Clinical Significance of Positive Isovolumetric Relaxation Velocity of Pulsed-Wave Tissue Doppler Imaging

Objective: Among the pulsed-wave tissue Doppler imaging (pw-TDI) parameters, there are two different pw-TDI velocities (IVRa and IVRb) after systolic velocity, but before Ea velocity. In our study, we investigated the clinical importance of these two velocities in left ventricular diastolic dysfunction (LVDDF) evaluation. Methods: One hundred and eighty cases without exclusion criteria were included in the study. Cases with a transmitral E to A flow (E/A) ratio below 1 were assigned to group 2. In cases with an E/A ratio between 1 and 2, the pw-TDI parameters were taken into consideration. Cases with an Ea/Aa ratio above 1 were assigned to group 1 and cases with an Ea/Aa ratio 1 or below than 1 were assigned to group 3. Group 1 (n: 68) represented normal diastolic left ventricular (LV) inflow while group 2 (n = 87) represented impaired relaxation and group 3 (n = 25) represented pseudonormal LV inflow. Results: In our study, we found that IVRa velocity was lower in group 1 compared to group 2 and group 3 (P < 0.001 and P = 0.038, respectively). Similarly, this velocity was significantly different in group 3 and group 2 such as it was higher in group 2 compared to group 3 (P = 0.022). There was no difference in IVRb velocity and IVRa/IVRb ratio among the groups. A negative correlation was found between IVRa velocity and Ea velocity (r = 44%, P < 0.001). Positive correlation was found between IVRa velocity and isovolumetric relaxation time (r = 18%, P = 0.014) and also between IVRa velocity and Aa velocity (r = 19%; P = 0.010). Conclusion: Based on the results of our study, we concluded that IVRa velocity is an important pw-TDI parameter in the evaluation of LVDDF, especially in differentiating pseudonormal LVDDF type from normal LV inflow.     

多普勒组织成像与脉冲多普勒方法对比评价高血压患者舒张功能

目的应用脉冲多普勒组织成像测量二尖瓣环平均舒张速度,以鉴别高血压患者舒张功能假性正常。方法在健康者(正常组200例)与高血压患者(高血压组47例)中,应用脉冲多普勒技术分别测量二尖瓣口舒张早期峰值速度(E)、舒张晚期峰值速度(A),肺静脉收缩波(S)、舒张波(D)及心房收缩波(Ar)。应用脉冲多普勒组织成像测量二尖瓣环各点舒张早期峰值速率(Ea)、舒张晚期峰值速率(Aa)。结果正常组与对照组患者二尖瓣E、A、E/A差异无显著性意义,肺静脉S、S/D、Ar差异有显著性意义,二尖瓣环平均Ea间差异有显著性意义,Aa间差异无显著性意义。结论二尖瓣环舒张早期速率可用于鉴别高血压舒张功能假性正常。     

用多普勒组织显像速度模式评价左心室收缩及舒张功能

目的 :初步评价多普勒组织显像 （DTI）检查左心室收缩和舒张功能的临床应用价值。方法 :用 DTI速度模式检测了正常健康组 114例和左室收缩功能降低 （左室缩短率 FS<2 5 % ）组 40例二尖瓣后叶瓣环位及左室后壁心肌的运动速度。结果 :各参数在正常男女间无显著差异 ,心功能降低组较正常组明显降低 （P<0 .0 1） ;正常组左室后壁心肌收缩速度与 FS间呈正相关 （r=0 .38）。结论 :用 DTI的速度模式检测局部室壁运动速度是评价心室收缩和舒张功能的一种较简便、直观、全面、准确的新方法     

Isovolumic contraction time by pulsed-wave Doppler tissue imaging in aortic stenosis.

