Hand-carried echocardiography for assessment of left ventricular filling and ejection fraction in the surgical intensive care unit

Purpose

To better define the reliability of left ventricular ejection fraction (LVEF) and left ventricular filling, as determined by either hand-carried ultrasound (HCU) or formal transthoracic echocardiography (TTE), in the critically ill surgical patient.

Materials and Methods

Prospective cross-sectional study of 80 surgical intensive care unit patients with concomitant (<30 minutes apart) formal TTE and clinician-performed cardiac HCU. Visual estimates of LVEF and left ventricular filling (“underfilled” vs “normally filled”) were recorded, both by clinicians performing HCU and fellowship-trained echocardiographers.

Results

Bland-Altman plot analysis of LVEF estimates revealed good interobserver agreement between HCU and formal TTE (% LVEF mean bias, −2.2; with 95% limits of agreement, ±22.1). This was similar to agreement between independent echocardiography observers (% LVEF mean bias, 1.3; with 95% limits of agreement, ±21.0). However, assessments of left ventricular filling demonstrated only fair to moderate interobserver agreement (κ = 0.22-0.40). Of note, a greater percentage of the 5 standard acoustic windows were obtainable using formal TTE (72% vs 56%).

Conclusions

Formal TTE offers no advantage over HCU for determination of LVEF in critically ill surgical patients, even though the former allows for a more complete examination. However, estimations of left ventricular filling only demonstrate fair to moderate interrater agreement and thus should be interpreted with care when used as markers of volume responsiveness.     

重症医学医师主导的床旁目标导向超声心动图检查在ICU应用的可行性研究

目的 评估由重症医学医师在重症监护病房(ICU)应用床旁彩色超声心动图对危重患者进行目标导向超声心动图(TTE)检查的可行性及其对临床决策的影响.方法 重症医学医师经过12 h的TTE培训,对88例经过初步心脏临床评价的ICU患者进行TTE检查(2～4个二维视窗,未使用多普勒和M型超声),评价患者的左室功能、容量状态、有无局部心室壁运动异常及心包积液;由心脏超声医师重复检查以评价TTE质量及重症医学医师解释的准确性.结果 重症医学医师成功完成了86例患者(97.7％)的TTE检查,正确解释了75例患者(85.2％)的超声心动图结果;TTE检查结果直接影响了22.7％患者的治疗(包括液体治疗、正性肌力药物及血管活性药物),45.5％患者获得有价值的信息,31.8％患者没有得到有用的信息;重症医学医师获得图像和解释的平均时间为(11.2±5.2) min.结论 经过短暂的正规训练,重症医学医师可以可靠地完成ICU危重症患者的TTE检查,能够为相当数量的患者提供新的信息并改变其治疗.这项研究支持在国内重症医学医师培训课程中加入床旁TTE检查培训.     

经胸三维彩色多普勒超声心动图定量评价左心室搏出量的临床研究

目的 评价经胸三维彩色多普勒超声心动图(3DCDE)测量左心室搏出量(LVSV)的准确性.方法 45例门诊患者,其中心内结构正常者15例,冠心病患者15例,扩张型心肌病患者15例.分别应用二维多普勒超声心动图(2DDE)、3DCDE和全容积三维超声心动图(3DE)测量LVSV.以3DE测量LVSV作为参考值,3DCDE及2DDE测量LVSV分别与之比较分析.结果 三种方法测算的LVSV平均值分别为:3DE(79.3±22.6)ml,2DDE(74.0±20.6)ml,3DCDE(78.7±22.6)ml.3DCDE测值与3DE测值比较差异无统计学意义(P=0.06);2DDE测量的LVSV较3DE测值显著低估(P<0.001).相关性分析显示,3DCDE和2DDE测值与3DE测值均具有良好的相关性(r:0.96和r:0.89),而3DCDE测值较2DDE测值具有更好的相关性.结论 应用经胸3DCDE技术测量左室流出道血流量可以准确方便地测量LVSV,较2DDE方法准确性更高,可能成为临床评价心功能有价值的工具.     

Effect of pericardium on left ventricular early filling assessed by pulsed Doppler echocardiography

Pericardial effect on left ventricular early filling was studied in six dogs by use of pulsed Doppler echocardiography. Rapid dextran infusion was used to manipulate left atrial pressure. Left ventricular peak early filling velocities before and after pericardiectomy were measured at different levels of left atrial pressure with right atrial and left ventricular pressures. Peak early filling velocity correlated with mean left atrial pressure before and after pericardiectomy. Before pericardiectomy, when mean right atrial pressure exceeded 12 mm Hg, further increase of the velocity was not observed in spite of volume loading. After pericardiectomy, peak early filling velocity became higher and the slope of the relation line between mean left atrial pressure and the velocity became steeper than before pericardiectomy. When the filling pressure was denoted by the transmural mean left atrial pressure, the points on the relation line before pericardiectomy fell along the relation line after pericardiectomy. We conclude the pericardium exerts an external constraint on left ventricular early filling. Therefore we should not consider the absolute but the transmural filling pressure when estimating left ventricular early diastolic function with use of Doppler-derived left ventricular early filling velocity.     

