Echocardiographic analysis of systolic and diastolic left ventricular wall motion during transient myocardial ischemia

Left ventricular (LV) wall motion (anterior and posterior) and simultaneous LV pressure were recorded during 30-second left anterior descending (LAD) or circumflex (CX) coronary artery occlusions in open-chest dogs to provide an echocardiographic model of the evolution of wall motion changes during myocardial ischemia. Prominent diastolic echocardiographic motion changes of progressive decrease in LV wall rapid-filling velocities (RFS), slow-filling velocities (SFS), and increased end-diastolic diameter were accompanied by a marked increase in initial and end-diastolic pressures (150% and 70%, respectively; all p < 0.05). Early (within ten seconds) and progressive decrease in rate (SES), amplitude (E), and duration (TTR) of systolic motion were noted with an increased systolic diameter (p < 0.05). Ischemic regions developed a characteristic pattern with early relaxation followed by a diastolic inward motion (DIM). These observations confirm and extend other investigators' findings on the motion of the ischemic myocardium and may be applicable to responses to transient myocardial ischemia noted in humans.     

多巴酚丁胺负荷超声心动图对左心室流出道动力性梗阻的研究

目的 应用多巴酚丁胺负荷超声心动图（DSE）检测左心室流出道血流速度，分析负荷后左心室流出道动力性梗阻的原因及其意义。方法 DSE检查待除外心肌缺血性疾病患者42例，分别于试验前后检测左心室流出道血流速度、压力阶差。试验中监测心电图、血压。试验后脱机分析。结果 DSE检查前42例患者左心室流出道血流速度均在正常范围，DSE达到峰值剂量后左心室流出道血流速度均增快，其中14例左心室流出道血流速度明显增快，大于215cm／s（218～627cm／s），压力阶差大于15mmHg（19．5～627．0mmHg，1mmHg=0．133kPa）。该14例患者均有左心室肥厚，其中不对称性以室间隔基底部肥厚为著者10例，对称性肥厚者4例。DSE试验仅3例同时出现心肌节段缺血改变。有明确高血压病史8例。相关分析显示，室间隔厚度与负荷后左心室流出道血流速度呈显著相关性，以室间隔基底肥厚更为显著（r=0．61，P〈0．001）。结论 DSE检测左心室流出道血流速度和压力阶差可明确左心室流出道梗阻，对基础状态左心室流出道压差正常、心室肥厚、临床症状明显者，DSE是明确左心室流出道动力性梗阻的重要手段。     

多巴酚丁胺负荷超声心动图对左室心尖部血栓与存活心肌的研究

目的 旨在探讨是否在常规2-DE左室心尖部血栓的出现预示无存活心肌的存在.方法 80例心肌梗死患者接受DSE检查,根据心室内有无血栓分为血栓组（1组）及无血栓组（2组）,比较两组的室壁运动积分及射血分数.结果 48例患者被证实/高度怀疑有左室血栓（1组）,32例患者无左室血栓（2组）.1组比2组有更高的室壁积分;1组的32（67%）例及2组中8（25%）例患者证明在心尖节段无收缩储备即无存活心肌.结论 在无存活心肌存在的相应节段左室心尖部血栓更易出现.     

多巴酚丁胺负荷核素心室显像对急性心肌梗死再灌流后左室舒张功能的评价

目的 :应用门电路核素心室显像及小剂量多巴酚丁胺 (DOB)负荷试验 ,对急性心肌梗死 (AMI)早期再灌注后左室舒张功能进行评价。方法 :指标采用高峰充盈率 (PFR)、平均充盈率 (MFR)、 1/ 3充盈率 (1/ 3FR) ,1/ 3充盈分数 (1/ 3FF)。结果 :DOB负荷前后 ,AMI组PFR、MFR、 1/ 3FR均显著低于对照组 (P <0 0 1及P <0 0 5 )。AMI组DOB负荷后上述指标均有一定程度的改善 (P <0 0 1)。结论 :AMI再灌注后左室舒张功能降低 ,而小剂量DOB负荷后可得到明显改善 ,表明缺血区域内存活心肌的贮备能被激活     