BACKGROUND: Doppler Tissue Imaging (DTI) has been evaluated in ischaemic heart disease and some cardiomyopathies. In patients with aortic stenosis (AS), left ventricular contraction is slowered. This study aimed to evaluate the possible role of the measurement of isovolumic contraction time (ICT) by DTI in the evaluation of AS severity. METHODS: The study population constitutes 30 patients: 15 with AS (nine severe and six non-severe) and 15 control subjects. All of them had normal systolic function, sinus rhythm, and absence of ischaemic heart disease of conduction abnormalities. ICT was defined as the time from the onset of the QRS complex to the beginning of the DTI systolic wave. The correlation between ICT and aortic area obtained by continuity equation, as well as the diagnostic value of ICT in the identification of severe AS were studied. RESULTS: ICT was significantly increased in patients with severe AS (98+/-27 versus 65+/-21 ms, p=0.024). There was a significant correlation between ICT and aortic area (r=-0.56; p=0.035). The receiver operator characteristic curve of ICT in the identification of severe AS yielded an area under the curve of 0.852 (95% confidence interval: 0.665-1.0). The two best cut-points were >73 ms (88% sensitivity, 77% specificity) and >85 ms (78% sensitivity, 83% specificity). A value of >41 ms had a 100% sensitivity, but only a 17% specificity, and >91 ms showed a 100% specificity, but only a 44% sensitivity. CONCLUSIONS: ICT measured by pulsed-wave DTI is increased in patients with aortic stenosis.     

多普勒组织成像评价正常人心肌舒缩运动速度

目的　探讨心肌舒缩运动变化的相关因素。方法　标准切面 (左心室长轴、短轴 )用脉冲多普勒组织成像(DTI)测定室间隔、前壁、下后壁的内膜下心肌及外膜下心肌运动峰值速度。结果　各个室壁及各层心肌收缩期 s峰值速度不相同。内膜下心肌的 s峰值速度大于外膜下心肌的 s峰值速度 ,室间隔左心室面 s峰值速度大于右心室面 s峰值速度 ,两者间存在速度阶差。长轴左心室后壁 s峰值速度大于室间隔 s峰值速度 ,短轴后壁 s峰值速度大于前壁 s峰值速度。 s峰值速度与年龄无相关 ,舒张期 a峰值速度与年龄呈中度相关 ,e/ a比与年龄呈中度负相关 ,室壁运动的 e/ a比与二尖瓣血流 E/ A比呈中度相关。结论　脉冲 DTI可用于评价心肌的舒缩功能     

Usefulness of pulsed-wave tissue Doppler echocardiography for the assessment of the left and right ventricular function in patients with clinical hypothyroidism

Clinical hypothyroidism (HT) is often associated with cardiovascular disorders, such as endothelial and myocardial dysfunction. Previous studies have explored left ventricular (LV) function using pulsed-wave tissue Doppler echocardiography (TDE) in HT. However, no study has utilized this technique in the assessment of right ventricular (RV) function in HT. Accordingly, we investigated the effects of clinical HT on LV and RV function by TDE. The study subjects included 35 newly diagnosed HT patients and 32 healthy normal controls. For each subject, serum FT3, FT4, TT3, TT4, and thyroid stimulating hormone (TSH) levels were measured, and standard echocardiography and TDE were performed. No statistically significant difference was found between patients and controls with regard to age, gender, body mass index, heart rate, and blood pressure. Compared to controls, TSH levels were significantly higher, and TT4 and FT4 levels were significantly lower. TDE showed that patients had significantly lower early diastolic tricuspid annular velocity (Ea) and early/late (Ea/Aa) diastolic tricuspid annular velocity ratio (P < 0.001 and P < 0.001, respectively), and significantly longer isovolumetric relaxation time (P < 0.001) than those of the controls. Aa, Sa, isovolumetric contraction time, and ejection time did not significantly differ. In addition, a significant relationship between some TDE indexes, and thyroid hormones (TT4 and FT4) and TSH was observed. We showed that patients with clinical HT are associated with impaired RV diastolic function, in addition to impaired LV diastolic function using TDE.     