超声心动图评估左心室充盈压的研究进展

心力衰竭是人类死亡的主要原因之一,其中左心室射血分数(LVEF)正常和LVEF减低的患者约各占一半[1-2].左心室充盈压(LVFP)升高是左心收缩功能不全的特征之一[3];LVEF正常的患者中,LVFP升高是左心舒张功能不全的主要指标[4-5].因此,评估LVFP在诊断心功能不全方面具有重要临床意义.LVFP即舒张期中左心室与左心房之间的压力阶差,反映了左心室的前负荷状况,受循环血容量、心肌收缩力和舒张特性等影响.     

超声心动图评估左心室充盈压的研究进展

心力衰竭是人类死亡的主要原因之一,其中左心室射血分数(LVEF)正常和LVEF减低的患者约各占一半[1-2].左心室充盈压(LVFP)升高是左心收缩功能不全的特征之一[3];LVEF正常的患者中,LVFP升高是左心舒张功能不全的主要指标[4-5].因此,评估LVFP在诊断心功能不全方面具有重要临床意义.LVFP即舒张期中左心室与左心房之间的压力阶差,反映了左心室的前负荷状况,受循环血容量、心肌收缩力和舒张特性等影响.     

Hyperdynamic left ventricular ejection fraction in the intensive care unit

IntroductionLimited information exists on the etiology, prevalence, and significance of hyperdynamic left ventricular ejection fraction (HDLVEF) in the intensive care unit (ICU). Our aim in the present study was to compare characteristics and outcomes of patients with HDLVEF with those of patients with normal left ventricular ejection fraction in the ICU using a large, public, deidentified critical care database.MethodsWe conducted a longitudinal, single-center, retrospective cohort study of adult patients who underwent echocardiography during a medical or surgical ICU admission at the Beth Israel Deaconess Medical Center using the Multiparameter Intelligent Monitoring in Intensive Care II database. The final cohort had 2867 patients, of whom 324 had HDLVEF, defined as an ejection fraction >70 %. Patients with an ejection fraction <55 % were excluded.ResultsCompared with critically ill patients with normal left ventricular ejection fraction, the finding of HDLVEF in critically ill patients was associated with female sex, increased age, and the diagnoses of hypertension and cancer. Patients with HDLVEF had increased 28-day mortality compared with those with normal ejection fraction in multivariate logistic regression analysis adjusted for age, sex, Sequential Organ Failure Assessment score, Elixhauser score for comorbidities, vasopressor use, and mechanical ventilation use (odds ratio 1.38, 95 % confidence interval 1.039–1.842, p =0.02).ConclusionsThe presence of HDLVEF portended increased 28-day mortality, and may be helpful as a gravity marker for prognosis in patients admitted to the ICU. Further research is warranted to gain a better understanding of how these patients respond to common interventions in the ICU and to determine if pharmacologic modulation of HDLVEF improves outcomes.     

Restrictive left ventricular filling and preserved ventricular function: a limitation in the noninvasive estimation of pulmonary wedge pressure by Doppler echocardiography.

Pulmonary wedge pressure (PWP) can be estimated from the ratio of transmitral early peak flow velocity to flow propagation velocity measured by Doppler. Discrepancies observed in the application of the method prompted us to design this prospective study, aimed at detecting potential limitations of the method. We studied a total of 32 patients admitted to a cardiac intensive care unit, using a Swan-Ganz catheter. Correlation between invasive- and Doppler-estimated PWP was fairly good (r = 0.58). Analysis of discrepant cases led to the identification of a subgroup of 6 patients in whom PWP was largely underestimated because of unexpectedly high values of flow propagation velocity (71 +/- 15 cm/s vs 37 +/- 10 cm/s in the rest of the group; P =.0001). All of them had in common a restrictive Doppler filling pattern and preserved left ventricular systolic function. Exclusion of this group showed an improvement in the correlation coefficient to r = 0.72. In conclusion, PWP can be estimated by the Doppler early peak flow velocity to flow propagation velocity ratio, although a significant underestimation of PWP may be observed in patients with a restrictive filling pattern and preserved ventricular function.     

