Cyclic variation of ultrasound backscatter in normal myocardium is view dependent: clinical studies with a real-time backscatter imaging system

Real-time ultrasound backscatter imaging is a new method of evaluating relative integrated backscatter in a clinically applicable manner. The potential clinical utility of real-time backscatter imaging of diseased tissue depends on recognition of normal variations in cyclic backscatter when measured from different echocardiographic image orientations. The view dependence of cyclic backscatter variation was studied in normal human volunteers. In twenty normal male subjects (mean age 28 +/- 5 years) cyclic variation in integrated backscatter (diastolic minus systolic backscatter) was assessed in multiple left ventricular regions with four standard two-dimensional echocardiographic views (parasternal long-axis and short-axis views, and apical two-chamber and four-chamber views). M-mode backscatter imaging was performed from the standard parasternal long-axis view. Cyclic variation in backscatter was present in the septum only when imaged from the parasternal long-axis view (2.7 +/- 3.1 [standard deviation] decibels [dB], p less than 0.01 for diastole versus systole). The posterior wall of the left ventricle demonstrated cyclic variation of integrated backscatter when imaged from both the parasternal long-axis (4.6 +/- 1.6 dB, p less than 0.01) and short-axis views (2.8 +/- 2.2 dB, p less than 0.01). Cyclic variation in integrated backscatter was not demonstrated in inferoseptal, septal, or lateral wall regions when imaged from the parasternal short-axis view. The apical views did not demonstrate cyclic variation in integrated backscatter in any of the segments studied.(ABSTRACT TRUNCATED AT 250 WORDS)     

应变率成像评价肥厚型心肌病左心室局部功能

目的探讨应变成像技术评价肥厚型心肌病患者左心室功能的价值。方法对17例肥厚型心肌病患者和42例健康志愿者行心脏超声检查,获取标准心尖四腔、二腔和长轴观以及胸骨旁短轴观,脱机分析测量纵向峰值收缩速度、应变、应变率,径向应变、应变率,周向应变、应变率。结果肥厚型心肌病组纵向峰值收缩速度S峰和舒张早期速度E峰明显低于正常对照组,且从基底段至心尖段的纵向速度（S峰、E峰、A峰）存在递减趋势。肥厚型心肌病组的舒张早期纵向应变率和周向应变率也明显低于对照组。结论应变成像技术能够定量评价左室功能。肥厚型心肌病患者虽然左室射血分数在正常范围内,但其局部心肌已经存在收缩和舒张功能异常。     

脉冲多普勒组织成像对正常右室心肌运动特点的研究

目的应用脉冲多普勒组织成像(PW-DTI)分析正常右室心肌舒缩运动的特点.方法通过PW-DTI记录39例健康成人右室游离壁各节段以及左室游离壁基底段的运动速度曲线.结果右室游离壁基底段收缩波运动速度最高,中间段次之,心尖段最慢.舒张波运动速度基底段与心尖段有显著性差异(P<0.05),基底段与中间段、心尖段与中间段差异不显著.右室游离壁基底段收缩波峰值速度高于左室(P<0.01),收缩波加速度低于左室(P<0.01),晚期舒张波峰值速度较左室为高(P<0.01),早期与晚期舒张波峰值速度比值较左室为低(P<0.05).结论 PW-DTI技术可以准确测定右室长轴运动的速度及时间指标,是一种无创性评价右室功能的新方法.     

Influence of aging on systolic left ventricular wall motion velocities along the long and short axes in clinically normal patients determined by pulsed tissue doppler imaging.

Our objective was to evaluate the influence of aging on left ventricular (LV) regional systolic function along the long and short axes in clinically normal patients. We recorded LV wall motion velocity patterns at the mid-wall portion of the middle of the LV posterior wall in the parasternal long-axis view (short-axis direction) and at the endocardial portion of the middle of the LV posterior wall in the apical long-axis view (long-axis direction) with pulsed tissue Doppler imaging in 80 normal patients (age range 15 to 78 years). In all patients the LV pressure curve and its first derivative (dP/dt) were recorded. The systolic wave of the LV posterior wall motion velocity pattern exhibited 2 peaks, the first (Sw(1)) and second (Sw(2)) systolic waves. No significant changes were seen with aging in the percent LV fractional shortening determined by M-mode echocardiography, LV ejection fraction determined by left ventriculography, the peak Sw(1) and Sw(2) along the short axis, the peak Sw(2) along the long axis, and the peak dP/dt. The peak Sw(1) along the long axis correlated inversely with age (P <.0001) but did not correlate significantly with the peak dP/dt. These results suggest that shortening of the longitudinal fibers in early systole is impaired with increased age in healthy individuals. This impairment results in insufficient spherical change in the LV cavity, although global LV pump function and myocardial contractility are maintained.     

