Evaluation of Normal Fetal Left Cardiac Function by Tissue Doppler Imaging

To explore the feasibility of using tissue Doppler imaging technique for the evaluation of fetus＇s left ventrieular diastolic function, and to confirm its reliability by comparing it with traditional methods, this study examined 61 pregnant women in whom satisfactory images were obtained of fetal eehoeardiography. The peak velocity of blood stream were measured, including E, A and E/A at mitral valve orifice on the four chamber view with pulse wave. And then tissue Doppler imaging mode was employed to measure the velocity of mitral valve annulus including Ea, Aa, Sa and Ea / Aa. Correlation analysis was conducted between the velocity of orifice and that of annulus in terms of gestation age. And then correlation analysis was performed between above data and gestation ages. A positive correlation was found between the velocity of orifice and that of annulus, and the velocity increased with the gestation age. The change was the most significant between the 28th and the 34th week of gestation age. Our study showed that it is feasible to evaluate the fetus＇s left ven trieular diastole function by tissue Doppler imaging. Its stability can avoid the influence of fetal heart rates and preload.

In Vitro Validation of Tissue Doppler Left Ventricular Regional Wall Velocities by Using a Novel Balloon Phantom

To investigate the validity and accuracy of tissue Doppler imaging (TDI) using a novel balloon phantom, validation of TDI myocardial velocity measurements has been carried out indirectly from conventional M mode images. However it is not a true and independent gold standard. We described a new TDI validation method by using a specially developed left ventricular balloon model mounted in a water bath and constructed using two pear shaped balloons. It was connected to a pulsatile flow pump at 8 stroke volumes (50-85 ml/beat). The displacement and velocity of the balloon walls were recorded simultaneously by video imaging and TDI on a GE Vingmed System Five with a 5 MHz phased array probe at the highest frame rates available. Conventional M mode and 2 D imaging verified that our balloon model mimicked the shape and wall motion of left ventricle. There was a good correlation and agreement between the maximum video excursion of the anterior and posterior walls of the phantom and the results of the temporal integration of digital distance data by TDI (Anterior wall: r =0.97, SEE=0.24 mm, ±s =0.04±0.24 mm; Posterior wall: r =0.95, SEE=0.22 mm, ±s =0.03±0.24 mm). Analysis of the velocity profile by the TDI method showed that the velocity at each measured point was correlated well with the velocity obtained from the video images (Anterior wall: r =0.97, SEE=0.30 mm, ±s =-0.04±0.28 mm; Posterior wall: r =0.97, SEE=0.30 mm, ±s =0.04±0.28 mm). Our balloon model provided a new independent method for the validation of TDI data. This study demonstrated that the present TDI system is reliable for measuring wall motion distance and velocity.

Tissue Doppler,speckling tracking and four-dimensional echocardiographic assessment of right ventricular function in children with dilated cardiomyopathy

BACKGROUND Right ventricular(RV)function is frequently overlooked during dilated cardiomyopathy(DCM)evaluation.AIM To evaluate RV function in children with idiopathic DCM using relatively recent echocardiographic modalities.METHODS We prospectively studied the cardiac function in 50 children with idiopathic DCM and 50 healthy children as a control group,using four-dimensional echocardiography(4-DE),Tissue Doppler Imaging(TDI),and two-dimensional-speckles tracking echocardiography(2-D-STE).RV EF was measured by 4-DE.RESULTS The auto left(LV)ejection fractions(EF)measured by 2-D-STE were significantly lower in the patients'group than in the control.The sphericity index was also significantly lower in children with DCM than in the control.RV EF measured by 4-DE was significantly lower in the patient's group than the control.RV S wave,e´/a'ratio,myocardial performance index(MPI),and tricuspid annular plane systolic excursion(TAPSE)were significantly impaired in children with DCM than in control.Both LV and RV global longitudinal strains(GLS)were significantly reduced in children with DCM than in control.RVGLS was significantly associated with the duration since diagnosis,tricuspid annulus S wave,RV MPI,and TAPSE,but not with the age of the patients,RV EF,or e´/a'ratio.CONCLUSION There was impairment of the RV LGS and other systolic and diastolic parameters in children with DCM.STE and TDI can help to detect the early decline of RV function.

