A visual approach for the accurate determination of echocardiographic left ventricular ejection fraction by medical students.

BACKGROUND: Previously published reports show that there is significant intraobserver, interobserver, and interinstitutional variability in the determination of left ventricular (LV) ejection fraction (EF) by echocardiography. With the increased deployment of echocardiography (eg, handheld devices), there exists a need for developing a simple, intuitive approach for evaluating LVEF that allows a wider range of physicians to accurately and rapidly determine LVEF. OBJECTIVE: We sought to create a system for assessing LVEF that relies on recognition and matching of patterns, rather than on mathematic calculations and geometric assumptions. METHODS: A library of videoclips of cardiac function was compiled from 54 patients who spanned the spectrum of LVEF. LVEFs were calculated for these patients using standard echocardiographic methods, with further validation of a subsample using cardiac magnetic resonance imaging measurement of LVEF. The library of images was used to create a software tool for assessing LVEF on the basis of a "template-matching" approach. The software tool was then tested on medical students (N=13) to determine whether it enabled relatively untrained individuals to make accurate LVEF estimates. RESULTS: Using a template-matching approach for interpretation of echocardiograms, medical students were able to accurately estimate LVEF after only a limited introduction to echocardiography. Their LVEF estimates showed good correlation and agreement with gold standard (r = 0.88, standard square of the estimate = 6.0, limits of agreement = +12.0%, -15.6%). CONCLUSIONS: A new visual approach for assessing cardiac function using template matching can accurately estimate LVEF. With minimal training, medical students can make LVEF estimates that correlate well with gold standard. The application of this new approach includes allowing for the interpretation of LVEF from echocardiograms to be performed by a broader spectrum of physicians.     

Measurement of right and left ventricular ejection fraction in dogs

Summary. Three techniques for measurement of right (RVEF) and two techniques for left (LVEF) ventricular ejection fraction were evaluated in five dogs. RVEF was measured with a first-pass radionuclide technique using erythrocytes labelled in vitro with Technetium-99m methylene disphosphonate (MDP) and compared with RVEF measured with a thermodilution technique. Thermodilution-determined RVEF was compared with RVEF values measured with cine angiocardiography. LVEF was measured with a radionuclide ECG-gated equilibrium technique and compared with cine angiocardiography. Measurements were performed before and during a continuous infusion of dopamine. There was an excellent correlation between RVEF measured with the first-pass and the thermodilution technique, r_s being 0·86, n = 9, P < 0·01. When RVEF measured with the thermodilution technique was compared with cine angiocardiography r_s was 0·75, n = 10, P < 0·01. LVEF measured with the ECG-gated equilibrium technique correlated well with cine angiocardiography (r_s= 0·91, n = 10, P < 0·01).     

Evaluation of left ventricular ejection fraction using through-time radial GRAPPA

Background

The determination of left ventricular ejection fraction using cardiovascular magnetic resonance (CMR) requires a steady cardiac rhythm for electrocardiogram (ECG) gating and multiple breathholds to minimize respiratory motion artifacts, which often leads to scan times of several minutes. The need for gating and breathholding can be eliminated by employing real-time CMR methods such as through-time radial GRAPPA. The aim of this study is to compare left ventricular cardiac functional parameters obtained using current gold-standard breathhold ECG-gated functional scans with non-gated free-breathing real-time imaging using radial GRAPPA, and to determine whether scan time or the occurrence of artifacts are reduced when using this real-time approach.

Methods

63 patients were scanned on a 1.5T CMR scanner using both the standard cardiac functional examination with gating and breathholding and the real-time method. Total scan durations were noted. Through-time radial GRAPPA was employed to reconstruct images from the highly accelerated real-time data. The blood volume in the left ventricle was assessed to determine the end systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) for both methods, and images were rated for the presence of artifacts and quality of specific image features by two cardiac readers. Linear regression analysis, Bland-Altman plots and two-sided t-tests were performed to compare the quantitative parameters. A two-sample t-test was performed to compare the scan durations, and a two-sample test of proportion was used to analyze the presence of artifacts. For the reviewers´ ratings the Wilcoxon test for the equality of the scores’ distributions was employed.

Results

The differences in EF, EDV, and ESV between the gold-standard and real-time methods were not statistically significant (p-values of 0.77, 0.82, and 0.97, respectively). Additionally, the scan time was significantly shorter for the real-time data collection (p<0.001) and fewer artifacts were reported in the real-time images (p<0.01). In the qualitative image analysis, reviewers marginally preferred the standard images although some features including cardiac motion were equivalently rated.

