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.

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.

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.

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 %.

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.

Diagnostic value of dobutamine stress Doppler tissue imaging in diabetic patients with suspected coronary artery disease

Background: Coronary artery disease (CAD) is often silent in diabetic patients, and it is typically in ad-vanced stages of development by the time it manifests. Various forms of stress testing have been investigated to detect obstructive CAD in diabetes mellitus. Ob-jectives: To assess the diagnostic value of dobutamine stress pulsed-wave Doppler tissue imaging (DTI) compared with standard wall motion analysis in de-tection of myocardial ischemia in diabetic patients with suspected CAD. Methods: The study comprised 46 diabetic patients with suspected CAD underwent dobutamine stress echocardiography (DSE) with DTI within 4 weeks before coronary angiography(CA). Dobutamine infusion started at 5 μ/kg/min and in-creased up to 40 μ/kg/min with additional atropine during submaximal heart rate responses. In addition to wall-motion score index (WMSI) analysis, pulsed- wave DTI examination of basal and mid segments of posteroseptal, lateral, anterior, inferior and antero- septal walls was performed. Myocardial velocities were measured at rest in the apical 4, 3 and 2-cham- ber views. The measurements were repeated at low dose (10 - 15 μ/kg/min) and at peak stress (40 μ/kg/min). DTI measurements included peak systolic velocity (S), peak early diastolic velocity (E) and peak late diastolic velocity (A) and the results were com-pared to WMSI analysis. Patients were classified into two groups according to CA results;group (I) di-abetics with positive CA (n = 27) and group (II) di-abetics with negative CA (n = 19). Results: There was no significant difference between the two groups in duration of diabetes, global WMSI at rest or the ? changes (stress-rest/rest) of WMSI (P > 0.05). Global S and global E were significantly lower in group I compared to group II at peak stress (11.3 ± 3.7 cm/sec vs. 14.5 ± 2.2 cm/sec, p < 0.01) and (11.3 ± 1.6 cm/sec vs. 13.1 ± 2.1 cm/sec, p < 0.01) respectively. The cutoff points for global S and global E to detect obstructive CAD in diabetics were 11.3 cm/s and 11.2 cm/s re-spectively with 75.7%, 73.4% sensitivity and 94.7%, 89.47% specificity respectively. An increment (? changes) less than 0.56 in S or 0.26 in E from rest to peak stress identified CAD with 78.8 %, 89.3% sensi-tivity and 94.7%, 90.7% specificity respectively. The accuracy of DTI parameters during peak stress was higher than WMSI analysis (sensitivity 74.1% vs. 59.3% and specificity 90% vs. 79%, P < 0.01 for each). In multivariate regression analysis, only ?S and ?E were independent predictors of obstructive CAD in diabetics (odd ratio: 36.16, 95% CI, 1.34- 532.01 and 63.77, 95% CI, 3.19-721.47) respectively. Conclusion: Quantitative analysis, using DTI during DSE, adds new dimension in diagnosis of myocardial ischemia. It is more sensitive, specific, accurate and reproducible compared with standard wall motion analysis for recognition of significant CAD in diabetic patients.

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 Pulsed Tissue Doppler Imaging in Predicting the Presence of Significant Coronary Artery Insufficiency

Background: Coronary artery disease (CAD) is a paramount cause of death. Global and regional left ventricular (LV) systolic function is an important non-invasive marker of CAD. We can use tissue Doppler imaging (TDI) to measure the low velocities generated by myocardium which are: S'-wave, E'-wave, and A'-wave. We aimed to examine the value of the S'-wave dispersion of TDI across mitral valve annular velocities to predict angiographically significant coronary artery obstruction. Patients and Methods: We included 100 patients with symptoms suggesting CAD. All patients had undergone full history taken and clinical examination;ECG, echocardiographic with assessment of LV function, and Doppler derived mitral valve velocities;TDI with measuring of S'-wave and coronary angiography. Lesions with ≥70% or more stenosis in major epicardial artery or ≥50% stenosis in the left main coronary artery were considered significant. Patients were classified into two groups according to the presence or absence of significant coronary stenosis. Results: Clinical and conventional echocardiographic and Tissue Doppler measures were comparable between the two groups;there was statisticallysignificant difference between Group I and Group II (P value;patients with significant coronary arteries lesions have higher S' wave dispersion as compared with patients with normal or mild significant coronary lesions. Conclusion: S'-wave dispersion may consider a good predictor of angiographically significant coronary artery disease.

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.

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 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.