Striking effect of left ventricular high filling pressure with mitral regurgitation on mitral annular velocity during early diastole. A study using colour M-mode tissue Doppler imaging.

AIMS: To evaluate the effect of considerably high left ventricular filling pressure with mitral regurgitation on mitral annular velocity during early diastole. SUBJECTS: Two hundred and forty-three patients who underwent cardiac catheterization for evaluation of chest pain. METHODS: Mitral annular velocity during early diastole was measured by colour M-mode tissue Doppler imaging. Patients were divided into the following three groups according to the cardiac catheterization data. Group A (n=147): patients having left ventricular relaxation time constant tau<46 ms and left ventricular end-systolic volume index <38 ml m(-2); group B (n=88): patients having tau>or=46 ms and/or end-systolic volume index >or=38 ml m(-2); group C (n=8): patients having mean pulmonary capillary wedge pressure >or=16 mmHg in addition to tau>or=46 ms and end-systolic volume index >or=38 ml m(-2). RESULTS: Mitral annular velocity during early diastole was significantly less in group B (4.8+/-1.4 cm s(-1)) than in group A (7.7+/-1.9 cm s(-1)). However, there was no significant difference between groups A and C (8.3+/-0.8 cm s(-1)). A transmitral E/A >1.0 was observed in 12/147 patients of group A, 10/88 of group B, and 8/8 of group C. The incidence of >or=Sellers' grade II mitral regurgitation was higher in group C than the others. CONCLUSIONS: A paradoxically faster mitral annular velocity during early diastole is found in patients having left ventricular dysfunction with moderate to severe mitral regurgitation and considerably high left ventricular filling pressure. Attention should be paid to an interpretation of mitral annular velocity during early diastole regarding left ventricular early diastolic performance in patients having mitral regurgitation with an E/A >1.0 in their transmitral flow.     

Assessment of left ventricular diastolic function and Tei index by tissue Doppler imaging in patients with Cushing's Syndrome

Background: The aim of this study was to assess left ventricular (LV) function and the Tei index by tissue Doppler imaging (TDI), and also to evaluate the relationship of serum cortisol level with the Tei index and LV function in patients with Cushing's Syndrome (CS). Methods: We prospectively evaluated 22 patients with CS and 23 control subjects. LV function was assessed by echocardiography. Early diastolic (Em), late diastolic (Am), peak systolic (Sm), mitral annular velocities, Em/Am, the Tei index, and E/Em were calculated by TDI. Mitral inflow velocities, color M-mode flow propagation velocity (Vp), relative wall thickness (RWT), and LV mass index (LVMI) were assessed by two-dimensional echocardiography. Result: Peak (E) velocity and the ratio of E to peak late (A) velocity (E/A) were lower in those with CS than in those without. Patients with CS had significantly higher RWT, IVRT, and LVMI than those controls. Vp was lower in the CS-patients than that in control subjects. Em and Em/Am were lower in patients with CS than those in controls. In patients with CS, the Tei index was significantly higher than control subjects. Conclusion: Serum cortisol level was positively correlated with the Tei index and E/Em ratio but negatively correlated with Em, Sm, and EF only in patients with CS. Serum cortisol level positively correlated with the Tei index and E/Em ratio but negatively correlated with Em, EF, and Sm. The parameters obtained from lateral mitral annulus by TDI can be used for identification of LV diastolic dysfunction in patients with CS.     