多巴酚丁胺负荷超声心动图中冠心病患者节段性室壁运？…

目的 评价多巴酚丁胺负荷超声心动图（ＤＳＥ）中冠心病（ＣＡＤ）患者节段性室壁运动异常（ＲＷＭＡ）的预后意义。方法 ＤＳＥ采用分级负荷方法,室壁运动采用１６节段分法和６节段分法,随访自ＤＳＥ之日开始,终点为出现心血管事件,结果 病例组中ＤＳＥ阳性者与ＤＳＥ阴性者免于心脏事件的累积生存率有显著性差异（Ｐ〈０．０１）,ＤＳＥ阳性、缺血节段百分数等是Ｃｏｘ比例风险模型中心脏事件的独立预测指标。结论 ＤＳＥ     

小剂量多巴酚丁胺负荷超声心动图对二尖瓣反流左室舒张功能的研究

探讨超声心动图评价二尖瓣反流左室舒张功能的可靠性方法。方法应用小剂量多巴酚丁胺负荷超声心动图（ＬＤＤＳＥ）对５０例二尖瓣反流（ＭＲ）患者进行了研究,其中包括２３例二尖瓣病变患者（Ａ组）和２７例扩张型或缺血性心肌病患者（Ｂ组）。结果Ａ组左室压力最大下降速率（－ｄｐ／ｄｔｍａｘ）和舒张期最大充盈速率（ＰＦＲ）显著高于Ｂ组,左室心肌松驰时间常数（Ｔ）显著短于Ｂ组的测值（Ｐ均〈０．００１）;给于多酚丁胺５     

Pre-ejectional left ventricular wall motions studied on conscious dogs using Doppler myocardial imaging: relationships with indices of left ventricular function

Duration of the pre-ejection period is a sensitive index of myocardial function. Our purpose was to document normal pre-ejectional left ventricular (LV) wall motions at rest and under dobutamine using Doppler myocardial imaging (DMI), and to correlate posterior wall velocities with indices of LV systolic function. M-mode recordings of both walls were imaged on eight conscious dogs chronically instrumented. Subendocardial pre-ejectional velocities were digitized and measured every 3.8 ms. DMI analysis consisted of sign recognition, velocity measurement, duration and timing from the Q wave of the electrocardiogram. Isovolumic contraction time (Ict) was represented by the time interval from onset to peak of the first derivative of LV pressure. Conventional Doppler labelling of velocity signs, positive toward and negative away from the transducer, was applied to the direction of encoded wall motions. For physiological understanding, wall motions of both walls were also labelled inward and outward with respect to the left ventricular cavity center. In each wall, PEP was shown as several colored strips, each strip representing the period of time that the wall was moving in one direction. Changes in velocity sign corresponding to changes in direction of motion were opposed in each wall (p < 0.001), featuring successive inward and outward wall motions. There was a markedly sustained inward motion during Ict. Its velocity amplitude increased with dobutamine. There was a positive correlation between velocities of the inward motion contemporaneous of Ict and ejection fraction (r = 0.72, p < 0.003). Values of Ict respectively drawn from DMI and from hemodynamics were also significantly correlated (r = 0.85, p < 0.007). Thus, the inward motion evidenced by DMI during Ict appears promising to assess myocardial function and effect of drugs.     