DTI对急性心梗患者左室功能动态改变的定量研究

目的 应用多普勒组织成像 (DTI)技术定量测定二尖瓣环及梗死节段室壁运动速度 ,动态观察急性初发前壁心梗患者 (AMI)冠状动脉内支架 (经桡动脉介入 )术后 ,左室局部及整体功能的改变。方法 经心尖二腔、四腔、心尖左室长轴三个切面 ,测定 15例正常对照 ,2 8例AMI患者的二尖瓣环、左室各壁中段及近心尖段 18个位点心肌组织峰值收缩速度(VS)、舒张早期速度 (VE)、舒张晚期速度 (VA) ,观察AMI患者术后 1周内、1个月及 3个月时心功能恢复情况。结果 反映左室整体功能的二尖瓣环平均VS、VE、VE/VA 及局部VS、VE,AMI患者较正常对照组显著减低。无室壁瘤组其梗死节段VS、VE 于术后 1个月时即有恢复 ,而整体功能术后 3个月较 1周内明显恢复。而有室壁瘤组局部及整体功能 3个月内均无改善。结论 多普勒组织成像技术可定量、精确反映心梗患者局部及整体功能 ,对鉴别梗死节段心肌存活性、预测左室重塑有一定临床价值。

DTI评价完全性左束支传导阻滞患者心室除极顺序

目的本文探讨多普勒组织成像（ＤＴＩ）技术评价完全性左束支传导阻滞（ＣＬＢＢＢ）患者心室除极的可行性。方法应用多普勒组织加速度图及脉冲频谱图检测１０例ＣＬＢＢＢ患者心室除极顺序，并与正常组（２５例）进行对照。结果①ＣＬＢＢＢ心室最早除极部位位于右室前壁心尖段，与正常组迥然不同（Ｐ＜０．０００１）；②剑下四腔切面显示ＣＬＢＢＢ心室除极顺序为：右室前壁心尖、室间隔心尖、右室前壁全部、室间隔全部、左室前侧壁心尖、左室前侧壁全部；正常人心室除极顺序则为：室间隔基中部、室间隔心尖、右室前壁心尖及左室前侧壁心尖、右室前壁全部、左室前侧壁基部。③和正常组比较，ＣＬＢＢＢ患者右室前壁电除极收缩耦联正常（Ｐ＞０．０５），而各左室壁除极明显延迟（Ｐ＜０．０００５），前间隔除极方向由心尖指向心底。结论能显示心室肌收缩顺序的ＤＴＩ技术可直观、实时、精确地反映ＣＬＢＢＢ的心室电除极状态。

负荷DTI二尖瓣环舒张期波形改变对心肌缺血的提示意义

目的 了解负荷DTI二尖瓣环舒张期波形改变对心肌缺血的提示意义。方法 利用DTI观测 104例冠状动脉造影(CA)患者的二尖瓣环舒张期 4个位点的e波与a波的比值在多巴酚丁胺应用前后的变化,并与CA结果进行比较。结果 基础状态下DTI二尖瓣环 4个取样点的e/a均<1. 0时,冠心病的检出率较高,而二尖瓣环 4个取样点的e/a均≥1.0时的冠脉病变率最低(P<0. 01);负荷条件下原本各点e/aann≥1. 0的一些病例中出现部分取样点的e/aann<1. 0改变,其冠脉病变率增高或有增高的趋势(P<0. 05),而试验前后维持e/aann≥1. 0波形的病例的冠脉病变率有下降的趋势。结论 负荷剂量下不同位点的e/aann发生变化使得DTI以e/aann<1. 0为指标提示冠心病的准确度、灵敏度、特异度、阳性预测值和阴性预测值和以e/aann≥1. 0为指标排除冠心病的准确度、特异度、阳性预测值均有所提高。

DTI诊断冠心病患者梗死缺血心肌的研究

目的运用多普勒组织成像(DTI)观测比较正常室壁心肌和梗死缺血心肌的运动变化,评估DTI对冠心病心肌梗死的诊断价值。方法对心肌梗死患者22例(前间壁梗死14例,下后壁梗死8例),健康人48人(对照组),于ap4cv、ap2cv、alax、pslax和pssax各切面,应用DTI观察正常室壁心肌与梗死缺血心肌运动的色彩变化及其DTI频谱曲线形态,并按左室壁16节段测量各室壁节段心肌运动曲线的速度指标(Sm、Em、MVGs、MVGe)。对DTI与二维(2D)超声检测梗死缺血心肌的诊断结果进行比较。结果(1)正常室壁心肌运动色彩均匀、鲜亮;梗死缺血心肌运动色彩较暗,频谱曲线S波较之正常低矮或紊乱。(2)DTI对心肌梗死患者室壁运动异常节段阳性检出率显著高于2D超声(前壁梗死组:43%vS25%;下壁梗死组:38%vs23%,均P<0.01)。结论DTI诊断冠心病心肌梗死优于2D超声。