Differences in echocardiographic assessment with standard Doppler and tissue Doppler imaging of left ventricular filling pressure in idiopathic and ischemic dilated cardiomyopathy

Background: In idiopathic and ischemic dilated cardiomyopathy (DCM) there are differences in left atrial and ventricular relaxation. We assessed the hypothesis of an influence of these dissimilarities in assessing left ventricular filling pressure (LVFP) in these two DCMs by standard Doppler and tissue Doppler imaging. In particular, we focused on early transmitral flow to early diastolic motion velocity of mitral annulus ratio (E/Ea), useful to estimate normal or elevated LVFP. However, when found in intermediate range (8–15), its role is unclear. Methods and Results: We evaluated 26 patients with ischemic and 21 patients with idiopathic DCM. To validate the echocardiographic estimation of LVFP, a sample (12 patients) underwent LVFP assessment by catheterization. In idiopathic DCM, E/Ea directly related to duration of retrograde pulmonary venous flow (ARd) (r = 0.66 P = 0001). In ischemic DCM E/Ea inversely related only to systolic to diastolic velocity ratio of pulmonary venous flow (S/D) (r =−0.56 P = 0002). After a mean follow up of 6 months, by a second echocardiogram we observed a direct relation between E/Ea and ARd percentage variation (r = 0.52 P = 0.02) in idiopathic DCM group, whereas in the ischemic DCM group there was an inverse relation between E/Ea and S/D percentage variation (r =−0.59 P = 0.02).Conclusions: In conclusion, ARd in idiopathic and S/D in ischemic DCM might be used as specific additional information to estimate LVFP when E/Ea falls within intermediate range.     

应用组织多普勒成像技术对高血压病左室舒张功能的评估

目的探求无创评价左室舒张功能的新方法。方法应用组织多普勒成像（DTI）及脉冲多普勒（PWD）技术检测高血压患者二尖瓣环舒张期运动速度（E、A）及二尖瓣口血流频谱（e、a）,并进行对比研究。结果①高血压病患者e、e/a较正常对照组明显降低（P<0.01）,左室等容舒张时间及减速时间显著延长（P<0.01）,但左室肥厚（LVH）组与non-LVH组间无显著差异。②正常人E/A与年龄呈负相关,高血压病患者的相关性减低（P<0.05,P<0.01）。③高血压病患者E、E/A较正常对照组明显减低（P<0.01）,且LVH组比non-LVH组降低更加显著（P<0.01）。④DTI检测左室充盈假性正常化组二尖瓣环E/A<1。结论DTI能更准确地测定高血压病患者二尖瓣环舒张期运动速度的改变,评价左室舒张功能受损程度优于传统的血流多普勒法。     

Evidence of left ventricular systolic and diastolic dysfunction by color tissue Doppler imaging despite normal ejection fraction in patients on chronic hemodialysis program

Background: Cardiovascular diseases are responsible for about half of deaths and are the major cause of mortality in hemodialysis patients. The aim of this study is to assess left ventricular (LV) longitudinal myocardial functions by color tissue Doppler imaging (TDI) in patients with chronic renal failure on a regular hemodialysis program. Methods: Thirty-one patients on a regular hemodialysis program (mean age 47 ± 12 years; 17 males, 14 females) were included into the study. Twenty-three healthy subjects (mean age 44 ± 8 years; 15 males, 8 females) were studied as a control group. The patients had been on maintenance hemodialysis for at least 1 month and hemodialysis sessions were three times per week. For color TDI, apical two- and four-chamber views of left ventricle were used. Sample volumes were placed on the mid-left ventricle in the inner half of the myocardium at the septum, lateral, inferior, and anterior walls. Peak LV strain, peak systolic strain rate, peak early diastolic strain rate, peak late diastolic strain rate, peak systolic tissue velocity, peak early diastolic tissue velocity, and peak late diastolic tissue velocity values were measured. Results: Mean peak LV strain, mean peak systolic strain rate, and mean peak systolic tissue velocity values were all lower in the hemodialysis group. Although mean peak late diastolic strain rate and mean peak late diastolic tissue velocity values were similar between the groups, mean peak early diastolic strain rate and mean peak early diastolic tissue velocity values were lower in the hemodialysis group. Conclusion: Patients with chronic renal failure on regular hemodialysis program show significant alterations at LV longitudinal myocardial function parameters assessed by color TDI.     