多普勒组织成像评价多巴酚丁胺负荷试验中左心室长轴局部心肌收缩功能

目的　探讨大剂量多巴酚丁胺负荷试验下脉冲多普勒组织成像技术 (PW DTI)评价左心室长轴局部心肌收缩功能的临床价值。方法　冠心病患者 3 0例 (至少 1支冠状动脉主支狭窄≥ 5 0 % ) ,对照组 2 5例 ,均行大剂量多巴酚丁胺负荷试验 ,分别于静息、峰值负荷下将PW DTI取样容积置于侧壁、室间隔、前壁、下壁心肌基底段、中段心内膜下心肌采样 ,获取各节段心肌运动速度曲线。PW DTI测量指标 :收缩期峰值运动速率 (Vs)、收缩期达峰时间 (timetopeakvelocity ,TPV)、收缩期速度时间积分 (velocity timeintegral,VTI)。 结果　根据多巴酚丁胺负荷超声心动图及冠状动脉造影结果将冠心病组患者心肌节段区分为正常节段与缺血节段。与对照组相应节段 (正常组 )比较 ,静息状态下 ,冠心病缺血节段组与正常组节段间Vs、TPV、VTI并无统计学差异 ;峰值负荷下冠心病缺血节段组各节段Vs、VTI明显减低 (P <0 .0 5 ) ,而TPV则显著延长 (P <0 .0 5 )。结论　PW DTI能准确评价多巴酚丁胺负荷试验中左室长轴局部心肌收缩功能 ,从而准确无创检测冠心病缺血心肌。     

实时三维超声心动图评价多巴酚丁胺对心肌顿抑和梗死犬左心室局部径向距离的影响

目的应用实时三维超声心动图(RT-3DE)定量评价多巴酚丁胺对心肌顿抑犬和心肌梗死犬左心室局部径向距离的作用。方法建立犬的心肌顿抑[冠状动脉(冠脉)结扎15 min,再灌注30 min]和急性心肌梗死(冠脉结扎180 min,再灌注30 min)模型。于冠脉结扎前和冠脉结扎-再灌注后,用微量输液泵经股静脉输注多巴酚丁胺5及10μg.kg-1.min-1,每一剂量持续5 min。应用RT-3DE获取实验犬静息状态及输注多巴酚丁胺10μg.kg-1.min-1后RT-3DE全容积数据库。脱机后,根据心尖长轴观8平面法重建收缩末期左室立体几何形状;以二尖瓣环中点至左室心尖部心内膜的连线为中心轴,将左室等分成与中心轴垂直的1.0 cm厚互相平行的短轴平面,从中选取室壁运动异常(WMA)面积最大者作为研究平面;在此平面上,以轴心与左室后壁连线所在位置为0°,逆时针每隔20°测量心内膜至轴心的距离(即径向距离R,共可测得18个值)。将冠脉结扎-再灌注后两组实验犬输注多巴酚丁胺前、后的平均R值与冠脉结扎前(设为基础状态)输注多巴酚丁胺前、后的相应R值进行比较。结果静息状态下,心肌顿抑组和心肌梗死组中所选研究平面结扎冠脉供血区平均R值均明显增大(均P<0.001)。输注多巴酚丁胺后,心肌顿抑组中上述异常增大的平均R值均明显减小(均P<0.001),但未恢复至基础状态水平(均P<0.05);心肌梗死组中上述异常增大的平均R值均无明显改变(均P>0.05)。结论通过应用RT-3DE分析输注多巴酚丁胺前、后左室局部径向距离的变化,可以识别心肌顿抑和心肌梗死。RT-3DE有望为临床定量评价左室局部几何形状提供一项有效手段。     

老年人左心室舒张功能减退窦性心率振荡的研究

目的 探讨老年人左心室舒张功能减退患者窦性心率振荡(HRT)特点,评价HRT对左心室舒张功能减退患者危险分层评估的价值. 方法 选择左心室舒张功能减退患者40例作为观察组,其中左心房增大组20例,正常组20例;选择体检健康者20例作为时照组.分析TO、TS与Macruz指数、二尖瓣舒张早期血流速度峰/舒张晚期血流速度峰值(E/A)比值以及心率变异性(HRV)的相关性. 结果 观察组T0升高(P<0.05),TS下降(P<0.01);左心房增大组TO>左心房正常组(P<0.05),TS<左心房正常组(P<0.01);TO与Macroz指数呈正相关(P<0.01),与SDNN,SDANN呈负相关(均P<0.05);TS与Macruz指数呈负相关(P<0.05),与E/A、SDNN、SDANN呈正相关. 结论 HRT在预测老年人左心室舒张功能减退患者危险性方面具有一定价值.     