解剖M型超声技术检测左心室室壁运动的准确性

目的评价解剖M型超声技术检测左室壁运动的准确性。方法两个月内两次测量30例行冠状动脉造影患者的左室短轴二尖瓣水平观和乳头肌水平观的6个节段以及心尖四腔观的4个节段的室壁收缩快速射血期最大厚度、舒张期末厚度和收缩期增厚率。结果两次测量结果显示,左室壁所有各节段的收缩快速射血期最大厚度、舒张期末厚度和室壁收缩期增厚率的平均值均没有显著统计学差异(p>0.05)。结论解剖M型超声技术测定左室壁各节段的收缩期增厚率等指标时有较好的可重复性,因此有可能用于准确定量分析左室壁节段性运动。     

Pulsed tissue Doppler imaging of left ventricular systolic and diastolic wall motion velocities to evaluate differences between long and short axes in healthy subjects.

Our objective was to evaluate in healthy subjects the left ventricular (LV) wall motion velocities along the long and short axes by means of pulsed tissue Doppler imaging (TDI) to clarify the differences in the LV systolic and diastolic function between both axes. Wall motion velocities were recorded at the mid-wall portion of the middle site of the LV posterior wall in the parasternal long-axis view, and at the subendocardial portion of the middle site of the LV posterior wall in the apical long-axis view by pulsed TDI in 35 healthy subjects (mean age 26 +/- 10 years, mean heart rate 72 +/- 7 bpm). In all subjects, the LV pressure curve, its first derivative (dP/dt), the LV wall motion velocity, the phonocardiogram, and the electrocardiogram were simultaneously recorded. The systolic wave of the LV posterior wall motion velocity exhibited 2 peaks: the first and second systolic waves (Swl and Sw2, respectively). The diastolic wave also exhibited 2 peaks, the early diastolic and atrial systolic waves. The Swl along the long axis was greater than either the Sw1 and Sw2 along the short axis or the Sw2 along the long axis. The peak Sw1 along the long axis coincided with the peak dP/dt and was slightly earlier than the peak Swl along the short axis. The onset of Sw1 along the long axis coincided with the onset of the first heart sound. The Sw2 along the short axis was greater than that along the long axis. The early diastolic wave along the short axis was greater than that along the long axis, whereas the atrial systolic wave along the long axis was greater than that along the short axis. Thus, in healthy subjects, shortening of the longitudinal fibers predominated over that of the circumferential fibers during early systole, whereas shortening of the circumferential fibers predominated over the longitudinal fibers during the ejection phase. During diastole, the circumferential fibers predominated in the LV wall expansion at early diastole, whereas the longitudinal fibers predominated at atrial systole. In conclusion, pulsed TDI provided information that is useful in understanding the characteristics of LV wall motion along the long and short axes.     

定量组织速度成像技术评价正常成人右心室局域心肌功能

目的评价健康成人的右心室局域心肌功能，并探讨正常增龄对其功能的影响。方法应用定量组织速度成像技术测量76例健康成人的右室局域心肌长轴功能。于心尖四腔观上将取样点分别置于右室游离壁基底段、中段和心尖段心肌的中点，记录并测量在等容收缩期、收缩期、等容舒张期、舒张早期和舒张晚期心肌运动的峰值速度（Vic，Vs，Vir，Ve，Va）、收缩期达峰时间（TQ-S）和Ve／Va值等；同时观察各测量指标随年龄增加的变化规律。结果右心室肌在长轴方向上呈现较强的收缩和舒张运动，峰值运动速度由心底至心尖方向逐渐递减（P〈0．05～0．01）。右室各节段心肌的Vic，Vs测值随年龄增加并无明显变化（r=-0．01～-0．04，P〉0．05）；而TQ-S随年龄增加相应延长，与年龄显示较好的正相关（r=0．39～0．55，P〈0．05～0．01）；Vir测值随正常增龄无明显变化（P〉0．05），而Ve随年龄增加而降低，并伴有Va的相应增加；这些变化在基底节段尤为明显。Ve／Va值则呈现随年龄增加而降低的趋势。结论定量组织速度成像技术可准确、客观地反映右心室局域心肌纤维的收缩和舒张特性。临床在评价右室心肌功能，尤其是舒张功能时，应充分考虑心肌老化因素的影响。     

