| The left ventricular mechanical motion included longitudinal motion,radial motion and twisting.And the twisting and untwisting of left ventricle have been new indexes of the heart function.Cardiac resynchronization therapy(CRT) has been shown to a valuble stragy for heart failure patients.In this study,we want to assess the twisting,untwisting and desynchronization of left ventricle in long and short axis,and the contents of this study were the following:1.Assessment of left ventricular twisting and untwistingof healthy volunteers 94 healthy volunteers were assigned to four groups by age,young-group(range 18-45 yr,mean age 31.71±10.04 yr,6 females and 15 males), middle-age-group(range 46-64 yr,mean age 55.86±9.57 yr,29 females and 15 males),older-age-group(range 65-79 yr,mean age 71.66±15.73 yr,12 females and 10 males) and very-old-age-group(80≥yr,mean age 83.00±4.17 yr,5 females and 2 males).The results show that LV rotation degree,rotation velocity at baseline and apex were regular changed with the cardiac cycle;the rotation direction was clockwise at the base and counterclockwise at the apex,and is combined to yield a systolic counterclockwise twisting as seen from the apex. With aging,Ptw,AVCtw,MVOtw,PTV and PUV increased significantly(P＜0. 05) and UntwR decreased significantly(P＜0.05) in the young-group, middle-age-group and older-age-group,However no difference in all indexes was noted among the older-age-group and very-old-age-group.Ptw at young-group, middle-age group,old-age group and very-old-age group were(16.33±3.63)°, (20.08±4.87)°,(23.24±5.84)°and(23.03±2.08)°,AVCtw at young-group, middle-age group,old-age group and very-old-age group were(13.40±3.32)°, (16.73±4.60)°,(18.95±5.36)°and(18.96±1.75)°,MVOtw at young-group, middle-age group,old-age group and very-old-age group were(8.93±3.13)°, (11.06±3.82)°,(12.66±4.07)°and(12.78±1.64)°,the UntwR at young-group, middle-age group,old-age group and very-old-age group were(0.59±0.20)%, (0.47±0.12)%,(0.39±0.11)%and(0.30±0.06)%.There was a good correlation between Ptw,AVCtw,MVOtw,PTV,PUV,UntwR and age.2.Assessment of left ventricular twisting and untwisting of DCM patients19 DCM patients(range 18-80 yr,mean age 50.52±17.52 yr,2 females) and 21 age- and sex-matched normal controls(range18-80 yr,mean age 49.05±16.94 yr,5 females) were enrolled into this study.Then DCM patients were divided into two groups:E/A＜2 group and E/A＞2 group.The routine echo showed the left ventricle dilated and EF decreased.The results show that LV rotation degree, rotation velocity at baseline and apex were irregular changeable with the cardiac cycle;the rotation direction was clockwise at the base and counterclockwise at the apex,and are combined to yield a systolic counterclockwise twisting as seen from the apex,but the rotation at the basal and apex were the same direction in some patients.Ptw,AVCtw,MVOtw,PTV,PUV decreased significantly in DCM patients,and the UntwR was significantly decreased in the E/A＜2 group.But there was no correlation between Ptw,AVCtw,MVOtw,PTV,PUV,UntwR and EF in DCM patients.3.Application of Velocity Vector Imaging in cardiac resynchronization therapyVelocity vector imaging was applied to of 28 patients with heart failure who underwent cardiac resynchronization therapy.That velocity vector imaging can quantify left ventricular mechanical desynchronization before CRT therapy,but the delay contractile position was different in different patient,and the posterior wall was the most common delay contractile position.Long-term response to CRT was defined as a＞15%reduction in the left ventricular end systolic volume at 3 months of follow-up,so there were 21 responders and 7 non-responders;CRT has been shown to improve the heart function,activity toleration and desynchronization in responders.In this study,and predict response.The Ts max-min basal velocity time delays of 97.5 ms predicted response with 81% sensitivity and 86%specificity when followed(12.08±7.51) months after resynchronization therapy.Therefore,we come to the conclusions:1.The rotation direction in normal people and DCM patients was clockwise at the base and counterclockwise at the apex,and are combined to yield a systolic counterclockwise twisting as seen from the apex2.With aging,Ptw,AVCtw,MVOtw,PTV and PUV increased significantly and UntwR decreased significantly in normal people.3.Ptw,AVCtw,MVOtw,PTV,PUV decreased significantly in DCM patients,the UntwR was significantly decreased in the E/A＜2 group,but increase in the E/A＞2 group,this result indicated the UntwR may be effected by the pre-load.4.There was desynchronization in dysfunction heart;CRT therapy can improve the heart function and activity toleration;Ts max-min basal can predict CRT response with the highest sensitivity and specificity in both the short and longitudinal axis desynchronization...
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