Mobility assessment: sensitivity and specificity of measurement sets in older adults

Panzer VP, Wakefield DB, Hall CB, Wolfson LI. Mobility assessment: sensitivity and specificity of measurement sets in older adults.

Objective

To identify quantitative measurement variables that characterize mobility in older adults, meet reliability and validity criteria, distinguish fall risk, and predict future falls.

Design

Observational study with 1-year weekly falls follow-up.

Setting

Mobility laboratory.

Participants

Community-dwelling volunteers (N=74; age, 65–94y) categorized at entry as 27 nonfallers or 47 fallers by using Medicare criteria (1 injury fall or >1 noninjury fall in the previous year).

Interventions

None.

Main Outcome Measures

Test-retest and within-subject reliability, criterion and concurrent validity; predictive ability indicated by observed sensitivity and specificity to entry fall-risk group (falls status), Tinetti Performance Oriented Mobility Assessment (POMA), computerized dynamic posturography Sensory Organization Test (SOT), and subsequent falls reported weekly.

Results

Measurement variables were selected that met reliability (intraclass coefficient of correlation >.6) and/or discrimination (P<.01) criteria (clinical variables: turn steps and time, gait velocity, step-in-tub time, downstairs time; forceplate variables: quiet standing Romberg ratio sway area, maximal lean anterior-posterior excursion, sit-to-stand medial-lateral excursion, sway area). Sets were created (3 clinical, 2 forceplate) using combinations of variables appropriate for older adults with different functional activity levels, and composite scores were calculated. Scores identified entry falls status and concurred with POMA and SOT scores. The full clinical set (5 measurement variables) produced sensitivity of 80% and specificity of 74% to falls status. Composite scores were more sensitive and specific overall in predicting subsequent injury falls and multiple falls compared with falls status and POMA or SOT score.

Conclusions

Sets of quantitative measurement variables obtained with this mobility battery provided sensitive prediction of future injury falls and screening for multiple subsequent falls by using tasks that should be appropriate to diverse participants.     

动态三维超声心动图多巴酚丁胺负荷试验中心肌梗死患者左室容积变化及意义

目的　探讨动态三维超声心动图（３ＤＥ） 多巴酚丁胺负荷试验（ ＤＳＴ） 中心肌梗死（ ＭＩ） 患者左室容积（ＬＶＶ） 变化的临床意义。方法　用３ＤＥ 方法测定了３２ 例正常人和３５ 例急性 ＭＩ 恢复期患者在ＤＳＴ 中的变化情况。结果　ＤＳＴ 中正常人和 ＭＩ 患者ＬＶＶ 和射血分数（ＥＦ） 呈现明显不同的变化趋势。结论　用３ＤＥ 方法测定ＤＳＴ 中ＭＩ 患者的ＬＶＶ 和ＥＦ 值变化能够判断 ＭＩ 患者的左心功能状态和心肌缺血反应。     

二维应变超声评价室壁运动正常的冠状动脉性心脏病患者的左心室扭转运动

目的 应用二维应变超声心动图(2DSE)定量分析常规方法显示室壁运动正常的冠状动脉性心脏病(CHD)患者的左心室扭转运动,探讨其临床应用价值.方法 采集经冠状动脉造影证实的38例CHD患者和31例对照组患者的左心室短轴二尖瓣环及心尖水平切面的二维灰阶动态图像,测量各项左心室扭转指标并获得相应曲线;二维双平面Simpson法测量左心室射血分数. 结果各项常规超声指标的组间差异均无统计学意义;心尖及瓣环扭转曲线的正负方向改变,组间差异有统计学意义(P＜0.01);整体扭转率的组间差异亦有统计学意义(P＜0.05). 结论 左心室的扭转方向及整体扭转率可以检出CHD左心室壁收缩异常,敏感性高于常规超声心动图检查.     

