixteen female Wistar rats were euthanized and the liquid perfluorocarbon FC-84 instilled into their lungs. 3D-19F-MRI was performed at various intrapulmonary pressures. Measurements of bronchial length and cross-sectional area were obtained from transversal 2D images for each pressure range. Changes in bronchial area were used to determine circumferential strain, while longitudinal strain was calculated from changes in bronchial length. Our method of 3D-19F-MRI allowed clear visualization of the great bronchi. Longitudinal strain increased significantly up to 31.1 cmH2O. The greatest strain could be found in the range of low airway pressures. Circumferential strain increased strongly with the initial pressure rise, but showed no significant changes above 10.4 cmH2O. Longitudinal strain was generally higher in distal airways, while circumferential strain showed no difference. Analysis of mechanical characteristics showed that longitudinal and circumferential airway expansion occurred in an anisotropic fashion. Whereas longitudinal strain still increased with higher pressures, circumferential strain quickly reached a 'strain limit'. Longitudinal strain was higher in distal bronchi, as dense PFCs gravitate to dependent, in this case to dorso-basal parts of the lung, acting as liquid positive end expiratory pressure

  16. Strain correction in interleaved strain-encoded (SENC) cardiac MR

    Science.gov (United States)

    Motaal, Abdallah G.; Osman, Nael F.

    2010-03-01

    The strain encoding (SENC) technique directly encodes regional strain of the heart into the acquired MR images and produces two images with two different tunings so that longitudinal strain, on the short-axis view, or circumferential strain on the long-axis view, are measured. Interleaving acquisition is used to shorten the acquisition time of the two tuned images by 50%, but it suffers from errors in the strain calculations due to inter-tunings motion of the heart. In this work, we propose a method to correct for the inter-tunings motion by estimating the motion-induced shift in the spatial frequency of the encoding pattern, which depends on the strain rate. Numerical data was generated to test the proposed method and real images of human subjects were used for validation. The proposed method corrected the measured strain values so they became nearly identical to the original ones. The results show an improvement in strain calculations so as to relax the imaging constraints on spatial and temporal resolutions and improve image quality.

  17. Regional Longitudinal Myocardial Deformation Provides Incremental Prognostic Information in Patients with ST-Segment Elevation Myocardial Infarction.

    Directory of Open Access Journals (Sweden)

    Tor Biering-Sørensen

    Full Text Available Global longitudinal systolic strain (GLS has recently been demonstrated to be a superior prognosticator to conventional echocardiographic measures in patients after myocardial infarction (MI. The aim of this study was to evaluate the prognostic value of regional longitudinal myocardial deformation in comparison to GLS, conventional echocardiography and clinical information.In total 391 patients were admitted with ST-Segment elevation myocardial infarction (STEMI, treated with primary percutaneous coronary intervention and subsequently examined by echocardiography. All patients were examined by tissue Doppler imaging (TDI and two-dimensional strain echocardiography (2DSE.During a median-follow-up of 5.3 (IQR 2.5-6.1 years the primary endpoint (death, heart failure or a new MI was reached by 145 (38.9% patients. After adjustment for significant confounders (including conventional echocardiographic parameters and culprit lesion, reduced longitudinal performance in the anterior septal and inferior myocardial regions (but not GLS remained independent predictors of the combined outcome. Furthermore, inferior myocardial longitudinal deformation provided incremental prognostic information to clinical and conventional echocardiographic information (Harrell's c-statistics: 0.63 vs. 0.67, p = 0.032. In addition, impaired longitudinal deformation outside the culprit lesion perfusion region was significantly associated with an adverse outcome (p<0.05 for all deformation parameters.Regional longitudinal myocardial deformation measures, regardless if determined by TDI or 2DSE, are superior prognosticators to GLS. In addition, impaired longitudinal deformation in the inferior myocardial segment provides prognostic information over and above clinical and conventional echocardiographic risk factors. Furthermore, impaired longitudinal deformation outside the culprit lesion perfusion region seems to be a paramount marker of adverse outcome.

  18. Evaluation of left ventricular regional myocardial systolic function in patients with diastolic heart failure using real-time triplane strain rate imaging%实时三平面应变率成像评价舒张性心力衰竭患者左心室局部心肌收缩功能

    Institute of Scientific and Technical Information of China (English)

    姜海燕; 王志斌; 聂晶; 李艳

    2011-01-01

    目的:应用实时三平面应变率成像检测舒张性心力衰竭患者左心室局部心肌收缩功能,探讨其临床意义.方法:选取舒张性心力衰竭患者29例、收缩性心力衰竭患者26例和正常人30例,应用实时三平面应变率成像测定左心室各壁基底段和中间段收缩期峰值应变率(SRs).结果:舒张性心力衰竭组、收缩性心力衰竭组左心室壁各节段SRs均小于正常组相应节段(P<0.05或P<0.01),且正常组、舒张性心力衰竭组、收缩性心力衰竭组各组SRs逐渐减小(P<0.05或P<0.01).结论:舒张性心力衰竭患者存在左心室局部心肌收缩功能异常,实时三平面应变率成像检测左心室局部心肌收缩功能在心力衰竭患者心脏功能评价中具有重要价值.%Objective: To evaluate the left ventricular regional myocardial systolic function in patients with diastolic heart failure using real-time triplane strain rate imaging and investigate its clinical significance.Methods: Twenty-nine patients with diastolic heart failure, 26 patients with systolic heart failure and 30 healthy subjects as control group were enrolled.The systolic peak strain rate (SRs) were measured at basal and middle segments in different left ventricular walls using real-time triplane strain rate imaging.Results: SRs in diastolic heart failure and systolic heart failure groups were significantly lower than in control group(P<0.05 or P<0.01).There was a significantly step-down change among normal, diastolic heart failure and systolic heart failure in SRs (P<0.05 or P<0.01).Conclusions: The left ventricular regional myocardial systolic dysfunction existed in patients with diastolic heart failure.Thus, assessing left ventricular regional myocardial systolic function using real-time triplane strain rate imaging has important clinical value in the comprehensive evaluation of cardiac function in heart failure.

  19. Tip clearance flow interaction with circumferential groove casing treatment in a transonic axial compressor

    Science.gov (United States)

    Ross, Mark Hamilton

    Experimental and computational studies were conducted to study the role of the tip leakage flow in axial compressor stall and the relationship between the tip clearance flow flow field and surge margin extension from circumferential groove casing treatment. The CFD results were used to identify the existence of an interface between the approach ow and the tip-leakage flow. The experiments used a surface streaking visualization method to identify the time-averaged location of this interface as a line of zero axial shear stress at the casing. The axial position of this line, denoted xzs, moved upstream with decreasing ow coefficient in both the experiments and computations. The line was consistently located at the rotor leading edge plane at the stalling flow coefficient, regardless of in flow boundary condition. These results were successfully modeled using a control volume approach that balanced the reverse axial momentum ux of the tip-leakage flow with the momentum flux of the approach fluid. Non-uniform tip clearance measurements demonstrated that movement of the interface upstream of the rotor leading edge plane leads to the generation of short length scale rotating disturbances. Therefore, stall was interpreted as a critical point in the momentum flux balance of the approach ow and the reverse axial momentum flux of the tip-leakage flow. Experimental measurements of surge margin extension from seven CGCT configurations with a fixed groove geometry demonstrated that the contribution of individual grooves in a multi-groove casing to surge margin extension is an (a) additive and (b) linear function of the smooth wall tip clearance axial momentum ux at the location of a each groove. Extending the axial momentum model to include the in uence of a CGCT showed that circumferential grooves reduce the tip leakage flow axial momentum through radial transport. The equivalent force due to a circumferential groove was demonstrated to be related to the smooth wall tip

  20. The Mechanism of Stall Margin Improvement in a Centrifugal Compressor with the Air Bleeding Circumferential Grooves Casing Treatment

    Science.gov (United States)

    Gao, P.; Chu, W. L.; Wu, Y. H.

    The air bleeding circumferential grooves casing treatment has the potential to extent the operating range of centrifugal compressor with no loss in efficiency. A time accurate 3-dimentional numerical simulation was performed in a low speed centrifugal compressor with the air bleeding circumferential grooves casing treatment. The numerical results agreed well with experimental test data for the global performance. Detailed analyses of the flow visualization at the tip of blades have exposed the different tip flow topologies between the cases with casing treatment and with untreated smooth wall, and the reasons how the second flow vortex is retrained. The mechanism of stall margin improvement is gained finally.

  1. Tangential stress analysis of myocardial wall by finite element method

    Institute of Scientific and Technical Information of China (English)

    Guan Qiu; Jiang Cao; Wang Xiaoyan; Chen Shengyong; Guan Fang

    2011-01-01

    A novel method is presented to build the triangular surface model and calculate the tangential stress and strain of myocardial wall ,which can be further used to reflect the left ventricle twisting-a sensitive index to assess the systolic and diastolic function of heart. Firstly, a point distribution model is used to obtain the feature points of the ventricular surface in medical images. Secondly, the surface model is constructed by triangular mesh, and then the subdivision strategy is introduced to refine the model. Thirdly, plane projection and finite element method ( FEM ) are applied to calculate the tangential stress and strain. Finally, the distribution of tangential modulus of elasticity is discussed. The stimulation results show that the proposed method can be used to compute the tangential stress and strain of myocardial wall effectively and the computing result is consistent with the results mentioned in the literatures.

  2. The Early Variation of Left Ventricular Strain after Aortic Valve Replacement by Three-Dimensional Echocardiography.

    Directory of Open Access Journals (Sweden)

    Yongle Chen

    Full Text Available Aortic stenosis (AS and aortic incompetence (AI are common aortic valve diseases. Both may deteriorate into irreversible myocardial dysfunction and will increase the risk of sudden death. In this study, we aimed to investigate the early variation trend of left ventricular function by three-dimensional speckle tracking echocardiography (3D-STE in the patients who underwent cardiac surgeries for aortic valve disease. Twenty patients with severe aortic AS and 16 patients with severe AI were enrolled. All of them underwent the aortic valve replacement (AVR procedures. The patients' global longitudinal strain (GLS and global circumferential strain (GCS were evaluated by 3D-STE before surgery and at 1 week after surgery. In addition, GLS and GCS were followed at 1 month as well as 3 months after AVR. In AS patients, the GCS after AVR altered little both at 1 week (p = 0.562 and at 1 month (p = 0.953 compared with the data before the surgery. And it increased significantly at 3 months of follow-up observation compared to that before AVR (p<0.05. Meanwhile, GLS increased progressively after AVR and improved significantly at 3 months after surgery (p<0.05. For the AI patients, GLS as well as GCS decreased at 1 week after AVR compared to those data at baseline (p<0.05. However, these two parameters recovered at 1 month after AVR. Furthermore, GLS and GCS improved significantly at 3 months after the surgery (p<0.05. Therefore, both GLS and GCS were influenced by AVR and would be improved at 3 months after surgery both in AS patients or AI patients. GLS and GCS can be finely evaluated by 3D-STE, and they are helpful to determine the variation tendency of left ventricular function in patients with AVR.

  3. Crack shape developments and leak rates for circumferential complex-cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brickstad, B.; Bergman, M. [SAQ Inspection Ltd., Stockholm (Sweden)

    1997-04-01

    A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

  4. Analysis of parameters likely to explain the secondary side circumferential cracking of steam generator

    International Nuclear Information System (INIS)

    In 1990, a new type of damage mechanism was brought to light by means of eddy current inspections in Steam Generator (SG) tube bundle. This is circumferential cracking, started on the outer wall of the tubes. These cracks generally appear below the level of the tube sheet. By the end of 1993, 89 tubes with this king of damage were discovered in the French nuclear power plants: 85 of these were located on the 6 SG's of 2 units of Dampierre. We present here the work carried out to provide better understanding of this phenomenon. It involves statistical analysis of data from experience feedback, together with analysis of the thermohydraulic conditions found on the tube sheet. (authors). 8 figs., 2 refs

  5. Circumferential resonance modes of solid elastic cylinders excited by obliquely incident acoustic waves.

    Science.gov (United States)

    Fan, Ying; Honarvar, Farhang; Sinclair, Anthony N; Jafari, Mohammad-Reza

    2003-01-01

    When an immersed solid elastic cylinder is insonified by an obliquely incident plane acoustic wave, some of the resonance modes of the cylinder are excited. These modes are directly related to the incidence angle of the insonifying wave. In this paper, the circumferential resonance modes of such immersed elastic cylinders are studied over a large range of incidence angles and frequencies and physical explanations are presented for singular features of the frequency-incidence angle plots. These features include the pairing of one axially guided mode with each transverse whispering gallery mode, the appearance of an anomalous pseudo-Rayleigh in the cylinder at incidence angles greater than the Rayleigh angle, and distortional effects of the longitudinal whispering gallery modes on the entire resonance spectrum of the cylinder. The physical explanations are derived from Resonance Scattering Theory (RST), which is employed to determine the interior displacement field of the cylinder and its dependence on insonification angle.

  6. Development of circumferential seal for helicopter transmissions: Results of bench and flight tests

    Science.gov (United States)

    Strom, T. N.; Ludwig, L. P.

    1975-01-01

    A modified circumferential segmented ring seal was designed for direct replacement of a helicopter transmission elastomeric lip seal operating on a shaft diameter of 13.91 centimeters (5.481 in.) at sliding velocities to 52.48 m/sec (10 330 ft/min). The modifications involved the garter spring tension, shaft roundness, seal housing flatness, and pumping grooves to inhibit leakage. Operation of the seals in bench tests under simulated helicopter transmission conditions revealed that the seal leakage rate was within acceptable limits and that the wear rate was negligible. The low leakage and wear rates were confirmed in flight tests of 600 and 175 hours (sliding speed, 48.11 m/sec (9470 ft/min)). An additional 200 hours of air worthiness qualification testing (aircraft tie down) demonstrated that the seal can operate at the advanced sliding conditions of 52.48 m/sec (10 330 ft/min).

  7. Lower bound limit load of a circumferentially cracked pipe under combined mechanical loading

    International Nuclear Information System (INIS)

    In a study on extension of the reference stress method, for J simplified assessment, to a three dimensional (3D) configuration under combined loading, lower bound limit analysis has been developed by J. Desquines. In the present paper the limit load for cracked pipe, with a 3D circumferential flaw, under pressure, tension and bending is detailed. The limit load is explicitly defined as a yield surface is the 3D space loading. A simple algorithm is proposed to solve the non linear problem associated to the reference stress calculation. Moreover, the lower bound solution is compared with elastic compensation method (ECM) results computed on a 3D finite element mesh of the cracked pipe. The lower bound yield surface underestimates the numerical limit loads with a discrepancy lower than 20%. (orig.)

  8. Quantitative lymphoscintigraphy in post-mastectomy lymphedema: correlation with circumferential measurements

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon Young; Lee, Kyung Han; Kim, Sang Eun; Kim, Byung Tae; Hwang, Jee Hea; Lee, Byung Boong [Samsung Medical Center, Seoul (Korea, Republic of)

    1997-07-01

    An objective measure for the severity and progression is important for the management of lymphedema. To evaluate the usefulness of lympho-scintigraphy in this regard, we compared various quantitative indices from upper extremity lymphoscintigraphy with circumferential measurements, before and after physiotheraphy. Upper extremity lymphoscintigraphy was performed in 38 patients with unilateral postmastectomy lymphedema. Tc-99m antimony sulfide colloid (37 MBq) was injected s.c. into the second and third interdigital spaces. The injection sites were imaged immediately after injection. After standardized exercise for 15 min, upper extremity images were acquired 30 min, 1 hr and 2 hr after injection. The clearance of the injection site (CL), and % uptake in regional lymph nodes (%LN) and soft tissue of the extremity (i.e., the degree of dermal backflow) (%EXT) compared to the initial injection site were calculated. Circumference of each extremity was measured at 7 levels; the severity of lymphedema was expressed as the percentage difference of total circumferential difference (TCD) between healthy and edematous extremities compared to the total circumference of healthy extremity (%TCD). In 19 patients who received physiotherapy, the therapeutic effect was measured by % decrease of TCD (%DTCD) before and after therapy (Raines. et al., 1977). The quantitative indices calculated in the image at 2 hr p.i. had better correlation with either %TCD or %DTCD than those from earlier images (Table). The CL, %LN and %EXT of edematous extremity had a significant correlation with TCD. The %EXT was correlated best with either TCD or %DTCD. The results suggest that the %EXT which corresponds to the degree of dermal backflow may be a simple and useful quantitative index for evaluating the severity and progression in lymphedema and predicting the effect of therapy.

  9. Silent myocardial ischemia.

    Science.gov (United States)

    Gutterman, David D

    2009-05-01

    Although much progress has been made in reducing mortality from ischemic cardiovascular disease, this condition remains the leading cause of death throughout the world. This might in part be due to the fact that over half of patients have a catastrophic event (heart attack or sudden death) as their initial manifestation of coronary disease. Contributing to this statistic is the observation that the majority of myocardial ischemic episodes are silent, indicating an inability or failure to sense ischemic damage or stress on the heart. This review examines the clinical characteristics of silent myocardial ischemia, and explores mechanisms involved in the generation of angina pectoris. Possible mechanisms for the more common manifestation of injurious reductions in coronary flow; namely, silent ischemia, are also explored. A new theory for the mechanism of silent ischemia is proposed. Finally, the prognostic importance of silent ischemia and potential future directions for research are discussed.

  10. Acute myocardial infarction.

    Science.gov (United States)

    Rischpler, Christoph

    2016-09-01

    Inflammatory processes after myocardial infarction have gained major interest in recent cardiovascular research. It is believed that not only the degree of cell recruitment to the heart plays a pivotal role in the quality of wound healing after myocardial infarction, but also the balance between different types or even subtypes of cells. It is also this balance which is thought to control key processes in tissue repair, such as apoptosis and neoangiogenesis. In this paper, we aim to review imaging strategies (with a special focus on nuclear molecular imaging strategies) that target cells and processes involved in postischemic inflammation and that have a high potential to be translated into clinic or that are already being used and evaluated in humans. PMID:27225319

  11. 超声斑点追踪二维纵向应变评价心绞痛患者冠状动脉介入治疗术前后左心室心肌收缩功能%Assessment of left ventricular myocardial function before and after percutaneous coronary intervention in patients with angina pectoris using two-dimensional longitudinal strain echocardiography

    Institute of Scientific and Technical Information of China (English)

    黄冬梅; 夏稻子; 张宇虹; 礼广森; 崔洪岩

    2011-01-01

    目的 应用超声二维纵向应变探讨心绞痛患者冠状动脉介入治疗术(PCI)前后左心室心肌收缩功能改变情况.方法 32例心绞痛(左前降支病变)患者和30例正常人(对照组),分别记录PCI术前、术后3个月和正常人心尖四腔切面,二腔切面,左心室长轴高帧频图像,应用二维应变软件测量各个节段的收缩期峰值纵向应变值.结果 PCI术前患者(术前组)与对照组比较,心肌节段的纵向应变值减低(P<0.05),且与冠状动脉造影左前降支病变分布范围相一致;与PCI术前相比,术后3个月患者(术后组)相应节段心肌收缩期纵向应变值较前改善(P<0.05),且部分节段与对照组比较差异无统计学意义(P>0.05).结论 超声斑点追踪二维纵向应变不但能定位诊断节段性室壁运动异常,而且能够定量地评价心绞痛患者PCI术后左心室心肌收缩功能改善情况.%Objective To explore the characteristics of two-dimensional strain of left ventricular myocardial function before and after percutaneous coronary intervention( PCI) in the patients with angina pectoris ( AP ) by speckle tracking echocardiography. Methods A total of 32 patients with AP and 30 healthy volunteers were involved. High frame rate two-dimensional images were recorded from the apical four-chamber view, two-chamber view and long-axis view of the left ventricle, respectively. The peak systolic longitudinal strain was measured in all of these views using two-dimensional strain software. Results Compared to the control group, the left ventricular peak systolic longitudinal strain values in part of segments were lower in patients with AP before and after PCI ( P < 0.05 ). Left ventricular peak systolic longitudinal strain values in part of segments were significantly improved at 3 month after PCI compared to those patients before PCI ( P<0. 05 ). Conclusions Two-dimensional strain echocardiography can be used to precisely quantify regional

  12. Myocardial protection in sepsis

    OpenAIRE

    Shakar, Simon; Brian D Lowes

    2008-01-01

    Sepsis with myocardial dysfunction is seen commonly. Beta-blockers have been used successfully to treat chronic heart failure based on the premise that chronically elevated adrenergic drive is detrimental to the myocardium. However, recent reports on the acute use of beta-blockers in situations with potential hemodynamic compromise have shown the risks associated with this approach. In critical situations, the main effect of adrenergic activation is to support cardiovascular function. Caution...

  13. Acute Myocardial Infarction 19922001

    OpenAIRE

    Robert Schmitz

    2005-01-01

    Heart disease is the leading cause of hospitalization and death in the United States among persons age 65 and older. Acute myocardial infarction (AMI), more commonly known as heart attack, accounted for more than 321,000 hospitalizations among Medicare beneficiaries in 2001. This report presents trends in AMI hospitalization, readmission, and mortality rates from 1992 through 2001 among Medicare fee-for-service beneficiaries across various demographic groups.

  14. Myocardial arterial spin labeling

    OpenAIRE

    Kober, Frank; Jao, Terrence; Troalen, Thomas; Nayak, Krishna S.

    2016-01-01

    Arterial spin labeling (ASL) is a cardiovascular magnetic resonance (CMR) technique for mapping regional myocardial blood flow. It does not require any contrast agents, is compatible with stress testing, and can be performed repeatedly or even continuously. ASL-CMR has been performed with great success in small-animals, but sensitivity to date has been poor in large animals and humans and remains an active area of research. This review paper summarizes the development of ASL-CMR techniques, c...

  15. Initial experience with circumferential pulmonary vein ablation guided by fusion of magnetic resonance imaging with three-dimensional electroanatomic mapping

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; MA Jian; MA Fu-sheng; JlA Yu-he; ZHANG Shu

    2006-01-01

    @@ Catheter ablation for the treatment of atrial fibrillation (AF) has been a focal target of electrophysiological study in recent years. Up to date,circumferential pulmonary vein ablation (CPVA)guided by three-dimensional (3-D) electroanatomic mapping (Carto, USA) has been one of the most favourable procedures for the treatment of AF.

  16. High speed OH-PLIF measurement of self-excited circumferential instabilities in an annular combustion chamber

    Science.gov (United States)

    Worth, Nicholas; Dawson, James

    2012-11-01

    Self-excited thermo-acoustic instabilities are a significant issue in the development of lean burn gas turbine combustors. Such instabilities arise through coupling of the unsteady heat release and acoustic waves, which can propagate both longitudinally and circumferentially in annular combustor geometries. Although a large number of studies have investigated longitudinal fluctuations in single axisymmetric flames, it is currently uncertain whether these results can be used to emulate circumferential oscillations in annular geometry. Therefore, the aim of the current project is to investigate the flame dynamics in an annular model gas turbine combustor during self-excited circumferential oscillations. Pressure measurements are used to characterise the circumferential oscillations, with high-speed OH chemiluminescence and OH-PLIF used to capture the flame dynamics. The flame structure and dynamics are significantly affected by both the proximity of neighbouring flames and the excitation mode; with different responses observed for small and large separation distances, and standing and spinning modes. These observations indicate that results from single flame investigations may only be representative of self-excited flames in annular geometry under in a limited set of conditions.

