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Objective To evaluate the left ventricular systolic circumferential strain by layer specific speckle tracking imaging in healthy volunteers and patients with left bundle branch block (LBBB).Methods Forty patients with LBBB were divided into two groups,LBBB1 group [left ventricular ejection fraction (LVEF≥50％] and LBBB2 group (LVEF＜50％),and 25 healthy subjects were selected as the control group.High frame rate two dimensional images were recorded from the left ventricular short-axis views at the levels of the mitral annulus,papillary muscle and apex respectively.The peak systolic circumferential strain of the endocardium,myocardium and epicardium were measured using layer-specific strain software.Results The circumferential strain of the epicardium and myocardium at the level of the apex showed a statistically significant difference between the LBBB1 group and the control group (P =0.004),while there was no statistically significant difference demonstrated at the levels of the mitral annulus and papillary muscle(P ＞0.01).The circumferential strain of the endocardium at the levels of the papillary muscle and apex showed a statistically significant difference between the LBBB1 group and the control group (P =0.000),while there was no statistically significant difference demonstrated at the level of the mitral annulus (P ＞0.01).The circumferential strain of the endocardium,myocardium and epicardium at the three short axis view levels showed statistically significant differences between the LBBB2 group and the control or LBBB1 groups respectively(P =0.000).Conclusions The circumferential strain of the endocardium at the level of the apex can provide more information about disease prognosis,especially in LBBB patients with a LVEF of ≥50％.
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Objective To compare the left ventricular function parameters of patients with sick sinus syndrome ( SSS ) and DDD pacemaker implantation during atrioventricular conduction ( AVC ) and right ventricular apex pacing ( RVAP ) mode . Methods Forty‐six consecutive patients with SSS who had undergone DDD pacemaker implantation were studied . Fifty volunteers were included as control group . Changing from AVC to RVAP mode ,the acute effect on echocardiographic parameters ,including LVEF , parameters of aortic/pulmonary artery pulse wave Doppler ,and parameters of left ventricular twist by speckle tracking imaging were measured respectively . Pacemaker implantation duration and cumulative ventricular pacing proportion ( Cum% VP) were recorded . The relationships of pacemaker parameter and above left ventricular function parameters were analyzed . Results Compared with control group ,values of peak rotation in LV apex and LV twist were significantly lower during AVC and RVAP mode . The value of peak rotation in LV base showed no significant difference between three groups .Apical‐basal rotation delay during RVAP was significantly longer than those during AVC and in control group respectively ( P <0 .05) . LVEF during RVAP decreased statistically ( P< 0 .05 ) ,but showed no difference during AVC , compared with the control group . The peak LV twist related positively with LVEF ,and negatively with Cum% VP . Conclusions RVA pacing decreases left ventricular function , which is independent of asynchrony contraction patterns caused by pacing . LVEF ,apical rotation and LV twist are more sensitive to demonstrate the LV dysfunction in patients with pacemaker implantation . LV twist related negatively with Cum% VP .
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Objective To analyze the left ventricular (LV) diastolic function parameters of patients with sick sinus syndrome (SSS) and DDD pacemaker implantation during atrioventricular conduction (AVC) and right ventricular apex pacing(RVAP)mode.Methods Forty-six consecutive patients with SSS who had undergone DDD pacemaker implantation were studied.Fifty volunteers were selected as control group.Changing from AVC to RVAP mode,the acute effect on echocardiographic left ventricular diastolic function parameters,including mitral inflow PW parameters,mitral annulus tissue Doppler imaging parameters,left atrial volume index,and LV∕apical∕basal untwist parameters were measured.And all subjects were classified into normal diastolic function or three degrees of LV diastolic dysfunction.Results Compared with control group,both AVC and RVAP mode of patients with DDD pacemaker implantation resulted in the worsening of LV diastolic function as shown by(1) prolonged deceleration time of E wave, decreased descending slope of E wave,as well as decreased early diastolic velocity at the septal mitral annulus,(2) the decrease of LV∕basal∕apical untwist velocity,(3) the increase in the degree of diastolic dysfunction.Conclusions In patients with DDD pacemaker implantation,both AVC and RVAP mode are associated with the deterioration of LV diastolic function,which is particularly obvious in RVAP mode.
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Objective To investigate the value of two-dimensional speckle tracking imaging (STI) in assessing regional myocardial dysfunction and myocardial fibrosis in a mouse model of myocardial infarction.Methods Twenty C57/B6 mice were randomly divided into two groups:myocardial infarction (MI) group (n =10) and sham-operation (SO) group (n =10).Echocardiography was performed four weeks after surgery.High frame rate two dimensional images were recorded in the left ventricular short axis views at the papillary muscle level and analysised at EchoPac workstation.Peak radical strain (PRS) and peak radical strain rate (PRSR) of each segment were measured at systolic period.Percent segmental fibrosis (PSF) was assessed from histological left ventricular cross sections stained by Masson trichrome.Results Compared with SO group,PRS and PRSR decreased significantly in all segments of MI group (P ＜ 0.01),especially in anterosepetal,anterior and lateral segments (P ＜0.05).PSF of anterosepetal,anterior,lateral and posterior segments in MI group increased significantly than those in SO group(P ＜0.01),and were negatively correlated with PRS and PRSR of these segments(r =-0.88,P ＜0.001 ; r =-0.77,P ＜0.001).Conclusions STI could accurately quantify regional myocardial function in a mouse model of myocardial infarction.Segmental radial strain and strain rate measured by STI were significantly correlated with PSF,which can be a non-invasive tool for monitoring myocardial fibrosis after myocardial infarction.