Effect of eicosapentaenoic acid on regional arterial stiffness:Assessment by tissue Doppler imaging

AIM: To evaluate the effects of eicosapentaenoic acid (EPA) on regional arterial stiffness assessed by strain rate using tissue Doppler imaging. METHODS: Nineteen eligible patients were prospectively studied (mean age 62 ± 8 years, 68% men). Subjects with large vessel complications and/or diabetes mellitus were excluded. The strain rate of the ascending aorta was measured by tissue Doppler imaging as an index of regional arterial stiffness, and brachial-ankle pulse wave velocity (baPWV) was measured as an index of degree of systemic arteriosclerosis. These indices were compared before and after administration of EPA at 1800 mg/d for one year. RESULTS: The plasma concentration of EPA increased significantly after EPA administration (3.0% ± 1.1% to 8.5% ± 2.9%, P < 0.001). There were no significant changes in baPWV (1765 ± 335 cm/s to 1745 ± 374 cm/s), low-density lipoprotein cholesterol levels (114 ± 29 mg/dL to 108 ± 28 mg/dL), or systolic blood pressure (131 ± 16 mmHg to 130 ± 13 mmHg) before and after EPA administration. In contrast, the strain rate was significantly increased by administration of EPA (19.2 ± 5.6 s-1, 23.0 ± 6.6 s-1, P < 0.05). CONCLUSION: One year of administration of EPA resulted in an improvement in regional arterial stiffness which was independent of blood pressure or serum cholesterol levels.

Tissue Doppler Study before and after PCI in Patients with Chronic Stable Angina and Apparent Normal Ventricular Function for Evaluation of Myocardial Function

Background: This study aimed to determine the impact of the percutaneous coronary intervention (PCI) on myocardial function assessed by tissue Doppler echocardiography. Methods: Conventional two-dimensional echocardiography and Myocardial tissue peak velocities were recorded at the lateral, ant.septal, post.septal, posterior, ant. and inferior angles of the mitral annulus as well as at the lateral tricuspid annulus by pulsed-wave tissue Doppler echocardiography before PCI, as well as 1 day and 6 weeks after intervention. Results: Fifty consecutive patients with chronic stable angina and preserved systolic left ventricular function (mean age, 58.3 ± 6.594 years;32 men) undergoing PCI were studied. Conventional echocardiographic revealed no statistically significant difference between pre- and post-PCI (1 day after PCI and 6 weeks after PCI) as regarding trans-mitral and trans-tricuspid flow velocities except as regarding LVEDD, LVESD and LVEF which showed a significant improvement post-PCI. Compared with pre-interventional values, systolic peak velocity and early diastolic velocities improved at all sites (P ≤ 0.05 for each). The most pronounced improvement occurred in the septal area. Similarly, late diastolic velocities improved at all sites (P ≤ 0.05 for each) except at post Wall A’. Also, there was a significant improvement of E’DT & E’/A’ ratio after PCI (P value is significant <0.05 for each) but there was insignificant difference between pre & post PCI for E/E’ (P-value = 0.154). There was a significant improvement in tissue Doppler measures of early, late diastolic function and E’/A’ at the lateral tricuspid annulus after PCI compared with baseline values (P value is significant <0.05) but there was an insignificant change in tissue Doppler measures at the lateral tricuspid annulus of E’DT & E/E’ after PCI (repeated measures ANOVA P-value is >0.05 for each). There were significant reductions in IVRT, IVCT & MPI after PCI (P value is significant <0.05 for each) but there was insignificant change in ET after PCI (P-value = 0.09) at the septal angle of the mitral annulus and the lateral angle of the tricuspid annulus. Conclusions: Tissue Doppler parameters of diastolic and systolic function improve early after successful PCI, and this effect persists to 6 weeks after the intervention that emphasizes its value in the improvement of regional and global LV functions and myocardial contractility.

