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Objective: strain rate imaging quantitative evaluation of myocardial function and segmental, estimation of myocardial ischemia / infarction range, but the degree of myocardial ischemia has not been studied. The purpose of this project is to (1) study the normal left ventricular strain epsilon, the SR parameter characteristics of the strain rate. (2) myocardial strain, strain rate SR age-related changes and their assessment of the feasibility and reproducibility of left ventricular function. (3) coronary angiography as the gold standard, the left coronary artery to left anterior descending artery light, moderate and severe stenosis strain rate parameters cut-off value. Methods: The study included 102 patients (15-74 years of age, 49 men) healthy volunteers and 34 patients (61.7 ± 12.1 years, 24 men) with stable angina pectoris of coronary heart disease and coronary angiography-positive patients. 1.102 cases of healthy volunteers were divided into 15-29, 30-39, 40-49, 50-59-year-old gt; 60-year-old five groups, line echocardiography mitral flow velocity E peak, A peak ratio. Apical four-chamber Simpson's method, left ventricular ejection fraction EF. The use of strain rate imaging apical four-chamber (left ventricular wall, after the interval), apical two-chamber (anterior, inferior wall), three-chamber apical (anterior septum, posterior) each segment were analyzed for three heart The cycle peak strain epsilon, systolic strain rate SRS early diastolic strain rate SRe isovolumic diastolic strain rate SRivr the corresponding SRS index, SRE index. 2.34 cases (61.7 ± 12.1 years, 24 men) clinical diagnosis of stable angina, coronary angiography-positive patients divided into three groups according to the left anterior descending artery stenosis (mild lt; 50%, moderate 50% -74 %, severe gt; 75%), the line strain rate imaging examination, left ventricular anterior wall, anterior septum segmental peak strain, systolic strain rate SRS early diastolic strain rate SRe isovolumic diastolic strain rate SRivr parameters. Selected from 102 healthy volunteers aged 50-59 gt; 60-year-old two groups of 35 patients as a control group. From 102 healthy volunteers were randomly selected 30 myocardial segments (basal segment, the middle segment, apical segment of the 10 above), check a month interval repetitive inspections, check the line the long axis of the left ventricular myocardial longitudinal strain and strain rate check whether statistically significant difference. Results: 1.102 cases of healthy volunteers 8.8% myocardial segments removed due to image quality and the effects of aliasing, SR basal segment, normal left ventricular long axis of the same wall ε and strain rate is greater than the intermediate segment and apical segments, systolic and early diastolic three segments were significant differences (P lt; 0.001). The same level wall myocardial strain and strain rate SR systolic and isovolumic relaxation period there was no significant difference, ε and strain rate SR age downward trend, statistically significant difference. Systolic strain index (SRS index) and left ventricular systolic function (LVEF) (r = 0.84, p lt; 0.01), the diastolic strain index (SRe index) and mitral inflow E peak (r = 0.88, p lt; 0.01) showed a high degree of correlation. 2.34 cases of stable angina pectoris in patients with coronary heart disease, can be analyzed segments of 201 segments, mild 54, moderate group 49, 50 severe group, collateral circulation group, 48 in the control group can be analyzed segment 182. ε (-6.4% ± 2.8% VS11.1% ± 3.2% in controls, p = 0.000), SRs (-0.78 ± 0.42 VS -1.25 ± 0.89S-1 in controls, p = 0.000), SRe (1.12 ± 0.57 VS 1.71 ± 0.76S-1 in controls, p = 0.000) compared with the control group decreased significantly, but SRivr tended to increase with increasing degree of stenosis (-0.63 ± 0.60 vs -0.1 ± 0.59 S-1 in controls, p = 0.000). Left coronary artery from the left anterior descending artery with mild stenosis and normal control group no significant difference failed to obtain the cut-off value of strain rate parameters; moderate stenosis (50% -74%) of the cut-off value SRivr -0.42 (sensitivity, 85% specificity resistance 80%); severe stenosis of (GT; 75%) were the intercept SRivr is -0.91 (sensitivity 91% specificity 90%). The check between strain, strain rate SR differences were 7.1 ± 5.0% and 10.8 ± 8.2%, check their own strain, strain rate SR differences were 9.2 ± 8.0% and 11.4 ± 8.6%. Conclusion: 1. The myocardial strain / strain rate reflect tissue deformation, quantitative analysis of regional myocardial function, is a non-invasive, repeatable evaluation of left ventricular function technology. Normal left ventricular long axis of the same wall ε and strain rate SR basal segment is greater than the middle segment and apical segments, there were significant differences. The same level wall myocardial strain and strain rate SR no significant difference, epsilon and strain rate SR downward trend with age, no significant difference. 3 isovolumic diastolic strain rate SRivr the accurate diagnosis of the left anterior descending artery with moderate or severe stenosis, strain rate imaging to quantitative evaluation of the severity of the ischemic myocardium, with high sensitivity and specificity.
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