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。     

Quantification of regional left ventricular wall motion in newborns by color kinesis.

BACKGROUND: Normal values for regional left ventricular wall motion, although documented in adults, have not been reported in healthy newborns. METHODS: This study prospectively evaluated global and segmental systolic and diastolic cardiac function by color kinesis in clinically asymptomatic healthy newborns. RESULTS: Eighty-eight asymptomatic infants who were less than 48 hours old were studied. Systolic and diastolic parameters of global and regional left ventricular function are reported as means +/- SD, medians, 5th and 95th percentiles to establish the normative values for newborns. The reported fractional area changes during systole and diastole are similar to the reported normal values for older subjects. Higher body surface area significantly correlated with an increased peak velocity during systole, and fractional area changes during filling of the lateral wall. CONCLUSIONS: Our report of left ventricular regional wall-motion characteristics of healthy newborns, as evaluated by color kinesis, may help in the objective evaluation and management of newborns suspected to have global or segmental ventricular dysfunction.     

斑点追踪成像技术评价心室起博对左心室壁运动影响的实验研究

目的 应用斑点追踪成像技术(STI)观察评价心室起搏对左室室壁运动的影响.方法 7只成年猪在全麻成功后切开胸骨及心包,暴露出心脏.将起搏器电极放在心外膜上行左室或右室起搏,并在起搏前后采集左室中段短轴切面超声图像.用STI软件对图像进行环向应变分析并得出时间应变曲线.以QRS波作为心动周期的起点,分析起搏前后的心肌收缩起始时间、终止时间及收缩总时间占整个心动周期的比率,并了解左室壁各节段收缩协调情况.结果 与窦性心律相比,所有心室起搏心律的收缩起始时间、终止时间及收缩总时间占整个心动周期的比率均增大.心室起搏可导致室壁各节段运动明显不协调.当起搏心率＞130次/min时,在起搏心电图正常情况下,左室整体及部分节段在一个心动周期中出现一次以上的收缩或舒张运动,并出现在相邻的几个心动周期中收缩幅度变异性很大情况.结论 心室起搏可引起左室收缩延迟及时间延长,并可引起左室室壁各节段运动不协调.高频率心室起搏还可能引起左室室壁不规则运动.

Abstract：

Objective To assess the change of left ventricular wall motion at ventricular pacing(VP)by using global circumferential strain (GCS) and segmental circumferential strain of speckle tracking imaging(STI). Methods Seven adult pigs were sedated,followed by median sternotomy and opening of the pericardium. Temporary pacing leads were placed on the right ventricular (RV) epicardium and LV epicardium for RV or LV pacing. A LV short axis view at the mid-level LV was acquired at sinus and VP rhythm. Analysis of circumferential strain by STI was performed offline. The onset of QRS wave was used to characterize the beginning of the cardiac cycle, and the ratio of beginning systolic time, end systolic time and total systolic time to cardiac cycle dyssynchrony was analyzed at sinus and VP rhythm. Results Compared with sinus rhythm,in VP rhythm all of the ratio of the beginning systolic time,end systolic time and total systolic time to cardiac cycle were increased (all P ＜0.05), and the construction of six segments were dyssynchrony,even segmental paradoxical movement. At VP ≥130 beats/min,both LV global and LV segments sometimes showed irregular motion while the EKG remained normal, which included: ( 1 ) multiple construction and diastole in one heart cycle; (2) A large variability of construction amplitude in several consecutive cardiac cycles. Conclusions VP can lead to several kinds of disturbance of left ventricular wall motion, including delay and lengthening of LV systole, dyssynchrony, and irregularity of systole and diastole.     

