Study Of Left Ventricular Tissue Velocity Imaging In Patients With Heart Failure

Heart failure (HF) is a variety of end-stage with organic heart diseases, the incidence increases year by year. HF is also a cause of death with heart disease. Therefore,it has become a research hot topic to reduce mortality, improve the quality of life for patients with HF in recent years. The current treatment of HF has great develop, except basic medication (ACEI,β-receptor blockers, diuretics and digitalis,etc.) and heart transplant surgery, left ventricular assist pump and biventricular pacing resynchronization therapy have also been made a lot of remarkable growth, especially in biventricular pacing resynchronization therapy progress, which makes patients's cardiac function and quality of life improved. 2005 ACC / AHA guidelines have made cardiac resynchronization therapy (CRT) as indication for IA category with eligible CHF patients.By application and research for these years,cardiac resynchronization therapy (CRT) has been proven to have significantly effect for improving cardiac function,improving exercise tolerance, reversal of myocardial remodeling,improving clinical symptoms and quality of life, and reducing mortality of patients with HF.The working principle of CRT is to synchronize movement of heart , so patients of cardiac mechanical asynchrony will be likely benefit from CRT. Tissue Doppler imaging (TDI) technology is a new means for observing the exercise of the long axis of the heart, in recent years which been widely used for studies in the long axis of the ventricular wall movement. TDI can measure the peak velocity in different parts of heart,the time,which corresponds to the speed,and the relationship between cardiac electrical activity and the time, which also be used for quantification of the myocardial segments movement,the quantitative evaluation and providing accurate information for asynchronous sport of the inter-chamber and the interior. Therefore,TDI maybe has a unique role in exploring the mechanism of CRT and selection of patients with indications for CRT .ObjectiveThe using tissue Doppler imaging technology in the left ventricular myocardial motion measured indicators, to explore characteristics of the left ventricular asynchrony in patients with HF and the relationship between it and left ventricular function. For cardiac resynchronization therapy to provide a theoretical basis.Materials and methods26 HF patients, age 32-84 years old ,average 53 years old. Average heart rate 83±9 times / min. Inclusion criteria:the fulfilling Framingham heart failure diagnostic criteria (NYHA classification III-IV) ejection fraction <45%, including 12 Patients with dilated cardiomyopathy, 14 Patients with ischemic cardiomyopathy. Exclusion criteria: patients with old myocardial infarction and those who are not satisfied with the image acquisition. 26 the control group volunteers, age 30 - 75 years old, average 52 years old, average heart rate 78±11 times / min. Inclusion criteria:no family history of coronary heart disease, normal electrocardiogram. All selected subjects are recorded age, ECG, Heart Rate(HR) and QRS time,and measured blood pressure, including systolic blood pressure (SBP) and diastolic blood pressure (DBP),end diastolic diameter of left ventricle(LVEDD). Using Simpson,left ventricular end-diastolic volume and left ventricular end systolic volume are derived, and then Ejective fraction of left ventricle(LVEF)is calculated.The Vivid 7 color Doppler imaging apparatus is used, the probe frequency is 3.0Hz ,which is equipped with analysis software of TSI (Tissue Synchronisation Imaging). Accessing to the apical four-chamber view, long-axis view of left ventricular, the two-chamber view under the TSI model, the sampling points will be placed in the mitral annulus, the following, the peak systolic velocities (Vs) are measured by TDI: anteroseptal, posteroseptal, lateral, posterior, former and inferior segments. The six segments'Vs Mean (mVs) are calculated. Under TSI mode, the time from onset of QRS complexes to peak velocity during systole and diastole(Ts and Te)are measured. Maximum difference in Ts and Te with the same segment (?Ts1, ?Te1),the same wall(?Ts2, ?Te2).Results1.The time differences(?Ts1 and ?Te1) from onset of QRS complexes to peak velocity during systole and diastole with the same segment of the different walls in Heart failure group were increased in varying degrees, compared with parameters of the control group (Table 2, Table 3) ,In HF group, ?Ts1 and ?Te1 were significantly prolonged,compared with parameters of the control group (P <0. 01).2.The time differences(ΔTs2 andΔTe2) from onset of QRS complexes to peak velocity during systole and diastole with the same wall of the different segments in Heart failure group were increased in varying degrees, compared with parameters of the control group (Table 4, Table 5) , In HF group, ?Ts2 and ?Te2 were significantly prolonged,compared with parameters of the control group (P <0. 01).3.In HF group,the relationship between the systolic peak velocity of left ventricular mitral annular (mVs) and LVEF (Figure 1): linear correlation analysis showed that the mVs was significantly correlated with LVEF(r = 0.776, P <0.01).The results suggestingIn this study,Ts and Te respectively show the entire schedule from the cardiac electrical machinery excited to systolic and diastolic peak velocity. Structure's or functionin's obstacles in any link would result in abnormal values of Ts and Te, therefore,Ts and Te are comprehensive evaluation index in the entire process of myocardial electrical—mechanical activities.In disease state, the degree of motion obstacles in different parts of the myocardium is different,so Ts and Te of all parts have differences,and then madingΔTs1,ΔTe1,ΔTs2,ΔTe2 increased. The greater these values are, the more serious the degree of non-synchronous movement is. The study finds that the above-mentioned indicators of HF group larger than the control group,which indicates the existence of left ventricular non-synchronous movement with HF patients, and then which not only existes in the same segment of the different walls, but also in the same wall of the different segments. To illustrate left ventricular segments exists the wide range of non-synchronous movement.When movement of ventricular is non-synchronous, the ventricular movement in time and space is in a uncoordinated status, resulting in inconsistencies in intracardiac blood flow,the centripetal force of systolic wall is damaged,and then which impacts the increased pressure and ejection direction,so the time required for ejection is shorten,stroke volume is reduced. Christina Jarnert,etc confirmed that patients with clinical heart failure,even if ejection fraction> 45%, in the tissue Doppler imaging, systolic and diastolic parameters have significant changed.There are also reports recently showed that patients with heart failure, whose heart's regional systolic peak velocity is lower, have the normal ejection fraction[9].Therefore,TDI can early find abnormal indicators of patients with heart failure, and which can be quantitative and positioning,so patients can be early and appropriate treated. The results of this study also showes that mVs and LVEF have good correlation. That indicate that it and left ventricular function are closely related. Therefore, mVs can be used to evaluate left ventricular function and after the CRT improvement of the left ventricular function. Conclusions1.In HF patients, asynchronous movement not only exists in the same segment of different walls, but also exists in the same wall of the different segments, what showes that the asynchronous movement in left ventricular is widespread.2.mVs has close relation with LVEF, mVs can be used to evaluate left ventricular function and may be used to evaluate the improving situation of left ventricular function after the CRT.3.TDI is a quantitative and positioning method,and which has a high degree of repeatability. It is also a valuable method to evaluate asynchronous movement of heart and may be used to guide CRT.