  17. Burn-out, Circumferential Film Flow Distribution and Pressure Drop for an Eccentric Annulus with Heated Rod

    DEFF Research Database (Denmark)

    Andersen, P. S.; Jensen, A.; Mannov, G.;

    1974-01-01

    Measurements of (1) burn-out, (2) circumferential film flow distribution, and (3) pressure drop in a 17 × 27.2 × 3500 mm concentric and eccentric annulus geometry are presented. The eccentric displacement was varied between 0 and 3 mm. The working fluid was water. Burn-out curves at 70 bar...... flow variation on burn-out is discussed....

  18. Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review

    Science.gov (United States)

    Fan, Lihong; Ge, Zhaogang; Zhang, Chen; Li, Jia; Yu, Zefeng; Dang, Xiaoqian; Wang, Kunzheng

    2015-03-01

    The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement.

  19. 超声二维应变技术评价急性心肌梗死患者急诊与延迟支架置入术的临床价值%Two-dimensional Strain Echocardiography in Evaluating Emergency Stent Implantation and Delayed Stent Implantation in Patients with Emergency Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    李阳; 夏稻子

    2011-01-01

    Objective To access two-dimensional strain echocardiography(2DSE) in evaluating the clinical effect of emergency stent implantation and delayed stent implantation in patients with acute myocardial infarction(AMI).Methods With two-dimensional strain software, peak systolic radial strain of the left ventricular and parameters of conventional ultrasound were measured in 48 patients with AMI and 30 healthy age-matched volunteers.Results (1)Compared with the control group, the peak systolic radial strain of the left vent ricular segments,Left ventricle ejection fraction(LVEF) and fractional shortening(FS) in patients with emergency stent implantation group(A group)and delayed stent implantation group(B group) decreased.Left antrum and ventricular diameter were higher than those in A group and B group.Difference between them was significant(P<0.05).(2) Compared A group and B group, left antrum and ventricular diameters of A group were lower than those in group B.LVEF and FS were higher than those in B group.Peak systolic radial strain of the left ventricular segments except posterior and inferior wall to basal segment,inferior wall to apical segment of B group decreased significantly(P<0.05).Conclusions Emergency stent implantation is better than delayed stent implantation in patients with acute myocardial infarction.%目的 应用超声二维应变技术(2DSE)分析急性心肌梗死(AMI)患者急诊与延迟支架置入术后的局部心肌应变,评价急诊与延迟支架置入术的临床效果.方法 48例AMI患者和30例正常对照组应用二维应变软件测量左室短轴室壁各节段的径向峰值收缩应变及常规超声参数.结果 (1)与对照组比较,急诊支架置入术后患者(A组)与延迟支架置人术后患者(B组)的左房、左室内径增大,LVEF、FS降低,各节段室壁应变降低,差异有统计学意义(P<0.05);(2)A组与B组比较,A组的左房、左室内径低于B组,LVEF、FS高于B组,A组各节段室壁应变除后

  20. 3D Myocardial Contraction Imaging Based on Dynamic Grid Interpolation: Theory and Simulation Analysis

    Science.gov (United States)

    Bu, Shuhui; Shiina, Tsuyoshi; Yamakawa, Makoto; Takizawa, Hotaka

    Accurate assessment of local myocardial contraction is important for diagnosis of ischemic heart disease, because decreases of myocardial motion often appear in the early stages of the disease. Three-dimensional (3-D) assessment of the stiffness distribution is required for accurate diagnosis of ischemic heart disease. Since myocardium motion occurs radially within the left ventricle wall and the ultrasound beam propagates axially, conventional approaches, such as tissue Doppler imaging and strain-rate imaging techniques, cannot provide us with enough quantitative information about local myocardial contraction. In order to resolve this problem, we propose a novel myocardial contraction imaging system which utilizes the weighted phase gradient method, the extended combined autocorrelation method, and the dynamic grid interpolation (DGI) method. From the simulation results, we conclude that the strain image's accuracy and contrast have been improved by the proposed method.

  1. Finite Element Limit Pressures for Circumferential Through-Wall Cracks in the Interface between Elbow and Pipe

    International Nuclear Information System (INIS)

    Among integrity assessment method based on a fracture mechanics concept for piping system, a limit load method is one of the important way to predict a maximum load carrying capacity in the materials with high ductility in the sense that it is used to either assess directly structural integrity of pipe based on fully plastic fracture mechanics or calculate elasticplastic fracture mechanics parameters based on reference stress concept. In nuclear power plants, piping system often involves elbows welded to straight pipe. Since welded regions are vulnerable to cracking, it is important to predict an accurate limit load for pipes with a crack in the interface between elbows and attached pipes. However, although extensive works have been made for developing limit analysis methods for cracked pipes, they were mainly for straight pipes. Recently, limit moment solutions for elbow that is attached to straight pipe with a circumferential through-wall crack(TWC) in the interface were proposed, whereas limit pressure for this geometry is not suggested yet. In this context, plastic limit pressures of circumferential TWCs between elbow and straight pipe were calculated in the present study considering geometric parameters such as an elbow curvature, a pipe size and a crack length. In the present study, the FE plastic limit analyses for circumferential TWC in the interface between elbow and pipe under internal pressure were conducted based on elastic perfectly plastic assumption. Based on the present FE results, it is found that plastic limit pressures of straight pipes with circumferential TWC are not appropriate for predicting plastic limit pressures of circumferential TWC in the interface between elbow and pipe for shorter crack length

  2. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill;

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...

  3. 速度向量成像技术评价犬心肌缺血与梗死状态下左心室节段性旋转特征%Assessment of regional rotation by velocity vector imaging in canine with myocardial ischemia and acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    张晓娟; 智光

    2011-01-01

    Objective To assess the regional rotation in canine with myocardial ischemia and acute myocardial infarction by velocity vector imaging( VVI ).Methods Myocardial ischemia and infarction model were successfully made by partly and fully ligating the left anterior descending coronary artery ( LAD ) in twelve mongrel dogs. The ventricle rotation and strain were measured by VVI. Results The results revealed: The LAD part ligation: rotation decreased in ventricular septal before LAD ligation status in LAD part ligation status( P <0. 05 ). The strain and strain rate has no significant difference. The LAD ful ligation: the rotation rate, rotation, circumferential strain and strain rate of the anterior septal, anterior wall and ventricular septal were significantly decreased in myocardial infarction status compared with those in the normal status, and were also significantly decreased compared with those in the myocardial ischemia status( P <0. 05 ). The strain and strain rate in the anterior septal,anterior wall and ventricular septal were significantly decreased in myocardial infarction status compared with those in the normal status( P <0. 05 ), but not significantly decreased compared with those in partly ligation status. Conclusion VVI can non-invasively and sensitively assess the left ventricular rotation and the results indicated the ventricular rotation is more sensitive than the strain and strain rate in evaluation of the ventricular systolic function.%目的 应用速度向量成像(VVI)技术评价心肌缺血及心肌梗死状态下犬心肌旋转运动特征.方法 选用杂种犬12只,在超声实时引导下结扎前降支定量制备前降支轻度狭窄(狭窄率:50%~75%)与完全闭塞模型,应用VVI技术分析前降支结扎前、轻度狭窄与完全闭塞状态下左心室旋转特征的改变.结果 12只杂种犬成功制备前降支轻度狭窄与完全闭塞模型,应用VVI技术对缺血与梗死状态下心肌旋

  4. Strain and strain rate: An emerging technology in the perioperative period.

    Science.gov (United States)

    Malik, Vishwas; Subramaniam, Arun; Kapoor, Poonam Malhotra

    2016-01-01

    Newer noninvasive parameters are being used for perioperative detection of myocardial ischaemia. TDI and global strain rate are some of these parameters. TDI signal is a modification of the routine Doppler flow signal. It is obtained by using thresholding and filtering algorithms that reject echoes originating from the blood pool (by-passing the high pass filter). Set-Up of the machine by activating the TDI function allows decreasing the system gain using a low pass filter and eliminates the signal produced by blood flow. Doppler shift obtained from myocardial tissue motion are of higher amplitudes (reflectivity 40 dB higher) and move about 10 times slower than blood (velocity range: 0.06 to 0.24 m/s). Speckle tracking echocardiography (tissue tracking, 2D strain) utilizes routine gray-scale 2D echo images to calculate myocardial strain. Interactions of ultrasound with myocardium result in reflection and scattering. These interactions generate a finely gray-shaded, speckled pattern (acoustic marker). This speckled pattern is unique for each myocardial region and relatively stable throughout the cardiac cycle. Spatial and temporal image processing of acoustic speckles in both 2D and 3D allows for the calculation of myocardial velocity, strain, and Strain rate.

  5. Measuring myocardial perfusion

    DEFF Research Database (Denmark)

    Qayyum, A A; Kastrup, J

    2015-01-01

    -pass of non-ionic and ionic contrast agents, respectively. Absolute quantification with CMR has yet to be established in routine clinical practice, while CT has yet to prove its diagnostic and prognostic value. The upcoming years may change the way we diagnose and treat patients suspected of having CAD......Recently, focus has changed from anatomical assessment of coronary arteries towards functional testing to evaluate the effect of stenosis on the myocardium before intervention. Besides positron-emission tomography (PET), cardiac MRI (CMR), and cardiac CT are able to measure myocardial perfusion...

  6. MYOCARDIAL INFARCTION TYPE 2. MYTH OR REALITY?

    OpenAIRE

    V. V. Zhelnov; N. V. Dyatlov; L. I. Dvoretsky

    2016-01-01

    According to The Third Definition of Myocardial Infarction there are five types of myocardial infarction depending on pathogenesis. This review provides actual data about myocardial infarction type 2 mechanism including diagnosis management, epidemiological characteristic and patient prognosis. Previously published data shows discordant information about myocardial infarction type 2 frequency, treatment and diagnostic options. Our clinical observation illustrates these severities in diagnosis...

  7. An Experimental Study of Myocardial Viability with Myocardial Contrast Echocardiography

    Institute of Scientific and Technical Information of China (English)

    张稳柱; 查道刚; 成官迅; 杨绍青; 刘伊丽

    2001-01-01

    Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous in fusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and Results MCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7dogs with constant venous infusions of microbubbles.The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects rnicrovascular cross- sectional area (or myocardial blood volume), and β reflects mean myocardial microbubble velocity. The product of A · β represents MBF. MBF was also obtained by radiolabeled microsphere method servered as reference.MBF derived by radiolabeled microsphere- method in the regions of normal, ischemia and infarction was 1.5±0.3, 0.7±0.3, 0.3±0.2mL·min-1· g-1respectively. The product of A · β obtained by MCE in those regions was 52. 46 ± 15.09, 24.36 ± 3.89, 3.74± ± 3.80 respectively. There was good correlation between normalized MBF and the normalized A · β (r =0. 81, P = 0. 001 ). Conclusions MCE has an ability to determine myocardial viability in myocardial in farction canine model.

  8. Valsartan after myocardial infarction.

    Science.gov (United States)

    Güleç, Sadi

    2014-12-01

    One of the important problems of the patients undergoing acute myocardial infarction (MI) is early development of heart failure. It has been revealed in various studies that renin-angiotensin-aldosterone system (RAAS) has a significant role in this process. The studies conducted with angiotensin converting enzyme (ACE) inhibitors have resulted in decreased mortality rate. Another RAAS blocker which was discovered about ten years later than other ACE inhibitors in historical process is angiotensin receptor blockers (ARB) inhibiting the efficiency of angiotensin 2 by binding to angiotensin 1 receptor. Valsartan is one of the molecules of this group, which has higher number of large-scale randomized clinical studies. In this review, following presentation of a general overview on heart failure after acute MI, the efficiency of ARBs in this patient group will be discussed. This discussion will mostly emphasize the construction, outcomes and clinical importance of VALIANT (VALsartan In Acute myocardial iNfarcTion), which is the study on valsartan after acute MI heart failure. PMID:25604205

  9. Simultaneously Combined Anterior-Posterior Approaches for Subaxial Cervical Circumferential Reconstruction in a Sitting Position.

    Science.gov (United States)

    Han, Yue; Xia, Qun; Hu, Yong-cheng; Zhang, Ji-dong; Lan, Jie; Ma, Xin-long

    2015-11-01

    The purpose of this article is to introduce and analyze the feasibility of simultaneously combined anterior-posterior approaches for subaxial cervical circumferential reconstruction in sitting position. A retrospective case review was performed for above surgery procedure. A 79-year-old man was confirmed subaxial cervical fracture and dislocation with facet locked by radiological examination, and the involved levels were C5-6. According to American Spinal Injury Association (ASIA) classification, the impairment scale was grade B. And the Subaxial Cervical Spine Injury and Severity Score (SLIC) were 9. The patient was restricted in sitting position with traction on a halo in extension to immobilize the head during the operation. A posterior laminectomy and pedicle screws insertion to the involved cervical spine was performed firstly. And then the anterior discectomy and strut graft were accomplished through an anterior cervical approach. The final fixation was finished by clamping the strut graft with pedicle screw system. Total blood loss was 600 ml and the total operating time was 150 min. The patient was followed up for 6 months. The symptom of neck pain improved distinctly and no evidence about implant failure was noted. Neurological status improvement was confirmed and the ASIA scale was improved to grade C. We believed that the simultaneously combined anterior-posterior approach in sitting position was safe and more advantageous for appropriate cases. PMID:26790982

  10. Leak before break behaviour of austenitic and ferritic pipes containing circumferential defects

    Energy Technology Data Exchange (ETDEWEB)

    Stadtmueller, W.; Sturm, D.

    1997-04-01

    Several research projects carried out at MPA Stuttgart to investigate the Leak-before-Break (LBB) behavior of safety relevant pressure bearing components are summarized. Results presented relate to pipes containing circumferential defects subjected to internal pressure and external bending loading. An overview of the experimentally determined results for ferritic components is presented. For components containing postulated or actual defects, the dependence of the critical loading limit on the defect size is shown in the form of LBB curves. These are determined experimentally and/or by calculation for through-wall slits, and represent the boundary curve between leakage and massive fracture. For surface defects and a given bending moment and internal pressure, no fracture will occur if the length at leakage remains smaller than the critical defect length given by the LBB curve for through-wall defects. The predictive capability of engineering calculational methods are presented by way of example. The investigation programs currently underway, testing techniques, and initial results are outlined.

  11. Fracture behavior evaluations for ferritic steel piping with circumferential double flaws on the inner surface

    International Nuclear Information System (INIS)

    Methods for assessing the structural integrity of nuclear components having some flaws are provided in the Rules on Fitness-for-Service for Nuclear Power Plants of the JSME code (JSME FFS code). Although the JSME FFS code provides such methods for piping with a single flaw, it does not describe any method for fracture assessment of piping with multiple flaws including flaw coalescence criteria. Some investigations on the fracture behavior of mainly austenitic stainless steel piping with multiple flaws, whose fracture mode is plastic collapse, have recently been reported and fracture assessment methods have been proposed. In the present study, fracture tests and analyses of carbon steel piping with a single and two circumferential flaw(s) on the inner surface were conducted to investigate a method for fracture assessment of ferritic steel piping with multiple flaws. It was found that fracture assessment based on the twice elastic slope method and the plastic collapse mechanism gave inadequate results for a large single flaw. Including this case, two kinds of elastic–plastic fracture assessment method, one using the Z-factor in the JSME FFS code and the other by ductile instability analysis, gave conservative estimates of fracture strength even when the structural factor SF was not considered (i.e. SF = 1)

  12. The Prognostic Value of Circumferential Resection Margin Involvement in Patients with Extraperitoneal Rectal Cancer.

    Science.gov (United States)

    Shin, Dong Woo; Shin, Jin Yong; Oh, Sung Jin; Park, Jong Kwon; Yu, Hyeon; Ahn, Min Sung; Bae, Ki Beom; Hong, Kwan Hee; Ji, Yong Il

    2016-04-01

    The prognostic influence of circumferential resection margin (CRM) status in extraperitoneal rectal cancer probably differs from that of intraperitoneal rectal cancer because of its different anatomical and biological behaviors. However, previous reports have not provided the data focused on extraperitoneal rectal cancer. Therefore, the aim of this study was to examine the prognostic significance of the CRM status in patients with extraperitoneal rectal cancer. From January 2005 to December 2008, 248 patients were treated for extraperitoneal rectal cancer and enrolled in a prospectively collected database. Extraperitoneal rectal cancer was defined based on tumors located below the anterior peritoneal reflection, as determined intraoperatively by a surgeon. Cox model was used for multivariate analysis to examine risk factors of recurrence and mortality in the 248 patients, and multivariate logistic regression analysis was performed to identify predictors of recurrence and mortality in 135 patients with T3 rectal cancer. CRM involvement for extraperitoneal rectal cancer was present in 29 (11.7%) of the 248 patients, and was the identified predictor of local recurrence, overall recurrence, and death by multivariate Cox analysis. In the 135 patients with T3 cancer, CRM involvement was found to be associated with higher probability of local recurrence and mortality. In extraperitoneal rectal cancer, CRM involvement is an independent risk factor of recurrence and survival. Based on the results of the present study, it seems that CRM involvement in extraperitoneal rectal cancer is considered an indicator for (neo)adjuvant therapy rather than conventional TN status. PMID:27097629

  13. The stability of through-wall circumferential cracks in cylindrical pipes subjected to bending loads

    International Nuclear Information System (INIS)

    Tada, Paris and Gamble have used the tearing modulus approach to show that when a circumferential through-wall crack exists in a 304 SS circular cylindrical pipe, and the pipe is subjected to an applied bending moment, then crack growth requires the rotation at the pipe-ends to be increased, (i.e. crack growth is stable), unless the pipe length is unduly large. On this basis it was concluded that unstable fracture is unlikely to occur in BWR SS piping, when the system is designed in accord with the ASME Code load levels for normal operation and anticipated transients. The Tada-Paris-Gamble analysis focuses on the inter-relation between instability and the onset of crack extension, and does not specifically consider the possibility that a crack might become unstable after some stable crack extension. The paper addresses this aspect of the crack stability problem using a crack tip opening angle criterion for crack extension, which has similarities with the tearing modulus approach. The results show that unstable fracture should not occur even after some stable crack extension, again provided that the pipe length is not unduly large. In other words, guillotine failure of a pipe in a BWR system is unlikely, even though the ASME Code limiting stress levels as might be exceeded, as may be the case with a very severe earthquake. (orig./HP)

  14. SERI Surgical Scaffold as an Adjunct for Circumferential Abdominoplasty and Lower Body Lift

    Directory of Open Access Journals (Sweden)

    Andrew Kornstein, MD, FACS

    2014-11-01

    Full Text Available Summary: Patients who have undergone massive weight loss typically have poor-quality skin and fascia and thus are prone to experiencing recurrent skin laxity, bulges, and poor scarring after body contouring efforts, even in the hands of experienced surgeons. Moreover, this challenging patient population often has nutritional deficiencies and concomitant medical problems, which may lead to delayed or suboptimal wound healing. A silk-derived biological scaffold (SBS and its facilitation of autogenous tissue generation may be viewed as a qualitative reinforcement of the superficial fascial system. Therefore, it may help support and stabilize a superficial fascial system that has been weakened by obesity and other factors. When employed in body lifting for patients with massive weight loss who desire long-lasting aesthetic results, it may represent a paradigm shift that has the potential to solve at least some issues that plague this patient population. In the present case of circumferential abdominoplasty and lower body lift, this silk-based bioresorbable scaffold was implanted in one side of the patient’s body but not the other. Throughout the 7-month follow-up period, the patient and her husband (who were blinded as to which side received the SBS and the author consistently observed more favorable results for the SBS side, which included greater postoperative comfort, better shape, higher buttock position, less recurrent laxity, and less descent of the scar.

  15. The Prognostic Value of Circumferential Resection Margin Involvement in Patients with Extraperitoneal Rectal Cancer.

    Science.gov (United States)

    Shin, Dong Woo; Shin, Jin Yong; Oh, Sung Jin; Park, Jong Kwon; Yu, Hyeon; Ahn, Min Sung; Bae, Ki Beom; Hong, Kwan Hee; Ji, Yong Il

    2016-04-01

    The prognostic influence of circumferential resection margin (CRM) status in extraperitoneal rectal cancer probably differs from that of intraperitoneal rectal cancer because of its different anatomical and biological behaviors. However, previous reports have not provided the data focused on extraperitoneal rectal cancer. Therefore, the aim of this study was to examine the prognostic significance of the CRM status in patients with extraperitoneal rectal cancer. From January 2005 to December 2008, 248 patients were treated for extraperitoneal rectal cancer and enrolled in a prospectively collected database. Extraperitoneal rectal cancer was defined based on tumors located below the anterior peritoneal reflection, as determined intraoperatively by a surgeon. Cox model was used for multivariate analysis to examine risk factors of recurrence and mortality in the 248 patients, and multivariate logistic regression analysis was performed to identify predictors of recurrence and mortality in 135 patients with T3 rectal cancer. CRM involvement for extraperitoneal rectal cancer was present in 29 (11.7%) of the 248 patients, and was the identified predictor of local recurrence, overall recurrence, and death by multivariate Cox analysis. In the 135 patients with T3 cancer, CRM involvement was found to be associated with higher probability of local recurrence and mortality. In extraperitoneal rectal cancer, CRM involvement is an independent risk factor of recurrence and survival. Based on the results of the present study, it seems that CRM involvement in extraperitoneal rectal cancer is considered an indicator for (neo)adjuvant therapy rather than conventional TN status.

  16. Interactions of a propeller with a stator-induced circumferentially varying flow

    Energy Technology Data Exchange (ETDEWEB)

    Farnsworth, John [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); US Air Force Academy, Department of Aeronautics, Colorado Springs, CO (United States); Amitay, Michael [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); Rensselaer Polytechnic Institute, Center for Flow Physics and Control (CeFPaC), Troy, NY (United States); Beal, David; Huyer, Stephen A. [Naval Undersea Warfare Center, Division, Vehicle Dynamics and Signature Control, Newport, RI (United States)

    2012-02-15

    The interactions of a circumferentially varying stator cascade and a downstream fixed pitch propeller were investigated experimentally. The global performance of the components and the coupled system were systematically investigated through force and moment measurements on the propulsor model in a water tunnel. In addition, the wake of the cyclic stator cascade with and without the propeller was investigated downstream from a propulsor model using the Stereoscopic PIV technique. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the flow field downstream of the stator array. The stator distribution alone produced a significant side force that increased linearly with stator pitch amplitude. When a propeller was incorporated downstream from the cyclic cascade, the side force from the stator cascade was reduced, but a small normal force and pitching moment were created. The generation of these secondary forces and moments can be related to the redistribution of the tangential flow from the cyclic cascade into the axial direction by the retreating and advancing blade states of the fixed pitch propeller. (orig.)

  17. Assessment of strain and strain rate in embryonic chick heart in vivo using tissue Doppler optical coherence tomography

    Science.gov (United States)

    Li, Peng; Liu, Aiping; Shi, Liang; Yin, Xin; Rugonyi, Sandra; Wang, Ruikang K.

