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[Background] the past 20 years, as the medical progress and development, living standards, the pace of life is change, and the aging of the population, diastolic heart failure (diastolic heart failure, DHF) accounted for all heart failure cases 38% to 54 % and DHF prognosis with systolic heart failure as serious, and thus become in recent years, basic and clinical research focus. Therefore, early and accurate evaluation of left ventricular diastolic function has important clinical value for the diagnosis of DHF, also need to be included in the diagnosis and treatment of a new standard. At present, the evaluation of left ventricular diastolic function: (1) left ventricular end-diastolic pressure was measured (hemodynamic Detection) is recognized as the evaluation of left ventricular diastolic function in the gold standard, but because of its invasive lead clinical difficult to widely used; (2) imaging studies such as MRI, MRI image quality is good, check not required injection of contrast agent, there is no ray radiation damage, easy to operate, check the time, do not have to make assumptions on ventricular morphology, measurement accuracy, can be more accurate evaluation of left ventricular diastolic function, has become the ideal inspection method for evaluation of cardiac function, and the radioactive by breathing affect the higher cost limits its application; (3) two-dimensional ultrasound, such as the E / A, traditional Doppler echocardiography to be able to measure the spectrum of the mitral flow. Widely used in the evaluation of left ventricular diastolic function. However, when the increased left atrial pressure, left ventricular compliance further retreat can pseudonormal mitral flow spectrum, although simple, but the accuracy is poor, therefore, the technical defects; (4) NT-proBNP (N terminal pro-brain natriuretic peptide) clinical studies have shown that elevated NT-proBNP levels in heart failure, and is consistent with the severity of heart failure to reduce heart failure caused by systolic dysfunction and diastolic function all such alterations, decreased with the improvement of cardiac function, NT-proBNP levels. NT-proBNP increased the degree of progress and prognosis of heart failure has good predictive value is relatively independent of DHF predictors. However, NT-proBNP levels factors affected more, including renal function, atrial fibrillation, myocardial ischemia, pulmonary embolism, chronic obstructive pulmonary disease, tumor, and other factors such as age, gender, diuretics and β-receptor blockers also have some impact on the results. Rely solely on NT-proBNP concentrations there are some limitations in the diagnosis of heart failure. (5) tissue Doppler (tissue Doppler imaging, TDI) directly extracted from myocardial Doppler shift signal, quantitative determination of wall motion speed can be intuitive and precise analysis of the ventricular wall and valve ring movement, non-invasive and easy to operate, can a more accurate evaluation of left ventricular diastolic function, However, due to the limitations of Doppler flow imaging, the angle between the direction of the Doppler ultrasound beam with the myocardial motion, heart during the cardiac cycle in the overall movement, breathing exercises, The instrument gain adjustment can affect the measurement results, the performance of the operational differences between the examiner and the lack of quantitative, it is poor reproducibility, and the inevitable presence of angular dependence, its accuracy subject to certain restrictions with the heart the development of ultrasound, especially the organization Doppler the emergence of a new method for the evaluation of left ventricular diastolic function. TDI is an application of the Doppler effect of ultrasound imaging of myocardial motion feature new technology, it is directly extracted from myocardial Doppler shift signal, the quantitative determination of wall motion speed, intuitive and precise analysis of the wall and the annulus movement literature has reported that the average velocity of the mitral annulus prospective evaluation of left ventricular systolic and diastolic function. However, due to the the the TDI technology uses the Doppler principle, so there are limitations Doppler flow imaging, the lack of quantitative, poor reproducibility, and the inevitable presence of angular dependence, its accuracy, subject to certain restrictions , thus limiting the application and development of the TDI evaluation of left ventricular diastolic function. Velocity vector imaging (velocity vetor imaging, VVI) is the establishment of a new study based on the principle of two-dimensional speckle tracking myocardial structural mechanics, analysis of local cardiac function acoustic diagnostic techniques, accurate ultrasound speckle tracking within the organization and determine spots the mutual positional relationship and establishing an angular dependency of the method of evaluation of myocardial function, image acquisition is also easier and thus significantly improve the accuracy of the measurement. In recent years, VVI evaluation of diastolic function has become a hotspot of clinical research at home and abroad caused by cardiovascular disease research attention. VVI using acoustic acquisition, no angle-dependent Doppler noise than traditional small, the display mode is intuitive, quantization in the myocardium long axis, minor axis and circumferential directions at any point on the structure of mechanical parameters, accurate quantification of the ventricular volume and radio blood score, used to assess the changes in cardiac function and anatomy mechanics of congestive heart failure, myocardial the synchronous dysfunction and myocardial function disorders, has opened up a new road for the clinical and research work, in the non-invasive evaluation of left ventricular diastolic function with greater advantage. Dogs with acute myocardial ischemia state Zhang Chuan VVI evaluation of left ventricular diastolic function studies that use different hemodynamic state the VVI and quantitative tissue velocity imaging (quantitative tissue 'velocity imaging in myocardial infraction patients with) were measured mitral ring cardiac diastolic velocity in the longitudinal results show that QTVI and VVI mode, E '(Early TD lengthening Velocity), the average of the two technologies EM with LVEDP has a good negative correlation, the two techniques measured Em are corresponding decline in left ventricular diastolic function impaired to varying degrees; using these two techniques to measure Em is a non-invasive evaluation of left ventricular diastolic function in a good way, and VVI mode Em LVEDP higher than QTVI. VVI evaluation of left ventricular diastolic function with a non-invasive, easy to operate, good reproducibility advantages are more worthy of the recommended evaluation of left ventricular diastolic function, has a broader application prospects. However, so far not undertaken any study to VVI evaluation of diastolic function of the normal population and give the reference values ??defined more by the VVI diastolic heart failure patients evaluate and define, and therefore there are still certain limitations of the clinical application of VVI. The purpose of this study: 1, to study the distribution of left ventricular diastolic function of the normal population VVI; 2, VVI defined left ventricular diastolic function of the normal population reference range. [Objective] To explore the application of velocity vector imaging (VVI) Assessment of normal left ventricular diastolic function and determine the normal reference range. [Method] combined ultrasound and NT-BNP, clinical symptoms, and other indicators of screening healthy people 97 Siemens Acuson Sequoia C512 echocardiography instrument using VVI measurements resting state the level of left ventricular mitral annulus the six wall: room interval, side walls, a front wall, a lower wall, before the interval, the rear wall of the myocardium early diastolic velocity (E), offline into the VVI workstation operator interface blinded to image the VVI analysis and calculator average Em, the measured E / Em, the reference values ??for the normal population range given reference defined. [Results] 97 patients with normal E / Em the reference range (unilateral boundaries to take 95% threshold) is (0,22.935); reference range of male E / Em (0,22.300), female E / Em The value of the reference range (0,24.766); reference range of 50-year-old male E / Em (0,22.413), the reference range of women under the age of 50 E / Em (0,24.314); 50 men over the age of E / Em reference range (0,15.410), the reference range of women over the age of 50 E / Em (0,24.870). By Mann-Whitney test non-parametric tests, male, female, E / Em values ??no significant difference (P = 0.296). [Conclusion] VVI as a new ultrasound technology, non-invasive evaluation of left ventricular diastolic function in a good way, to provide a reliable means of accurate clinical evaluation of left ventricular diastolic function.
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