Objective To appraise the clinical value of velocity vector imaging(VVI) by analyzing the peak systolic velocities,strain and strain rate of ventricular segments in patients with DDD pacing. Methods eventeen patients with DDD pacing were enrolled in this study. The peak systolic velocities, strain andstrain rate of ventricular segments were measured with VVI. The difference at baseline and after pacemaker implantation was analyzed. Results Left and right ventricular (LV and RV) longitudinal peak velocities at baseline and after DDD pacing were significantly decreasing from basal, mid to apical segments. But no significant difference was found in longitudinal strain,strain rate and radial motion characteristic of LV. The mean systolic velocities and strain rate at baseline and after pacemaker implantation and strain with pacing of RV posterior septum and free wall were higher than those of posterior septum and lateral segment of LV respectively. The mean strain and strain rate of RV after pacing were higher than that of LV. Compared with the values at baseline, mean strain of LV with pacing was lower significantly. Conclusions VVI can accurately assess ventricular systolic function in patients with DDD pacing, and can become a powerful means in assessing the regional myocardial function.

Objective To assess alternations in left ventricular volume and systolic synchrony in patients with frequent premature ventricular complexes(PVCs) from the right ventricular outflow tract(RVOT).Methods Twenty-nine patients with frequent isolated PVCs from RVOT were included and 30 healthy subjects as control.Instantaneous full-volume imaging(IFI) was performed to evaluate left ventricle volumetric parameters,including end-systolic volume (ESV),end-diastolic volume (EDV),stroke volume (SV),ejection fraction (EF),and systolic synchrony parameters,including systolic dyssynchrony index (SDI),dispersion end-systole (DISPES),mean end-systolic time (MES),pre-contraction time volume (PreContr) and post-contraction time volume (PostContr).Contraction front mapping was performed to visualize volumetric contraction sequence.All values of patients with PVCs were recorded during sinus beats (PVC-S) and premature ventricular beats (PVC-V) respectively.Results Significant differences were observed in left ventricular systolic volumetric and synchrony parameters between PVC-V and control subjects (P＜0.01),as well as in MES and PreContr between PVC-S and control subjects (P＜0.01).Conclusions Left ventricular systolic dysynchrony was demonstrated in patients with PVCs from RVOT.IFI was a novel tool to analyze left ventricular global and regional volumetric alternations.

Objective To evaluate the immediate impact of radiofrequencycatheter ablation on left atrial (LA)volumes and function by velocity vector imaging(ⅤⅥ)and compare the LA function with and without atrial fibrillation after the operation.Methods Ten consecutive patients with paroxysmal AF were studied at baseline and within 3 days after ablation.Ten consecutive patients with persistent AF were studied within 3 days after ablation,in sinus rhythm.Ten patients with normal ventricular function were included in the study.ⅤⅥ was performed to assess LA sizes and strain,strain rate,velocity of the septum,lateral wall and the atrial roof from the apical four-chamber view.Results In patients with paroxysmal AF,global and regioal LA function was not significantly impaired after the ablation procedure.Subgroup analysis demonstrated that there were no significant difference in LA function betwwen patients with paroxysmal AF and control subjects,but the indexed LAVmax was significantly larger in all AF patients compared with control subjects.The global function of LA,including LAEF,LAaEF and LA expansion index significantly decreased in persistent AF patients.By contrast,the LA septal strain,velocity and lateral strain were lower than controls.Conclusions Radiofrequency catheter ablation has no influence on LA function assessed by ⅤⅥ within three days after the operation for patients with paroxysmaI AF.The function of persistent AF patients is absolutely lower than control subjects.

Objective To evaluate the left ventricular(LV)global and segmental myocardial systolic function in patients with permanent DDD pacemaker implantation by speckle tracking imaging.Methods Myocardial imaging of LV apical long views and parasternal LV short axis views were performed in 9 patients with right ventricular(RV)septum pacing(RV septum group),15 patients with RV apex pacing(RV apex group)and 13 healthy subjects(control group).Peak systolic longitudinal strain(S_L),peak systolic radial strain(S_R)were measured,and the average of S_L and S_R among LV 18 segments were calculated respectively as corresponding GS_L and GS_R.Results The GS_L[-(18.29±2.67)%]of RV apex group showed significant decrease compared with RV septum group[-(20.54±2.29)%]and control group[-(21.07±2.08)%](P＜0.05),while no significant difference was found between RV septum and control group.The GS_R of the pacing groups were both lower than control group[(36.26±9.37)%in control group,(28.59±6.06)%in RV septum group,(26.85±7.73)%in RV apex group,P＜0.05],but RV apex group showed more decrease trend.The S_L and S_R of the LV myocardial segments close to the pacing sites in both pacing groups showed significant decrease compared with control group,but RV septum group preserved similar LV strain distribution with control group while RV apex group showed abnormal LV strain pattern.Conclusions Speckle tracking imaging is a useful modality to evaluate global and segmental myocardial systolic function of LV with pacing at different right ventricular sites.