    2011-11-01

    We present a method to assess the in vivo radial strain and strain rate of the myocardial wall, which is of great importance to understand the biomechanics of cardiac development, using tissue Doppler optical coherence tomography (tissue-DOCT). Combining the structure and velocity information acquired from tissue-DOCT, the velocity distribution in the myocardial wall is plotted, from which the radial strain and strain rate are evaluated. The results demonstrate that tissue-DOCT can be used as a useful tool to describe tissue deformation, especially, the biomechanical characteristics of the embryonic heart.

  18. Regional left ventricular myocardial contraction abnormalities and asynchrony in patients with hypertrophic cardiomyopathy evaluated by magnetic resonance spatial modulation of magnetization myocardial tagging

    Energy Technology Data Exchange (ETDEWEB)

    Mishiro, Yuichiro; Oki, Takashi [Tokushima Univ. (Japan). School of Medicine; Iuchi, Arata [and others

    1999-06-01

    Global left ventricular (LV) pump function is generally preserved in patients with hypertrophic cardiomyopathy (HCM). However, it is unknown whether regional myocardial contractility is impaired, especially in nonhypertrophied regions. The purpose of this study was to evaluate regional LV myocardial contraction in patients with HCM using magnetic resonance (MR) spatial modulation of magnetization (SPAMM) myocardial tagging. The study group comprised 20 patients with asymmetric septal hypertrophy (HCM group) and 16 age-matched normal patients (control group), and data were collected using transthoracic M-mode and 2-dimensional echocardiography, and MR SPAMM myocardial tagging. The systolic strain ratio, maximum systolic strain velocity, and time from end-diastole to maximum systolic strain ({Delta}T) in the anterior, ventricular septal, inferior and lateral regions for 2 LV short-axis sections at the levels of the chordae tendineae and papillary muscles were measured at 50-ms intervals by MR myocardial tagging. The end-diastolic anterior and ventricular septal wall thicknesses and LV mass index were significantly different between the HCM and control groups. The systolic strain ratio for all 4 walls, particularly the anterior and ventricular septal regions, was significantly lower in the HCM group. In the HCM group, the maximum systolic strain velocity was significantly lower and {Delta}T was significantly shorter for all 4 walls, particularly the anterior and ventricular septal regions. The standard deviation for the {Delta}T, calculated from the {Delta}T for the 8 regions of the 2 LV short-axis sections, was significantly greater in the HCM group. In conclusion, regional LV myocardial contraction is impaired in both hypertrophied and nonhypertrophied regions, and systolic LV wall asynchrony occurs in patients with HCM. (author)

  19. Evaluation of myocardial involvement in muscular dystrophy with thallium-201 emission computed tomography

    International Nuclear Information System (INIS)

    The clinical usefulness of thallium-201 myocardial perfusion scanning with emission computed tomography (ECT) for evaluation of left ventricular myocardial fibrosis was assessed on 47 patients with Duchenne (DMD), facioscapulohumeral (FSH), limb-girdle (LG) and myotonic (MT) dystrophy. Trans-, long- and short-axial images were interpreted quantitatively by circumferential profile analysis, and the fibrotic tissue size (%FIB) was estimated by integration of hypoperfused areas in 6 to 8 consecutive short-axial slices. Lung/mediastinum count ratios (L/M ratio), LV cavity dilatation, aneurysm formation and cardiac malrotations were also assessed with ECT. Distinct ECT perfusion defect was observed in 26 of 29 DMDs, and in 11 of 18 patients with other types. Perfusion defect was demonstrated in 95 of total 235 segments, and was observed specifically in the posterior wall (82 %) and the apex (65 %) in DMD, and was scattered in all LV wall segments in FSH, LG, and MT. Percent FIB correlated significantly with L/M ratio (r = 0.82, p < 0.01), and did not with age or clinical stage score. ECT showed marked LV dilatation in 7, apical aneurysm in 5 and cardiac malrotation in 23 of the 47 patients. In conclusion, ECT was considered to be a useful clinical means of evaluating myocardial involvement in patients with muscular dystrophy. (author)

  20. Evaluation of myocardial involvement in muscular dystrophy with Thallium-201 emission computed tomography

    International Nuclear Information System (INIS)

    The clinical usefulness of quantitative analysis of thallium-201 emission computed tomography (ECT) for evaluation of left ventricular myocardial fibrosis was assessed on 45 patients with Duchenne(D), facioscapulohumeral(FSH), limbgirdle(LG) and myotonic(M) dystrophy. Trans-,long- and short-axial images were interpreted quantitatively using circumferential profile analysis, and the fibrotic tissue size (%FIB) was estimated by integration of hypoperfused areas in 6 to 8 consecutive short-axial slices. Lung/mediastinum count ratios (L/M ratio) were also assessed. Distinct ECT defects were found in 42 patients (all cases of D, FSH and LG, and 2 of 5 MTs). ECT defects were observed specifically in the posterolateral wall (71%) and apex (58%) in D, and were scattered in all LV walls in FSHG, LG and MT. ECG and VCG underestimated the extent of myocardial fibrosis in 17 patients (40%). Percent FIBs coincided with fibrotic tissue sizes proven by autopsy. Body-surface ECG should be influenced by cardiac position and rotation in the thorax, which were often observed in these disease entities. These factors were also assessed with ECT. The authors conclude; ECT to be useful for non-invasive evaluation of myocardial fibrosis in patients with various types of muscular dystrophy

  1. Three different speckle-tracking techniques in assessment of left ventricular myocardial strains in healthy subjects%三种超声斑点追踪技术评价正常人左心室心肌应变

    Institute of Scientific and Technical Information of China (English)

    钱胜利; 杨莉; 高菡静; 李延; 张俊; 乔伟

    2015-01-01

    目的 探讨三种超声斑点追踪成像(STI)技术[包括二维STI(2D-STI)、三平面STI (3P-STI)及四维应变(4D-strain)]评价健康成人左心室心肌应变的价值.方法 采用2D-STI、3P-STI及4D-strain技术对141名健康成人行心肌运动分析,测量左心室整体及各节段的纵向、圆周、径向及面积应变,比较3种方法所测指标的差异及相关性.结果 2D-STI和3P-STI的整体纵向应变(GLS)及同一水平各节段纵向峰值应变(LS)比较差异无统计学意义(P>0.05),但均高于4D-strain(P<0.05).2D-STI在同一水平前间隔及后间隔圆周峰值应变(CS)高于4D-strain,其余各节段均低于4D-strain,而在同一水平各节段径向峰值应变(RS)均低于4D-strain(P均<0.05).不同水平及同一水平不同节段面积应变(AS)比较,差异均无统计学意义(P>0.05).4D-strain存储图像和分析图像所用时间短于2D-STI(P<0.05).2D-GLS与3P-GLS和4D-GLS有相关性(r=0.718,P<0.001;r=0.397,P=0.006).三种方法观察者间和观察者内一致性均较好.结论 2D-STI和3P-STI技术获得LS具有较好的一致性.4D-strain是一种评价左心室心肌纵向、圆周、径向和面积应变的新方法,具有快捷、全面、重复性好的优点,对定量评价室壁运动具有很好的临床应用价值.

  2. Myocardial perfusion at fatal infarction

    DEFF Research Database (Denmark)

    Hvid-Jacobsen, K; Møller, J T; Kjøller, E;

    1992-01-01

    In a consecutive study of myocardial scintigraphy in acute ischemic syndrome, four patients had 99mTc-hexamibi injected intravenously before they developed fatal cardiogenic shock. Planar scintigraphy was performed after death. Slices of the hearts after autopsy were analyzed for scintigraphic......, where 83%-92% of the myocardium showed ischemia as defined by a 99mTc-hexamibi uptake below an arbitrary limit on half maximum uptake. Myocardial hypoperfusion might thus aggravate the functional impairment at myocardial infarction and lead to cardiogenic shock....

  3. Mismatch Limit Load Analyses for V-groove Welded Pipe with Through-wall Circumferential Defect in Centre of Weld

    International Nuclear Information System (INIS)

    The present work reports the mismatch limit loads for a V-groove welded pipe for a circumferential crack using finite element (FE) analyses. To integrate the effect of groove angles on mismatch limit loads, one geometry related slenderness parameter was modified by relevant geometric parameters including the groove angle, crack depth, and root opening based on plastic deformation patterns in the theory of plasticity. Circumferential through-wall cracks are located at the centre of the weldments with two different groove angles (45 .deg., 90 .deg.). With regard to the loading conditions, axial (longitudinal) tension and bending are applied for all cases. For the parent and weld metal, elastic-perfectly plastic materials are considered to simulate and analyze under- and over-matching conditions in plasticity. The overall results from the proposed solutions are found to be similar to the FE results

  4. Oxytocin ameliorates the immediate myocardial injury in heart transplant through down regulation of the neutrophil dependent myocardial apoptosis

    Directory of Open Access Journals (Sweden)

    F Fadhil Al-Amran

    2014-01-01

    Conclusion: Oxytocin ameliorates myocardial injury in heart transplant through down-regulation the myocardial inflammatory response, reactive oxygen species, and neutrophil-dependant myocardial apoptosis.

  5. Measurement of strain and strain rate in embryonic chick heart using spectral domain optical coherence tomography

    Science.gov (United States)

    Dou, Shidan; Suo, Yanyan; Liang, Chengbo; Wang, Yi; Zhao, Yuqian; Liu, Jian; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

    2016-03-01

    It is important to measure embryonic heart myocardial wall strain and strain rate for understanding the mechanisms of embryonic heart development. Optical coherence tomography (OCT) can provide depth resolved images with high spatial and temporal resolution, which makes it have the potential to reveal the complex myocardial activity in the early stage embryonic heart. We develop a novel method to measure strain in embryonic chick heart based on spectral domain OCT images and subsequent image processing. We perform 4D(x,y,z,t) scanning on the outflow tract (OFT) of chick embryonic hearts in HH18 stage (~3 days of incubation). Only one image sequence acquired at the special position is selected based on the Doppler blood flow information where the probe beam penetrates through the OFT perpendicularly. For each image of the selected sequence, the cross-section of the myocardial wall can be approximated as an annulus. The OFT is segmented with a semi-automatic boundary detection algorithm, thus the area and mean circumference of the annular myocardial wall can be achieved. The myocardial wall thickness was calculated using the area divided by the mean circumference, and then the strain was obtained. The results demonstrate that OCT can be a useful tool to describe the biomechanical characteristics of the embryonic heart.

  6. 心肌应变率成像——定量评价局部心肌功能的新技术%Strain rate imaging an innovative technique quantification of regional myocardial function

    Institute of Scientific and Technical Information of China (English)

    刘娟

    2010-01-01

    @@ 心肌应变率成像(strain rate imaging,SRI)是在组织速度成像(tissue doppler imaging,TDI)基础上发展起来的一种定量评价局部心肌功能的超声技术.1998年,Heimdal等[1]首次报道采用实时超声应变率显像来评价左心室功能,从而为SRI在心脏超声领域的应用开辟了新窗口,至此SRI的应用一直是国际心脏超声的研究热点.现就近年来国内外这方面的研究进展及应用现状作一综述.

  7. Comparison of treatment for 153 cases of circumferential facial paralysis by low-power laser and galvan acupuncture

    Science.gov (United States)

    Li, Hai-Ling; Zhuo, Qing-shan

    1993-03-01

    Seventy-six patients were treated by low power He-Ne laser irradiation on Yangbai, Sibai, and other related acupoints. The other 77 cases were treated by Galvan-acupuncture with infrared radiation on the same acupoints. There was little difference between the therapeutic effects of these two groups (P > 0.05). However, the laser group had a much shorter treatment time than the other group. According to the theory of traditional Chinese medicine, circumferential facial paralysis is caused by exposure to cold which blocks the channel of vital energy resulting in the damage of bodily function. Acupuncture and moxibustion on certain acupoints can warm up the channels and remove the stasis allowing vital energy to pass through their passages to regulate bodily functions. Laser can do the same effectively with much less time. The laser therapy also features painlessness, safeness, and is free of bacteria. Circumferential facial paralysis is a common disease, which is clinically treated by acupuncture with reliable results. However, acupuncture is not fit for children who are not cooperative and those patients who are afraid of the pain accompanied with acupuncture. So we applied low power laser irradiation in the treatment of circumferential facial paralysis starting in 1985. The results were favorable. And the treatment time was shortened. The treatment procedures are reported.

  8. 三维斑点追踪成像技术评价急性前壁心肌梗死患者左心室收缩功能%Evaluation of Left Ventricular Systolic Function in Acute Anterior Myocardial Infarction with Three-dimensional Speckle Tracking Imaging

    Institute of Scientific and Technical Information of China (English)

    于蓝; 王银荣; 田永梅; 李玉宏

    2014-01-01

    Purpose To discuss the feasibility of evaluating left ventricular systolic function in patients with acute anterior myocardial infarction (AAMI) with three-dimensional speckle tracking imaging (3D-STI). Materials and Methods Thirty AAMI patients were examined with 3D-STI technique in terms of left ventricular longitudinal strain (LS), radial strain (RS), circumferential strain (CS), area strain (AS), global longitudinal strain (GLS), global riadial strain (GRS), global circumferential strain (GCS) and global area strain (GAS). The results were compared with those of 30 healthy persons and the strain values in normal segments of those AAMI patients. The threshold, sensibility and specificity of those parameters in diagnosing myocardial infarction were analyzed. Results Compared with healthy group, LS reduced in 12 out of 17 segments (12/17), RS reduced in 10/17, CS in 9/17 and AS in 11/17;they mainly focused in the base segment, middle and apex of anterior wall, the base segment and the middle of anterior septal, the apex of aboral septal, and the middle segment, apex of the lateral wall. The GLS, GRS, GCS and GAS were all lower than those in healthy group (differences with statistic signiifcance:P<0.05). In AAMI patient, LS, RS, CS and AS in the infarcted segments were lower compared with those in the normal segments (differences with statistic signiifcance:P<0.05). ROC curve analysis showed that the sensitivity of LS, RS, CS and AS were 89.2%, 79.0%, 77.9%, 85.3%, respectively in the diagnosis of myocardial infarction, and the speciifcity were 65.8%, 71.0%, 66.9%and 92.3%, respectively. The sensitivity of the GLS, GRS, GCS and GAS were 91.2%, 74.0%, 68.9%, 85.3%, respectively in the diagnosis of myocardial infarction, and the speciifcity were 69.8%, 71.0%, 76.9%and 93.3%, respectively. Conclusion 3D-STI can detect the strain values of LV segments efficiently and accurately so as to discriminate normal and infracted segments, which provides a reliable measurement

  9. Early-phase changes of P-wave characteristics after circumferential pulmonary vein isolation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liang; JIANG Wei-feng; ZHOU Li; LIU Xu

    2013-01-01

    Background Circumferential pulmonary vein isolation (CPVI),as the basal ablation strategy for treating atrial fibrillation (AF),not only isolates the connection between the left atrium (LA) and the pulmonary veins (PVs),but also induces extensive atrial endocardia damage.This could have an effect on the sinus pulse conduction in the LA and subsequently result in changes of P-wave characteristics of surface electrocardiogram (ECG).Methods Fifty consecutive patients underwent CPVI for symptomatic drug-refractory paroxysmal AF.The 12-lead ECGs were recorded one day before CPVI and seven days after CPVI at sinus rhythm by a standard resting ECG device.Measured characteristics of the P-wave consisted of P-wave duration (PWD),P-wave amplitude (PWA),P-wave polarity (PWP),P-wave notch,P-wave dispersion and P-wave index.Results After CPVI,a prevalent decrease of PWD,PWA,and P-wave dispersion was observed; a transition of P-wave polarity was observed in the leads of Ⅲ,aVL and aVF.The rate of P-wave notch decreased significantly in all leads,especially in the leads of Ⅱ,Ⅲ,aVF and V3.Patients with sinus rhythm had a shorter P-wave dispersion and P-wave index and had a lower rate of P-wave notch compared with the patients with recurrent atrial tachyarrhythmia.Conclusion Observations from using the surface ECG showed that CPVI has instant effects on the electrical conduction in the LA,and several changes of P-wave characteristics associated with development of AF are improved by CPVI.

  10. Single-stage Posterior Spondylectomy,Circumferential Decompression and Reconstruction Using Mesh Cage for Spinal Tumors

    Institute of Scientific and Technical Information of China (English)

    Yong Zhu; Hong Zhao; Giu-xing Qiu; Jian-guo Zhang; Ye Tian; Shu-gang Li; Suo-mao Yuan

    2009-01-01

    Objective To explore the feasibility and clinical results of circumferential decompression and threecolumn reconstruction through single-stage posterior transpedicular approach for spinal tumor treatment.Methods Totally,24 patients with spinal tumor underwent tumor resection and spinal reconstruction through single-stage posterior transpedicular approach.Preoperatively,according to the Frankel classification,12 patients were grade E,9 grade D,and 3 grade C.Anterior column was reconstructed with non-expandable titanium cages.Posterior segmental instrumentation was used to maintain the stability of spine in all cases.Anterior and posterolateral fusion was performed with autograft and allogenic bone.The following data were followed up in these patients:deformity angle,local recurrence,neurological function,and spinal bony fusion.Results The average operating time and blood loss was 5.6 hours and 3 400 ml respectively.No intraoperative and postoperative complications were observed in this group.Postoperatively,21 patients were Frankel grade E,2 grade D,and 1 grade C.Four patients reported significant functional restoration and twenty patients reported complete resolution of pain.At follow-up(range,6-42 months),implant failure or recurrent neurological symptoms was not found.Conclusions The tumor resection and spinal reconstruction through single-stage posterior transpedicular approach is a safe and effective technique for the treatment of spinal tumor.It can fully decompress the neurological structures,correct the kyphosis,and achieve early weight-bearing.This technique can improve life quality for the patients with spinal tumor.

  11. Different bone regeneration patterns in periimplant circumferential gap defects grafted with two types of osteoconductive biomaterial.

    Science.gov (United States)

    Lee, Jung-Seok; Sohn, Joo-Yeon; Lim, Hyun-Chang; Jung, Ui-Won; Choi, Seong-Ho

    2016-08-01

    This study aimed to determine healing patterns in periimplant gap defect grafted with demineralized bovine bone mineral (DBBM) and porous titanium granules (PTG), which are known to induce a minimal tissue reaction and to undergo minimal biodegradation in healing process. Experiments were performed using a standardized periimplant gap-defect model in dogs with two observational periods: 4 and 8 weeks. Circumferential defects were surgically induced around dental implants on unilateral mandibles in five dogs, and collagen barrier membranes were placed over the DBBM and PTG grafts at two experimental sites and over a nongrafted site. Four weeks later, the same procedures were performed on the contralateral mandible, and the animals allowed to heal for a further 4 weeks, after which they were sacrificed and their mandibles with graft/control sites harvested for histologic evaluation. Both types of grafted biomaterials significantly enhanced the defect fill with newly formed bone, but the bone-to-implant contact (BIC) was significantly increased only at sites that had been grafted with DBBM. The two experimental sites exhibited different healing patterns, with new bone formation being observed on the surface of the DBBM particles throughout the defect, while there was no de novo bone formation on the PTG surface, but rather appositional bone growth from the base and lateral walls of the defect. It has been suggested that gap-defect filling with DBBM around dental implants may enhance both BIC and defect fill; however, the present findings show that defect grafting with PTG enhances only defect fill and not BIC. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1202-1209, 2016. PMID:26087247

  12. A tissue-level model of the left ventricle for the analysis of regional myocardial function

    Science.gov (United States)

    Le Rolle, Virginie; Hernandez, Alfredo I.; Richard, Pierre-Yves; Donal, Erwan; Carrault, Guy

    2007-01-01

    This paper presents a model-based method for the analysis of regional myocardial strain, based on echocardiography and Tissue Doppler Imaging (TDI). A multi-formalism, tissue-level electromechanical model of the left ventricle is proposed. The parameters of the model are identified in order to reproduce regional strain signal morphologies obtained from a healthy subject and a patient presenting a dilated cardiomyopathy. The parameters identified for the DCM patient allow the localization of the failing myocardial segments and may be useful for a better design of cardiac resynchronization therapy on heart failure patients. PMID:18002171

  13. National registry of myocardial infarction

    OpenAIRE

    Amin Daemi; Mehdi Jafari

    2016-01-01

    The Registry of Myocardial Infarctions (MI Registry) is a national registry in Iran that collects and reports the data on myocardial infarctions. Its main advantage is that it covers the whole country and is mandatory for hospitals to register the MI cases in it. Then, the qualified individuals at the provincial and national levels can get intended reports and make appropriate decisions. Such reports, further to the policy makers and managers, can be very valuable for researchers. The regi...

  14. 10.11.Myocardial disease

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920088 Effect and significance of neuro-peptide Y on synthesis of myocardial pro-tein.WANG Tao (王涛),et al.Cardiovasc Lab,3rd Hosp,Beijing Med Univ.Chin Cir J 1991; 6 (5):354-356.The rate of myocardial protein synthesis andthe cardiac content of neuropeptide Y (NPY) inrats were measured by ~3H-leucine incorporation

  15. Intracoronary adenosine improves myocardial perfusion in late reperfused myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Myocardial perfusion associates with clinical syndromes and prognosis.Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours,but few data are available on late perfusion of myocardial infarction (MI).This study aimed at quantitatively evaluating the value of intracoronary adenosine improving myocardial perfusion in late reperfused MI with myocardial contrast echocardiography(MCE).Methods Twenty-six patients with anterior wall infarcts were divided randomly into 2 groups:adenosine group(n=12) and normal saline group(n=14).Their history of myocardial infarction was about 3-12 weeks.Adenosine or normalsaline was given when the guiding wire crossed the lesion through percutaneous coronary intervention(PCI),then the balloon was dilated and stent(Cypher/Cypher select)was implanted at the lesion.Contrast pulse sequencing MCE with Sonovue contrast via the coronary route was done before PCI and 30 minutes after PCI.Video densitometry and contrast filled-blank area were calculated with the CUSQ off-line software.Heart function and cardiac events were followed up within 30 days.Results Perfusion in the segments of the criminal occlusive coronary artery in the adenosine group was better than that in the saline group(5.71±0.29 vs 4.95±1.22,P<0.05).Ischemic myocardial segment was deminished significantly afterPCI,but the meliorated area was bigger in the adenosine group than in the saline group((1.56±0.60)cm2 vs(1.02±0.56) cm2,P<0.05).The video densitometry in critical segments was also improved significantly in the adenosine group (5.53±0.36 vs 5.26±0.35,P<0.05).Left ventricular ejection fraction(LVEF)was improved in all patients after PCI,but EF was not significant between the two groups((67±6)% vs(62±7)%,P>0.05).There was no in-hospital or 30-day major adverse cardiac event(MACE)in the adenosine group but 3 MACE in the saline group in 30 days after PCI.Conclusions Adenosine could improve myocardial microvascular

  16. Does postsystolic motion or shortening predict recovery of myocardial function after primary percutanous coronary intervention?

    DEFF Research Database (Denmark)

    Terkelsen, Christian Juhl; Poulsen, Steen Hvitfeldt; Nørgaard, Bjarne Linde;

    2007-01-01

    or shortening appears more frequently in the acute phase in myocardial segments with impaired systolic function compared with normally functioning segments. However, presence of postsystolic contraction is not associated with improvement in strain or wall-motion score at follow-up, and does not seem......OBJECTIVE: The purpose of the study was to evaluate whether presence of postsystolic motion or shortening defined by Doppler tissue imaging may predict recovery of regional myocardial function in patients with ST-elevation myocardial infarction. METHODS: Echocardiography was performed a few hours......); and normal myocardial function in the acute phase (type E, n = 759). RESULTS: There were no differences among type A, B, C, and D segments with regard to the proportion presenting postsystolic tissue velocity equal to or greater than 1.0 cm/s (0.52, 0.54, 0.60, and 0.47, respectively, P = .20...