Novel approach to measure myocardial performance index: pulsed-wave tissue Doppler echocardiography

A simple, reproducible, noninvasive myocardial performance index (MPI) for the assessment of overall cardiac function has been described previously. The purpose of this study was to compare the MPI obtained by pulse Doppler method with the MPI obtained by tissue Doppler echocardiography (TDE) in normal subjects and patients with dilated cardiomyopathy (DCMP). Fifteen patients with DCMP and 15 healthy subjects were included. In order to calculate MPI by TDE, isovolumetric contraction (IVCT), relaxation time (IVRT), and ejection time (ET) were measured at two different sites of mitral annulus: septum and lateral. MPI was calculated by dividing the sum of IVCT and IVRT by ET at each site of measurement. The mean MPI value was found by dividing the sum of these MPI values into two. The same parameters were measured using the mitral inflow and left ventricular outflow velocity time intervals in pulsed Doppler method. At all sites measured, MPI by TDE correlated well with conventional MPI both in healthy subjects and patients with DCMP. The highest correlation was observed in mean values of MPI by TDE:r = 0.94, P < 0.0001in healthy subjects; andr = 0.95, P < 0.0001in patients with DCMP. In conclusion, this study clearly demonstrated that MPI could be measured by TDE and it correlated well with conventional MPI in normal and diseased heart.     

Effect of obesity on left ventricular structure and myocardial systolic function: assessment by tissue Doppler imaging and strain/strain rate imaging

BACKGROUND: Obesity is associated with heart failure, cardiovascular morbidity, and mortality. A direct effect of weight on left ventricle (LV) structure and myocardial function is not well-established. AIM: The aim of our study is to determine the effect of obesity on LV morphology and systolic function by using LV standard Doppler echocardiographic indices, myocardial Doppler imaging and strain/strain rate imaging indices. METHODS: We studied 33 obese and 34 age, sex-adjusted control subjects who had no other pathological conditions. Standard transthoracic Doppler echocardiographical measurements, reconstructed spectral pulsed wave tissue Doppler velocities, strain and strain rate imaging of six different myocardial regions were obtained. Peak systolic velocity (SR), peak systolic strain (I), peak systolic strain rate (SR) for each region and as a global systolic longitidunal LV function mean of peak systolic strain of six myocardial regions (glsca) were compared. RESULTS: Age, body surface area, blood pressure, and heart rate were comparable between the two groups. Obese subjects had significantly increased LV end-diastolic volume, septal wall thickness, left atrial diameter, and decreased transmitral early to late diastolic velocity ratio. In obese subjects, reconstructed spectral pulsed-wave tissue Doppler analysis showed significantly decreased basal lateral peak systolic (Sm) velocity (6.68 +/- 1.89 vs. 8.08 +/- 2.50, P < 0.05), mid lateral Sm (5.01 +/- 2.17 vs. 6.78 +/- 3.22, P < 0.05). Differences in regional strain rate (mid septal SR, 1.45 +/- 0.23 vs. 1.63 +/- 0.18, P < 0.05), regional strain (basal septum I, 19.13 +/- 3.83 vs. 22.09 +/- 4.60, P < 0.05; mid-septum I, 18.03 +/- 2.91 vs. 20.25 +/- 4.77, P < 0.05; radial I, 27.50 +/- 7.32 vs. 35.53 +/- 9.48, P < 0.05), and global strain (glsca, 19.38 +/- 1.34 vs. 21.24 +/- 2.82, P < 0.05) were identified between obese and the referent subjects. CONCLUSIONS: Obesity is associated with morphologic alterations in left ventricle and left atrium and subclinical changes in left ventricle systolic function which can be detected by strain and strain rate imaging even without overt heart disease.     