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Objective To evaluate left ventricular(LV)myocardial contraction patterns and function when pacing in different right ventricular(RV)sites and discuss echocardiogarphic method to evaluate physiologcal pacing mode.Methods This study included 26 patients with paroxysmal supraventricular tachycardia without organic heart disease.Four pacing modes including right atrium pacing(AAI),RV apex pacing(VVI-RVA),RV septal pacing(VVI-IVS)and RV outflow tract pacing(VVI-RVOT)were performed on the patients in a random order after succussful radiofrequency ablation.The parameters measured in each pacing mode included(1)LV systolic function parameters:LV twist angle(Twist),aortic systolic velocity-time integral(VTIAo)and LV global strain(Gε)；(2)LV contracting pattern:segmental peak systolic strain(Sε),the time to peak value(TPε),and the distribution of segmental Sε,TPε in each layer or wall.The relationship between Sε,TPε of each wall was analyzed.[Results]Pacing from RV sites showed lower Twist,VTIAO and Gε than AAI mode.Gε demonstrated significant difference in three RV sites pacing mode(VVI-RVOT＞VVI-IVS＞VVI-RVA,P＜0.05).Compared with the AAI mode,the distribution of segmental Sε,TPε in the each layer or wall alerted significantly in three RV sites pacing mode,especially in VV1-RVA.The distribution pattern was similar in VVI-RVOT and VVI-IVS.Furthermore,the wall Sε collated negtively with wall TPε(r =-0.51,P＜0.001).[Conclusions]Compared with AAI mode,RV pacing,especially the VVI-RVA induced the alternation of LV contraction patterns and reduction of systolic function.Longitudinal strain parameters can be used to assess the myocardial contraction patterns and function in different pacing mode.
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Objective To evaluate the patterns of intracardiac flow of left ventricle (LV) in patients with premature ventricular complexes (PVCs) from the right ventricular outflow tract (RVOT) by analyzing the vortex during isovolumetric contraction phase and the distribution rules of flow-time curves in each layer of LV.Methods Twenty-seven patients with frequent isolated PVCs from RVOT were involved and 25 healthy subjects as control.The color Doppler image of LV at apical four-chamber view was acquired.Vector flow mapping (VFM) was performed to assess the parameters of vortex during isovolumic contraction phase, including diameter (transverse and vertical diameter), velocity (maximal positive and negative velocity) and the number of vortex rings.Positive flow during systole and negative flow during diastole of LV in each layer were measured by flow-time curve.All values of patients with PVCs were recorded during sinus beats (PVC-S) and PVC (PVC-V) respectively.Results Significant differences were demonstrated in all parameters of vortex between the PVC-V and control subjects.And the flow-time curves disarrayed in PVC-V.The velocity of vortex in PVC-S was lower than that in control subjects.And the distribution pattern of flow-time curves in LV of PVC-S differed from that of control subjects.Conclusions Alternation of intracardiac fluid pattern in LV was demonstrated in patients with PVCs from RVOT during both sinus beats and PVC.VFM can be used to analyze the intracardiac flow field in normal and pathological electrical activation.
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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.
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Aim To study the effects of telmisartan upon serum calcineurin.Methods 92 male SD rats with the same age were randomly divided into control group (N), sham operation group (S), 2K1C+distilled water group (K) and 2K1C+telmisartan group (T).S rats were performed the open-abdomen surgery without being restricted any renal artery, but the K and the T rats were restricted their left renal artery. Beginning from the third week after the surgery, the K rats started to be treated with the intragastric infusion of distilled water 10 ml·(kg·d)~(-1) , while the T rats with telmisartan 10 mg·(kg·d)~(-1) .And after being treated for 2, 4 and 8 weeks, rats were respectively measured the systolic blood pressure (SBP), the diastolic blood pressure (DBP) of the abdominal aorta. Before and after the operation, ultrasonography with probe of 7.5 MHz was used to obtain the structure and functional indexes, such as IVSd, IVSs, LVPWd, and serum calcineurin were evaluated by ELISA and colorimetric assay kit.Result Compared with the S group and the N group, ① the results of blood pressure (SBP, DBP) were significantly higher in K group (all P <0.01), after use of telmisartan, blood pressure was significantly reduced(P <0.01);② the thickness of interventricular septal and left ventricular posterior wall at the end of diastolic and systolic were significantly higher in K group (all P <0.01), after use of telmisartan, the thickness of those declined(all P <0.01);③ the level and activity of serum calcineurin were significantly higher in K group (all P <0.01), after use of telmisartan, the level and activity of calcineurin significantly fell(P <0.01).Conclusion The serum calcineurin of artery was also raised in the left ventricular remodeling. Telmisartan ameliorates ventricular remodeling effectively, which may be associated with decreasing the expression of artery serum calcineurin.
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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.
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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.
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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.
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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.
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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.