  17. Quantification of myocardial infarct size by thallium-201 single-photon emission computed tomography: experimental validation in the dog

    International Nuclear Information System (INIS)

    To evaluate the potential advantages of thallium-201 (201T1) single-photon emission computerized tomography (SPECT) to assess myocardial infarct size in the experimental animal, six normal dogs and 14 dogs with 6 to 8 hr closed-chest coronary occlusion (eight left anterior descending and six left circumflex) were studied. Ten minutes after intravenous administration of 2 mCi of 201T1, 30 projections were obtained over 1800. The dogs were killed and their hearts sliced and stained by triphenyl tetrazolium chloride (TTC). Pathologic infarct size was calculated for each slice and for the entire left ventricular myocardium as percent weight. Tomograms were quantified by automatically generating maximum-count circumferential profiles, which were compared with normal limit profiles derived from the six normal dogs. Tomographic infarct size was defined as the percentage of circumferential points falling below normal for each tomogram. SPECT and TTC infarct size on 71 slices correlated highly (mean +/- SD 27.9 +/- 23.4% and 26.7 +/- 25.3%, respectively; r = .93, p less than .001, SEE = 9.4%). To determine SPECT infarct size as percent total left ventricular myocardial weight, infarct sizes from each slice were added to one another after each was multiplied by a coefficient that reflected the contribution of that slice to the total left ventricular weight. SPECT and TTC infarct size for the entire left ventricle correlated closely (mean +/- SD 20.5 +/- 7.6% and 19.3 +/- 8.3%, respectively; r = .86, p less than .001, SEE = 4.5%). It is concluded that 201T1 SPECT is a valid method for the noninvasive assessment of experimental myocardial infarct size

  18. Value of two-dimensional speckle tracking imaging in assessing myocardial injury in various degree of rats%二维超声斑点追踪成像评估大鼠不同程度心肌损伤的应用价值

    Institute of Scientific and Technical Information of China (English)

    付倩; 谢明星; 王新房; 吕清; 方凌云; 王静; 覃小娟

    2010-01-01

    -five Wistar rats were randomly divided into myocardial infarction(MI) group ( n =45) and sham-operation(SO) group ( n = 10).To establish rats acute myocardial infarction model with different infarct extent, MI group were randomly divided into MI15 group,MI30 group and ML60 group( n = 15,respectively) which underwent occlusion of left anterior descending coronary artery for 15 minutes, 30 minutes and 60 minutes respectively. Echocardiography was performed at baseline and 24 hours after reperfusion. High frame rate twodimensional images were recorded from the left ventricular short-axis views at the papillary muscle level.Left ventricular global circumferential strain(GSc) and strain rate(GSRc) were measured using EchoPAC work station. Left ventricular internal diameter at diastole (LVIDd) and systole ( LVIDs), fractional shortening(FS) and ejection fraction(EF) were measured by anatomical M-model echocardiography. Area of necrosis(AN) of each segment was measured after triphenyl tetrazolium chloride(TTC) staining. Results ① Compared with baseline and SO group, LVIDd and LVIDs of MI15, MI30 and MI60 group significantly increased respectively,whereas FS and EF significantly decreased( P <0. 05). Compared with MI15 group and MI30 group, LVIDd and LVIDs of MI60 group significantly increased, whereas FS and EF significantly decreased(P <0. 05). ② Compared with baseline and SO group,GSc and GSRc of MI15 group, MI30 group and MI60 group significantly decreased. GSc and GSRc of MI group decreased with ischemia duration ( P <0.05). ③ GSc and GSRc significantly correlated with AN respectively ( P <0. 01) while the correlation coefficient was 0. 90 and 0. 88 respectively, and GSc and GSRc were significantly predictors of AN( P <0.01) while the Beta was 0.558 and 0.491 respectively.④AN increased with ischemia duration( P <0.05). Conclusions Left ventricular global circumferential strain and strain rate index measured by 2D-STI,which decreased significantly as the area of necrosis

  19. CAD of myocardial perfusion

    Science.gov (United States)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  20. Rat myocardial protein degradation.

    Science.gov (United States)

    Steer, J H; Hopkins, B E

    1981-07-01

    1. Myocardial protein degradation rates were determined by following tyrosine release from rat isolated left hemi-atria in vitro. 2. After two 20 min preincubations the rate of tyrosine release from hemi-atria was constant for 4 h. 3. Skeletal muscle protein degradation was determined by following tyrosine release from rat isolated hemi-diaphragm (Fulks, Li & Goldberg, 1975). 4. Insulin (10(-7) M) inhibited tyrosine release from hemi-atria and hemi-diaphragm to a similar extent. A 48 h fast increased tyrosine release rate from hemi-diaphragm and decreased tyrosine release rate from hemi-atria. Hemi-diaphragm tyrosine release was inhibited by 15 mmol/l D-glucose but a variety of concentrations of D-glucose (0, 5, 15 mmol/l) had no effect on tyrosine release from hemi-atria. Five times the normal plasma levels of the branched-chain amino acids leucine, isoleucine and valine had no effect on tyrosine release from either hemi-atria or hemi-diaphragm.

  1. 二维应变方法对左心室心肌机械运动特性的观察%Mechanical motion characteristics of left ventricular myocardium in two-dimensional strain echocardiography

    Institute of Scientific and Technical Information of China (English)

    章晨; 孙寅光; 朱佳; 黄洁; 王琳; 葛卫力; 唐礼江

    2012-01-01

    目的 研究正常人心肌机械运动特性.方法 研究对象为60例正常志愿者,男34例,年龄(42.0±13.0)岁;女26例,年龄(37.0±10.0)岁,应用超声心动图二维斑点成像技术评价左心室纵向、径向和圆周向运动的心肌机械运动参数,包括收缩应变、收缩应变率和舒张应变率及其达峰时间.结果左心室收缩应变纵向运动和圆周向表现出自基底部至心尖部收缩应变的绝对值递增,纵向运动基底部、中间部至心尖部收缩应变的绝对值分别为:20.2±4.2,20.4±4.3,22.5±6.4(P<0.05);圆周向运动基底部、中间部至心尖部收缩应变的绝对值分别为:20.1±7.7,23.4±8.1,27.1±7.1(P<0.01),而径向运动的表现则不同,基底部、中间部与心尖部收缩应变的绝对值分别为40.9±17.4,41.8±17.6,28.8±17.1(P<0.01);3个方向的收缩应变率表现完全不一致,没有明显规律.3个方向舒张早期应变率均表现为自基底部至心尖部递增的趋势.重复性检验提示纵向收缩峰值应变,重复性最佳.结论心肌机械运动是一个极其复杂的过程,二维应变超声心动图有助于揭示生理和病理状态下心肌运动特性.%Objective To study myocardial characteristics of mechanical motion in normal subjects. Methods Sixty healthy volunteers were included,male 34 cases,aged (42. 0±13. 0) years;female 26 cases,aged (37. 0± 10, 0) years,two- dimensional speckle imaging technique was used to measure the left ventricular myocardial longitudinal, radial and circumferential movement of mechanical motion parameters including systolic strain,systolic strain rate and diatolic strain rates,as well as time-to-peak. Results The performance of left ventricular radial motion was different in absolute strain value, compared to longitudinal and circumferential systolic strains which increased from the base to the apex. The absolute value of longitudinal strain from base to apex respectively was 20. 2±4. 2,20. 4±4

  2. Myocardial infarction in children: Two interesting cases

    Directory of Open Access Journals (Sweden)

    Suryawanshi Suresh

    2011-01-01

    Full Text Available Myocardial infarction in children is extremely rare and can have various etiologies. The following two case reports highlight rare but important causes of myocardial infarction in children.

  3. Cryoinjury : a model of myocardial regeneration

    NARCIS (Netherlands)

    van Amerongen, Machteld J.; Hamsen, Martin C.; Petersen, Arien H.; Popa, Eliane R.; van Luyn, Marja J. A.

    2008-01-01

    Introduction: Although traditionally adult cardiomyocytes are thought to be unable to divide, recent observations provide evidence for cardiomyocyte proliferation after myocardial injury. Myocardial cryoinjury has been shown to be followed by neovascularization. We hypothesize that, in addition to n

  4. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Sujatha. M

    2015-12-01

    Full Text Available Introduction: The segment of epicardial coronary artery that traverses intramurally through the myocardium and bridged by a bunch of cardiac muscle fibers is called tunneled artery or intramural artery. The band of cardiac muscle fibers passing over the tunneled artery segment is named as myocardial bridge. During angiography milking effect is observed during systole due to the external pressure of muscle fibers on the tunneled artery that leads to narrowing of vessel lumen and further ischemia. Materials & Methods: It is a prospective study performed from 2012- 2015 in cardiac centers available around Tirupati, Andhra Pradesh, South India. A total number of 2015 adult patients who underwent diagnostic coronary angiography were evaluated to detect myocardial bridges. With the informed consent the relevant data was collected from the patients and analyzed. Results: The prevalence of myocardial bridges was 3.17%. Among the 2015 patients 70.7% are males and 29.2% are females. Among 64 myocardial bridge positive cases 62.5% were male and 37.5% were female patients. Regarding coronary dominance 84% were right dominant and 14.4% were left dominant and 1.6% are balanced. The percentage incidence of myocardial bridging according to dominance was 3.01% for right dominant patients, 4.12% for left dominant patients and 3.1% for balanced dominant patients. In all the myocardial bridge positive cases they were located on the left anterior descending artery (LAD. According to diagnosis the patients with normal coronaries were 22.6%, patients with MILD CAD were 17.9%, patients with single vessel disease were 23.4%, patients with two vessel disease were 14.7% and the patients with triple vessel disease were 21.3%. The 64 myocardial bridging cases were grouped in to three groups according to their age. Incidence of double bridges was observed in 3 cases of which 66.7% males & 33.3% in females. Conclusion: These results show that Andhra Pradesh population are

  5. Myocardial protection during heart surgery in China

    Institute of Scientific and Technical Information of China (English)

    Bingyang Ji; Jinping Liu

    2007-01-01

    @@ Myocardial protection (MP) is the key for cardiopulmonary bypass (CPB) heart surgery. MP during cardiac surgery (CS) aims to preserve myocardial function while providing a bloodless and motionless operating field. Strategies on how to attenuate or prevent post-ischemic myocardial dysfunction that occurs intra-operatively during CS have been discussed for more than half a century. In 1950, Bigelow et al1 first reported to decrease myocardial oxygen demand by means of hypothermia.

  6. Acute Myocardial Infarction Due To Electrical Injury

    OpenAIRE

    Uzkeser M et al.

    2011-01-01

    Rhythm abnormalities (conduction defects, tachycardia, and arrhythmia)due to electric shock are common. Rarely, myocardial infarction may beseen in these patients. This situation is generally caused by coronaryartery vasospasm and direct myocardial damage. In this report, wepresent a rare case of myocardial infarction due to electric shock.

  7. Fracture Toughness (K1C) evaluation for dual phase medium carbon low alloy steels using circumferential notched tensile (CNT) specimens

    OpenAIRE

    Kenneth Kanayo Alaneme

    2011-01-01

    The fracture behavior of dual phase medium carbon low alloy steels produced using two different chemical compositions (A - 0.34C, 0.75Mn, 0.12Cr, 0.13Ni steel and B - 0.3C, 0.97Mn, 0.15Cr steel) was investigated using circumferential notched tensile (CNT) specimens. Intercritical treatments were performed on samples with composition A by 1) austenitizing at 860 °C for 1 hour cooling in air, then treating at 770 °C for 30 minutes before oil quenching; 2) austenitizing at 860 °C for 1 hour quen...

  8. K{sub I}-T estimation for embedded flaws in pipes - Part II: Circumferentially oriented cracks

    Energy Technology Data Exchange (ETDEWEB)

    Qian Xudong, E-mail: cveqx@nus.edu.s [Department of Civil Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore)

    2010-04-15

    This paper, in parallel to the investigation on axially embedded cracks reported in the companion paper, presents a numerical study on the linear-elastic K{sub I} and T-stress values over the front of elliptical cracks circumferentially embedded in the wall of a pipe/cylindrical structure, under a uniform pressure applied on the inner surface of the pipe. The numerical procedure employs the interaction-integral approach to compute the linear-elastic stress-intensity factor (SIF) K{sub I} and T-stress values for embedded cracks with practical sizes at different locations in the wall of the pipe. The parametric study covers a wide range of geometric parameters for embedded cracks in the pipe, including: the wall thickness to the inner radius ratio (t/R{sub i}), the crack depth over the wall thickness ratio (a/t), the crack aspect ratio (a/c) and the ratio of the distance from the centerline of the crack to the outer surface of the pipe over the pipe wall thickness (e{sub M}/t). The parametric investigation identifies a significant effect of the remaining ligament length on both the T-stress and K{sub I} values at the crack-front location (denoted by point O) nearest to the outer surface of the pipe and at the crack-front location (denoted by point I) nearest to the inner surface of the pipe. The numerical investigation establishes the database to derive approximate functions from a nonlinear curve-fitting procedure to predict the T-stress and K{sub I} values at three critical front locations of the circumferentially embedded crack in a pipe: points O, I and M. The proposed T-stress and K{sub I} functions utilize a combined second-order polynomial and a power-law expression, which presents a close agreement with the T-stress and K{sub I} values computed from the very detailed finite element models. The comparison between the circumferentially embedded crack and the axially embedded crack indicates that both the T-stress and K{sub I} values at crack-front points O and

  9. Contribution to the Evaluation of the Circumferentially-Cracked Round Bar for Fracture Toughness Determination of Reactor Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, M

    1999-06-01

    The subject of this PhD dissertation is the use of the Circumferentially-Cracked Round Bar (CRB) for fracture toughness measurements. The main advantages of CRB are the relatively small size requirements of the testing specimens, the low cost to machine the specimen, the rotating bending fatigue allowing for easy precracking of specimens, the use of standard tensile test fixture and the axisymmetry of the specimen that avoids time consuming 3D finite element calculations. An in-depth study of the most widely used precracking technique for CRB, namely the rotating bending fatigue, is made.

  10. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill;

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...... in the anterior myocardial wall were (mean +/- SD) Ki = 54 +/- 10 ml/100 g/min, lambda = 30 +/- 3 ml/100 g, Vb = 9 +/- 2 ml/100 g, delta T = 3.2 +/- 1.1 s. These results are in good agreement with similar results obtained by other methods....

  11. Tissue Velocities and Myocardial Deformation in Asymptomatic and Symptomatic Aortic Stenosis

    DEFF Research Database (Denmark)

    Carstensen, Helle Gervig; Larsen, Linnea Hornbech; Hassager, Christian;

    2015-01-01

    BACKGROUND: Assessment of myocardial longitudinal function has proved to be a sensitive marker of deteriorating myocardial function in aortic stenosis, demonstrated by both color Doppler tissue imaging and recently by two-dimensional speckle-tracking echocardiography. The aim of this study...... was to compare velocity (color Doppler tissue imaging) and deformation (two-dimensional speckle-tracking echocardiography) in relation to global and regional longitudinal function in asymptomatic and severe symptomatic aortic stenosis. METHODS: In a cross-sectional design, 231 patients with aortic stenosis were...... = 59). RESULTS: Among all global (peak systolic s', diastolic e' and a', longitudinal displacement, and global longitudinal strain and strain rate) and regional longitudinal (basal, middle, and apical longitudinal strain and strain rate) parameters, only diastolic e', longitudinal displacement...

  12. Layer-specific strain assessment of early changes of left ventricular function in patients with hypertension%应用分层应变技术评价高血压患者左心室各层心肌功能的早期改变

    Institute of Scientific and Technical Information of China (English)

    魏常华; 丁晓; 朱好辉; 孙静平; 陈纪昀; 王一洒; 高帆; 屈雪蒸; 袁建军

    2015-01-01

    目的:探讨分层应变技术评价高血压患者左室三层心肌功能早期改变的应用价值。方法对38例左室构型正常的高血压患者和30例健康志愿者行二维超声心动图检查。常规测量并采集图像后应用 EchoPAC 113软件分析二维动态图像,获得左室18个节段的收缩期峰值圆周应变(CS)、纵向分层应变(LPS)及整体的全层应变值。结果常规测量参数:与对照组比较,高血压组左室射血分数(LVEF)、左室心肌质量指数(LVMI)、相对室壁厚度(RWT)和 E/e'增加(P 0.05);整体内层、中层心肌 CS 明显增强(P 0.05);整体全层 CS 增强(P 0.05);整体内层心肌 LPS 明显低于对照组(P 0.05)。结论分层应变技术可定量分层评价高血压患者左室心肌的整体及局部功能,具有一定的临床应用价值。%Objective To investigate the value of layer-specific strain in evaluation of the early changes of left ventricular three layers myocardial function in patients with hypertension.Methods In 38 patients with hypertension and 30 healthy volunteers (control group),two-dimensional echocardiography were performed.Left atrial diameter (LAD),left ventricular end systolic and diastolic diameter(LVIDs, LVIDd),left ventricular ejection fraction(LVEF),left ventricular myocardial mass index(LVMI),relative wall thickness (RWT ) and E/e' were obtained by two-dimensional echocardiography.Peak systolic circumferential strain(CS)and longitudinal strain(LPS)were determined for total wall thickness and for three myocardial layers(subendocardial,mid-myocardial and epicardial)in a 1 8-segment model by the off-line EchoPAC 1 13 software.Results LVEF,E/e',LVMI,RWT were higher in the hypertension group than those in the control group (P 0.05 ).Global CS of subendocardial and mid-myocardial were significant higher in the hypertension group than those in the control group(P 0.05). Global LPS of subendocardial layer was significantly lower in the

  13. Dynamic CT myocardial perfusion imaging.

    Science.gov (United States)

    Caruso, Damiano; Eid, Marwen; Schoepf, U Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie; Spandorfer, Adam; Laghi, Andrea; De Cecco, Carlo N

    2016-10-01

    Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  14. 二维应变成像技术评价冠心病患者经皮冠状动脉介入治疗手术前后局部心肌收缩功能的研究%Evaluation of regional myocardial systolic function in patients with coronary artery disease before and after percutaneous coronary intervention by two-dimensional strain imaging

    Institute of Scientific and Technical Information of China (English)

    刘莹莹; 陈立新; 刘启云; 姚琼; 冯程; 范海波; 李剑; 刘士龙

    2016-01-01

    Objective To evaluate regional myocardial systolic function in patients with coronary heart disease by two-dimensional strain imaging, and to compare their regional myocardial function before and after percutaneous coronary intervention (PCI). Methods Thirty-one patients diagnosed with coronary artery disease were treated with PCI surgery. Before and after PCI, they were performed echocardiography. According to the results of coronary angiography , myocardial segments were divided into four classes as the differences of coronary stenosis: ① no stenosis, no coronary stenosis; ②mild stenosis, coronary stenosis <50%; ③ moderate stenosis group, coronary stenosis ≥50%, and <70%; ④ severe stenosis, coronary stenosis ≥70%. Meantime, 20 healthy people were chosen as control group. The myocardial longitudinal strain(Speak) and strain rate(SRpeak) before and after PCI, were measured and compared. Results ①Among coronary heart disease patients, there was no significant difference in Speak between the mild coronary stenosis and the control group. While SRpeak of patients with mild coronary stenosis were lower than that of controls (P<0.05). ② Speak and SRpeak of patients with moderate coronary stenosis were significantly lower than that of normal controls(P<0.05); while Speak and SRpeak further lower in severe coronary artery stenosis group(P<0.05). ③ In PCI-intervention group(severe coronary artery stenosis group), Speak and SRpeak postoperative significantly increased than preoperative (P<0.05). However, in non PCI-intervention group, there was no significant difference in strain parameters before and after PCI. Conclusion The strain and strain rate index can accurately assess regional myocardial function in patients with coronary heart disease , and provide a new non-invasive means for PCI effect observation.%目的:运用二维应变成像技术评价冠状动脉粥样硬化性心脏病(冠心病)患者局部心肌收缩功能,并对其经皮冠

  15. Evaluation of Viable Myocardium by Two-dimensional Strain Combined with Low Dose Dobutamine Stress Echocardiography%多巴酚丁胺负荷二维应变评价心肌存活性的研究

    Institute of Scientific and Technical Information of China (English)

    卢岷; 王志刚; 冉海涛; 曹小玲; 张群霞; 孙幼屏; 李宜蓁

    2011-01-01

    目的 探讨二维应变技术联合负荷超声评价犬急性心肌缺血再灌注模型存活心肌的应用价值.方法 24只健康杂种犬,阻断其左冠状动脉前降支90 min后再灌注120 min.运用二维斑点追踪显像(speckle tracking imaging,SRI)分别检测静息状态、再灌注状态和小剂量多巴酚丁胺负荷状态下左室前壁、前间壁各节段收缩期峰值纵向应变(peak-systolic longitudinal strain,SLpeak)、径向应变(peak-systolic radial strain,SRpeak)、圆周应变(peak-systolic circumferential strain,SCpeak).以用氯化三苯基四氮唑(2,3,5-triphenyltetrazoliumchloride,TTC)和伊文思蓝(Evans blue,EB)染色结果为标准,将前壁、前间隔各节段分为存活节段组和非存活节段组.结果 (1)基础状态下,存活节段组和非存活节段组之间SLpeak、SRpeak、SCpeak无显著性差异(P>0.05);(2)再灌注后,存活组和非存活组SLpeak、SRpeak、SCpeak均降低,但两组比较无显著性差异(P>0.05);(3)与负荷试验前比较,多巴酚丁胺负荷后存活节段组SLpeak、SRpeak、SCpeak显著性增加(P<0.05),非存活节段组各指标无明显变化(P>0.05);存活节段组与非存活节段组比较有显著性差异(P<0.05).结论 小剂量多巴酚丁胺负荷超声联合二维应变可准确评价心肌存活性.%Objective To evaluate the myocardial viability by two-dimensional strain combined with low dose dobutamine stress echocardiography. Methods In twenty four anesthetized mongrel dogs, the left anterior descending artery was occluded for 90 min followed by 120 min reperfusion. Two-dimensional strain of anterior wall and anterior septum, include peak systolic longitudinal strain (Slpeak), circumferential strain (Scpeak) and radial strain (Srpeak), were measured at baseline, after reperfusion and dobutamine stress. To assess viable or nonviable myocardium, triph-enyl tetrazolium chloride (TTC) and Evans blue staining were applied. Results During baseline

  16. Dynamic changes in myocardial matrix metalloproteinase activity in mice with viral myocarditis

    Institute of Scientific and Technical Information of China (English)

    MENG Xiao-hui 孟晓慧; SONG Guo-jie 宋国杰; WANG Yi 汪翼; ZHUANG Jian-xin 庄建新; HAN Xiu-zhen 韩秀珍; CHEN Yao 陈瑶; JIN You-peng 靳有鹏; WANG Yu-lin 王玉林; YU Yong-hui 于永慧; James P. Spires

    2004-01-01

    Background Matrix metalloproteinases (MMPs) are the major regulators of collagen degradation involved in the pathogenesis of several diseases of the heart. The purpose of this study was to investigate the dynamic changes in myocardial MMP activity in mice with viral myocarditis (VM), the relationship between MMP activity and both cardiac function and the quantity of myocardial collagen, and the role MMPs playing in the pathological lesions of VM.Methods Sixty-five six-week-old male DBA/2 mice were divided into two groups. Mice in the infected group (n=50) were inoculated intraperitoneally with 0.14 ml of Coxsackievirus B3 (CVB3, Nancy strain). Control mice (n=15) were inoculated intraperitoneally with 0.14 ml of Eagle's medium. Eight infected mice and three control mice were sacrificed on each of days 3, 7, 10, 21 and 30 after inoculation. MMP activity was measured on an SDS-PAGE substrate gel embedded with type Ⅰ gelatin (zymography). Echocardiographic studies were performed under anesthesia with 3% chloralhydrate administered intraperitoneally (0.01 ml/g-0.015 ml/g). Cardiac systolic function indices, such as peak velocity of the aorta (Vp), flow velocity integral of the aorta (Vi), ejection fraction (EF), and fractional shortening (FS) were determined by echocardiography. Histological cross sections of the hearts were stained with hematoxylin-eosin and myocardial histopathological scores were determined under an optical microscope. The amount of myocardial collagen was measured by means of hydroxyproline quantification. Results In virus-infected mice, both MMP-2 and MMP-9 activities were significantly higher than in control mice, reaching a peak on day 10 (P0.05). However, the amount of myocardial collagen in infected mice at the recovery stage (on days 21 and 30) was significantly greater than those of the control mice. MMP-2 and MMP-9 activities positively correlated with myocardial histopathological scores (r=0.801,0.821, P<0.01) and negatively correlated

  17. Design and Testing of the Strain Transducer for Measuring Deformations of Pipelines Operating in the Mining-deformable Ground Environment

    Directory of Open Access Journals (Sweden)

    Gawedzki Waclaw

    2015-10-01

    Full Text Available Design and laboratory test results of the strain transducer intended for monitoring and assessing stress states of pipelines sited in mining areas are presented in this paper. This transducer allows measuring strains of pipelines subjected to external forces - being the mining operations effect. Pipeline strains can have a direct influence on a tightness loss and penetration of the transported fluid into the environment. The original strain gauge transducer was proposed for performing measurements of strains. It allows measuring circumferential strains and determining the value and direction of the main longitudinal strain. This strain is determined on the basis of measuring component longitudinal strains originating from axial forces and the resultant bending moment. The main purpose of investigations was the experimental verification of the possibility of applying the strain transducer for measuring strains of polyethylene pipelines. The obtained results of the transducer subjected to influences of tensile and compression forces are presented and tests of relaxation properties of polyethylene are performed.