应用定量组织速度成像技术和组织追踪法研究急性期川崎病患儿左心收缩功能

目的应用定量组织速度成像技术和组织追踪法研究急性期川崎病(Kd)患儿左心收缩功能,以寻求川崎病早期心脏损害的诊断指标。方法通过M-型超声获得左室射血分数(EF);应用定量组织速度成像技术和组织追踪分析软件测量31例急性期川崎病患儿与20例正常儿童前间隔、后壁、前壁、下壁、后间隔和侧壁的二尖瓣环处、基底部和中间部的收缩期峰值速度(Vs)、收缩期最大位移(D),并比较两组间各参数。结果患儿组左室射血分数与正常组相比无统计学差异;患儿组各室壁的二尖瓣环处和部分室壁的基底部、中间部的Vs低于正常组(P<0.05)。6个室壁的平均Vs在二尖瓣环水平、基底部和中间部两组间均有统计学差异(P<0.05)。患儿各室壁各节段的收缩期最大位移均低于正常儿童,在所有二尖瓣环水平和部分室壁基底部、中间部两组间有统计学差异(P<0.05)。结论川崎病急性期左室整体和部分室壁局部收缩功能受损;定量组织速度成像技术和组织追踪法能够定量急性期川崎病左室功能改变。     

二维应变超声心动图定量评价左心室整体和局部心肌应变的价值

目的探讨二维应变超声心动图（2D-SE）定量评价心肌局部和整体应变的临床应用价值。方法分别采集25例心力衰竭患者与30例正常对照者心尖左室长轴、心尖四腔和心尖左室二腔观的二维灰阶动态图像。应用自动功能成像软件自动测量长轴方向左室18节段收缩应变（εs）和心尖左室长轴观总应变（GLS-LAX）、四腔观总应变（GLS-A4C）、二腔观总应变（GLS-A2C）及左室长轴平均总应变（GLS-Avg）。同时采用二维Simpson法分别测量三个切面观的左室射血分数（2D-EF）。比较心力衰竭组与对照组各参数测值,分析2D-EF与二维应变（2D-GLS）的相关性。结果心力衰竭组18个节段的εS、GLS-LAX、GLS-A4C、GLS-A2C及GLS-Avg均显著低于正常组（P〈0.001）。2D-EF与2D-GLS有良好的相关性（r=0.94）。正常对照组各室壁自基底段向心尖段εS逐渐增加,各壁间差异无统计学意义;扩张型心肌病组各段室壁εS绝对值均明显低于正常对照组（均P〈0.05）,各节段间差异无统计学意义;前壁心肌死梗组中左前降支供血节段的εS绝对值明显低于正常对照组。结论2D-SE可用于定量测量左室整体和局部心肌的应变,为临床提供了一种快速准确、操作简便、可重复性好的无角度依赖的定量左室功能的新方法。     

定量组织速度成像对肥厚型心肌病患者左心室局部收缩功能的研究

目的　应用定量组织速度成像 (QTVI)评价肥厚型心肌病 (HCM)患者左心室局部收缩功能。方法　应用QTVI离线分析 3 1例HCM患者和 2 0例正常对照者左室长轴和短轴方向各心肌节段的速度曲线 ,测量收缩期峰值速度 (Vs) ,计算左室后壁和室间隔各心肌节段在长轴与短轴方向速度的比值。结果　HCM组肥厚与非肥厚心肌节段的平均Vs降低 ,与对照组相比 ,绝大部分心肌节段差异有显著性意义 (P<0 .0 5) ,但HCM组肥厚与非肥厚心肌节段的平均Vs之间差异无显著性意义 (P >0 .0 5)。正常人长轴与短轴方向速度的比值均 >1,而HCM患者其比值明显降低 ,大部分比值 <1。结论　HCM患者尽管左室射血分数正常 ,但左室长轴方向各心肌节段收缩功能受损 ,损害不仅发生在肥厚的左室壁 ,非肥厚的室壁同样受到损害 ;QTVI能定量评价HCM患者左室局部收缩功能     

