Left Ventricular Longitudinal Function In Cardiomyopathy Quantitatively Assessed By Velocity Vector Imaging

Backgroud: Both dilated cardiomyopathy (DCM) and ischemiccardiomyopathy (ICM) have the same clinical manifestation such as heartenlargement (left cardiac ventricle and/or right cardiac ventricle), heart failure,arrhythmia and embolism. The main difference in ultrasonic echocardiography(ECHO) is ventricular movement reduced extensively in DCM and segmentallyin ICM. But the routine technique of ECHO could only estimate the globalheart movement and could not evaluate effectively local myocardiummovement. Recently developed new technique-velocity vector imaging (VVI)can conquer the angle-dependency, the drag of surrounding myocardial andinterference of the global heart movement and can estimate exactly regionalmyocardium function. No scholars at home and abroad had studied the the leftventricular longitudinal function in DCM and ICM by VVI previously.Objective:To investigate the regional longitudinal contraction andrelaxation of left ventricle in DCM and ICM patients by velocity vectorimaging (VVI). To characterize the regularity of left ventricular longitudinalfunction in patients with DCM, patients with ICM and the normal persons. Todiscuss the important clinical value of velocity vector imaging in quantitativelyevaluating regional longitudinal function of left ventricle.Methods: We examined respectively 30 patients diagnosed DCM andICM and 30 normal persons. They were matched with for sex. and age.Exclusion criteria for all subjects were HBP, cardiac valve disease, congenital heart disease, Diabetes mellitus, thyroid disease, metabolic disease,connective tissue disease, dystrophy, severe dysfunction of liver and kidney,contact of toxic, alcohol abuse, pregnant woman in perinatal period. Threegroup indexes below were obtained from 1 heart beat in 16 segmentsrespectively to assess left ventricular longitudinal contraction and relaxation:Ⅰ-systolic max velocity(SVmax), systolic max strain (SSmax), systolic maxstrain rate(SSRmax);Ⅱ-diastolic max velocity(DVmax), diastolic maxstrain(DSmax), diastolic max strain rate(DSRmax);Ⅲ-peak time ofvelocity(PTV), peak time of strain(PTS), peak time of strain rate(PTSR).Results: The Vmax were graduately decrease from base to apex and theSmax and SRmax were not obvious different from the base to apex in normalgroup. The PTV, PTS and PTSR had good coherence among 16 myocardiumsegments in normal group. The change trends of the Vmax, Smax and SRmaxwere similar with the normal group in DCM, but the values were obvious lowerthan normal group in DCM (P＜0.01). The PTV, PTS and PTSR had also goodcoherence among 16 myocardium segments in DCM, but the values wereobvious larger than normal group in DCM (PTS, P＜0.05; PTV and PTSR,P＜0.01). The Vmax, Smax and SRmax were also obvious lower than normalgroup in ICM (P＜0.01), while the basal part of lateral wall and posterior wallwere larger than other segments (P＜0.05). The PTV, PTS and PTSR had badcoherence among 16 myocardium segments in ICM.Conclusion: The regional contraction and relaxation were obvious decrease in DCM and ICM than normal group, but there were not segmentaldifferences in DCM while with segmental difference in ICM. The parameterschange trends were similar with the normal in DCM. VVI is a novelnoninvasive tool to quantitatively and objectively assess LV regional systolicand diastolic function, providing another useful method to diagnose anddifferentiate cardiomyopathy.