  18. The Aerodynamic Performance of an Over-the-Rotor Liner With Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

    Science.gov (United States)

    Bozak, Richard F.; Hughes, Christopher E.; Buckley, James

    2013-01-01

    While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1 percent which is within the repeatability of this experiment.

  19. Refinement and evaluation of crack-opening-area analyses for circumferential through-wall cracks in pipes

    International Nuclear Information System (INIS)

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for crack-opening-area analyses of pipes with circumferential through-wall cracks. Twenty-five pipe experiments were analyzed to determine the accuracy of the predictive models. Several practical aspects of crack-opening such as; crack-face pressure, off-center cracks, restraint of pressure-induced bending, cracks in thickness transition regions, weld residual stresses, crack-morphology models, and thermal-hydraulic analysis, were also investigated. 140 refs., 105 figs., 41 tabs

  20. A maximum likelihood approach to diffeomorphic speckle tracking for 3D strain estimation in echocardiography

    NARCIS (Netherlands)

    A.H. Curiale (Ariel H.); G. Vegas-Sanchez-Ferrero (Gonzalo); J.G. Bosch (Johan); S. Aja-Fernández (Santiago)

    2015-01-01

    textabstractThe strain and strain-rate measures are commonly used for the analysis and assessment of regional myocardial function. In echocardiography (EC), the strain analysis became possible using Tissue Doppler Imaging (TDI). Unfortunately, this modality shows an important limitation: the angle b

  1. Reproducibility and observer variability of tissue phase mapping for the quantification of regional myocardial velocities.

    Science.gov (United States)

    Lin, Kai; Chowdhary, Varun; Benzuly, Keith H; Yancy, Clyde W; Lomasney, Jon W; Rigolin, Vera H; Anderson, Allen S; Wilcox, Jane; Carr, James; Markl, Michael

    2016-08-01

    To systematically investigate the reproducibility of global and segmental left ventricular (LV) velocities derived from tissue phase mapping (TPM). Breath held and ECG synchronized TPM data (spatial/temporal resolution = 2 × 2 mm(2)/20.8 ms) were acquired in 18 healthy volunteers. To analyze scan-rescan variability, TPM was repeated in all subjects during a second visit separated by 16 ± 5 days. Data analysis included LV segmentation, and quantification of global and regional (AHA 16-segment modal) metrics of LV function [velocity-time curves, systolic and diastolic peak and time-to-peak (TTP) velocities] for radial (Vr), long-axis (Vz) and circumferential (VΦ) LV velocities. Mean velocity time curves in basal, mid-ventricular, and apical locations showed highly similar LV motion patterns for all three velocity components (Vr, VΦ, Vz) for scan and rescan. No significant differences for both systolic and diastolic peak and TTP myocardial velocities were observed. Segmental analysis revealed similar regional peak Vr and Vz during both systole and diastole except for three LV segments (p = 0.045, p = 0.033, and p = 0.009). Excellent (p TPM based analysis of global and regional myocardial velocities can be performed with good reproducibility. Robustness of regional quantification of long-axis velocities was limited but spatial velocity distributions across the LV could reliably be replicated. PMID:27116238

  2. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  3. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  4. The Orchestra of Myocardial Regeneration

    NARCIS (Netherlands)

    Siddiqi, S.

    2014-01-01

    A glimpse on previous and current literature ignites the recognition of the luxurious era that cardiac science has reached. In particular, the past fifteen years have provided tremendous advancements in the field of myocardial biology with the characterization of cardiac stem cells, reprogramming of

  5. Spousal Adjustment to Myocardial Infarction.

    Science.gov (United States)

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  6. Neonatal Myocardial Infarction or Myocarditis?

    NARCIS (Netherlands)

    de Vetten, Leanne; Bergman, Klasien A.; Elzenga, Nynke J.; van Melle, Joost P.; Timmer, Albertus; Bartelds, Beatrijs

    2011-01-01

    We report a 29 week-gestation preterm infant who presented during his second week of life with cardiogenic shock. Clinical presentation and first diagnostics suggested myocardial infarction, but echocardiographic features during follow-up pointed to a diagnosis of enteroviral myocarditis. The child

  7. Myocardial ischemia and angina pectoris

    International Nuclear Information System (INIS)

    Ambulatory monitoring of ST segment changes was performed in 60 patients presenting with angina, positive ECG stress tests and coronary artery disease, 85% of ischemic ECG events were asymptomatic, 37% occurred with no increase in heart rate and 15% of episodes either lasted 20 minutes or more or fluctuated in severity. A controlled pilot study in ten patients showed depression. Radionuclide studies in 50 patients with angina and coronary artery disease have shown that stress (i.e., atrial pacing) produced different patterns of disturbed regional myocardial perfusion related to the patient's exercise capacity and eventually leading to a decrease in regional myocardial perfusion during the ischemic episode. ST segment depression appeared only after the decrease in regional myocardial perfusion. These findings combined with past research suggest that patients with angina and coronary artery disease can suffer frequent asymptomatic disturbances of the regional myocardial perfusion. The frequency of these episodes and the time course for the recovery of the metabolic consequences mean that segments of ventricular myocardium may be constantly abnormal. The relative importance of changes in coronary tone and malfunction of platelets in the diseased coronary tree needs to be examined in clinical research. Pilot studies of antiplatelet agents have shown a significant beneficial effect on episodes of ischemia occurring at night and those occurring without any increase in heart rate. The techniques and observations in these patients with coronary artery disease all suggest that acute transient regional myocardial ischemia is caused by a variety of mechnisms. Further research using objective methods is required to discover the causes of ischemia and to rationalize treatment. (orig./MG)

  8. Biochemical Markers of Myocardial Damage.

    Science.gov (United States)

    Bodor, Geza S

    2016-04-01

    Heart diseases, especially coronary artery diseases (CAD), are the leading causes of morbidity and mortality in developed countries. Effective therapy is available to ensure patient survival and to prevent long term sequelae after an acute ischemic event caused by CAD, but appropriate therapy requires rapid and accurate diagnosis. Research into the pathology of CAD have demonstrated the usefulness of measuring concentrations of chemicals released from the injured cardiac muscle can aid the diagnosis of diseases caused by myocardial ischemia. Since the mid-1950s successively better biochemical markers have been described in research publications and applied for the clinical diagnosis of acute ischemic myocardial injury. Aspartate aminotransferase of the 1950s was replaced by other cytosolic enzymes such as lactate dehydrogenase, creatine kinase and their isoenzymes that exhibited better cardiac specificity. With the availability of immunoassays, other muscle proteins, that had no enzymatic activity, were also added to the diagnostic arsenal but their limited tissue specificity and sensitivity lead to suboptimal diagnostic performance. After the discovery that cardiac troponins I and T have the desired specificity, they have replaced the cytosolic enzymes in the role of diagnosing myocardial ischemia and infarction. The use of the troponins provided new knowledge that led to revision and redefinition of ischemic myocardial injury as well as the introduction of biochemicals for estimation of the probability of future ischemic myocardial events. These markers, known as cardiac risk markers, evolved from the diagnostic markers such as CK-MB or troponins, but markers of inflammation also belong to these groups of diagnostic chemicals. This review article presents a brief summary of the most significant developments in the field of biochemical markers of cardiac injury and summarizes the most recent significant recommendations regarding the use of the cardiac markers in

  9. Study progress of cardiac MRI technology in assessment of myocardial viability after myocardial infarction

    International Nuclear Information System (INIS)

    Acute myocardial infarction (AMI) is one of the most common diseases that cause disability and death around the world. Correctly and effectively assessing the myocardial viability after myocardial infarction can reduce the disabled rate and mortality rate. At present, many methods could be used to assess myocardial viability. The cardiac magnetic resonance imaging (CMR) technology has a lot of advantages compared to other methods. In this paper, we reviewed the research progress of CMR in assessment of myocardial viability after myocardial infarction, and compared CMR with other technologies. (authors)

  10. Assessment of Right Ventricular Free Wall Longitudinal Myocardial Deformation Using Speckle Tracking Imaging in Normal Subjects

    Institute of Scientific and Technical Information of China (English)

    Chun TONG; Chunlei LI; Jialin SONG; Hongyun LIU; Youbin DENG

    2008-01-01

    To assess right ventricular free wall longitudinal myocardium deformation and examine the changes with normal age by speckle tracking imaging (STI), myocardial systolic peak strain (ε), systolic peak strain rate (SRs), early diastolic peak strain rate (Sre), late diastolic peak strain rate (Sra), the ratio of Sre/Sra were measured in the basal, middle and apical segments of right ventricular free wall in 75 healthy volunteers (age range: 21-71 y) by STI from the apical 4-chamber view. RV longitudinal strain and strain rate were highest in the basal segment of the free wall. Older subjects had lower early diastolic strain rate (Sre) than younger subjects, but they had higher late diastolic strain rate (Sra). A negative correlation between age and the ratio of Sre/Sra was found in all RV free wall segments (r=-0.466 - -0.614, P<0.01). It is concluded that RV diastolic strain rate changes with age and STI can be used for the study of RV myocardial deformation.

  11. Circumferential fusion is dominant over posterolateral fusion in a long-term perspective: cost-utility evaluation of a randomized controlled trial in severe, chronic low back pain

    DEFF Research Database (Denmark)

    Soegaard, Rikke; Bünger, Cody E; Christiansen, Terkel;

    2007-01-01

    STUDY DESIGN: Cost-utility evaluation of a randomized, controlled trial with a 4- to 8-year follow-up. OBJECTIVE: To investigate the incremental cost per quality-adjusted-life-year (QALY) when comparing circumferential fusion to posterolateral fusion in a long-term, societal perspective. SUMMARY...... no significant difference between posterolateral and circumferential fusion reporting cost-effectiveness from a 2-year viewpoint. METHODS: A total of 146 patients were randomized to posterolateral or circumferential fusion and followed 4 to 8 years after surgery. The mean age of the cohort was 46 years (range...... of the labor market due to sickness. The EQ-5D instrument was applied for the measurement of health-related quality of life and costs (2004 U.S. dollars) were measured in a full-scale societal perspective. Productivity costs were valued by the Friction Cost method, and both costs and effects were discounted...

  12. Comparison of circumferential pulmonary vein anatomy mapping guided by 3D mapping versus a mesh mapping catheter

    Institute of Scientific and Technical Information of China (English)

    Yi-Wen Yan a; Gang Chen a; Feng Zhang; Song-Wen Chen; Wei-Dong Meng; Shao-Wen Liu

    2015-01-01

    Objective: Catheter-based pulmonary vein isolation (PVI) is an established therapy for paroxysmal atrial fibrillation. The high-density mesh mapper (HDMM) guides circumferential PV-atrium isolation without the 3D electroanatomic mapping. This study aims to compare circumferential pulmonary vein (CPV) anatomy mapping between guiding by a 3D mapping system and the HDMM. Methods: Forty-four consecutive patients with paroxysmal atrial fibrillation were scheduled for a first procedure for PVI. A CPV ostial anatomy map guided by HDMM was set up in the CARTO system while the operator was blinded to the CARTO screen. Then CARTO-guided ipsilateral PV maps were obtained and PVI was performed. This established another set of CPV ostial anatomy maps. The differences between the two mapping images were compared and analyzed. Results: All 176 PVs in 44 patients could be mapped by both HDMM and CARTO. About 44.9%of the PV ostial anatomies were generally similar between the two different map images. The average point-to-point straight distance between the HDMM-guided map and the CARTO-guided map was 6.2 ± 1.4 mm. The area of the circumferential right PV (CRPV) in the HDMM map was larger than that in the CARTO map (P ¼ 0.013). After a mean follow-up of 18.3 ± 4.3 months (6e24 months), 72.7%of patients (32/44) were free of atrial arrhythmia without anti-arrhythmic drugs (AADs). Conclusion: Compared to the CARTO-guided CPV anatomy image, a highly similar figure could be achieved by mapping guided by the HDMM. (Clinical trial.gov number, ChiCTR-TNRC-11001390.) Copyright © 2015, Chinese Medical Association Production. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

  13. Early posterior spinal canal decompression and circumferential reconstruction of rotationally unstable thoracolumbar burst fractures with neurological deficit

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guo-quan; WANG Yan; TANG Pei-fu; ZHANG Yong-gang; ZHANG Xue-song; GUO Yi-zhu; TAO Sheng

    2013-01-01

    Background Among the various treatments of neurologically involved unstable thoracolumbar burst fractures,the combination of anterior and posterior instrumentation provides the most stable reconstruction.However,the use of both approaches on a trauma patient may increase the morbidity.This study is a retrospective matched cohort study to evaluate the advantages of a single stage posterior approach for spinal canal decompression in combination with circumferential reconstruction by comparing the clinical and radiographic results.Methods From March 2005 to September 2009,patients with matched type spinal fracture,ages at surgery,and involved levels in our institute underwent either a single stage posterior approach (group one,n=12) or traditional combined approach (group two,n=14) for spinal canal decompression and circumferential reconstruction were reviewed.Pre-and post-operative X-ray films were reviewed and changes in Cobb angle of thoracolumbar spine were documented.Intra-operative,post-operative,and general complications were registered.Results The mean follow-up was (27.7±9.6) months (range,14 to 56 months) in group one and (29.2±7.4) months (range,20 to 60 months) in group two (P >0.05).The mean operation time was 214 minutes (range,186-327 minutes) in group one and 284 minutes (range,219-423 minutes) in group two (P <0.05).The average volume of intraoperative blood loss was 1856 ml (range,1250-3480 ml) in group one and 2453 ml (range,1600-3680 ml) in group two (P <0.05).There was no statistical difference between the groups one and two in average vertebral body height loss at the injured level and the average Cobb angle in sagittal plane before and immediately after surgery.Postoperatively,there was an epidural hematoma in one patient in group one and two patients in group two.Bony union after stabilization was obtained in all patients,without loosening or breakage of screws.Loss of correction (5°) was seen in 1 patient in group one at the 6th month

  14. Chasing myocardial outcomes: perioperative myocardial infarction and cardiac troponin.

    Science.gov (United States)

    Royo, Marc B; Fleisher, Lee A

    2016-02-01

    Perioperative myocardial infarction represents the most common cardiovascular complication following non-cardiac surgery, but frequently presents without the usual clinical signs and symptoms consistent with acute coronary syndrome. Given the silent nature of this event, a clinician's reliance on risk stratification tools and cardiac specific biomarkers to assist in the identification of at-risk individuals is heightened in the perioperative setting. Although cardiac troponin elevations following non-cardiac surgery have been consistently linked to increased mortality, uncertainty remains over how to clinically intervene to prevent harm. This decision is further complicated by the increasing sensitivity of the newest generation of cardiac biomarker immunoassays. In this narrative review, the growing body of evidence surrounding cardiac troponin elevations in the perioperative setting, how the evidence has been integrated into recent clinical practice guidelines, and its implications for the detection of perioperative myocardial infarction are discussed. PMID:26634279

  15. Assessment of myocardial perfusion and systolic function in patients with coronary artery disease after percutaneous coronary intervention by real-time myocardial contrast echocardiography and two-dimensional strain echocardiography%实时心肌超声造影结合二维应变评价经皮冠状动脉重建术后心肌灌注与收缩功能改变

    Institute of Scientific and Technical Information of China (English)

    钱建芬; 汤裕华; 林银康

    2012-01-01

    目的 应用实时心肌超声造影(RT-MCE)结合二维应变(2DS)、左心室射血分数(LVEF)评价急性心肌梗死经皮冠状动脉介入术(PCI)后心肌灌注情况与收缩功能的变化.方法对45例急性心肌梗死患者PCI术后1周内行RT-MCE,按照目测定性和半定量法将所有患者分成再灌注良好组、无灌注组和再灌注减弱组,采用Qlab软件计算出各组心肌的充盈速度和心肌的血容量.3组术后3个月复查常规超声心动图测量LVEF及应用2DS软件测量各个节段的收缩期纵向峰值应变(SRs),并将3组LVEF和SRs进行比较.结果 心肌再灌注良好组术后3个月LVEF为(0.60±0.06)%,较术后1周LVEF(0.54±0.05)%增大,差异有统计学意义( t=3.402,P<0.01).术后3个月时,心肌灌注良好组LVEF、左心室心肌SRs分别为(0.60±0.06)%、(-0.96±0.35)s-1,无灌注组分别为(0.41±0.08)%、(-0.43±0.14)s-1,两组比较差异有统计学意义(t= 2.819、3.214,P均<0.01);心肌灌注减弱组LVEF、左心室心肌SRs分别为(0.53±0.05 )%、(-0.59±0.31)s-1,与无灌注组比较差异有统计学意义(t= 2.209、2.418,P<0.05).结论 PCI术后心肌灌注改善与否可以反映心肌功能恢复的趋势,而2DS可较好地定量评价局部心肌收缩功能.%Objective To assess the changes of myocardial perfusion and systolic function in patients with acute myocardial infarction after revascularization by real -time intravenous myocardial contrast echocardiography ( RT-MCE) combined with 2D-3train(2DS). Methods Forty-five patients were examined by RT-MCE within one week after percutaneous coronary intervention (PCI). These patients were divided into groups according to qualitation and demi-quantitation method. The myocardial filling speed and blood volume were calculated by Qlab software. Three months later, the echocardiography was rechecked again to measure the left ventricular ejection fraction (LVEF) and 2DS was used to measure the SRs of every segment of left

  16. Numerical simulation and experimental investigation of temperature distribution in the circumferentially butt GTAW of Incoloy 800H pipes

    International Nuclear Information System (INIS)

    The multi-pass circumferential butt GTAW process of Incoloy 800H pipes was modelled with the FEM in 3D. The element birth and death technique was used for the addition of filler material. Goldak model was used to simulate the distribution of arc heat source. The validation of the simulation model was carried out based on the precise temperature measurements within the HAZ of the welds by thermocouples as well as metallographic characterisation of the cross section of the welds. A good agreement was found between the simulation and experimental results for both thermal field and weld zone shape. The present model showed that increasing the heat input resulted in a wider weld zone as well as a higher HAZ peak temperature. These effects were related to the net heat input and not to either welding current or welding speed, individually. The developed simulation model is a useful tool to investigate the welding thermal regime and the weld pool profile.

  17. Transverse shear effects on the stress-intensity factor for a circumferentially cracked, specially orthotropic cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1977-01-01

    The problem of a cylindrical shell containing a circumferential through crack is considered by taking into account the effect of transverse shear deformations. The formulation is given for a specially orthotropic material within the confines of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions regarding moment and stress resultants on the crack surface. Consequently, aside from multiplicative constants representing the stress intensity factors, the membrane and bending components of the asymptotic stress fields near the crack tip are found to be identical. The stress intensity factors are calculated separately for a cylinder under a uniform membrane load, and that under a uniform bending moment. Sample results showing the nature of the out-of-plane crack surface displacement and the effect of the Poisson's ratio are presented.