Quantitative Tissue Doppler Echocardiography: Physiological Nonuniformity of Left Ventricular Transmural Myocardial Wall-Motion Velocities and Gradients

Tissue Doppler echocardiography (TDE) is a new method by which transmural myocardial function can be studied noninvasively. In order to investigate physiology and reproducibility, 24 young, healthy volunteers were examined by M-mode TDE. Nonuniformity of transmural tissue layer velocities became apparent: Subendocardial and subepicardial velocities of the anteroseptal myocardial wall (AW) were 3.5 ± 0.7 and 1.3 ± 0.5 cm/sec (P < 0.0001 , t- test), whereas in the posterolateral wall (PW) values of 3.6 ± 0.6 and 1.2 ± 0.4 cm/sec (P < 0.0001 , t- test ), respectively, were revealed. The ratios, termed "myocardial velocity gradients" as a new indicator of left ventricular performance, were 3.1 ± 1.0 and 3.4 ± 1.1, respectively. AW and PW did not differ (N.S.). Tolerance borders did not overlap, and intraobserver variability did not reach intersubject variability (P < 0.0001, F-ratio test). TDE provides new and more sophisticated insights into left ventricular performance. It seems to be accurate and reliable and therefore worth introducing into the clinical arena.     

Usefulness of a new proposed tissue Doppler imaging global function index in hypertrophic cardiomyopathy

BACKGROUND: A global function index (GFI) derived from tissue Doppler imaging (TDI) has been proposed to improve the diagnosis of hypertrophic cardiomyopathy (HCM). We aimed to evaluate the usefulness of this index in a large selected HCM population. METHODS: GFI =[E/Ea]/Sa, was calculated at mitral annulus lateral and septal borders in 164 HCM patients and in 40 healthy volunteers. Group comparisons and correlations between GFI and other variables were performed. RESULTS: Of the 164 patients, 69 (42%) had a peak gradient >30 mmHg in the left ventricle outflow tract (LVOT). GFI (lateral or septal) was not normally distributed. There were differences among controls, obstructive HCM, and nonobstructive HCM (P < 0.0001), but significant overlap of GFI values were observed between groups. GFI was correlated to septal thickness (r = 0.44; P < 0.0001), left atrial diameter (r = 0.52; P < 0.0001), and LVOT gradient (r = 0.58; P < 0.0001). CONCLUSION: In a selected HCM population, GFI was limited by its asymmetrical distribution and significant overlap of values between groups. Further studies are necessary to verify the reliability of GFI in the clinical practice and its position among other tissue Doppler indices.     

组织多普勒对缘对缘二尖瓣成形术后左心室舒张功能评价

目的:EMVP技术将脱垂的二尖瓣叶相对应的前后叶缝合起来,形成一个双孔二尖瓣,从而改变了二尖瓣的解剖形态,本文旨在研究组织多普勒在缘对缘二尖瓣成形术后左心室舒张功能的作用.方法:30例二尖瓣关闭不全患者根据成形方式被分成A、B组,A组:15例二尖瓣后叶脱垂患者接受后叶楔形切除;B组:15例前叶或双叶脱垂患者接受缘对缘二尖瓣成形术,所有患者均同时接受二尖瓣环成形.术前及术后1周,运用彩色多普勒、组织多普勒测定患者左心室舒张功能指标,包括:术前和术后E峰与A峰血流速比值(E/A),舒张期E峰血流速度与舒张早期二尖瓣环的最大运动速度的比值(E/Em), 舒张早期二尖瓣环的最大运动速度与舒张晚期二尖瓣环的最大运动速度的比值(Em/Am).结果:A组与B组成形术后二尖瓣口面积及二尖瓣反流程度均明显减小,E/A、E/Em及Em/Am在手术前后组间及组内之间均无明显变化.结论:组织多普勒能较好客观地评价缘对缘二尖瓣成形后左心室舒张功能,缘对缘二尖瓣成形技术效果良好,对左心室的舒张功能无明显影响.     