Objective To assess left ventricular(LV)twisting parameters in different layers with velocity vector imaging(VVI)in both healthy subjects and premature ventricular contraction(PVC)bigeminy from right ventricle(RV)patients,and investigate the rules of LV myocardium dynamics in sinus rhythm and PVC from RV.Methods Ten patients with PVC bigeminy from RV and twelve healthy subj ects underwent the examination of two-dimensional ultrasound,in which the standard LV mitral valve(MV)and apical short-axis views were acquired.The twisting angle(TA)and untwisting starting time(UST)were measured.Results In healthy subjects myocardium of LV MV short-axis twisted in clockwise,while the myocardium of LV apical short-axis twisted in counter-clockwise.TA of endocardium was higher than that of epieardium(P＜0.01).In PVC bigeminy from RA patients,their TA during sinus contraction was lower than that of healthy subjects both in MV and apical short axis respectively(P＜0.05),and UST was earlier(P＜0.05).In PVC the TA curve is bidirectional.and in early systolic TA twisted reversely compared with that of healthy subjects and sinus contraction in PVC patients.Conclusions Twisting parameters could be used to assess myocardium dynamics during different ventricular mechanical activation.VVl was a novel tool to analyze myocardium twisting.

Objective To evaluate left ventricular(LV) systolic synchrony and sequence in patients with premature ventricular complexes(PVCs) from right ventricular outflow tract (RVOT).Methods Thirty patients with frequent isolated PVCs from RVOT and 30 healthy subjects as control were included.Speckle tracking imaging (STI) was performed to assess the time-to-peak segmental systolic strain in longit udinal(TsL), circumferential (TsC) and radial (TsR) direction.The standard deviation (SD) of TsL,TsC and TsR of 18 LV segments were calculated respectively.All values of patients with PVCs were recorded during sinus beats(PVC-S) and PVC beats(PVC-V) respectively.LV systolic sequence in PVC-V was analyzed.Results Significant differences were observed in the SD values between the PVC-V and control subjects in three directions,as well as between the PVC-S and control subjects in circumferential and radial direction.In PVC-V significance difference was seen in TsL and TsR from apical to basal level,as well as in TsL and TsC in different walls.Conclusions LV systolic synchrony was demonstrated in patients with PVCs from RVOT during both sinus beats and PVC beats.Systolic sequence in PVC beats from RVOT exhibit certain rules.

Objective To investigate the expression and clinical significance of lipoxin A4,leukotrienc C4,lipoxygenase-5 in peripheral blood of pregnant women with different types of severe preeclampsia.Methods Forty-five singleton pregnant women who accepted antenatal care and delivered in First Affiliated Hospital of Wenzhou Medical College were enrolled in this study from December 2010 to June 2011.All objects were divided into normal pregnancy group (n=20),early onset severe preeclampsia group (n=10) and late onset severe preeclampsia group (n=15).Enzymelinked immunosorbent assay was used to detect lipoxin A4 and leukotriene C4 levels in peripheral blood.The level of lipoxygenase-5 mRNA in white blood cells was detected by real time fluorescence quantitative reverse transcription-polymerase chain reaction.The differences of lipoxin A4,leukotriene C4 and lipoxygenase-5 mRNA among groups were compared by analysis of variance and LSD-t test;and correlations among their expressions were analyzed by linear regression.Results Lipoxin A4 level in early and late onset severe preeclampsia group was (355.3±116.0) pg/ml and (389.7±117.5) pg/ml,which were both significantly lower than that in normal pregnancy group [(555.0±139.8) pg/ml] (t=-4.03 and-3.77,P＜0.05 respectively).The leukotriene C4 level in early and lateonset severe preeclampsia and normal pregnaney group was (591.3±185.5) pg/ml,(510.3±197.1) pg/ml and (496.9 ± 158.8) pg/ml,no statistical difference were found (F=0.889,P＞0.05) ; neither did the expression of lipoxygenase 5 mRNA,which was 4.2± 1.9 in normal pregnancy group,4.8 ± 2.0 in early onset severe preeclampsia group and 4.4 ± 1.2 in late onset severe preeclampsia group (F=0.311,P＞0.05).There was no correlation among the levels of lipoxin A4,leukotriene C4 and lipoxygenase-5 mRNA in each group (P ＞ 0.05).Conclusions Early and remarkable decreasing of lipoxin A4 level might contribute to the development of early onset severe preeclampsia.

Objective To assess the left ventricular(LV)contraction synchrony in patients with DDD pacing by velocity vector imaging(VVI).Methods Acoustic clip capture was performed in 13 patients before and after pacemaker implantation and obtained high-frame rate B-mode echocardiographic images.VVI was done in all three standard LV apical views and parasternal LV short axis(SAX)views.The time to peak systolic longitudinal velocity(Tvl)and systolic longitudinal strain(Ts1)in the LV apical views and the time to peak systolic radial velocity(Tvr)and systolic circumferential strain(Tsc)in the LV SAX views were measured bv VVI.The standard deviation of Tvl,Tsl,Tvr and Tsc(Tvl-SD,Tsl-SD,Tvr-SD and TscSD)and the maximal temporal difference of Tvl,Tsl,Tvr and Tsc(Tvl-d,Tsl-d,Tvr-d and Tsc-d)of 18 segments were calculated.Results Compared with the values at baseline,Tvr-SD,Tsc-SD,Tsl-d,Tvr-d and Tsc-d increased significantly in patients after pacemaker implantation(P＜0.05).Conclusions The longitudinal,radial and circumferential systolic asynchrony of the LV was commonly existed in patients after DDD pacing.VVI can be used to evaluate the systolic synchrony of the LV in patients with DDD pacing.