Age-dependency of left ventricular filling dynamics and relaxation as assessed by pulsed Doppler echocardiography

Summary. Left ventricular diastolic function was assessed from transmitral flow velocity curves as measured by Doppler echocardiography in healthy individuals aged 21–69 years, each decade comprising 12 subjects. By ageing, progressive changes in the various filling parameters were observed. When comparing the youngest and oldest age groups, the ratio between peak velocities in early and late diastole decreased from 2.0±0.3 to 1.2±0.3 (P<0.001). The filling fraction of first third of diastole decreased from 54 ± 5% to 45 ± 4% (P<0.001). Isovolumic relaxation time increased from 61 ± 11 ms to 77 ± 12 ms (P<0.01). Correlation coefficients of velocity ratio, filling fraction and isovolumic relaxation time vs. age were r= -0.71 (P<0.001), r= -0.56 (P<0.001) and r= 0.44 (P<0.001), respectively. When isovolumic relaxation time and age were used together in multivariate regression analysis, only age was an independent predictor of velocity ratio and filling fraction. Stroke volume, peak velocity in left ventricular outflow tract, heart rate and systolic blood pressure were similar in all age groups. Thus, velocity ratio and filling fraction indicated a relative filling shift towards late diastole by ageing and were more sensitive than s?ystolic parameters in reflecting age-related changes in cardiac function. The changes could be explained neither by delayed relaxation nor by change in systolic parameters. When using Doppler echocardiography for evaluation of left ventricular filling, agematching of reference groups is necessary.     

经胸三维超声心动图评价左室收缩功能方法的初步研究

目的　探讨采用磁场定位系统经胸三维超声心动图(3DE)测定左室收缩功能的方法及可行性。方法　健康志愿者17例。利用磁场发射及接收装置通过手动控制探头在心尖区扇形扫描进行三维数据采集。每例受检者均分别采集60、30及10幅图像（3D60、3D30、3D10）各自进行三维重建。同时记录采集时间。采用圆盘总和法（disksummation）测定左室舒张末期容积（LVEDV）和左室收缩末期容积（LVESV）,得出每搏输出量（SV）及左室射血分数（LVEF）。同时用常规二维Simpson法测量LVEF。结果　①3D10重建后的左室短轴图像不完整,左室壁有不规则中断,心腔内结构难以评价。3D60及3D30重建后的左室短轴图像完整,内膜、二尖瓣及瓣下结构清晰可辨。②二维超声心动图(2DE)测得LVEF为0.62±0.06,与3D60及3D30的测值显著相关（r值分别为0.87,0.83,P<0.001）。③3D60测定的EDV,ESV,SV及EF分别为（88.11±18.08）ml、（38.01±9.23）ml、（50.09±13.30）ml和0.57±0.07;3D30测定的EDV,ESV,SV及EF分别为（87.51±15.58）ml、（37.18±9.62）ml、（50.33±11.48）ml和0.58±0.08;二者间各项测值差异无显著性意义（P均>0.1）,且显著相关（r值分别为0.94,0.88,0.88,0.87,P均<0.001）。④3D60的采集时间为（152.55±53.27）s,3D30的采集时间为（72.82±17.16）s,比3D60的时间节省48％。结论　磁场定位系统扇形扫描经胸3DE测定正常人左室收缩功能是准确可行的。采集30幅图像与采集60幅图像得到的左室收缩功能指标无显著差异,前者可缩短约一半的检查时间,更加迅速方便,有利于临床应用。     

Augmentation of atrial contribution to left ventricular filling in IDDM subjects as assessed by Doppler echocardiography

Left ventricular diastolic function was assessed by pulsed Doppler echocardiography in 21 subjects (mean age 48 yr) with insulin-dependent diabetes mellitus (IDDM) and without evidence of ischemic heart disease and in 21 healthy control subjects of similar age and sex distribution. The peak mitral valve flow velocities during the early rapid filling phase (E) and during late atrial filling (A) were measured, and the ratio of these peak flow velocities (E:A) was calculated. E was similar in both groups, but A was higher (P less than .01) in the diabetic group. Thus, E:A was lower (1.19 +/- 0.24 vs. 1.65 +/- 0.67; P less than .01) in the diabetic subjects than in the control subjects. On subgroup analysis, 6 patients with cardiac autonomic neuropathy had lower E:A than the patients with no such disorder (0.99 +/- 0.15 vs. 1.29 +/- 0.25; P less than .05). E:A was not related to the duration of diabetes, presence of retinopathy, HbA1, or blood glucose levels. In conclusion, the atrial contribution to left ventricular filling seems to be augmented in diabetic subjects. This finding indirectly supports the view that left ventricular compliance is already reduced in asymptomatic diabetic subjects.     