Conclusion

Real-time functional CMR with through-time radial GRAPPA performed without ECG-gating under free-breathing can be considered as an alternative to gold-standard breathhold cine imaging for the evaluation of ejection fraction in patients.     

Effect of PGE1 on the left ventricular ejection fraction

12 patients with impaired left ventricular function were submitted to left ventricular ejection fraction measurements before and after increasing doses of PGE1 administered by i.v. or i.a. infusion. 6 responders out of the 12 patients showed a significant (p less than 0.01) improvement in LVEF, whereas the LVEF remained unchanged in the remaining 6 patients. 4 of the responders had received intravenous and 2 had received intraarterial PGE 1. Afterload reduction, venous tonisation, increased myocardial contractility and metabolic effects may be causative factors. These results suggest that PGE 1 therapy may be of therapeutic benefit in some patients with impaired LVEF.     

Treatment of heart failure with decreased left ventricular ejection fraction

Original Article Class I recommendations for treating patients with current or prior symptoms of heart failure with reduced left ventricular ejection fraction (LVEF) include using diuretics and salt restriction in individuals with fluid retention. Use angiotensin-converting enzyme (ACE) inhibitors, beta blockers, and angiotensin II receptor blockers if intolerant to ACE inhibitors because of cough or angioneurotic edema. Nonsteroidal anti-inflammatory drugs, most antiarrhythmic drugs, and calcium channel blockers should be avoided or withdrawn. Exercise training is recommended. Implant cardioverter-defibrillator (ICD) is recommended in individuals with a history of cardiac arrest, ventricular fibrillation, or hemodynamically unstable ventricular tachycardia. ICD is indicated in patients with ischemic heart disease for at least 40 d post-myocardial infarction or nonischemic cardiomyopathy, an LVEF of 30% or less, New York Heart Association (NYHA) class II or III symptoms on optimal medical therapy, and an expectation of survival of at least 1 yr. Cardiac resynchronization therapy should be used in individuals with an LVEF of 35% or below, NYHA class III or IV symptoms despite optimal therapy, and a QRS duration greater than 120 ms. An aldosterone antagonist can be added in selected patients with moderately severe to severe symptoms of heart failure who can be carefully monitored for renal function and potassium concentration (serum creatinine should be ≶2.5 mg/dL in men and ≶2.0 mg/dL in women; serum potassium should be <5.0 mEq/L).     

Impedance cardiography fails to measure accurately left ventricular ejection fraction

The purpose of this study was to describe the technique proposed to measure left ventricular ejection fraction (LVEF) with the impedance cardiogram and to compare these values with those measured by radionuclide angiocardiography. Characteristics (mean +/- SE) of the healthy control group were: age, 32 +/- 3 yr; weight, 75 +/- 6 kg; and height, 177 +/- 3 cm. Characteristics of the patient population of 46 men and 49 women were: age, 63 +/- 1 yr; weight 74 +/- 2 kg; and height, 170 +/- 1 cm. LVEF was measured by impedance (ZEF) and multiple-gated scans (MEF) while in the supine position. The control group ZEF averaged 72% (range 67% to 78%) and the MEF averaged 71% (range 65% to 77%). There were no differences between the average ZEF (56 +/- 1%) and MEF (53 +/- 2%) in the patients. Correlations, however, between ZEF and MEF were unacceptably low for the several clinical populations within this group (-0.17 to 0.16). Furthermore, MEF correlated well with regional wall motion (r = .84) while ZEF did not (r = .00). Subdividing the patients according to heart function as determined by regional wall motion failed to improve the correlation between MEF and ZEF. The use of a previously published regression equation to predict LVEF from the systolic time interval ratio of pre-ejection period/left ventricular ejection time derived from the impedance cardiogram also proved ineffective. These data suggest that the previously proposed analysis of the impedance cardiogram to measure LVEF should not be used to make a clinical diagnosis.     

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.     

Validity and reproducibility of echocardiographic measurement of left ventricular ejection fraction by acoustic quantification with tissue harmonic imaging technique.