  18. Ductile fracture behavior of 3-inch diameter carbon steel piping with a circumferential through-wall crack under bending load

    International Nuclear Information System (INIS)

    In order to introduce Leak-Before-Break (LBB) concept into the piping design criteria of the LWR pressure boundary pipings, it is necessary to investigate the pipe fracture behaviors, such as fracture condition and crack opening area, etc. At JAERI, pipe fracture tests of stainless steel and STS42 carbon steel pipes under bending load have been conducted as a part of the LBB research program. This report summarizes the four-point bending test results of 3-inch diameter STS42 carbon steel pipe with a circumferential through-wall crack. Tests were carried out at room temperature. In the tests, the fracture behavior of pipes was investigated to evolute the validity of Net-section collapse criterion, J-R curve and crack opening area. It is shown that the Net-section collapse criterion gives a conservative evaluation for the fracture load of 3-inch diameter carbon steel pipes. (author)

  19. The stability of growth of a through-wall circumferential crack in a cylindrical pipe subjected to bending deformation

    International Nuclear Information System (INIS)

    Tada, Paris and Gamble have used the tearing modulus approach to examine the stability of growth of a through-wall circumferential crack in a 304 stainless steel circular cylindrical pipe subject to bending deformation. They showed that crack growth is stable, in the sense that growth requires the rotation imposed at the pipe-ends to be increased, provided the pipe length is less than a critical length Lsub(c), which is given by their analysis. The Tada-Paris-Gamble analysis focuses on the question of the stability, or otherwise, of crack growth at the onset of crack extension. The analysis does not consider the possibilities that (a) instability might occur after some stable crack growth, and (b) arrest might occur after some unstable growth. A study of these aspects of the circumferential crack growth problem using the tearing modulus approach is precluded by the geometry dependence of the J-crack growth resistance curve. Consequently the present paper uses a crack tip opening angle criterion to describe crack growth, and thereby demonstrates that possibilities (a) and (b) should both occur, depending on the initial crack length and pipe length. In terms of relevance to the technologically important problem of cracking in Boiling Water Reactor piping, the important conclusion stemming from the paper's analysis is that stability of crack growth after the onset of crack extension is assured if the pipe length is less than a critical length L'sub(c). L'sub(c) is less than Lsub(c), the critical length relevant to the onset of crack extension, but it is still appreciably greater than the pipe run lengths in actual reactor piping systems, and safety against guillotine failure of a pipe is therefore generally assured. (author)

  20. OUTCOME OF POSTEROLATERAL FUSION VERSUS CIRCUMFERENTIAL FUSION WITH CAGE FOR LUMBAR STENOSIS AND LOW DEGREE LUMBAR SPONDYLOLISTHESIS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To evaluate the outcome of two methods for stabilization and fusion: posterolateral fusion and circumferential fusion involving posterior lumbar interbody fusion for lumbar stenosis with Grades 1 and 2 lumbar spondylolisthesis. Methods From April 1998 to April 2003, 45 patients suffering from lumbar stenosis with low degree lumbar spondylolisthesis treated in our hospital were retrospectively reviewed and assigned to two groups. Among them, 24 patients (group A) were treated with instrumented posterolateral fusion and 21 patients (group B) with instrumented circumferential fusion. The two groups were compared for clinical and radiological outcomes. Results All patients were followed up for 12 to 72 months. In group A, results showed preoperative clinical symptoms disappeared completely in 12 of 24 patients, and pain relief was seen in 91.7% (22/24). Two cases suffered from residual symptoms. Twenty-two cases obtained complete reduction of olisthy vertebral bodies, and anatomical reduction rate was 91.7%. No infection or neurological complication occurred in this group. In group B, results showed preoperative clinical symptoms disappeared completely in 13 of 21 patients, and pain relief was seen in 90. 5% ( 19/21 ). One case suffered from residual symptoms. Twenty cases obtained complete reduction of the olisthy vertebral bodies, and anatomical reduction rate was 95.2%. Four cases of infection or neurological complication occurred in this group. Both groups indicated no significant difference in clinical outcomes and anatomical reduction rate during followup. But group A had better intraoperative circumstances and postoperative outcome than group B, while group B had better postoperative parameters in X-ray of Angle of Slipping and Disc Index than group A.Conclusions The first choice of surgical method for lumbar stenosis with low degree lumbar spondylolisthesis is instrumented posterolateral fusion. Only when patients suffer from severe preoperative disc

  1. Mortality rate in type 2 myocardial infarction

    DEFF Research Database (Denmark)

    Saaby, Lotte; Poulsen, Tina Svenstrup; Diederichsen, Axel Cosmus Pyndt;

    2014-01-01

    BACKGROUND: The classification of myocardial infarction into 5 types was introduced in 2007. The prognostic impact of this universal definition, with particular focus on type 2 myocardial infarction, has not been studied prospectively in unselected hospital patients. METHODS: During a 1-year period......, all hospitalized patients having cardiac troponin I measured were considered. The diagnosis of a myocardial infarction was according to the universal definition, and specified criteria were used in the classification of type 2 myocardial infarction. Follow-up was at least 1 year, with mortality...... as the end point. RESULTS: A total of 3762 consecutive patients were studied, of whom 488 (13%) had a myocardial infarction. In 119 patients a type 2 myocardial infarction was diagnosed. After a median of 2.1 years (interquartile range, 1.6-2.5 years), 150 patients had died, with a mortality rate of 49% (58...

  2. Novel adjunctive treatments of myocardial infarction

    DEFF Research Database (Denmark)

    Schmidt, Michael Rahbek; Pryds, Kasper; Bøtker, Hans Erik

    2014-01-01

    Myocardial infarction is a major cause of death and disability worldwide and myocardial infarct size is a major determinant of prognosis. Early and successful restoration of myocardial reperfusion following an ischemic event is the most effective strategy to reduce final infarct size and improve...... by endovascular infusion of cold saline all reduce infarct size and may confer clinical benefit for patients admitted with acute myocardial infarcts. Equally promising, three follow-up studies of the effect of remote ischemic conditioning (RIC) show clinical prognostic benefit in patients undergoing coronary...... clinical outcome, but reperfusion may induce further myocardial damage itself. Development of adjunctive therapies to limit myocardial reperfusion injury beyond opening of the coronary artery gains increasing attention. A vast number of experimental studies have shown cardioprotective effects of ischemic...

  3. Depressive Symptoms Are Associated with Mental Stress-Induced Myocardial Ischemia after Acute Myocardial Infarction

    OpenAIRE

    Jingkai Wei; Pratik Pimple; Shah, Amit J.; Cherie Rooks; Douglas Bremner, J.; Nye, Jonathon A.; Ijeoma Ibeanu; Nancy Murrah; Lucy Shallenberger; Paolo Raggi; Viola Vaccarino

    2014-01-01

    Objectives Depression is an adverse prognostic factor after an acute myocardial infarction (MI), and an increased propensity toward emotionally-driven myocardial ischemia may play a role. We aimed to examine the association between depressive symptoms and mental stress-induced myocardial ischemia in young survivors of an MI. Methods We studied 98 patients (49 women and 49 men) age 38–60 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion ...

  4. [Myocardial infarction caused by exertion].

    Science.gov (United States)

    Bernard, F; Weber, S

    1997-01-01

    Myocardial infarction is the main cause of sudden death during physical exercise, particularly in subjects over 40 and may even occur in high-performance young athletes. Sports and physical activity have a beneficial effect in preventing cardiovascular diseases, but certain rules of prudence must be followed to avoid the risk of a severe coronary event. Myocardial infarction always occurs in particularly susceptible subjects with several risk factors, predominantly smoking, hypercholesterolemia, family history of atherosclerosis. Dietary factors, either before, during or after the exercise, are always found. Distribution of coronary lesions differs with age. Before 40 years, the coronary network is normal in 40% of the cases. The infarction is partially explained by platelet hyperaggregahility and coronary spasms at exercise or in the post-exercise period.

  5. Myocardial infarction and stem cells

    Directory of Open Access Journals (Sweden)

    K Ananda Krishna

    2011-01-01

    Full Text Available Permanent loss of cardiomyocytes and scar tissue formation after myocardial infarction (MI results in an irreversible damage to the cardiac function. Cardiac repair (replacement, restoration, and regeneration is, therefore, essential to restore function of the heart following MI. Existing therapies lower early mortality rates, prevent additional damage to the heart muscle, and reduce the risk of further heart attacks. However, there is need for treatment to improve the infarcted area by replacing the damaged cells after MI. Thus, the cardiac tissue regeneration with the application of stem cells may be an effective therapeutic option. Recently, interest is more inclined toward myocardial regeneration with the application of stem cells. However, the potential benefits and the ability to improve cardiac function with the stem cell-based therapy need to be further addressed. In this review, we focus on the clinical applications of stem cells in the cardiac repair.

  6. Myocardial infarction and subsequent pregnancy

    Directory of Open Access Journals (Sweden)

    Tedoldi Citânia Lúcia

    2000-01-01

    Full Text Available We report the case of a 40-year-old woman with 2 previous myocardial infarctions, revascularization surgery, and an ongoing pregnancy complicated with preeclampsia and fetal hypoxia. Her follow-up performed by a multidisciplinary team made possible the birth through cesarean section of a premature infant of the female sex with a very low birth weight, but without severe respiratory distress of the hyaline membrane disease type. Three months after the delivery, mother and daughter were healthy.

  7. Enteroviruses in Acute Myocardial Infarction

    OpenAIRE

    A Gholoobi; MS Nabavinia; T Mohamadpoor; MS Alavi; Z Meshkat

    2012-01-01

    Background: Human enteroviruses (EVs) may have a role as a possible risk factor in the pathogenesis of MI. The aim of this study was to evaluate the presence of enterovirus genomic RNA in peripheral blood samples of patients with acute myocardial infarction (MI). Methods: We investigated the presence of enterovirus genomic RNA in the peripheral blood of 115 patients with acute MI hospitalized in the Coronary Care Unit of Imam Reza and Ghaem University Hospitals (Mashhad, Iran) by RT-PCR using...

  8. SERUM MAGNESIUM IN ACUTE MYOCARDIAL INFARCTION

    OpenAIRE

    Nambakam Tanuja; Girish P

    2015-01-01

    BACKGROUND: In myocardial infarction, there occurs functional deficit of available magnesium due to trapping of free magnesium in adipocytes. Magnesium has been implicated in the pathogenesis of acute myocardial infarction and its complications. Magnesium ions are considered essential for the maintenance of functional integrity of myocardium. The serum magnesium concentration was found to have g reat significance in acute myocardial infarction. The present study was un...

  9. Acute myocardial involvement after heroin inhalation

    Directory of Open Access Journals (Sweden)

    Ritu Karoli

    2012-01-01

    Full Text Available Amongst the illicit drugs cocaine, amphetamines and cannabis have been studied and documented well to cause myocardial infarction by different mechanisms but there is very sparse data available on myocardial involvement after heroin abuse. We report a young man who developed acute myocardial injury after heroin inhalation and alcohol binge drinking. Heroin induced cardio toxic effect and vasospasm compounded by alcohol were suspected to be the cause of this.

  10. Leukocytosis: a risk factor for myocardial infarction

    OpenAIRE

    Kotla SK

    2012-01-01

    Suman K KotlaDepartment of Internal Medicine, Memorial Medical Center, Johnstown, PA, USAAbstract: Myocardial infarction commonly results from atherosclerotic lesions in the coronary arteries. Approximately 5% of patients with acute myocardial infarction do not have atherosclerotic disease. In this case report, we present an unusual leukostatic complication in a patient with acute myeloblastic leukemia and extreme hyperleukocytosis who presented with an acute myocardial infarction that resolv...

  11. Acute myocardial involvement after heroin inhalation

    OpenAIRE

    Ritu Karoli; Fatima, J.; Pushker Singh; Kazmi, Khursheed I.

    2012-01-01

    Amongst the illicit drugs cocaine, amphetamines and cannabis have been studied and documented well to cause myocardial infarction by different mechanisms but there is very sparse data available on myocardial involvement after heroin abuse. We report a young man who developed acute myocardial injury after heroin inhalation and alcohol binge drinking. Heroin induced cardio toxic effect and vasospasm compounded by alcohol were suspected to be the cause of this.

  12. Myocardial tissue tagging with cardiovascular magnetic resonance

    OpenAIRE

    Bluemke David A; Osman Nael F; Cheng Susan; Shehata Monda L; Lima João AC

    2009-01-01

    Abstract Cardiovascular magnetic resonance (CMR) is currently the gold standard for assessing both global and regional myocardial function. New tools for quantifying regional function have been recently developed to characterize early myocardial dysfunction in order to improve the identification and management of individuals at risk for heart failure. Of particular interest is CMR myocardial tagging, a non-invasive technique for assessing regional function that provides a detailed and compreh...

  13. Myocardial bridging as a cause of acute myocardial infarction: a case report

    Directory of Open Access Journals (Sweden)

    Emiroglu Yunus

    2002-09-01

    Full Text Available Abstract Background Systolic compression of a coronary artery by overlying myocardial tissue is termed myocardial bridging. Myocardial bridging usually has a benign prognosis, but some cases resulting in myocardial ischemia, infarction and sudden cardiac death have been reported. We are reporting a case of myocardial bridging which was complicated with acute myocardial infarction associated with inappropriate blood donation. Case presentation A 33 year-old-man was admitted to our emergency with acute anteroseptal myocardial infarction after a blood donation. The electrocardiography showed sinus rhythm and was consistent with an acute anteroseptal myocardial infarction. We decided to perform primary percutanous intervention (PCI. Myocardial bridging was observed in the mid segment of the left anterior descending coronary artery on coronary angiogram. PCI was canceled and medical follow up was decided. Blood transfusion was made because he had a deep anemia. A normal hemaglobin level and clinical reperfusion was achieved after ten hours by blood transfusion. At the one year follow up visit, our patient was healthy and had no cardiac complaints. Conclusions Myocardial bridging may cause acute myocardial infarction in various clinical conditions. Although the condition in this case caused profound anemia related acute myocardial infarction, its treatment and management was unusual.

  14. Cardiac MRI for myocardial ischemia.

    LENUS (Irish Health Repository)

    Daly, Caroline

    2013-01-01

    Proper assessment of the physiologic impact of coronary artery stenosis on the LV myocardium can affect patient prognosis and treatment decisions. Cardiac magnetic resonance imaging (CMR) assesses myocardial perfusion by imaging the myocardium during a first-pass transit of an intravenous gadolinium bolus, with spatial and temporal resolution substantially higher than nuclear myocardial perfusion imaging. Coupled with late gadolinium enhancement (LGE) imaging for infarction during the same imaging session, CMR with vasodilating stress perfusion imaging can qualitatively and quantitatively assess the myocardial extent of hypoperfusion from coronary stenosis independent of infarcted myocardium. This approach has been validated experimentally, and multiple clinical trials have established its diagnostic robustness when compared to stress single-photon emission computed tomography. In specialized centers, dobutamine stress CMR has been shown to have incremental diagnostic value above stress echocardiography due to its high imaging quality and ability to image the heart with no restriction of imaging window. This paper reviews the technical aspects, diagnostic utility, prognostic values, challenges to clinical adaptation, and future developments of stress CMR imaging.

  15. Myocardial ischaemia during tracheal intubation and extubation.

    Science.gov (United States)

    Edwards, N D; Alford, A M; Dobson, P M; Peacock, J E; Reilly, C S

    1994-10-01

    The incidence of myocardial ischaemia during tracheal intubation and extubation was compared using ambulatory ECG monitoring in 60 patients undergoing a variety of different surgical operations. Seven patients had myocardial ischaemia after tracheal intubation and seven patients during tracheal extubation. The patients who developed myocardial ischaemia during tracheal extubation had significantly greater rate-pressure products immediately before tracheal extubation (P < 0.05) and 1 min after tracheal extubation (P < 0.01) compared with those patients who did not develop myocardial ischaemia during extubation. PMID:7999498

  16. Regional Myocardial Substrate Uptake in Hypertensive Rats: A Quantitative Autoradiographic Measurement

    Science.gov (United States)

    Yonekura, Yoshiharu; Bertrand Brill, A.; Som, Prantika; Yamamoto, Kazutaka; Srivastava, Suresh C.; Iwai, Junichi; Elmaleh, David R.; Livni, Eli; Strauss, H. William; Goodman, Mark M.; Knapp, Furn F.

    1985-03-01

    Severe hypertension causes global and regional changes in myocardial perfusion and substrate utilization. Regional perfusion and fatty acid utilization were evaluated by dual-tracer autoradiography in normotensive and hypertensive rats of the Dahl strain. The regional distributions of perfusion and fatty acid utilization were homogeneous in normotensive rats. Severe hypertension was associated with a homogeneous pattern of regional perfusion, but fatty acid utilization was focally decreased in the free wall of the left ventricle. The decrease in fatty acid uptake was associated with a concomitant increase in glucose utilization. These findings suggest that severe hypertension is associated with uniform myocardial perfusion and focal alterations in the substrates used for the performance of myocardial work.

  17. An initial study on the feasibility of diagnosing myocardial ischemia with CT first-pass myocardial perfusion imaging at rest

    Institute of Scientific and Technical Information of China (English)

    汪奇

    2013-01-01

    Objective To assess the feasibility and accuracy of CT first-pass myocardial perfusion imaging(CT first-pass MPI)at rest for diagnosis of myocardial ischemia.Results of adenosine-induced myocardial perfusion scintigraphy(MPS)

  18. 经皮冠状动脉介入治疗对冠心病非心肌梗死患者心肌二维应变的影响%Evaluation on the impact of percutaneous coronary intervention in patients with non-infarcted coronary artery disease with two-dimensional strain

    Institute of Scientific and Technical Information of China (English)

    范怡婷; 黄国倩; 朱志栋; 朱雯; 李勇

    2012-01-01

    目的 运用速度向量成像(VVI)技术评价冠心病非心肌梗死患者心肌二维应变以及经皮冠状动脉介入治疗(PCI)的疗效.方法 选取经冠脉造影证实并接受PCI手术的非心肌梗死患者20例(PCI组),以及性别、年龄匹配的经冠脉造影除外冠心病的患者20例(对照组).在术前、出院前及术后3个月接受VVI,测量左心室心肌纵向、径向、圆周方向上的应变及应变率,以及左心室扭转角度,评价病变冠状动脉灌注区内的心肌功能及PCI术后改善情况.结果 与对照组对应的血管灌注节段相比,PCI组术前的病变血管灌注节段径向应变、径向收缩期峰值应变率、径向舒张晚期峰值应变率显著降低(均P<0.05);PCI组术前左心室内膜扭转角度较对照组明显下降.PCI组出院前径向应变较PCI组术前出现改善(P<0.01),经向收缩期峰值应变率和好张晚期峰值应变率在术后3个月得到改善.结论 VVI技术可用于识别灌注异常导致的内眼无法识别的心肌功能损害;PCI术后早期即可出现径向应变的改善.%Objective To observe the value of two-dimensional strain using velocity vector imaging (VVT) in evaluating the therapeutic effect of percutaneous coronary intervention (PCI) in patients with non-infarcted coronary artery disease (CAD). Methods Twenty non-infarcted CAD patients underwent PCI (PCI group) and 20 age and sex matched subjects (control group) confirmed by coronary angiography (CAG) were enrolled. VVI were acquired before CAG and PCI procedures for all subjectsi and were repeated in PCI group before discharge and 3 months after PCI. The longitudinal, radial, circumferential regional strain and strain rate, as well as left ventricular torsion were analyzed. The regional myocardial deformation parameters in territory of the stenostic coronary artery in PCI group (ischemic segments) were compared with those of corresponding segments in control group (normal segments

  19. Total hip replacement using hemi-circumferential interposition acetabuloplasty for acetabular deficiency in post-Perthes deformities: technique and long-term results

    NARCIS (Netherlands)

    D. Haverkamp; H. Eijer; R.K. Marti

    2006-01-01

    We describe a technique of hemi-circumferential interposition grafting that allows placement of the cup in the anatomical position of the original acetabulum in the rare cases of post-Perthes or Perthes-like deformities of the femoral head combined with a steep and shallow acetabulum. This technique

  20. Rehabilitation program for prosthetic tracheojejunal voice production and swallowing function following circumferential pharyngolaryngectomy and neopharyngeal reconstruction with a jejunal free flap

    NARCIS (Netherlands)

    L.W.J. Baijens; R. Speijer; N. Roodenburg; F.J.M. Hilgers

    2011-01-01

    The case of a 68-year-old woman with postoperative speech and swallowing problems following a circumferential pharyngolaryngectomy and neopharyngeal reconstruction with a jejunal free flap is presented. The primary tumor was an extended papillary thyroid carcinoma (pT4N0M0). For vocal restoration, a

  1. Systemic Atherosclerotic Inflammation Following Acute Myocardial Infarction: Myocardial Infarction Begets Myocardial Infarction

    OpenAIRE

    Joshi, Nikhil V; Toor, Iqbal; Shah, Anoop S V; Carruthers, Kathryn; Alex T. Vesey; Alam, Shirjel R; Sills, Andrew; Hoo, Teng Y; Melville, Adam J; Langlands, Sarah P; Jenkins, William S A; Uren, Neal G; Mills, Nicholas L.; Fletcher, Alison M; van Beek, Edwin J.R.

    2015-01-01

    BACKGROUND: Preclinical data suggest that an acute inflammatory response following myocardial infarction (MI) accelerates systemic atherosclerosis. Using combined positron emission and computed tomography, we investigated whether this phenomenon occurs in humans.METHODS AND RESULTS: Overall, 40 patients with MI and 40 with stable angina underwent thoracic 18F-fluorodeoxyglucose combined positron emission and computed tomography scan. Radiotracer uptake was measured in aortic atheroma and nonv...

  2. MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2015-12-01

    Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

  3. Screening for silent myocardial ischemia caseof diabetics : interest of myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Silent myocardial ischemia is a major cause of morbidity and mortality in diabetic patients. Its diagnosis by noninvasive means such as myocardial SPECT would improve the management of these patients. The purpose of this study is to assess the frequency of silent myocardial ischemia in asymptomatic diabetics and their evolution. As a result, the myocardial SPECT is a reliable tool for screening for silent myocardial ischemia in diabetic patients. Its prognostic value allows to stratify the cardiac risk and guide therapeutic management. Its integration into a screening strategy in Tunisia seems limited by its low availability and cost. The latter could be reduced by better patient selection.

  4. Thrombolysis significantly reduces transient myocardial ischaemia following first acute myocardial infarction

    DEFF Research Database (Denmark)

    Mickley, H; Pless, P; Nielsen, J R;

    1992-01-01

    In order to investigate whether thrombolysis affects residual myocardial ischaemia, we prospectively performed a predischarge maximal exercise test and early out-of-hospital ambulatory ST segment monitoring in 123 consecutive men surviving a first acute myocardial infarction (AMI). Seventy...... less than 0.02). Thrombolysis resulted in a non-significant reduction in exercise-induced ST segment depression: prevalence 43% vs 62% in controls. However, during ambulatory monitoring the duration of transient myocardial ischaemia was significantly reduced in thrombolysed patients: 322 min vs 1144...... myocardial ischaemia. This may explain the improvement in myocardial function during physical activities, which was also observed in this study....

  5. The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

    Science.gov (United States)

    Chadwick, W.W.; Jonsson, Sigurjon; Geist, Dennis J.; Poland, M.; Johnson, Daniel J.; Batt, S.; Harpp, Karen S.; Ruiz, A.

    2011-01-01

    The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45–60°) toward the caldera at the surface and more gently dipping (~12–14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another.

  6. Advanced echocardiography in adult zebrafish reveals delayed recovery of heart function after myocardial cryoinjury.

    Directory of Open Access Journals (Sweden)

    Selina J Hein

    Full Text Available Translucent zebrafish larvae represent an established model to analyze genetics of cardiac development and human cardiac disease. More recently adult zebrafish are utilized to evaluate mechanisms of cardiac regeneration and by benefiting from recent genome editing technologies, including TALEN and CRISPR, adult zebrafish are emerging as a valuable in vivo model to evaluate novel disease genes and specifically validate disease causing mutations and their underlying pathomechanisms. However, methods to sensitively and non-invasively assess cardiac morphology and performance in adult zebrafish are still limited. We here present a standardized examination protocol to broadly assess cardiac performance in adult zebrafish by advancing conventional echocardiography with modern speckle-tracking analyses. This allows accurate detection of changes in cardiac performance and further enables highly sensitive assessment of regional myocardial motion and deformation in high spatio-temporal resolution. Combining conventional echocardiography measurements with radial and longitudinal velocity, displacement, strain, strain rate and myocardial wall delay rates after myocardial cryoinjury permitted to non-invasively determine injury dimensions and to longitudinally follow functional recovery during cardiac regeneration. We show that functional recovery of cryoinjured hearts occurs in three distinct phases. Importantly, the regeneration process after cryoinjury extends far beyond the proposed 45 days described for ventricular resection with reconstitution of myocardial performance up to 180 days post-injury (dpi. The imaging modalities evaluated here allow sensitive cardiac phenotyping and contribute to further establish adult zebrafish as valuable cardiac disease model beyond the larval developmental stage.