Estimation of left ventricular end-diastolic pressure by color M-mode Doppler echocardiography and tissue Doppler imaging.

OBJECTIVES: The aim of this study was to estimate left ventricular end-diastolic pressure (LVEDP) noninvasively by tissue Doppler imaging and color M-mode echocardiography. MATERIAL AND METHODS: We studied 3 groups of patients who were proven by angiography to be free of significant coronary artery lesions (<40% stenosis) with an LVEDP < 10 mm Hg (group A: n = 24; 16 men, 18 women; mean age +/- SD = 55 +/- 13 years), an LVEDP of 10 to 15 mm Hg (group B: n = 21; 17 men, 4 women; mean age 56 +/- 11 years), or an LVEDP > 15 mm Hg (group C: n = 35; 20 men, 15 women; mean age 58 +/- 9 years). Tissue Doppler imaging of the lateral mitral annulus and color M-mode imaging of the mitral valve in the apical 4-chamber view were obtained with an echocardiographic system. Early and late diastolic velocities (Em and Am, respectively), Em deceleration time (EmDT), Am time (Am-t), and mitral propagation velocity time delay (VpDT) were measured in each patient. RESULTS: In group A, sensitivity and specificity for EmDT < or = 100 ms, Am-t < or = 90 ms, Em/Am > or = 1, and VpDT < or = 45 ms were found to be 0.57 and 0.89, 0.66 and 0.88, 0.86 and 0.92, and 0.73 and 0.89, respectively. In group B, sensitivity and specificity for EmDT 100 to 120 ms, Am-t 90 to 110 ms, Em/Am 1 to 0.5, and VpDT 45 to 60 ms were found to be 0.57 and 0.84, 0.69 and 0.82, 0.66 and 0.75, and 0.55 and 0.83, respectively. In group C, sensitivity and specificity for EmDT > 120 ms, Am-t > 110 ms, Em/Am < 0.5, and VpDT > 60 ms were found to be 0.88 and 0.81, 0.71 and 0.80, 0.86 and 0.72, and 0.78 and 0.86, respectively. CONCLUSION: The EmDT, Am-t, Em/Am, and VpDT measurements obtained noninvasively by left ventricular tissue Doppler imaging and mitral flow propagation velocity were found to be useful in the estimation of LVEDP.     

多普勒超声心动图对经胸放疗期间左室舒张功能的评价

目的：应用多普勒超声心动图监测经胸放疗期间左室舒张功能的变化。方法：36例经胸放射治疗的患者，进行两次多普勒超声心动图检查，首诊检查：放射治疗前1～3天；复诊检查：放射治疗结束当天。测量舒张期二尖瓣口血流频谱及二尖瓣环运动频谱的两峰比值（E／A，e／a）。结果：舒张期二尖瓣口血流频谱及二尖瓣环运动频谱的两峰值比率均显示．两次测量结果间存在显著性差异（E／A：0．77±0．19 vs 0．69±0．13，e／a：0．82＋0．31 vs 0．75±0．19，均P〈0．05）。结论：经胸放疗期间左室舒张功能受损，多普勒超声心动图可及时作出诊断。     

彩色多普勒超声对冠脉搭桥术前术后左心功能评价的研究

目的 应用彩色多普勒超声心动图对冠脉搭桥术前后左心功能进行评价。方法 对99例冠脉搭桥术患者(男69例,女30例,年龄45-66岁)分别于术前术后测量其左室射血分数(EF)、心输出量(CO)、二尖瓣口血流E/A波频谱和时相及观察二维室壁运动情况。结果 79例(80%)术后EF值均有不同程度升高(P<0.01);59例(60%)CO值增加(P<0.01);93例(95%)E/A比例有术前倒置变为正常或变大(P<0.01),统计学上均有显著性差异。结论 彩色超声成像对冠脉搭桥术前术后左心功能及手术本身的评价,不失为一种较为有效的无创性方法。     

Diagnosis of left ventricular diastolic dysfunction by Doppler echocardiography

Left ventricular(LV) diastolic dysfunction with preserved LV systolic function is common among patients with hypertension, especially with LV hypertrophy. Doppler echocardiography is one of the most useful clinical tools for the evaluation of diastolic function. Mitral inflow and pulmonary venous flow velocities are used not only for the assessment of diastolic function but also for predicting prognosis. Recently, tissue Doppler echocardiography has been also applied to evaluate diastolic function. Accurate assessment of diastolic function has been demonstrated by measuring both mitral annulus and mitral inflow velocity. In this article, We review the diagnosis of diastolic dysfunction by Doppler echocardiography using mitral inflow velocity, pulmonary venous flow velocity and mitral annulus velocity measured by tissue Doppler imaging.     