Tissue Doppler imaging study of right ventricular myocardial systolic activation in subjects with pulmonary arterial hypertension

Background Tissue Doppler imaging （TDI） has provided an objective means to quantify global and regional left ventricular （LV） and right ventricular （RV） function with improved accuracy and greater reproducibility than conventional echocardiography. This study was conducted to assess RV myocardial systolic activation by TDI in subjects with pulmonary arterial hypertension （PAH）. Methods A total of 30 patients with PAH and 30 healthy volunteers, all comparable in age and sex, underwent standard Doppler echo and TDI. Using pulsed Doppler echocardiography combined with TDI, the following regional parameters were evaluated in three different myocardial segments （RV basal lateral wall, basal septal, and LV basal lateral） on apical 4-chamber view： systolic （Sm）, early- and late-diastolic （Em and Am） peak velocities. RV myocardial systolic activation delay was defined as the difference in time to peak TDI systolic velocities between the RV basal lateral wall and basal septal. In addition, RV end-diastolic and end-systolic areas were measured to calculate RV fractional area change from the same apical 4-chamber view. Results Compared with the control group, patients with PAH showed increased RA and RV end-diastolic diameter （RA： （4.5±1.2）cm vs （3.0±0.8）cm, P〈0.05 and RV： （4.8±1.9）cm vs （3.4±0.5）cm, P〈0.05） and reduced RV fractional area change; （35±14）% vs （56±9）%, P〈0.05. These PAH patients showed lower myocardial peak velocities and a significant activation delay compared with controls （P〈0.05）. Moreover, a strong correlation between RV myocardial systolic activation delay and RV fractional area change was shown in patients with pulmonary arterial hypertension （r = -0.82）. Conclusions In PAH, RV myocardial systolic activation was markedly delayed, which was directly related to the RV fractional area change. RV myocardial systolic activation delay assessed by TDI could offer a unique approach to predict RV dysfunction.

Effect of Shenmai Injection(参麦注射液)on Ventricular Diastolic Function in Patients with Chronic Heart Failure:An Assessment by Tissue Doppler Imaging

Objective：To assess the effect of Shenmai Injection（参麦注射液,SMI） on left ventricular diastolic function（LVDF） in patients with chronic heart failure（CHF） by tissue Doppler imaging（TDI）.Methods：Sixty-four CHF patients were randomly assigned to two groups,the observation group and the control group.Basic treatment including polarized liquid therapy was given to all the patients.In addition,SMI was given to patients of the observation group.The treatment duration was 14 days.TDI was performed in all the patients 3 days prior to the initiation of the treatment and one week after the medication to measure the average movement velocity of the mitral ring of the left ventricle at the early systolic stage and late diastolic stage（Ea and Aa）;the outcomes were compared with the corresponding parameters obtained from blood flow Doppler echocardiography, namely,the velocity of the E-wave（E） and A-wave（A）.Results：After treatment,Ea and Ea/Aa increased and Aa decreased significantly in the observation group（P〈0.05）.In the control group,although some improvement was seen,there was no statistically significant change（P〉0.05）.No statistical significance was shown between groups in these parameters after treatment.Conclusion：TDI assessment shows that SMI could effectively improve the LVDF in CHF patients.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension： Assessment by Tissue Doppler Imaging

Background： Hypertension （HT） is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging （TDI） is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction. Methods： Seventy-six patients with HT （41 males, mean age 52.6 i 9.0 years） and 41 controls （22 males, mean age 49.8 ± 7.9 years） were included in the study. Atrial electromechanical coupling at the right （PRA）, left （PLA）, interatrial septum （PIS） were measured with TDI. Intra- （right： PIS-PRA, left： PLA-PIS） and inter-atrial （PLA-PRA） electromechanical delays were calculated. Maximum P-wave duration （Pmax） was calculated from 12-lead electrocardiogram. Results： Atrial electromechanical coupling at PLA （76.6 ± 14.1 ms vs. 82.9 ±15.8 ms, P - 0.036）, left intra-atrial （10.9 ±5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023）, right intra-atrial （10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P= 0.035）, and interatrial electromechanical （21.4± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003） delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular （LV） mass index and Pmax were significantly associated with PLA （P = 0.001 and P = 0.002, respectively）, and the LV mass index was the only related factor for interatrial delay （1~ = 0.001）. Conclusions： Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients.