Variability in frame by frame analysis of left ventricular wall motion from contrast angiograms

Background. Measurement of the timing of left ventricular (LV) wall motion, of asynchrony, and of diastolic function from contrast angiograms requires delineation of the endocardial border frame by frame through the cardiac cycle. This study was performed to determine the magnitude of intraobserver and interobserver variability in manual border tracing, and to measure the impact of this variability on the derived functional parameters. Methods. The contrast ventriculograms of 25 patients with coronary artery disease (CAD) or with normal coronary arteries were analyzed frame by frame, by two observers or twice by the same observer. Motion was measured using the centerline method at each twelfth of systole and of diastole. Variability was calculated as the absolute difference between repeated measurements of: wall motion, asynchrony, and the time at which each region of the LV reached 10%, 50%, and 100% of peak contraction, and 50% of filling. Results. Intraobserver and interobserver variability in wall motion were similar, and varied with time in the cycle, and with location on the LV contour. Variability was highest at end systole, when it averaged 8% of the normal mean for wall motion. Variability in timing was highest at peak contraction; however, the variability in measuring asynchrony averaged only 18 msec. Conclusion. Analysis of the magnitude and synchrony of regional LV wall motion through the cardiac cycle from contrast ventriculograms can be performed with reproducibility comparable to that at end systole.     

Improvement in echocardiographic evaluation of left ventricular wall motion using still-frame parametric imaging.

BACKGROUND: Conventional echocardiographic assessment of left ventricular wall motion is based on visual interpretation of dynamic images, which depends on readers' experience. We tested the feasibility of evaluating endocardial motion using still-frame parametric images. METHODS AND RESULTS: In protocol 1, integrated backscatter images were obtained in 8 anesthetized pigs at baseline, 5, and 60 seconds after left anterior descending coronary occlusion and during reperfusion. Images from 1 cardiac cycle were analyzed offline to create a parametric image of local video intensity oscillations. Ischemia-induced changes were quantified by segmenting the parametric images and calculating regional pixel-intensity profiles. In protocol 2, parametric images were obtained from contrast-enhanced echocardiograms in 30 patients (18 with wall-motion abnormalities; 12 control subjects). "Gold standard" for wall motion was determined from independent interpretations of dynamic images made by 3 experienced reviewers. Dynamic images were independently classified by 3 inexperienced and 3 intermediate-level readers. Interpretation was then repeated in combination with parametric images. Parametric images showed a bright band in the area spanned by endocardial motion, which gradually decreased in brightness and thickness in the left anterior descending territory during coronary occlusion in all animals. In patients, the agreement with the gold standard correlated with the readers' experience (68% inexperienced, 87% intermediate) and significantly improved by adding parametric images (83% and 91%, respectively). CONCLUSION: Parametric imaging provides a still-frame display of regional endocardial motion, sensitive to track ischemia-induced abnormalities. When combined with dynamic images, this technique improves the accuracy of the interpretation of wall motion, especially by less experienced echocardiographers.     

Three-dimensional echocardiographic assessment of left ventricular wall motion abnormalities in mouse myocardial infarction.

We applied 3-dimensional echocardiographic reconstruction to assess left ventricular (LV) volumes, function, and the extent of wall motion abnormalities in a murine model of myocardial infarction (MI). Consecutive parasternal short-axis planes were obtained at 1-mm intervals with a 13-MHz linear array probe. End-diastolic and end-systolic LV volumes were calculated by Simpson's rule, and the ejection fraction and cardiac output were derived. Echocardiography-derived cardiac output was validated by an aortic flow probe in 6 mice. Echocardiography was then performed in 9 mice before and after the left anterior descending coronary artery was ligated. Wall motion was assessed, and the ratio of the abnormally to normally contracting myocardium was calculated. After MI occurred, LV end-diastolic volume and LV end-systolic volume increased (33 +/- 10 vs 24 +/- 6 microL, P <.05 and 24 +/- 9 vs 10 +/- 4 microL, P <.001), whereas cardiac output decreased (4.2 +/- 1.5 mL/min vs 6.6 +/- 2.3 mL/min, P <.01). Forty percent of the myocardium was normokinetic, 24% was hypokinetic, and 36% was akinetic. Echocardiography can measure LV volumes and regional and global function in a murine model of myocardial infarction, thereby providing the potential to quantitate and compare the responses of various transgenic mice to MI and its therapies.