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 a...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.展开更多
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 ...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.展开更多
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 th...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.展开更多
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 ...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.展开更多
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 incl...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.展开更多
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