Cardiac function evaluated by Tei index of tissue doppler imaging and brain natriuretic peptide in patients with acute coronary syndrome and hyperglycemia

Background Recent studies demonstrated that N-terminal pro-brain natriuretic peptide（NT-pro BNP） increases in patients with diabetes mellitus and raised concerns about the diagnostic validity of NT-pro BNP in assessment of cardiac function in patients with hyperglycemia.Current investigation was carried out to observe the influence of hyperglycemia on the correlation of NT-pro BNP and cardiac function index in patients with acute coronary syndrome（ACS）.Methods Fifty patients with ACS were enrolled and divided into hyperglycemia group（fasting plasma glucose（FPG） ≥ 6.1 mmol/L） and euglycemia group（FPG 〈 6.1 mmol/L）.All the patients underwent routine transthoracic ecocardiagraphy and tissue Doppler imaging（TDI） investigation.Blood sample were obtained with 24 hours of hospitalization for measuring of NT-proBNP level.Relation between TDI-Tei index and the level of NT-proBNP were analyzed in the two groups respectively.Result TDI-Tei index,systolic index and diastolic index were all significantly higher in hyperglycemia group than that in euglycemia group（0.679 ± 0.139 vs 0.600 ± 0.093,P = 0.022;0.294 ± 0.074 vs 0.258 ± 0.035,P = 0.036;0.385 ± 0.069 vs 0.342 ± 0.068,P = 0.032）.TDI-Tei index was significantly negatively correlated with the level of log NT-pro BNP in both hyperglycemia group and euglycemia group（rp = 0.673,P = 0.000;rp = 0.354,P = 0.000）.Conclusions（1）Cardiac function in patients with ACS complicated with hyperglycemia is inferior to that in patients with euglycemia;（2）Assessment of cardiac function with NT-proBNP is reliable in patients with hyperglycemia.

Experimental Study of Assessment on Ventricular Activation Origin and Contraction Sequence by Doppler Tissue Imaging

To evaluate the possibility and accuracy of Doppler tissue image (DTI) on assessment of normal and abnormal ventricular activation and contraction sequence, 9 open chest canine hearts were analyzed by acceleration mode, M mode, and spectrum mode DTI. Our results showed that: (1) Acceleration mode DTI could show the origin of activation and conduction sequence on line; (2) M mode DTI revealed that the activation in mid interventricular septum was earlier than that in mid left ventricular posterior wall at sinus activation; (3) Spectrum DTI showed the ventricular endocardium was activated earlier than the ventricular epicardium in all segments at sinus rhythm. The earliest site of activation of the normal ventricular wall was at middle interventricular septum; the latest site was at basal posterior wall; the contraction sequence was different at the different walls; (4) During abnormal ventricular activation, mid left ventricular posterior wall was activated earliest in accordance with the pacing sites. Abnormal ventricular activation was slower than sinus activation, and the contraction sequence varied at different sites of ventricular wall. It is concluded that DTI can be used to localize the origin of normal or abnormal myocardial activation and to assess the contraction sequence conveniently, accurately and non invasively.

ASSESSMENT OF LEFT VENTRICULAR FUNCTION IN HEALTHY SUBJECTS BY PUSLED WAVE DOPPLER TISSUE IMAGING

Objective To examine the clinical application of pulsed Doppler tissue imaging(DTI)for regional left ventricular function assessment in normal subjects. Methods We examined 50 healthy subjects(range 12-42 years,mean age 28.3 ± 6.9 years)using pulsed Doppler tissue imaging to characterize the diastolic and systolic velocity profiles of mitral annulus. Recordings were made along the long axis in the apical 4-chamber, 2-chamber, and long apical views of 6 sites(posterior-septum, lateral, anterior, inferior, anterior-septum, posterior)at the mitral annulus. Myocardial velocities were determined with use of variance F statistical analysis. Correlation analysis was employed to test the relationship between age and mitral annular velocities. Results Both early diastolic and systolic velocities at the septum were lower than other sites. There were no differences in mitral annulus late diastolic velocities. Mean early diastolic and systolic velocities was negatively correlated with age. Conclusions Doppler tissue imaging can directly reflect regional left ventricular function.