The tissue harmonic imaging technique can enhance detection of the cardiac endocardial border. When combined with an acoustic quantification (AQ) method, an improvement of accuracy and reproducibility of real-time measurement of left ventricular (LV) function might be expected. However, few data exist regarding the measurement of LV function by AQ with the harmonic imaging technique. Therefore, we evaluated the validity and reproducibility of AQ measurement of LV ejection fraction with or without harmonic imaging technique. A total of 50 patients (mean age 58 +/- 10 years) who underwent left ventriculography were included in our study. The LV end-diastolic and end-systolic volumes by ventriculography were 131 +/- 52 mL and 72 +/- 43 mL, respectively, and were underestimated by both conventional (70 +/- 32 mL and 36 +/- 25 mL) and harmonic (67 +/- 30 mL and 34 +/- 22 mL) AQ obtained in the apical 4-chamber view. The calculated ejection fraction by ventriculography was 0.49 +/- 0. 11 and correlated with that by conventional AQ (0.51 +/- 0.11; y = 0. 72x + 0.152; r = 0.73). This was a marked improvement when compared with the ejection fraction by harmonic AQ (0.50 +/- 0.11; y = 0.89x + 0.065; r = 0.91). Interestingly, interobserver and intraobserver variabilities of conventional AQ, which were 15.6% and 8.6%, respectively, were much improved by harmonic AQ (8.9% and 4.5%, respectively). These results indicate the feasibility of real-time measurement of LV ejection fraction by harmonic imaging, although absolute LV volume can be underestimated even by this technique.     

Determination of right ventricular ejection fraction by two-dimensional echocardiographic single plane subtraction method

Right ventricular ejection fraction is a useful measurement for evaluating right ventricular function in various states, including coronary artery disease, chronic obstructive pulmonary disease, and both congenital and valvular heart diseases. The right ventricular geometry has made it difficult to evaluate right ventricular ejection fraction by simple echocardiographic methods. In this study 36 consecutive patients were examined by two-dimensional echocardiography within 4 hours of radionuclide-determined right ventricular ejection fraction to test a simplified method for calculating right ventricular ejection fraction by two-dimensional echocardiography. Echocardiographic measurements were independently determined in the subcostal and apical four-chamber views. Correlation with first pass radionuclide right ventricular ejection fraction was r = 0.89 and 0.84. Right ventricular ejection fraction could be calculated from one of two views in 92% of patients studied. This technique for determination of right ventricular ejection fraction offers a simple noninvasive method of evaluating right ventricular function.     

ECToolbox软件计算左心室射血分数的适用性

目的 评价ECToolbox软件中R0、R1、R2公式计算门控心肌灌注显像左心室射血分数(LVEF)的适用性.方法 64例患者[冠状动脉粥样硬化性心脏病(CHD)44例;高血压病20例]接受静息态门控心肌灌注显像(~(99m)Tc-MIBI)和平衡法门控心血池显像(~(99m)Tc-RBC),用ECToolbox软件中的R0、R1、R2公式分别计算LVEF,称为R0 LVEF、R1 LVEF、R2 LVEF.将三种公式的计算结果与平衡法门控心血池显像计算结果对比分析.结果 R0、R1、R2公式LVEF值与门控心血池显像LVEF值均有相关性(r=0.905、0.905、0.903,P均<0.05);χ~2检验三种公式LVEF值落入门控心血池显像LVEF值±15%准确率分别为54.30%、71.40%、22.90%,±30%的准确率为81.40%、88.60%、74.30%;Wilcoxon配对检验结果示R1公式计算结果与门控心血池显像计算结果差异无统计学意义,R0、R2公式计算结果与门控心血池显像计算结果差异有统计学意义.结论 门控心肌灌注显像用ECToolbox软件计算CHD和高血压患者的LVEF时,R1公式最为适用.     

实时三维超声心动图评价正常人左室射血分数的初步研究

目的　探讨实时三维超声心动图评价正常人左室射血分数的可行性和价值。方法　应用实时三维超声心动图与常规M型超声心动图测量 2 4例正常志愿者的左室射血分数 ,比较两种测量方法一致性和相关性。结果　所有志愿者均可获得满意实时三维与M型超声图像 ;两种方法所得测值之间差异无显著性 (P >0 .0 5 ) ,并具有良好相关性 (P <0 .0 0 1)。结论　实时三维超声心动图评价正常人左室射血分数是准确和可性行的     

Assessment of left ventricular ejection fraction measured by quantitative gated SPECT

Purpose: The purpose of this study was to evaluate the reliability of left ventricular ejection fraction (LVEF) measured by quantitative gated SPECT (QGS). We compared the efficacy of LVEF assessment among Tc-99m tetrofosmin gated SPECT imaging, contrast left ventriculography (LVG), and first-pass radionuclide angiography (FP). Patients: One-hundred and seven patients with ischemic heart disease underwent QGS and LVG simultaneously within 3 months, and 92 of the 107 patients also underwent FP at the same time. Results: QGS progressively overestimated LVEF at the lower range of end-systolic volume (ESV), especially in patients with small hearts. Moreover, the QGS technique systemically tended to underestimate LVEF in comparison with LVG. However, linear regression analysis demonstrated a good correlation between the LVEF values measured by QGS and those measured by both LVG (p<0.0001) and FP (p<0.0001). Conclusion: Although QGS has a tendency to overestimate LVEF in patients with small hearts, and to systemically underestimate LVEF compared with LVG, this technique is still a reliable clinical tool for measurement of LVEF.     

