Evaluate The Left Ventricular Function Of Hypertrophic Cardiomyopathy By Speckle Tracking Imaging

Speckle tracking imaging(STI)is based on similar principles that are utilized with tagged MRI.One of the main differences is that instead of using external,short-lived magnetic tags,speckle tracking imaging uses inherent features(natural acoustic marker)for frame-to-frame tracking of the myocardial tissue.STI is a new technology by which to observe the global and regional myocardial function.Speckle tracking imaging is a natural extension of one-dimensional motion analysis provided by DTI(doppler tissue imaging).However, Doppler-only-based techniques are limited due to angle dependence of the signal.As a result,certain myocardial areas are excluded.For example,the lateral myocardium in the apical views,as well as large portions of the myocardium in the parasternal views and especially the short-axis views.The purpose of this research was to evaluate the systolic,diastolic, twist function and myocardial synchrony of hypertrophic cardiomyopathy in longitudinal,radial,transverse and circumferential direction.This research includes three parts:1.Evaluation of regional myocardial systolic function of left ventricular in hypertrophic cardiomyopathy using ultrasound speckle tracking imaging.Objective:To evaluate the regional myocardial systolic function in the patients with hypertrophic cardiomyopathy(HCM)by ultrasound speckle tracking imaging.Methods:Myocardial imaging of 20 HCM patients(HCM group)and 27 healthy subjects(control group)was collected,and their regional velocity, peak systolic strain and strain rate,displacement in longitudinal,radial, transverse and circumferential motion was measured respectively.The data was compared and analyzed between the two groups.Results:In normal subjects,left ventricular longitudinal strain was significantly increased at apical segment.No significant difference was found in radial motion characteristic of left ventricule.Circumferential motion was larger at septum and anteroseptum.The longitudinal average strain value of HCM group was significantly lower than that of control group,no significant difference was found in circumferential,radial average value of strain.Circumferential and radial strain and strain rate was significantly lower in septum and anteroseptum.Longitudinal motion was more impaired than radial and circumferential.The Velocity in systolic,diastolic and atrial systolic periods,the displacement in longitudinal,radial and transverse motion was decreased,but have no significant correlation with the extend and site of hypertrophy.Conclusions:Ultrasound speckle tracking imaging can quantitatively assess left ventricular global and regional function,providing another useful equipment.2.Evaluation of twist function of left ventricle using ultrasound speckle tracking imagingObjective:To evaluation of left ventricular(LV)torsion,time to peak torional velocity and torional velocity in hypertrophic cardiomyopathy (HCM)and normal subjects using ultrasound speckle tracking imaging.Methods:Myocardial imaging of 20 HCM patients(HCM group)and 21 healthy subjects(control group)was collected,and their left ventricular torsion,time to peak torional velocity and torional velocity was measured respectively.The data were compared and analyzed between the two groups.Results:During systole,the LV performs a wringing motion with a counterclockwise rotation at the apex and clockwise rotation at the base. Peak LV twist was significantly higher,and the rate of LV untwisting significantly reduced and delayed in HCM patients.Initial counterclockwise motion and its interval in basal rotation decreased in HCM patients.Conclusions:Ultrasound speckle tracking imaging is a useful method to assess LV torional deformation and may make the assessment more available in clinical and research cardiology.3.Evaluation of myocardial synchrony of left ventricular in hypertrophic cardiomyopathy using ultrasound speckle tracking imagingObjective:To evaluate myocardial synchrony in the patients with HCM by ultrasound speckle tracking imaging.Methods:Myocardial imaging of 20 HCM patients(HCM group)and 27 healthy subjects(control group)was collected,and their regional time to peak systolic strain and strain rate in longitudinal,radial and circumferential motion was measured respectively.The data were compared and analyzed between the two groups.Results:No significant difference was found about time to systolic strain and strain rate in longitudinal,radial and circumferential motion of left ventricular in normal subjects.The time to peak systolic strain was longer than those in normal subjects in longitudinal motion.The time to peak systolic strain in basal segments of posterior septum and inferior wall in circumferential motion,all basal segments in radial motion was shorter than those in normal subjects.The time to peak systolic strain rate in certain segments in longitudinal and circumferential motion was shorter than those in normal subjects.Conclusions:Ultrasound speckle tracking imaging can quantitatively assess left ventricular myocardial synchrony,indicate that STI was a useful tool in assessing the myocardial synchrony.