  7. Do episodes of anger trigger myocardial infarction?

    DEFF Research Database (Denmark)

    Möller, J; Hallqvist, J; Diderichsen, Finn;

    1999-01-01

    Our objectives were to study anger as a trigger of acute myocardial infarction (MI) and to explore potential effect modification by usual behavioral patterns related to hostility.......Our objectives were to study anger as a trigger of acute myocardial infarction (MI) and to explore potential effect modification by usual behavioral patterns related to hostility....

  8. Nifedipine for angina and acute myocardial ischemia

    NARCIS (Netherlands)

    P.G. Hugenholtz (Paul); J.W. de Jong (Jan Willem); P.D. Verdouw (Pieter); P.W.J.C. Serruys (Patrick)

    1983-01-01

    textabstractThis paper reviews the mechanisms believed to be responsible for myocardial ischaemia and the mode of action of calcium antagonist drugs. The clinical management of patients with myocardial ischaemia is discussed in the context of current knowledge about patho-physiology and drug action.

  9. Myocardial infarction and nocturnal hypoxaemia

    Directory of Open Access Journals (Sweden)

    Penčić Biljana

    2007-01-01

    Full Text Available Introduction: There is an increased risk of cardiovascular morbidity and mortality in patients with nocturnal intermittent hypoxaemia. Objecive. The aim of this study was to evalute the influence of nocturnal hypoxaemia on ventricular arrhythmias and myocardial ischaemia in patients with myocardial infarction (MI. Method. We studied 77 patients (55.8±7.9 years with MI free of complications, chronic pulmonary diseases, abnormal awake blood gases tension. All patients underwent overnight pulse oximetry and 24-hour electrocardiography. Patients were divided into two groups according to nocturnal hypoxaemia. Total number of ventricular premature complex (VPC; maximal VPC/h; incidence of VPC Lown class>2 and occurrence of ST-segment depression were analyzed for nocturnal (10 PM to 6 AM, daytime (6 AM to 22 PM periods and for the entire 24 hours. Results. Both groups were similar in age, gender, standard risk factors, myocardial infarction size and did not differ in VPC during the analyzed periods. The number of nocturnal maximal VPC/h was insignificantly greater in group 1 (with hypoxaemia compared to group 2 (without hypoxaemia, (p=0.084. Maximal VPC/h did not differ significantly either for daytime or for 24 hours among the groups. Nocturnal VPC Lown>2 were significantly more frequent in group 1 (25% vs 0%, p=0.002. The incidence of VPC Lown>2 was similar during the daytime, and during 24 hrs in both groups. Occurrence of ST-segment depression did not differ between groups 1 and 2. Conclusion. Nocturnal hypoxaemia was associated with complex nocturnal ventricular arrhythmias in patients with MI. .

  10. [Fibrinolysis in acute myocardial infarct].

    Science.gov (United States)

    Bleifeld, W

    1987-10-24

    Fibrinolysis has opened up a new avenue in the treatment of acute myocardial infarction (AMI). In principle, the rate of reperfusion depends on the type of compound used, the mode of administration and the time between onset of symptoms and the beginning of treatment. With intracoronary streptokinase the reperfusion rate is of the order of 85%. Intravenous urokinase administered as a bolus results in a reopening rate of 50-60%; a similar rate of reperfusion is achieved with rt-PA as infusion, while i.v. streptokinase produces about 50% reopened coronary vessels. The final infarct size is decreased in 70% of patients if fibrinolysis is initiated within 2.5 hours after the onset of symptoms and followed by reopening of the occluded vessel. This results in a lowering of in-hospital mortality, which in various studies is of the order of 45-60%.- Bearing in mind the contraindications, fibrinolysis should be initiated within 3 hours. Hemodynamic improvement by a decrease of infarct size may also be achieved beyond 3 hours in large anterior myocardial infarctions and in posterior infarctions with cardiogenic shock. Early initiation of thrombolysis is of major importance in improving left ventricular function and lowering mortality following acute myocardial infarction. Therefore, prehospital thrombolytic therapy should be considered. - In the postinfarction phase coronary angiography is indicated in patients with angina at rest, stable angina of ECG signs of ischemia. In this situation transfer to a specialized cardiology division for possible percutaneous transluminal angioplasty is indicated. - Reocclusion after successful thrombolysis occurs in 20-30%, and it is therefore important to avoid reinfarction to improve the long term prognosis after AMI.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3321420

  11. Radiofrequency Ablation Mapping with Circumferential Catheter for Paroxys-mal Atrial Fibrillation Originating From the Pulmonary Veins

    Institute of Scientific and Technical Information of China (English)

    刘震; 吴书林; 杨平珍; 方咸宏; 李海杰; 陈泗林; 詹贤章; 薛玉梅

    2002-01-01

    Objectives To assessed thefeasibility and effectiveness of electrophysiologicalmapping of pulmonary veins with a circumferential 10-electrode catheter and radiofrequency catheter abla-tion therapy for patients with paroxysmal atrial fibril-lation. Background Standard mapping and ablationof focal sources of atrial fibrillation are associated withvery long procedure times and low efficacy. Mappingand ablation pulmonary veins guide with a circularcatheter could overcome these limitations. Methods16 patients [male 11, female 5, mean age (51 +14.5) years] with paroxysmal atrial fibrillation refrac-tory to antiarrhythmic drugs were included in thisgroup. A circumferential 10-electrode catheter wasused to pulmonary vein mapping during sinus rhythm orCSd pacing to determine the origin of atrial prematurecontractions. When the ablative target pulmonary veinwas found, the pulmonary vein potentials' distributionand activation were assessment pulmonary veins' ostialablation was performed at the segments showing earliestactivation of pulnonary vein potentials. The end pointwas designed: 1 ) elimination of pulmonary vein po-tential; 2) pulmonary vein potential dissociation fromatrial waves; 3) atrial ectopic beats disappear. ResultsA total of 36 pulmonary veins were ablated, in-cluding 16 left superior, 12 right superior, 7 left in-ferior and 1 right inferior. 1 pulmonary vein in 2 pa-tients was ablated, 2 pulmonary veins in 8 patientswere ablated, 3 pulmonary veins were ablated in 5patients and 4 pulmonary veins were ablated in 1 pa-tient. Procedure duration and fluoroscopy time respec-tively were 186.7 _+ 63.8 min and 51.5 + 15.0 min.During the follow-up 1- 12 months, 11 patients(68.7 % ) were free of AF without any antiarrhythmicdrugs, 2 of them were reablation, effective in 3/16(18.7%) and unsuccessful in 2/16 (12.6%) . 2cases recurred with atrial premature, 1 was treated withamiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with

  12. Solar activity and myocardial infarction.

    Science.gov (United States)

    Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

    1983-01-01

    The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism. PMID:6851574

  13. Early Echocardiographic Deformation Analysis for the Prediction of Sudden Cardiac Death and Life-Threatening Arrhythmias After Myocardial Infarction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Valeur, Nana; Andersen, Mads Jønsson;

    2013-01-01

    This study sought to hypothesize that global longitudinal strain (GLS) as a measure of infarct size, and mechanical dispersion (MD) as a measure of myocardial deformation heterogeneity, would be of incremental importance for the prediction of sudden cardiac death (SCD) or malignant ventricular ar...

  14. Myocardial wall-thickness transducer

    Science.gov (United States)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H.

    1976-01-01

    Device consists of highly compliant circular beam attached to piezoresistive strain gage and barbed needle. Radial deflection of myocardium is measured with minimal disturbance of normal heart functions.

  15. Myocardial MR tagging. Analysis of regional and global myocardial function; Kardiales MR-Tagging. Analyse regionaler und globaler Myokardfunktion

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, U.; Fenchel, M. [Universitaet Tuebingen, Abt. fuer Diagnostische und Interventionelle Radiologie, Radiologische Klinik, Tuebingen (Germany); Hennemuth, A. [Fraunhofer MEVIS, Bremen (Germany)

    2010-06-15

    Myocardial MR tagging is a powerful method which allows for assessment of myocardial function and may become an important tool for clinical evaluation of cardiac dysfunction, particularly in ischemic heart disease. In addition to visual assessment it allows direct quantification of myocardial deformation and strain to measure contractility. The use of myocardial tagging has provided new insights into the (patho)physiology of regional wall motion, and several parameters have been described as being useful to identify an ischemic response of the myocardium. One challenge encountered with tagging at 1.5 T is the fading of tags at end-diastole, greatly limiting the evaluation of myocardial function during diastole. Due to longer T{sub 1} relaxation times of the myocardium, tagging at 3 T has shown to have a higher CNR{sub Tag} and better tag persistence when compared to current clinical gradient-echo tagging protocols at 1.5 T. As a consequence, tagging at higher field strengths may be well suited for the characterization of the diastolic portion of the cardiac cycle in future applications. (orig.) [German] Das myokardiale Tagging mittels der kardialen Magnetresonanztomographie (MRT) stellt ein spezielles Verfahren dar, das eine quantitative Analyse der regionalen Myokardfunktion erlaubt. Mit der Analyse der regionalen Wandbewegung koennen pathologische Bewegungsablaeufe fruehzeitig erkannt und kardiale Dysfunktionen differenziert werden. Neben der visuellen Analyse ist es in erster Linie die quantitative Bestimmung der aus der Echokardiographie bekannten Funktionsparameter, die den Vorteil des Taggings bei der Charakterisierung der myokardialen Funktion ausmachen. Die quantitative Erfassung des Rotations- und Kontraktionsverhaltens mit dem myokardialen Tagging eroeffnet bei verschiedenen Erkrankungen des Herzens neue Einblicke in die Pathophysiologie. Eine intrinsische Limitation dieses Verfahrens besteht in dem insbesondere in der diastolischen Phase des Herzzyklus

  16. Psychosocial work environment and myocardial infarction: improving risk estimation by combining two complementary job stress models in the SHEEP Study

    OpenAIRE

    Peter, R.; Siegrist, J; Hallqvist, J; Reuterwall, C; Theorell, T.

    2002-01-01

    Objectives: Associations between two alternative formulations of job stress derived from the effort-reward imbalance and the job strain model and first non-fatal acute myocardial infarction were studied. Whereas the job strain model concentrates on situational (extrinsic) characteristics the effort-reward imbalance model analyses distinct person (intrinsic) characteristics in addition to situational ones. In view of these conceptual differences the hypothesis was tested that combining informa...

  17. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    Science.gov (United States)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  18. Crack-tip Stress Field of Fully Circumferential Surface Cracked Pipe Under Combined Tension and Thermal Loads

    International Nuclear Information System (INIS)

    Under excessive plasticity, the fracture toughness of a material depends on its size and geometry. Under fully yielded conditions, the stresses in a material near its crack tip are not unique but rather depend on the geometry. Therefore, the single-parameter J-approach is limited to a high-constraint crack geometry. The JQ theory has been proposed for establishing the crack geometry constraints . This approach assumes that the crack-tip fields have two degrees of freedom. In this study, the crack-tip stress field of a fully circumferential surface-cracked pipe under combined loads is investigated on the basis of the JQ theory by using finite element analysis. The combined loads are a tensile axial force and the thermal gradient in the radial direction. Q-stresses of the crack geometry and its loading state are used to determine the constraint effects. The constraint effects of secondary loading are found to be greater than those of primary loading. Therefore, thermal shock is believed to be the most severe loading condition of constraint effects

  19. New matrix method for response analysis of circumferentially stiffened non-circular cylindrical shells under harmonic pressure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the governing equation of vibration of a kind of cylindrical shells written in a matrix differential equation of the first order, a new matrix method is presented for steady-state vibration analysis of a noncircular cylindrical shell simply supported at two ends and circumferentially stiffened by rings under harmonic pressure. Its difference from the existing works by Yamada and Irie is that the matrix differential equation is solved by using the extended homogeneous capacity precision integration approach other than the Runge-Kutta-Gill integration method. The transfer matrix can easily be determined by a high precision integration scheme. In addition, besides the normal interacting forces, which were commonly adopted by researchers earlier, the tangential interacting forces between the cylindrical shell and the rings are considered at the same time by means of the Dirac-δ function. The effects of the exciting frequencies on displacements and stresses responses have been investigated. Numerical results show that the proposed method is more efficient than the aforementioned method.

  20. Nondestructive Evaluation of Functionally Graded Subsurface Damage on Cylinders in Nuclear Installations Based on Circumferential SH Waves

    Directory of Open Access Journals (Sweden)

    Zhen Qu

    2016-01-01

    Full Text Available Subsurface damage could affect the service life of structures. In nuclear engineering, nondestructive evaluation and detection of the evaluation of the subsurface damage region are of great importance to ensure the safety of nuclear installations. In this paper, we propose the use of circumferential horizontal shear (SH waves to detect mechanical properties of subsurface regions of damage on cylindrical structures. The regions of surface damage are considered to be functionally graded material (FGM and the cylinder is considered to be a layered structure. The Bessel functions and the power series technique are employed to solve the governing equations. By analyzing the SH waves in the 12Cr-ODS ferritic steel cylinder, which is frequently applied in the nuclear installations, we discuss the relationship between the phase velocities of SH waves in the cylinder with subsurface layers of damage and the mechanical properties of the subsurface damaged regions. The results show that the subsurface damage could lead to decrease of the SH waves’ phase velocity. The gradient parameters, which represent the degree of subsurface damage, can be evaluated by the variation of the SH waves’ phase velocity. Research results of this study can provide theoretical guidance in nondestructive evaluation for use in the analysis of the reliability and durability of nuclear installations.

  1. EXPERIMENTAL RESEARCH ON AERODYNAMIC PERFORMANCE AND EXIT FLOW FIELD OF LOW PRESSURE AXIAL FLOW FAN WITH CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, the low pressure axial flow fan with circumferential skewed rotor blade, including the radial blade, the forward-skewed blade and the backward-skewed blade, was studied with experimental methods. The aerodynamic performance of the rotors was measured. At the design condition at outlet of the rotors, detailed flow measurements were performed with a five-hole probe and a Hot-Wire Anemometer (HWA). The results show that compared to the radial rotor, the forward-skewed rotor demonstrates a wider Stable Operating Range (SOR), is able to reduce the total pressure loss in the hub region and make main loading of blade accumulating in the mid-span region. There is a wider wake in the upper mid-span region of the forward-skewed rotor. Compared to the radial rotor, in the backward-skewed rotor there is higher total pressure loss near the hub and shroud regions and lower loss in the mid-span region. In addition, the velocity deficit in the wake is lower at mid-span of the backward-skewed rotor than the forward-skewed rotor.

  2. Effect of anxiety and depression on the recurrence of persistent atrial fibrillation after circumferential pulmonary vein ablation

    Institute of Scientific and Technical Information of China (English)

    YU Sheng-bo; HU Wei; ZHAO Qing-yan; QIN Mu; HUANG He; CUI Hong-ying; HUANG Cong-xin

    2012-01-01

    Background The effects of anxiety and depression on the recurrence of persistent atrial fibrillation (AF) after circumferential pulmonary vein ablation (CPVA) are not clear.Whether CPVA can alleviate the anxiety and depression symptoms of persistent AF patients is unknown.Methods One hundred and sixty-four patients with persistent AF,of which 43 treated with CPVA (CPVA group) and 103 treated with anti-arrhythmics drugs (medicine group),were enrolled.The Zung Self-Rating Anxiety Scale (SAS),and Zung Self-Rating Depression Scale (SDS) were assessed before and 12 months after treatment in all patients.Results The scores of SAS (40.33±7.90 vs.49.76±9.52,P <0.01) and SDS (42.33±8.73 vs.48.17±8.77,P <0.01)decreased 12 months after CPVA.Over 12 months follow-up,AF relapsed in 17 patients in CPVA group.Compared with the data in the recurrent group (17 patients),the scores of SAS and SDS were significantly lower in the non-recurrent group (26 patients) at baseline.The results of multivariate Logistic regression analysis showed normal scores of SAS and SDS were the independent risk factors of AF recurrence after CPVA.Conclusions Anxiety and depression increase the recurrence risk of persistent AF after CPVA.CPVA can ameliorate the anxiety and depression symptoms in patients with persistent AF.

  3. Circadian influences on myocardial infarction.

    Science.gov (United States)

    Virag, Jitka A I; Lust, Robert M

    2014-01-01

    Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  4. Contemporaryperspective on endogenous myocardial regeneration

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Considering the complex nature of the adult heart,it is no wonder that innate regenerative processes,while maintaining adequate cardiac function, fall shortin myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well asrestricted regeneration. In this review, the backgroundas well as potential mechanisms of endogenousmyocardial regeneration are summarized. We presentand analyze the available evidence in three subsequentsteps. First, we examine the experimental researchdata that provide insights into the mechanisms andorigins of the replicating cardiac myocytes, includingcell populations referred to as cardiac progenitor cells(i.e. , c-kit+ cells). Second, we describe the role ofclinical settings such as acute or chronic myocardialischemia, as initiators of pathways of endogenousmyocardial regeneration. Third, the hitherto conductedclinical studies that examined different approachesof initiating endogenous myocardial regeneration infailing human hearts are analyzed. In conclusion, wepresent the evidence in support of the notion thatregaining cardiac function beyond cellular replacementof dysfunctional myocardium via initiation of innateregenerative pathways could create a new perspectiveand a paradigm change in heart failure therapeutics.Reinitiating cardiac morphogenesis by reintroducingdevelopmental pathways in the adult failing heart mightprovide a feasible way of tissue regeneration. Basedon our hypothesis "embryonic recall", we present firstsupporting evidence on regenerative impulses in themyocardium, as induced by developmental processes.

  5. Microstructure and Ductility-Dip Cracking Susceptibility of Circumferential Multipass Dissimilar Weld Between 20MND5 and Z2CND18-12NS with Ni-Base Filler Metal 52

    Science.gov (United States)

    Qin, Renyao; Duan, Zhaoling; He, Guo

    2013-10-01

    The large circumferential multipass dissimilar weld between 20MND5 steel and Z2CND18-12NS stainless steel welded with FM52 filler material was investigated in terms of the diluted composition, the grain boundary precipitation, and the ductility-dip cracking (DDC) susceptibility of the weld. The diluted composition of the weld is composed of 37 to 47 pct Ni, 21 to 24 pct Cr, and 28 to 40 pct Fe, which are inhomogeneous along the depth and over the width of the deep weld. The carbon content has a distribution in the region of the surface weld from a high level (~0.20 pct) in the zone near 20MND5 steel to a normal level (~0.03 pct) in the zone near Z2CND18-12NS stainless steel. The carbon distribution is corresponding to the grain boundary carbides. The minimum threshold strains for DDC occur in the temperature range of 1223 K to 1323 K (950 °C to 1050 °C), which are 0.5, 0.35, and 0.4 pct for the root weld, middle region, and the surface weld, respectively. The dissimilar weld has the largest susceptibility to the DDC compared to the filler metal 52 and the Inconel 690.

  6. Effects of incremental beta-blocker dosing on myocardial mechanics of the human left ventricle: MRI 3D-tagging insight into pharmacodynamics supports theory of inner antagonism.

    Science.gov (United States)

    Schmitt, Boris; Li, Tieyan; Kutty, Shelby; Khasheei, Alireza; Schmitt, Katharina R L; Anderson, Robert H; Lunkenheimer, Paul P; Berger, Felix; Kühne, Titus; Peters, Björn

    2015-07-01

    Beta-blockers contribute to treatment of heart failure. Their mechanism of action, however, is incompletely understood. Gradients in beta-blocker sensitivity of helically aligned cardiomyocytes compared with counteracting transversely intruding cardiomyocytes seem crucial. We hypothesize that selective blockade of transversely intruding cardiomyocytes by low-dose beta-blockade unloads ventricular performance. Cardiac magnetic resonance imaging (MRI) 3D tagging delivers parameters of myocardial performance. We studied 13 healthy volunteers by MRI 3D tagging during escalated intravenous administration of esmolol. The circumferential, longitudinal, and radial myocardial shortening was determined for each dose. The curves were analyzed for peak value, time-to-peak, upslope, and area-under-the-curve. At low doses, from 5 to 25 μg·kg(-1)·min(-1), peak contraction increased while time-to-peak decreased yielding a steeper upslope. Combining the values revealed a left shift of the curves at low doses compared with baseline without esmolol. At doses of 50 to 150 μg·kg(-1)·min(-1), a right shift with flattening occurred. In healthy volunteers we found more pronounced myocardial shortening at low compared with clinical dosage of beta-blockers. In patients with ventricular hypertrophy and higher prevalence of transversely intruding cardiomyocytes selective low-dose beta-blockade could be even more effective. MRI 3D tagging could help to determine optimal individual beta-blocker dosing avoiding undesirable side effects. PMID:25888512

  7. Comprehensive Cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE

    Directory of Open Access Journals (Sweden)

    Zhong Xiaodong

    2011-12-01

    Full Text Available Abstract Background Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. Methods A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. Results Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 ± 0.17, -0.13 ± 0.03, and -0.18 ± 0.14 for Err, Ecc, and Ell, respectively. Peak end-systolic values for the shear strains were 0.00 ± 0.08, 0.04 ± 0.12, and 0.03 ± 0.07 for Erc, Erl, and Ecl, respectively. The peak end-systolic normalized torsion was 5.6 ± 0.9°. Conclusions Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.