ASSESSMENT OF DIASTOLIC FUNCTION IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY BY DOPPLER TISSUE IMAGING

To determine the clinical application of pulsed Doppler tissue imaging in assessing the left ventricular diasto-lic function and in discriminating between normal subjects and patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction. Methods We measured the peak diastolic velocities of mitral annulus in 81 patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction and 50 normal volunteers by Doppler tissue imaging using the apical window at 2-ch-amber and long apical views, respectively. The myocardial velocities were determined with use of variance F statistical analysis. Results Early diastolic myocardial velocities of mitral annulus were higher in normal subjects than in patients with hy-pertrophic cardiomyopathy with either delayed relaxation, pseudonormal filling, or restrictive filling. However, peak myocar-dial velocities of mitral annulus during atrial contraction were similar in normal subjects and patients with hypertrophic cardiomyopathy. Conclusion Doppler tissue imaging can directly reflect upon left diastolic ventricular function. Early phase of diastole was the best discriminator between control subjects and patients with hypertrophic cardiomyopathy.

Pig model of chronic myocardial ischemia and its investigation by ultrasonic integrated backscatter and Doppler tissue imaging

Objective: To construct an animal model of chronic ischemic myocardium, and evaluate it by ultrasonic integrated backscatter (IBS) and Doppler tissue imaging (DTI). Methods: An Ameroid constrictor was placed around the porcine left circumflex coronary artery (LCX). The calibrated average image intensity (%AII), cyclic variation of IBS (CVIB), transmural gradient index (TGI) of CVIB in lateral-posterior wall (LPW), and DTI spectrum of LPW in left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) at normal state, 2, 4, 6 and 8 weeks postoperatively were measured. Results: Normal %AII, CVIB and TGI were 2.29±0.32, 9.69±2.22dB and 0.22±0.08, respectively. The %AII increased gradually postoperatively. The CVIB decreased also gradually, and the decrease was higher in subepicardium than in subendocardium. Most of TGI decrease occurred from 2 to 4 weeks postoperatively and became zero at 8 weeks (P<0.01); Normal V S (peak systolic velocity) of AP-4CV was higher than that of LVPM-SAM (P<0.01). V E (peak early diastolic velocity) of AP-4CV was lower than that of LVPM-SAM (P<0.05). V S and V E were all decreased after operation (P<0.01). The decrease of V S in AP-4CV was greater than that in LVPM-SAM. Conclusion: The pathological changes of the myocardium in human ischemic heart disease (IHD) are similar to that of Ameriod model. IBS and DTI can detect echo changes and ventricular wall motion in chronic ischemic myocardium, and provide more information for clinical investigation and treatment of IHD.

Value of Low Dose Dobutamine Doppler Tissue Imaging for Detecting Hibernating Myocardium

Summary: In order to assess the value of Doppler tissue imaging (DTI) in detecting viable hibernating myocardium, 20 patients with coronary artery disease and chronic left ventricular dysfunction underwent low dose dobutamine stress echocardiography and low dose dobutamine stress DTI. The results showed that among the 100 asynergic segments, 35 segments showed improvement after dobutamine infusion (group H) and no changes were observed in the remaining 65 segments (group N). The left ventricular echocardiographic score index decreased from 1.60±0. 35 to 1.44±0.36 ( n =20, P <0.01). During low dose dobutamine stress DTI, there was no difference in the values of velosity of S wave (V s) before dobutamine infusion between two groups. However, after dobutamine infusion, the values of V s and VR in group H were significantly higher than those in group N (V s:10.1±3.0 cm/s vs 7.3±2.2 cm/s, P <0.01; VR: 60 %±41 % vs 25 %±32 %, P <0.001). 95.7 % asynergic myocardial segments with VR≤0 had no viability while 86 % asynergic segments with VR>80 % were viable myocardium. It is concluded that the different reactions to dobutamine stress between hibernating and necrosis myocardium could be showed by DTI and it is more clinically significant when VR≤0 and VR>80 %.