Autostrain RV技术联合TDI-Tei指数对肺心病患者右心室收缩功能的评估价值

目的 探讨右心室自动应变定量技术(Autostrain RV)联合组织多普勒(TDI)-Tei指数对慢性肺源性心脏病(CPHD)患者右心室收缩功能的评估价值。方法 根据肺动脉收缩压(PASP)将111例CPHD伴三尖瓣反流患者分为3组:A组(35~49 mmHg, 1 mmHg=0.133 kPa)40例,B组(50~69 mmHg)36例,C组(≥70 mmHg)35例,纳入同期40名健康体检者作为对照组,测量4组常规超声参数及TDI-Tei指数,应用Autostrain RV技术获取右心室整体长轴应变(RV4CSL)、右心室游离壁纵向应变(RVFWSL)、游离壁基底部纵向应变(B-RVFWSL)、中部纵向应变(M-RVFWSL)及心尖部纵向应变(A-RVFWSL)数据,比较各组间差异。结果 与对照组相比,A、B、C组RV4CSL、RVFWSL、B-RVFWSL、M-RVFWSL、A-RVFWSL绝对值及三尖瓣环收缩期平面位移(TAPSE)均减小(P<0.05),且随着PASP升高依次降低,TDI-Tei指数升高(P<0.05),且随着PASP升高依次升高,组间比较差异均有统计学意义(P<0.05)。相关分析显示TDI-Tei指数与RVFWSL相关性较高(r=0.553,P<0.001)。ROC曲线显示Autostrain RV技术、TDI-Tei指数单独及联合评估右心室收缩功能的AUC均大于0.70,联合评估价值更高。结论 Autostrain RV技术能够敏感、准确地评价CPHD患者早期心肌功能障碍,联合TDI-Tei指数可进一步提高评估效能,为临床及时干预提供客观依据。

负荷条件下二尖瓣环DTI舒张期部分位点波形改变的临床意义

目的探讨负荷超声心动图条件下二尖瓣环DTI部分位点舒张期波形改变的临床意义。方法观察对象共98例,入选标准是：根据负荷试验后二尖瓣环处4个DTI测量位点波形E/A〉或≤1.0改变的点位数在1-3处者。结果冠状动脉造影证实本组98例患者中56例的冠状动脉有1支以上分支的管腔狭窄≥50%,冠脉病变的发病率为57.1%。负荷条件下舒张期二尖瓣环处4个取样点DTI波形的改变可分为两组：Ⅰ组是试验前部分波形E/A≤1.0的测点,试验后转为〉1.0,即部分位点的波形向正常人转变,称之为波形改善组,共27例,冠状动脉造影阳性10例、阴性17例,分别占37.0%、63.0%;Ⅱ组是试验前部分波形E/A〉1.0的测点,试验后转为≤1.0,即部分位点的波形向异常人转变,称之为波形变差组,共71例,冠状动脉造影阳性46例、阴性25例,分别占64.8%、35.2%。结论试验后部分位点转为E/Aann≤1.0组的冠状动脉造影阳性率明显高于试验后部分位点转为E/Aann〉1.0组,DSE使得安静状态下较潜隐局部左室舒张功能的损害改变得以较明确的显示,因此,DSE条件下,二尖瓣环部分位点舒张期E/Aann的改变,尤其是出现由E/Aann〉1.0转向E/Aann≤1.0时,应提示有冠脉病变的可能性较大。

DTI检测缺血心肌左室舒张功能损伤特征的研究

目的 利用DTI技术研究缺血心肌左室舒张功能损伤特征。方法 对 2 4例疑似冠心病患者进行冠脉造影 ,在造影前后同步检测左室压力和左室后壁心肌舒张期运动速度的变化。结果 心肌缺血后左室舒张最低压显著升高 (P <0 0 5 ) ,而左室%Ddp/dt、LVEDP和T常数无明显变化 ;心肌缺血后舒张早期左室后壁心肌运动速度明显下降 (P <0 0 1) ,晚期运动速度无明显变化 ;心肌缺血时左室后壁心肌舒张早期心内膜运动速度显著下降(P <0 0 1) ,心内 外膜速度梯度负值增大 (P <0 0 1)。结论 心内膜对缺血最敏感 ,缺血首先使舒张期心内膜运动速度下降 ,导致舒张早期室壁运动减弱 ,舒张功能异常。