Longitudinal ventricular function: normal values of atrioventricular annular and myocardial velocities measured with quantitative two-dimensional color Doppler tissue imaging.

OBJECTIVE: Quantitative 2-dimensional color Doppler tissue imaging is a new method to reveal impairment of left ventricular (LV) and right ventricular (RV) longitudinal function, which is a potential marker of early myocardial disease. The aim of this study was to obtain normal values for atrioventricular annular and regional myocardial velocities using this method. METHODS: A total of 123 healthy patients (age range: 22 to 89 years) underwent echocardiography including color Doppler tissue imaging using a scanner (Vivid 5, GE Vingmed, Horten, Norway) with postprocessing analysis (Echopac 6.3, GE Vingmed). Regional myocardial velocities were measured at 12 LV segments in 3 apical views and 2 segments of the free RV wall. Mitral annular velocities from 6 sites, and tricuspid annular velocities at its lateral site, were also assessed. At each site, systolic (S(m)), early diastolic (E(m)), and late diastolic (A(m)) velocities were measured, and the E(m)/A(m) ratio was calculated. RESULTS: Patients were classified into 4 groups aged 20 to 39, 40 to 59, 60 to 79, and >/=80 years. Mitral annular velocity and regional LV myocardial S(m) and E(m) progressively decreased with age. A(m), whereas low in the youngest age group, increased significantly in patients more than 40 years of age. The E(m)/A(m) ratio gradually declined with aging. There were no differences between age groups in S(m) measured at the tricuspid annulus and free RV wall, but the pattern of age-related changes of diastolic velocities and E(m)/A(m) ratio was the same as in the LV. Slight but significant sex-related differences were observed in middle-aged groups. The intraobserver and interobserver reproducibility was highest for atrioventricular annular velocities. CONCLUSIONS: A progressive decrease in S(m) reveals a decline in longitudinal systolic LV function with age, whereas systolic RV function remains unaffected. Atrioventricular annular velocity and regional E(m) decrease with aging in both ventricles, suggesting a deterioration in the diastolic properties of the myocardium, whereas A(m) increases from middle age implying a compensatory augmentation of atrial function. The study results can be used as reference data for the quantitative assessment of longitudinal LV and RV function in patients with cardiac disease.     

New method of on-line quantification of regional wall motion with automated segmental motion analysis.

We have recently developed an automated segmental motion analysis (A-SMA) system, based on an automatic "blood-tissue interface" detection technique, to provide real-time and on-line objective echocardiographic segmental wall motion analysis. To assess the feasibility of A-SMA in detecting regional left ventricular (LV) wall motion abnormalities, we performed 2-dimensional echocardiography with A-SMA in 13 healthy subjects, 22 patients with prior myocardial infarction (MI), and 9 with dilated cardiomyopathy (DCM). Midpapillary parasternal short-axis and apical 2- and 4-chamber views were obtained to clearly trace the blood-tissue interface. The LV cavity was then divided into 6 wedge-shaped segments by A-SMA. The area of each segment was calculated automatically throughout a cardiac cycle, and the area changes of each segment were displayed as bar graphs or time-area curves. The systolic fractional area change (FAC), peak ejection rate (PER), and filling rate (PFR) were also calculated with the use of A-SMA. In the control group, a uniform FAC was observed in real time among 6 segments in the short-axis view (60% +/- 10% to 78% +/- 9%), or among 5 segments in either the 2-chamber (59% +/- 12% to 75% +/- 16%) or 4-chamber view (58% +/- 13% to 72% +/- 12%). The variations of FAC, PER, and PFR were obviously decreased in infarct-related regions in the MI group and were globally decreased in the DCM group. We conclude that A-SMA is an objective and time-saving method for assessing regional wall motion abnormalities in real time. This method is a reliable new tool that provides on-line quantification of regional wall motion.     