Doppler Tissue Imaging Assessment of Left Ventricular Systolic Dyssynchrony in Severe Heart Failure Patients With a Normal QRS Duration

Objectives To assess the prevalence of systolic dyssynchrony of the left ventricular （LV） walls in patients of heart failure（HF） with a normal QRS duration by Doppler tissue imaging （DTI）. Methods 20 patients of HF with a normal QRS duration and 20 healthy individuals were investigated with DTI to quantitatively analyze their pulsed-wave Doppler spectrum of basal and middle segments in six walls of left ventricle. The time between the onset of the QRS complex of the surface ECG and the onset of the systolic wave of pulsed-wave Doppler spectrum was measured （TS）. LV systolic synchronization was assessed by the maximal difference （MD） in time of TS, the standard deviation （SD） and the coefficient of variation （CV） of TS in the all 12 LV segments. Results When a TS-MD of TS〉 53.08 ms, a TS-SD of TS 〉18.08 ms and a TS-CV of TS 〉 0.91 （＋1.65 SD of normal controls） was used to define significant systolic dyssynchrony, the prevalence of systolic dyssynchrony was 55.0 %, 55.0 % and 55.0 %, respectively, in the HF patients group, significantly higher than those in the normal control and the locations of delayed contraction of these patients were different. Conclusions LV systolic dyssynchrony could be commonly demonstrated by DTI in HF patients with a normal QRS duration. This finding will support the view about the possibility that more HF patients could benefit from cardiac resynchronization therapy.

Pulsed Doppler Tissue Imaging for Assessment of Left Ventricular Systolic and Diastolic Synchronicity in Normal Subjects

Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging （DTI） for the assessment of left ventricular systolic and diastolic synchronicity. Methods Twenty and six healthy subjects were studied by pulsed DTI. The septal and lateral, anterior and inferior walls of the left ventricle were displayed respectively, and basal and middle segments of each wall were selected for myocardial motion spectrum sampling. DTI parameters were： peak systolic myocardial velocity （s）, regional pre-ejection period （PEP）, time to the peak of s wave （Ts）, regional ejection time （ET） ; peak early diastolic velocity （e）, peak late diastolic velocity （a）, e/a ratio, time to the beginning of e wave （QE）, time to the peak of e wave （Te） and regional isovolumic relaxation time （IVRT）. Results The e and e/a were significantly different among basal segments, and s and e/a were significantly different among middle segments, with the highest value in lateral segments and the lowest value in septal segments. The s, e and a were all significantly higher in basal segments than middle segments. None of the systolic time intervals （PEP, Ts and ET） and diastolic time intervals （QE, Te and IVRT） were significantly different among basal segments and middle segments, neither were they when basal segment was compared with middle segment. Conclusions In normal subjects, the longitudinal myocardial systolic and diastolic velocities of the left ventricle are not homogeneous, but the contraction and relaxation are highly synchronized. Pulsed DTI can be used to quantitatively analyze the systolic and diastolic synchronicity of the heart.

Transvenous versus open chest lead placement for resynchronization therapy in patients with heart failure： comparison of ventricular electromechanical synchronicity