  8. Regional myocardial function after intracoronary bone marrow cell injection in reperfused anterior wall infarction - a cardiovascular magnetic resonance tagging study

    Directory of Open Access Journals (Sweden)

    Arnesen Harald

    2011-03-01

    Full Text Available Abstract Background Trials have brought diverse results of bone marrow stem cell treatment in necrotic myocardium. This substudy from the Autologous Stem Cell Transplantation in Acute Myocardial Infarction trial (ASTAMI explored global and regional myocardial function after intracoronary injection of autologous mononuclear bone marrow cells (mBMC in acute anterior wall myocardial infarction treated with percutaneous coronary intervention. Methods Cardiovascular magnetic resonance (CMR tagging was performed 2-3 weeks and 6 months after revascularization in 15 patients treated with intracoronary stem cell injection (mBMC group and in 13 controls without sham injection. Global and regional left ventricular (LV strain and LV twist were correlated to cine CMR and late gadolinium enhancement (LGE. Results In the control group myocardial function as measured by strain improved for the global LV (6 months: -13.1 ± 2.4 versus 2-3 weeks: -11.9 ± 3.4%, p = 0.014 and for the infarct zone (-11.8 ± 3.0 versus -9.3 ± 4.1%, p = 0.001, and significantly more than in the mBMC group (inter-group p = 0.027 for global strain, respectively p = 0.009 for infarct zone strain. LV infarct mass decreased (35.7 ± 20.4 versus 45.7 ± 29.5 g, p = 0.024, also significantly more pronounced than the mBMC group (inter-group p = 0.034. LV twist was initially low and remained unchanged irrespective of therapy. Conclusions LGE and strain findings quite similarly demonstrate subtle differences between the mBMC and control groups. Intracoronary injection of autologous mBMC did not strengthen regional or global myocardial function in this substudy. Trial registration ClinicalTrials.gov: NCT00199823

  9. Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction by Biomarkers

    Science.gov (United States)

    2016-01-25

    Acute Myocardial Infarction (AMI); Acute Coronary Syndrome (ACS); ST Elevation (STEMI) Myocardial Infarction; Ischemic Reperfusion Injury; Non-ST Elevation (NSTEMI) Myocardial Infarction; Angina, Unstable

  10. 超声斑点追踪技术评价微泡造影剂介导SERCA2a基因治疗心肌梗死大鼠的实验研究%Ultrasound-mediated destruction of microbubbles directs SERCA2a gene delivery to rats with myocardial infarction by two-dimensional ultrasound speckle tracking imaging

    Institute of Scientific and Technical Information of China (English)

    姜新魁; 穆玉明; 王春梅; 唐琪; 关丽娜

    2010-01-01

    Objective To evaluate the therapeutic effects of rAAV2-SERCA2a gene targeted to myocardium by the ultrasound mediated microbubbles in rats with myocardial infarction(MI) using speckle tracking echocardiography (STE). Methods Thirty-five male SD rats were divided into Sham group, MI group and gene therapy group. rAAV2-SERCA2a was attached to the surface of SonoVue, sulphur hexafluoride-filled microbubbles. Therapy group animals were infused with those mixed fluids through tail vein. The other two groups were infused with SonoVue microbubbles. These bubbles were infused with simultaneous echocardiography. Four weeks after ultrasound microbubbles destructed,Circumferential strain rate(SRcir), radial strain rate(SRrad) and left ventricular torsion (LVtor) of regional myocardium were measured in short-axis view using speckle tracking imaging software for each animal. Results Compared with the M1 group,there were significant increase in SRcir-S,SRcir-E, SRrad-S,SRrad-E and LVtor in rats of gene therapy group( P <0. 01 ). There was no significant difference between gene therapy group and sham group. Conclusions rAAV2-SERCA2a gene targeted to myocardium by the ultrasound mediated microbubbles could enhance cardiac function of rats with MI.%目的 应用二维超声斑点追踪显像技术评价超声微泡造影剂介导rAAV2-SERCA2a基因靶向治疗心肌梗死大鼠左心室功能的疗效.方法 健康雄性SD大鼠35只,随机分为3组:假手术组、心肌梗死组和基因治疗组.心肌梗死组及基因治疗组结扎冠状动脉左前降支近端,造成前壁心肌梗死.假手术组单纯开胸不结扎冠状动脉.4周时,基因治疗组注射rAAV2-SERCA2a与造影剂混合液,假手术组及心肌梗死组仅注射造影剂,以上各组均给予心肌定点超声辐照.干预4周时,测量各组大鼠左心室短轴观乳头肌水平径向应变率(radial strain rate,SRrad)和圆周应变率(circumferential strain rate,SRcir)的收缩期峰值(SRrad-S

  11. Myocardial structural alteration and systolic dysfunction in preclinical hypertrophic cardiomyopathy mutation carriers.

    Directory of Open Access Journals (Sweden)

    Kai Hang Yiu

    Full Text Available BACKGROUND: To evaluate the presence of myocardial structural alterations and subtle myocardial dysfunction during familial screening in asymptomatic mutation carriers without hypertrophic cardiomyopathy (HCM phenotype. METHODS AND FINDINGS: Sixteen HCM families with pathogenic mutation were studied and 46 patients with phenotype expression (Mut+/Phen+ and 47 patients without phenotype expression (Mut+/Phen- were observed. Twenty-five control subjects, matched with the Mut+/Phen- group, were recruited for comparison. Echocardiography was performed to evaluate conventional parameters, myocardial structural alteration by calibrated integrated backscatter (cIBS and global and segmental longitudinal strain by speckle tracking analysis. All 3 groups had similar left ventricular dimensions and ejection fraction. Basal anteroseptal cIBS was the highest in Mut+/Phen+ patients (-14.0±4.6 dB, p-19.0 dB basal anteroseptal cIBS or >-18.0% basal anteroseptal longitudinal strain had a sensitivity of 98% and a specificity of 72% in differentiating Mut+/Phen- group from controls. CONCLUSION: The use of cIBS and segmental longitudinal strain can differentiate HCM Mut+/Phen- patients from controls with important clinical implications for the family screening and follow-up of these patients.

  12. Nanog expression in heart tissues induced by acute myocardial infarction.

    Science.gov (United States)

    Luo, Huanhuan; Li, Qiong; Pramanik, Jogen; Luo, Jiankai; Guo, Zhikun

    2014-10-01

    Nanog is a potential stem cell marker and is considered a regeneration factor during tissue repair. In the present study, we investigated expression patterns of nanog in the rat heart after acute myocardial infarction by semi-quantitative RT-PCR, immunohistochemistry and Western blot analyses. Our results show that nanog at both mRNA and protein levels is positively expressed in myocardial cells, fibroblasts and small round cells in different myocardial zones at different stages after myocardial infarction, showing a spatio-temporal and dynamic change. After myocardial infarction, the nanog expression in fibroblasts and small round cells in the infarcted zone (IZ) is much stronger than that in the margin zone (MZ) and remote infarcted zone (RIZ). From day 7 after myocardial infarction, the fibroblasts and small cells strongly expressed nanog protein in the IZ, and a few myocardial cells in the MZ and the RIZ and the numbers of nanog-positive fibroblasts and small cells reached the highest peak at 21 days after myocardial infarction, but in this period the number of nanog-positive myocardial cells decreased gradually. At 28 days after myocardial infarction, the numbers of all nanog-positive cells decreased into a low level. Therefore, our data suggest that all myocardial cells, fibroblasts and small round cells are involved in myocardial reconstruction after cardiac infarction. The nanog-positive myocardial cells may respond to early myocardial repair, and the nanog-positive fibroblasts and small round cells are the main source for myocardial reconstruction after cardiac infarction.

  13. Histochemical and immunohistochemical analyses of the myocardial scar fallowing acute myocardial infarction

    OpenAIRE

    Tatić Vujadin; Rafajlovski Sašo; Kanjuh Vladimir; Gajanin Radoslav; Suščević Dušan; Balint Bela; Obradović Slobodan

    2012-01-01

    Background/Aim. The heart has traditionally been considered as a static organ without capacity of regeneration after trauma. Currently, the more and more often asked question is whether the heart has any intrinsic capacities to regenerate myocytes after myocardial infarction. The aim of this study was to present the existence of the preserved muscle fibers in the myocardial scar following myocardial infarction as well as the presence of numerous cells of various size and form that diffe...

  14. Myocardial Structural and Biological Anomalies Induced by High Fat Diet in Psammomys obesus Gerbils.

    Directory of Open Access Journals (Sweden)

    Abdelhamid Sahraoui

    Full Text Available Psammomys obesus gerbils are particularly prone to develop diabetes and obesity after brief period of abundant food intake. A hypercaloric high fat diet has been shown to affect cardiac function. Here, we sought to determine whether a short period of high fat feeding might alter myocardial structure and expression of calcium handling proteins in this particular strain of gerbils.Twenty Psammomys obesus gerbils were randomly assigned to receive a normal plant diet (controls or a high fat diet. At baseline and 16-week later, body weight, plasma biochemical parameters (including lipid and carbohydrate levels were evaluated. Myocardial samples were collected for pathobiological evaluation.Sixteen-week high fat dieting resulted in body weight gain and hyperlipidemia, while levels of carbohydrates remained unchanged. At myocardial level, high fat diet induced structural disorganization, including cardiomyocyte hypertrophy, lipid accumulation, interstitial and perivascular fibrosis and increased number of infiltrating neutrophils. Myocardial expressions of pro-apoptotic Bax-to-Bcl-2 ratio, pro-inflammatory cytokines [interleukin (IL-1β and tumor necrosis factor (TNF-α], intercellular (ICAM1 and vascular adhesion molecules (VCAM1 increased, while gene encoding cardiac muscle protein, the alpha myosin heavy polypeptide (MYH6, was downregulated. Myocardial expressions of sarco(endoplasmic calcium-ATPase (SERCA2 and voltage-dependent calcium channel (Cacna1c decreased, while protein kinase A (PKA and calcium-calmodulin-dependent protein kinase (CaMK2D expressions increased. Myocardial expressions of ryanodine receptor, phospholamban and sodium/calcium exchanger (Slc8a1 did not change.We conclude that a relative short period of high fat diet in Psammomys obesus results in severe alterations of cardiac structure, activation of inflammatory and apoptotic processes, and altered expression of calcium-cycling determinants.

  15. Stress Intensity Factor for a Circumferential Crack in a Finite-Length Thin to Thick Walled Cylinder under an Arbitrary Biquadratic Stress Distribution on the Crack Surfaces

    OpenAIRE

    MESHII, Toshiyuki; WATANABE, Katsuhiko

    2001-01-01

    This paper presents the development of a practical method, by using prepared tabulated data, tocalculate the mode I stress intensity factor (SIF) for an inner surface circumferential crack in a finitelength cylinder. The crack surfaces are subjected to an axisymmetric stress with an arbitrary biquadraticradial distribution. The method was derived by applying the authors’ weight function for the crack. Thiswork is based on the thin shell theory and the Petroski-Achenbach method. Our method is ...

  16. Leakage Failure Reason Analysis of Circumferential Weld for Natural Gas Pipeline%天然气输送管道环焊缝泄漏失效分析

    Institute of Scientific and Technical Information of China (English)

    胡美娟; 刘迎来; 朱丽霞; 齐丽华; 杨放

    2014-01-01

    通过断口形貌、金相分析以及力学性能检测等方法对某X80天然气输送管道环焊缝泄漏产生的原因进行了失效分析。分析结果表明,环焊缝焊接接头的拉伸性能符合Q/SY GJX 0110-2007《西气东输二线管道工程线路焊接技术规范》要求,但焊缝和热影响区的冲击性能均未达到焊接技术规范的要求,管道环焊缝泄漏裂纹位于环焊缝6点位置根焊区域,此位置根焊进行过内补焊作业,补焊焊缝焊趾处存在的焊接缺陷是环焊缝开裂泄漏的主要原因。%The leakage failure reason of circumferential weld for some X80 natural gas pipeline was analyzed by means of fracture morphology, microstructure observation and mechanical properties tests. The results showed that the tensile performance of welded joint for circumferential weld accord with the requirements of Q/SY GJX 0110-2007 Welding Technology Specification for the Second West-to-East Gas Pipeline Project, and the impact toughness of weld and HAZ both fail to meet the welding requirements of technical specification. The leaking crack of circumferential weld lies in the six position of root welding zone, and repair welding was implemented in the six position of root welding. The main leakage failure reason of circumferential weld was the welding defects close to the toe zone of the repair welding.

  17. Myocardial involvement in muscular dystrophy evaluated by thallium-201 emission computed tomography

    International Nuclear Information System (INIS)

    The clinical usefulness of thallium-201 myocardial emission computed tomography (ECT) for evaluating left ventricular myocardial fibrosis was assessed in 47 patients with Duchenne (MD), facio-scapulo-humeral (FSH), limb-girdle (LG) and myotonic (MT) dystrophy. 1. Trans-, long- and short-axial images were interpreted quantitatively by circumferential profile analysis, and the extent of fibrotic tissue (%FIB) was estimated by integrating hypoperfused areas in six to eight consecutive short-axial slices. Lung/mediastinum count ratio (L/M ratio), LV cavity dilatation, aneurysm formation and cardiac malrotation were also assessed with ECT. 2. Distinct ECT defects were demonstrated in 95 of a total of 235 LV segments (40 %) and in 37 of 47 cases (85 % of DMD, 71 % of FSH, 50 % of MT and 60 % of LG). They were observed specifically in the posterior wall (82 %) and the apex (65 %) in DMD, and were scattered in all LV wall segments in FSH, LG, and MT. 3. There was a significant correlation between %FIB and the L/M ratio (r = 0.79, p < 0.001), and the L/M ratio was significantly higher in DMD than in MT (0.67 ± 0.36 vs 0.34 ± 0.25, p < 0.05). 4. ECT showed marked LV dilatation in seven (15 %), apical aneurysm in five (11 %) and vertical heart in 12 (26 %) of the 47 patients. 5. There were no significant correlations between age or clinical stage scores and numbers of defect segments or %FIB in each group. 6. During the one-year follow-up period of these patients, a DMD boy with the largest %FIB (54 %) and the highest L/M ratio (1.4) together with LV dilatation had complications of refractory heart failure and he died eight months following the ECT examination. 7. Thallium-201 planar imaging and standard 12-lead ECG underestimated the perfusion defects which were evaluated with ECT. (author)

  18. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

  19. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  20. Experimental myocardial ischemia. Pt. 2

    International Nuclear Information System (INIS)

    The comparative effects of meglumine sodium diatrizoate (MSD), sodium meglumine calcium metrizoate (SMCM), and metrizamide (M) were studied in an isolated canine heart preparation. The parameters observed were coronary blood flow (CBF), myocardial contractile force (MCF), positive and negative dF/dt, and perfusion pressure during normal and ischemic perfusion conditions. MSD had an initial negative inotropic effect but baseline MCF returned in 1 min during normal perfusion and 2 min under ischemic conditions. SMCM and M had only a positive inotropic effect under normal perfusion. However, during ischemia, the positive effect of SMCM was followed by a decrease in contractile force. M showed only a positive effect on force during ischemia. Our results indicate that calcium additive may increase the risk of coronary arteriography in patients with severe coronary artery disease. (orig.)

  1. Steady thermal stress and strain rates in a rotating circular cylinder under steady state temperature

    Directory of Open Access Journals (Sweden)

    Pankaj Thakur

    2014-01-01

    Full Text Available Thermal stress and strain rates in a thick walled rotating cylinder under steady state temperature has been derived by using Seth’s transition theory. For elastic-plastic stage, it is seen that with the increase of temperature, the cylinder having smaller radii ratios requires lesser angular velocity to become fully plastic as compared to cylinder having higher radii ratios The circumferential stress becomes larger and larger with the increase in temperature. With increase in thickness ratio stresses must be decrease. For the creep stage, it is seen that circumferential stresses for incompressible materials maximum at the internal surface as compared to compressible material, which increase with the increase in temperature and measure n.

  2. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    International Nuclear Information System (INIS)

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting

  3. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Iannicelli, Elsa; Di Renzo, Sara [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ferri, Mario [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Pilozzi, Emanuela [Department of Clinical and Molecular Sciences, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Di Girolamo, Marco; Sapori, Alessandra [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ziparo, Vincenzo [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); David, Vincenzo [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy)

    2014-07-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

  4. Sparing Sphincters and Laparoscopic Resection Improve Survival by Optimizing the Circumferential Resection Margin in Rectal Cancer Patients.

    Science.gov (United States)

    Keskin, Metin; Bayraktar, Adem; Sivirikoz, Emre; Yegen, Gülcin; Karip, Bora; Saglam, Esra; Bulut, Mehmet Türker; Balik, Emre

    2016-02-01

    The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors.Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann-Whitney U test and the Mantel-Cox log-rank sum test.A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics or surgical treatment between the patients who had positive CRM and who had negative CRM, but a higher positive CRM rate was observed in patients undergone abdominoperineal resection (APR) (P CRM status. Logistic regression analysis revealed that APR (P CRM status. Moreover, positive CRM was associated with decreased 5-year overall and disease-free survival (P = 0.002 and P = 0.004, respectively).This large single-institution series demonstrated that APR and open resection were independent predictive factors for positive CRM status in rectal cancer. Positive CRM independently decreased the 5-year overall and disease-free survival rates.

  5. [Stem cell perspectives in myocardial infarctions].

    Science.gov (United States)

    Aceves, José Luis; Archundia, Abel; Díaz, Guillermo; Páez, Araceli; Masso, Felipe; Alvarado, Martha; López, Manuel; Aceves, Rocío; Ixcamparij, Carlos; Puente, Adriana; Vilchis, Rafael; Montaño, Luis Felipe

    2005-01-01

    Myocardial infarction is the leading cause of congestive heart failure and death in industrializated countries. The cellular cardiomyoplasty has emerged as an alternative treatment in the regeneration of infarted myocardial tissue. In animals' models, different cellular lines such as cardiomyocites, skeletal myoblasts, embryonic stem cells and adult mesenchymal stem cells have been used, resulting in an improvement in ventricular function and decrease in amount of infarcted tissue. The first three cells lines have disvantages as they are allogenics and are difficult to obtain. The adult mesenchymal stem cells are autologous and can be obtained throught the aspiration of bone marrow or from peripherical circulation, after stimulating with cytokines (G-CSF). The implantation in humans with recent and old myocardial infarction have shown improvements similar to those shown in animal models. These findings encourage the continued investigation in the mechanism of cellular differentiation and implantation methods in infarcted myocardial tissue.

  6. Exosomes and cardiac repair after myocardial infarction.

    Science.gov (United States)

    Sahoo, Susmita; Losordo, Douglas W

    2014-01-17

    Myocardial infarction is a leading cause of death among all cardiovascular diseases. The analysis of molecular mechanisms by which the ischemic myocardium initiates repair and remodeling indicates that secreted soluble factors are key players in communication to local and distant tissues, such as bone marrow. Recently, actively secreted membrane vesicles, including exosomes, are being recognized as new candidates with important roles in intercellular and tissue-level communication. In this review, we critically examine the emerging role of exosomes in local and distant microcommunication mechanisms after myocardial infarction. A comprehensive understanding of the role of exosomes in cardiac repair after myocardial infarction could bridge a major gap in knowledge of the repair mechanism after myocardial injury.

  7. Myocardial hypoperfusion on conventional contrast computed tomography.

    Science.gov (United States)

    Ching, Shing; Chung, Tak Shun

    2015-10-01

    Non–electrocardiogram (ECG)–gated contrast computed tomography (CT) is commonly performed to exclude aortic dissection in chest pain patients. Besides evaluating the aorta for dissection flap, attention should be paid to the myocardium for areas of hypoenhancement that may suggest ischemia. Current models of multidetector CT enable assessment of myocardial perfusion with minimal motion artifact even without ECG gating. Transmural hypoenhancement with preserved wall thickness in a coronary distribution is highly specific for acute myocardial infarction. We report 2 cases of acute chest pain with initial nondiagnostic studies that underwent CT aortogram to exclude dissection. Instead, the CT showed myocardial hypoenhancement in left anterior descending artery territory. Myocardial hypoenhancement occurred before ST-segment elevation on ECG, suggesting that recognition of this important finding may lead to earlier revascularization decisions. PMID:26321167

  8. A fast and accurate method for echocardiography strain rate imaging

    Science.gov (United States)

    Tavakoli, Vahid; Sahba, Nima; Hajebi, Nima; Nambakhsh, Mohammad Saleh

    2009-02-01

    Recently Strain and strain rate imaging have proved their superiority with respect to classical motion estimation methods in myocardial evaluation as a novel technique for quantitative analysis of myocardial function. Here in this paper, we propose a novel strain rate imaging algorithm using a new optical flow technique which is more rapid and accurate than the previous correlation-based methods. The new method presumes a spatiotemporal constancy of intensity and Magnitude of the image. Moreover the method makes use of the spline moment in a multiresolution approach. Moreover cardiac central point is obtained using a combination of center of mass and endocardial tracking. It is proved that the proposed method helps overcome the intensity variations of ultrasound texture while preserving the ability of motion estimation technique for different motions and orientations. Evaluation is performed on simulated, phantom (a contractile rubber balloon) and real sequences and proves that this technique is more accurate and faster than the previous methods.

  9. Quantitative Evaluation of Left Ventricular Regional Systolic Function in Patients with Different Location of Myocardial Infraction by 3D Speckle Tracking Echocardiography%超声三维斑点追踪技术定量评价不同部位心肌梗死患者心功能的研究

    Institute of Scientific and Technical Information of China (English)

    王丁; 邓又斌; 黄润青; 汤乔颖; 孙杰; 刘琨

    2013-01-01

    目的 应用超声三维斑点追踪技术定量评价不同部位心肌梗死(myocardial infarction,MI)患者左室心肌应变特征及与左室整体收缩功能的相关性.方法 使用三维斑点追踪技术对24例心梗患者及20例正常人进行心肌运动分析,自动计算左室射血分数(left ventricular ejection fraction,LVEF)和左室整体及各节段纵向、圆周、径向与面积收缩期峰值应变.结果 与正常对照组对比,前壁心肌梗死组左室12/17节段的面积峰值应变减低;集中于前、侧壁、室间隔及心尖部;下壁心肌梗死组左室11/17节段面积峰值应变减低,集中于下、后壁.与非梗死节段比较,梗死节段的纵向、圆周、径向及面积峰值应变均显著降低(P<0.01).前壁心肌梗死组整体纵向、圆周、径向及面积峰值应变均与LVEF显著相关(r=-0.752,r=-0.892,r=0.828,r=-0.876,P<0.01),下壁心肌梗死组各整体峰值应变与LVEF无显著相关(r=-0.08,r=0.113,r=0.044,r=-0.019,P>0.05).结论 超声三维斑点追踪技术是准确、定量评价心脏局部室壁运动异常及整体收缩功能新的无创方法.面积应变峰值可能是全面、准确、定量评价心功能的新指标.%Objective This study was performed to evaluate the value and characteristics of left ventricular systolic strain and its relation to the left ventricular global systolic function in patients with myocardial infarction(MI) which were in different location by using 3D speckle tracking echocardiography (3D-STI).Methods In 24 patient with MI and 20 control subjects,the myocardial motion was recorded and analyzed with 3D-STI.Left ventricular cjection fraction (LVEF),longitudinal strain(LS),circumferential strain(CS),radial strain(RS) and area strain(AS) in regional myocardial segments were measured automatically.Results Compared with control subjects,AS reduced in 12/17 myocardial segments of the anterior wall MI group,and its reduced segments were mainly in

  10. Regional myocardial free fatty acid metabolism

    International Nuclear Information System (INIS)

    Experimental evidence to date has confirmed the potential value of radioactive labelled free fatty acid (FFA) and their analogs for the assessment of regional myocardial FFA metabolism despite a number of current limitations. It is emphasized that with these agents only one specific aspect of myocardial metabolism, that of FFA, can be tested and that with these compounds information on the overall metabolic state cannot always be obtained. (WU)

  11. Acute myocardial infarction following a hornet sting

    OpenAIRE

    Cvetković-Matić Danica; Ašanin Milika; Matić Dragan; Ivanović Branislava; Simić Dragan; Kalezić Nevena; Stojanov Vesna

    2009-01-01

    Background. The occurrence of an acute myocardial infarction following a hornet sting has been very rarely reported in the previous literature. Pathogenetic mechanisms include direct action of the venom components on the coronary endothelium and allergic reaction with mediators released from mast cells. The anaphylactic reaction and venom components can produce acute coronary artery thrombosis. Case report. We reported a 45-year-old man with acute myocardial infarction after a hornet sting in...

  12. Headache: A Symptom of Acute Myocardial Infarction

    OpenAIRE

    Yasmine Elgharably; Cesar Iliescu; Stefano Sdringola; Syed Wamique Yusuf

    2013-01-01

    ABSTRACT:We present a case of 55 year old man, with myocardial infarction and coronary thrombosis, whose initial presentation was with severe headache and review the literature.INTRODUCTION:Coronary ischemia typically presents with retrosternal pain that radiates to left arm (1). present atypically in various forms like indigestion (2), otalgia (3), facial pain (4) and syncope (5). Headache as the sole presentation of myocardial infarction (MI) is rare; however it has been reported previously...

  13. Improved exercise myocardial perfusion during lidoflazine therapy

    International Nuclear Information System (INIS)