多普勒组织成像检测肥厚型心肌病与高血压性心脏病的参数比较

目的初步探讨多普勒组织成像技术（TDI）对肥厚型心肌病（HCM）与高血压性心脏病鉴别诊断的临床价值。方法应用TDI技术对HCM患者、高血压性心脏病患者及正常人分别测量二尖瓣环收缩期峰值速度（Vs）、舒张早期峰值速度（Ve）及舒张晚期峰值速度（Va）。常规超声检查测得左室射血分数（LVEF）、左室短轴缩短率（FS）、二尖瓣口血流峰值速度E、A,计算E/A。结果HCM组、高血压性心脏病组各峰值速度均减低,与正常组比较差异有显著性意义（P<0.05）;HCM组部分心肌节段峰值速度与高血压性心脏病组比较有显著性差异（P<0.05）。结论TDI技术对HCM与高血压性心脏病鉴别诊断提供可行、实用的信息。     

多普勒组织成像评价冠心病患者的左室整体收缩功能

目的 :探讨应用多普勒组织成像 （DTI）检测二尖瓣环收缩期运动速度评估冠心病左室整体收缩功能的应用价值。方法 :应用 DTI技术 ,对 5 4例临床确诊 （其中 30例经冠脉造影证实 ）的冠心病患者收缩期二尖瓣环峰值运动速度 （Sa）进行测定 ,并与二维超声心动图 （2 DE）检查结果对照分析。结果 :冠心病患者二尖瓣环 Sa与△ D%及L VEF均呈显着正相关。左室整体收缩功能 （GL VSF）正常组的 Sa显着高于 GL VSF减低组 （P<0 .0 1）。以 Sa≥ 6.8cm/s为标准诊断左室整体收缩功能正常的敏感度、特异度及准确度分别为 74% ,87%和 81%。结论 :DTI技术检测二尖瓣环收缩期运动速度可用于无创评价冠心病左室整体收缩功能。     

Effect of angular error on tissue Doppler velocities and strain

One of the major criticisms of ultrasound Doppler is its angle dependency, that is its ability to measure velocity components directly to or from the transducer only. The present article aims to investigate the impact of this angular error in a clinical setting. Apical two- and four-chamber views were recorded in 43 individuals, and the myocardium was marked by hand in each image. We assume that the main direction of the myocardial velocities is longitudinal and correct for the angular error by backprojecting measured velocities onto the longitudinal direction drawn. Strain was calculated from both corrected and uncorrected velocities in 12 segments for each individual. The results indicate that the difference between strain values calculated from corrected and uncorrected velocities is insignificant in 5 segments and within a decimal range in 11 segments. The biggest difference between measured and corrected strain values was found in the apical segments. Strain is also found to be more robust against angular error than velocities because the difference between corrected and uncorrected values is smaller for strain. Considering that there are multiple sources of noise in ultrasound Doppler measurements, the authors conclude that the angular error has so little impact on longitudinal strain that correction for this error can safely be omitted. (ECHOCARDIOGRAPHY, Volume 20, October 2003)     

应用多普勒组织成像评价冠心病患者左心室舒张功能

目的 :探讨应用多普勒组织成像 （DTI）检测二尖瓣环运动速度评估冠心病左室舒张功能的临床应用价值。方法 :应用 DTI技术 ,对 5 3例冠心病患者和 48例正常对照者二尖瓣环运动速度进行测定 ,并与常规多普勒超声心动图检查结果对照分析。结果 :与正常组相比 ,冠心病患者舒张早期 DTI速度峰值 （Ve）显著减低 （P<0 .0 1） ,舒张早期与舒张晚期 DTI速度峰值的比值 （Ve/ Va）显著减低 （P<0 .0 5 ）。冠心病患者 Ve/ Va比值异常检出率显著高于二尖瓣血流 E/ A比值的异常检出率 （P<0 .0 5 ）。 Ve/ Va比值与 E/ A比值之间存在高度相关性 （P<0 .0 1）。结论 :DTI技术检测二尖瓣环舒张期运动速度参数可用于无创评价冠心病左室舒张功能 ,尤其对鉴别伪正常具有一定应用价值。