心肺运动试验参数与左心室射血分数的相关性

目的探讨心肺运动试验(CPET)参数与左心室射血分数(LVEF)的相关性。方法入选行CPET检查且同时具备CPET 1周内超声心动图资料的患者175例。根据LVEF将患者分为LVEF正常组及LVEF减低组。收集患者的一般情况(年龄、性别、体质量指数),合并疾病,CPET 1周内超声心动图测得的LVEF及主要CPET参数,对LVEF与CPET参数行相关性分析。结果 LVEF正常组LVEF与CPET参数并无统计学相关,LVEF减低组特别是合并心肌梗死的患者,LVEF与CPET各参数(无氧阈时代谢当量及摄氧量、峰值时代谢当量及摄氧量)均呈正相关关系,相关系数(r)在0.535~0.601(P均<0.05)。结论对于LVEF正常的患者,LVEF与CPET参数无明显相关性,不能用静息态心功能(LVEF)推测患者的运动耐量。而对于LVEF减低的患者,特别是冠心病合并心肌梗死的患者,其LVEF与CPET参数呈正相关关系。     

心脏超声造影评价恶性肿瘤化疗患者左心室射血分数与左心室容积

目的比较心脏超声造影与常规超声心动图测量恶性肿瘤化疗患者左心室射血分数（LVEF）与左心室容积的可重复性,探讨心脏超声造影评估恶性肿瘤化疗患者左心功能的价值。 方法选择2016年7至12月华中科技大学同济医学院附属同济医院119例接受了常规超声心动图检查的恶性肿瘤化疗患者。其中图像清晰者42例,图像欠佳者77例。采集所有患者的胸骨旁左心室长轴、心尖四腔、二腔、左心长轴观以及三维动态图像,对于图像欠佳组患者还需采集心脏超声造影状态下的胸骨旁左心室长轴、心尖四腔、二腔、左心长轴观以及三维动态图像。两位资历相当的检查者分别运用EchoPac工作站测得所有患者不同测量方法的LVEF与左心室容积。 结果图像清晰组双平面Simpson法与三维全容积法测量的LVEF差异有统计学意义（t=4.224,P<0.01）,而左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）差异均无统计学意义;但图像欠佳组双平面Simpson法与三维全容积法测量的LVEF、LVEDV差异均有统计学意义（t=8.650、6.207,P<0.01）,而LVESV差异无统计学意义。对于图像清晰组,无论采用双平面Simpson法还是三维全容积法,2位检查者间测量的LVEF、LVEDV、LVESV差异均无统计学意义。而对于图像欠佳组,无论采用双平面Simpson法还是三维全容积法,2位检查者间测量的LVEF、LVEDV差异均有统计学意义（t=4.286、3.645、3.308、4.189,P<0.01）,而LVESV差异均无统计学意义;行心脏超声造影后,对于图像欠佳组,无论采用双平面Simpson法还是三维全容积法,2位检查者间测量的LVEF、LVEDV、LVESV差异均无统计学意义。组内相关系数（ICC）显示,图像清晰组、图像欠佳组造影前后双平面Simpson法、三维全容积法测量LVESV的可重复性均较好（ICC=0.901、0.858、0.935、0.920、0.884、0.952）。图像清晰组双平面Simpson法、三维全容积法测量LVEF、LVEDV的可重复性均较好（ICC=0.946、0.895、0.776、0.815）。对于图像欠佳组,双平面Simpson法测量LVEF的可重复性较差（ICC=0.625）,但行心脏超声造影后有明显提高（ICC=0.858）;双平面Simpson法、三维全容积法测量LVEDV的可重复性均较差（ICC=0.630、0.712）,但行心脏超声造影后均有明显改善（ICC=0.863、0.914）。 结论心脏超声造影能明显改善图像显示欠佳的化疗患者LVEF与左心室容积测量的可重复性。     

The corrected left ventricular ejection fraction: a potential new measure of ventricular function

The International Journal of Cardiovascular Imaging - Left ventricular ejection fraction (LVEF) has a limited role in predicting outlook in heart diseases including heart failure. We quantified the...     

Left atrial ejection fraction is an indicator of left ventricular diastolic function

The International Journal of Cardiovascular Imaging - Left atrial ejection fraction (LAEF) has been previously shown to accurately distinguish between patients with and without clearly defined left...