Quantification of regional left and right ventricular radial and longitudinal function in healthy children using ultrasound-based strain rate and strain imaging.

BACKGROUND: Noninvasive assessment of left (LV) and right (RV) ventricular function in children could benefit from a technique that would characterize local myocardial deformation. Color Doppler myocardial imaging (CDMI) allows the calculation of either local longitudinal or radial Strain Rate (SR) and Strain (epsilon). To determine the clinical feasibility and reproducibility of longitudinal and radial SR and epsilon, the following study was carried out. METHODS: CDMI data were obtained from 33 healthy children (4-16 years). To quantify regional longitudinal and radial function SR and epsilon data were obtained from apical and parasternal views respectively. From the extracted SR curves, peak values for systole, early diastole, and late diastole were calculated. From the extracted epsilon curves the systolic, early and late diastolic epsilon values were calculated. RESULTS: LV longitudinal deformation were homogeneous for LV basal, mid and apical segments (peak systolic SR: -1.9 +/- 0.7 s(-1), systolic epsilon -25% +/- 7%). Longitudinal SR and epsilon values were significantly higher and heterogeneous in the RV (compared with LV walls) and were maximal in the mid part of the RV free wall (peak systolic SR: -2.8 +/- 0.7 s(-1), systolic epsilon -45% +/- 13%). The RV inferior wall showed homogeneous but lower longitudinal SR and epsilon values. The LV systolic and diastolic SR and epsilon values were higher for deformation in the radial direction compared with the longitudinal direction (radial peak systolic SR: 3.7 +/- 0.9 s(-1), radial systolic epsilon 57% +/- 11%; P <.0001). The interobserver variability for radial systolic epsilon and SR was 10.3% and 13.1%, respectively. CONCLUSION: Ultrasound-based Strain SR/epsilon imaging is a practical, reproducible clinical technique, which allows the calculation of regional longitudinal and radial deformation from both LV and RV segments. The combination of regional SR/epsilon indices and the timing of specific systolic or diastolic regional events may offer a new noninvasive approach to quantifying regional myocardial function in congenital and acquired heart disease in children.     

High-frame-rate tissue harmonic imaging enhances anatomic M-mode sections of the left ventricle in short-axis view.

BACKGROUND: High-frame-rate echocardiography (HFRE) and tissue harmonic imaging (THI) may improve image quality, thereby enabling anatomic M-mode sections of left ventricular (LV) wall segments to be visualized in various planes in the short-axis view. OBJECTIVES: The goals of this study were to compare image quality between HFRE and conventional-frame-rate echocardiography (CFRE) and between fundamental imaging (FI) and THI, and to obtain anatomic M-mode values of basal short-axis LV segments from healthy subjects for use in the evaluation of abnormal segments in patients with myocardial infarction (MI). METHODS AND RESULTS: The study included 28 healthy subjects and 15 patients with MI who underwent 2-dimensional echocardiography with an ultrasonographic system equipped with THI and anatomic M-mode. Left ventricular image cineloops at the basal short-axis view that were obtained with 3 combinations of imaging techniques (FI + CFRE, FI + HFRE, and THI + HFRE) were digitized and displayed side-by-side in random order for comparison by blinded readers. M-mode sections were done in 3 planes: anteroseptal-posterior, inferoseptal-lateral, and anterior-inferior basal segments. The THI + HFRE combination showed the best image quality with significant reduction in noise artifacts, resulting in a good signal-to-noise ratio and good tractability of all LV segments by anatomic M-mode. In healthy subjects, significant intersegmental differences existed in the diastolic and systolic thicknesses and in the percent systolic thickening of LV segments. In patients with MI, LV systolic thickening was significantly decreased in abnormal segments. No significant differences were noted in ejection fraction and fractional shortening among the 3 anatomic M-mode planes. CONCLUSION: High-frame-rate tissue harmonic imaging improved image quality, thereby allowing reproducible anatomic M-mode measurements in various planes in the short-axis view and providing a convenient objective evaluation of global and regional LV function.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.     

速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.