Transthoracic echocardiography for the diagnosis of left ventricular thrombosis in the postoperative care unit

Introduction  

Transthoracic echocardiography (TTE) is a reliable, noninvasive imaging method that is useful in the evaluation of cardiovascular thrombosis. We conducted a retrospective study of all the echocardiograms from patients in the postoperative care unit to assess the role of TTE in thrombus identification in the left ventricle.     

超声向量血流图对人体左心室涡流的初步探讨

目的 应用向量血流图(vector flow mapping,VFM)初步研究人体左心室内流场结构,寻求人体左心室内漩涡形成规律及漩涡描述参数.方法 选取60名健康志愿者为观察对象,应用VFM技术得到心腔内血流速度向量和流线图,采用DSA-RS1软件测量漩涡直径、漩涡位置、漩涡最大向量速度及漩涡圈数.结果 应用VFM技术可清晰显示心腔内血流速度的矢量图,观察结果显示舒张早期和晚期通过二尖瓣口的血流在左室内形成两个相对靠近二尖瓣环的小漩涡,且前者比后者的漩涡向量速度高,漩涡圈数多(P＜0.05);而舒张中期和等容收缩期左室内的回旋血流形成一个较大的涡环,且前者比后者的漩涡向量速度高.漩涡圈数多(P＜0.05).结论 VFM图像能显示心室内血液流场的变化,研究得出的涡描述参数能够反映这一变化,并能初步定量研究心腔内复杂流场结构.     

多普勒超声心动图评价兔左心室舒张功能与充盈压

目的 探讨舒张早期二尖瓣口血流速度(E)、瓣环运动速度(Ea)及E/Ea比值等多普勒指标在评价左心室舒张功能和充盈压方面的价值.方法 采用缩窄腹主动脉法建立18只左心室压力超负荷兔舒张功能不全模型(模型组),应用多普勒超声心动图观察左心大小、室壁厚度、射血分数(EF)及舒张功能指标,心导管测量左心室舒张末压(LVEDP).8只健康兔作为LVEDP对照(对照组).结果 模型组左心房增大、左心室肥厚、LVEDP明显增高(P＜0.01);多普勒指标Ea降低、E/Ea增高(P均＜0.01),而E/A无明显变化;LVEDP与E/Ea呈正相关(r=0.54,P<0.05).结论 在左心室肥厚所致的舒张功能不全动物模型中,Ea降低反映心肌主动松弛功能减退,E/Ea与LVEDP结合,可综合评价左心室舒张功能及充盈压.     

床旁超声心动图对急性心肌梗死后左室舒张功能的评价

目的　应用床旁超声心动图动态观察心肌梗死急性期左室舒张功能 (LVDF)的变化 ,评价溶栓治疗对其的影响。方法　对 61例首发急性心肌梗死 (AMI)患者行系列床旁超声心动图检查。检测指标包括 :舒张早晚期最大充盈速率比值 (VE/VA)及其时间流速积分比值 (ETVI/ATVI)和等容舒张时间 (IVRT )。结果　AMI患者IVRT均延长 ,前壁心肌梗死溶栓组和下壁心肌梗死组VE/VA下降 ,前壁心肌梗死未溶栓组VE/VA正常。溶栓再通组第 3dIVRT、ETVI/ATVI明显改善 ,第 7d、3周末持续改善。溶栓未通组、未溶栓组各指标无显著变化。前壁溶栓再通组与溶栓未通组及未溶栓组同期比较IVRT有显著性差异。结论　AMI患者急性期LVDF减退 ,溶栓再通后LVDF明显改善 ,但存在舒张顿抑。床旁超声心动图评价AMI后LVDF的变化有良好的临床应用价值。     

彩色M型多普勒超声评价肾移植病人的左室舒张功能

目的应用彩色M型多普勒超声心动图测量舒张早期左室内血流传播速度（Vp）,评价肾移植病人的左室舒张功能。方法肾移植组105例（50岁以下者71例;50～60岁者23例;60岁以上者11例）。正常对照组123例（50岁以下者69例;50～60岁者36例;60岁以上者18例）。取心尖四腔或二腔心平面测量左室内血流传播速度（Vp）,二尖瓣和肺静脉血流曲线。结果肾移植病人的Vp值较正常人降低（P〈0.05）,血流形态异常。结论应用彩色M型多普勒超声心动图测量舒张早期左室内血流传播速度,不受心脏负荷及年龄的影响,作为评价肾移植病人左室舒张功能的指标有临床意义。