Background Transvenous lead placement is the standard approach for left ventricular （LV） pacing in cardiac resynchronization ther- apy （CRT）, while the open chest access epicardial lead placement is currently the most frequently used second choice. Our study aimed to compare the ventricular electromechanical synchronicity in patients with heart failure after CRT with these two different LV pacing tech- niques. Methods We enrolled 33 consecutive patients with refractory heart failure secondly to dilated cardiomyopathy who were eligible for CRT in this study. Nineteen patients received transvenous （TV group） while 14 received open chest （OP group） LV lead pacing. Intraand inter-ventricular electromechanical synchronicity was assessed by tissue Doppler imaging （TDI） before and one year after CRT procedure. Results Before CRT procedure, the mean QRS-duration, maximum time difference to systolic peak velocity among 12 left ventricle segments （LV Ts-12）, standard deviation of time difference to systolic peak velocity of 12 left ventricle segments （LV Ts-SD）, and inter-ventficular mechanical delay （IVMD） in OP and TV group were 166 ± 17 ms and 170 ± 21 ms, 391 ±42 ms and 397 ± 36 ms, 144 ± 30 ms and 148 ± 22 ms, 58 ± 25 ms and 60 ± 36 ms, respectively （all P 〉 0.05）. At one year after the CRT, the mean QRS-duration, LV Ts-12, LV Ts-SD, and IVMD in TV and OP group were 128 ± 14 ms and 141 ± 22 ms （P = 0.031）, 136 ± 37 ms and 294 ± 119 ms （P = 0.023）, 50± 22 ms and 96 ± 34 ms （P = 0.015）, 27 ± 11 ms and 27 ± 26 ms （P = 0.86）, respectively. The LV lead implantation procedure time was 53.4±16.3 rain for OP group and 136 ± 35.1 min for TV group （P = 0.016）. The mean LV pacing threshold increased significantly from 1.7 ± 0.6 V/0.5 ms to 2.3 ± 1.6 V/0.5 ms （P 〈 0.05） in TV group while it remained stable in the OP group. Conclusions Compared to conventional endovascular approach, open chest access of LV pacing for CRT leads to better improvement of the intraventricular synchronization.

Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation

We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler（PW） and pulse tissue Doppler imaging（PW-TDI）.A total of 25 consecutive in-patients with persistent atrial fibrillation,who restored sinus rhythm after ablation procedure,were recruited in our cardiac center.Echocardiography was performed on each patient at 2 hours,1 day,5 days,1 month and 3 months after the ablation therapy,and atrial electromechanical delay was measured simultaneously by PW and PW-TDI.There was no significant difference between PW and TDI in measuring atrial electromechanical delay.However,at postoperative 2 hours,peak A detection rates were mathematically but nonsignificantly greater by PWTDI than by PW.Second,there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months,but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time.Lastly,patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval,by the PW or by PW-TDI,respectively.In patients with persistent atrial fibrillation,atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later,and was significantly related to patients＇ duration of atrial fibrillation.Atrial electromechanical interval,as a potential predicted factor,is recommended to be measured by either PW or TDI after24 hours,when patients had recovered sinus rhythm by radiofrequency ablation.

Determination of the optimal atrioventricular and interventricular delays in cardiac resynchronization therapy

Objective In order to provide the maximum benefit of cardiac resynchronization therapy(CRT),we tried to use an echocardiography method to optimize the atrioventricular and interventricular delay.Methods The study included 6 patients who underwent implantation of biventricular pacemakers for drug-resistant heart failure.Two-dimensional echocardiography and tissue Doppler imaging were carried out before and after the pacemaker implantation.The optimal AV delay was defined as the AV delay resulting in maximum timevelocity integral(TVI)of transmitral filling flow,the longest left ventricular filling time(LVFT)and the minimum mitral regurgitation(MR).The optimal VV delay was defined as the VV delay producing the maximum LV synchrony and the largest aortic TVI.Results CRT was successfully performed in all patients.After pacemaker implantation,an acute improvement in left ventricular ejection fraction(LVEF)was observed from 26.5%to 35%.Meanwhile,the QRS duration decreased from 170ms to 150ms.The optimal AV delay was programmed at 130,120,120,120,150 and 110ms respectively with heart rate corrected,LVFT significantly lengthened and TVI of MR decreased(non-optimal vs optimal AV delay:LVFT:469ms vs 523ms;TVI of MR:16.43cm vs 13.06cm,P<0.05).The optimal VV delay was programmed at 4,4,4,8,12 and 8ms with LV preactivation respectively.Programming the optimal VV delay increased the aortic TVI from 17.33cm up to 21.42cm(P<0.05).In the septal and lateral wall,peak systolic velocities improved from2.70cm/s to 3.02cm/s(P>0.05)and froml.31cm/s to 2.50cm/s(P<0.05)respectively.The septal-to-lateral delay in peak velocity improved from 56.4ms to 13.3ms after CRT(P<0.01).Conclusions Optimization of AV and VV delays may further enhance the efficacy of CRT.However,there was interindividual variability of optimal values,warranting individual patient examination.