Estimation Of Left Ventricular Function Research Articles

Echocardiography strain: why is it used more and more?

In the last decade, speckle tracking echocardiography (STE) has acquired a fundamental role in the evaluation of the systolic function of the left ventricle, with several advantages over the Doppler method, including angle independence, greater reproducibility, and rapidity of image acquisition. Speckle tracking finds application in various pathologies, ranging from ischaemic heart disease, to cardiomyopathies, to heart failure, both with reduced and preserved ejection fraction (EF), in which the EF is not a reliable prognostic marker and the estimate of left ventricular function by means of 'strain' is of crucial utility. In addition, the strain of the left atrium finds application in many clinical contexts as an early index of diastolic dysfunction and left ventricular filling pressures. Finally, the strain of the right ventricle is of particular prognostic importance in the evaluation of heart failure, particularly in its advanced form, becoming an indispensable index in the evaluation of patients who are candidates for advanced therapeutic strategies. This document aims to describe the various fields of clinical application of STE, with particular emphasis on its diagnostic and prognostic role, so much that it is now integrated into the algorithms for managing multiple pathologies in daily clinical practice.

Biomarkers and heart failure events in patients with atrial fibrillation in the ARISTOTLE trial evaluated by a multi-state model

Atrial fibrillation (AF) and heart failure (HF) often coexist. We investigated the prognostic impact of biomarkers on the development of HF and death in patients with AF and different left ventricular systolic function considering the influence of competing events. The study included 11,818 patients with AF from the ARISTOTLE trial who at entry had information on history of HF, an estimate of left ventricular function and plasma samples for determination of biomarkers representing cardiorenal dysfunction (NT-proBNP, troponin T, cystatin C) and inflammation (GDF-15, IL-6, CRP). Patients were categorized into: (I) HF with reduced ejection fraction (HFrEF, n=2,048), (II) HF with preserved ejection fraction (HFpEF, n=2,520), and (III) No HF (n=7,250). Biomarker associations with HF hospitalization and death were analyzed using a multi-state model accounting also for repeated events. Baseline levels of NT-proBNP, troponin T, cystatin C, GDF-15, IL-6, and CRP were highest in HFrEF and lowest in No HF. During median 1.9 years follow-up, 546 patients were hospitalized at least once for HF and 819 died. Higher levels of all investigated biomarkers were associated with both outcomes (all P< .0001), with highest event rates in HFrEF and lowest in No HF. The associations remained after adjustments and were more pronounced for first than for recurrent events. In anticoagulated patients with AF, biomarkers indicating cardiorenal dysfunction and inflammation improve the identification of patients at risk of developing HF or worsening of already existing HF. These biomarkers might be useful for targeting novel HF therapies in patients with AF.

Automated contouring of non-contrast echocardiograms result in similar estimates of left ventricular function to manually contoured contrast-enhanced images in chemotherapy patients

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Ultromics Ltd Introduction Transthoracic echocardiography (TTE) assessment of left ventricular (LV) function has a central role in early detection and treatment of cancer-therapy related cardiac dysfunction (CTRCD). Contrast TTE is recommended to aid accurate and reproducible LV contouring , but contrast agents are underused and high variability remains. Using machine learning (ML) to automatically contour the LV reduces variability, and may provide comparable clinical benefit to contrast-enhanced TTE. Purpose Retrospective single site study evaluating agreement between LV volumes and function from manually contoured contrast-enhanced TTE and automated contouring of non-contrast enhanced images. Methods Adults at risk of developing CTRCD who underwent TTE were recruited. LV volumes (end-diastolic and systolic; EDV and ESV, respectively) and function (ejection fraction; EF) were measured from contrast-enhanced images using manual contouring (MAN-CONT), and non-contrast enhanced images using automation (AUTO-NON). Method comparisons were summarised based on: (i) statistical equivalence (two one-sided t-tests), (ii) systematic difference between methods, via root mean-squared error (RMSE; Deming regression), and (iii) average bias (Bland-Altman). Statistical equivalence bounds were conservatively determined from reproducibility estimates in a similar cohort (EDV, 20 mL; ESV, 15 mL; EF, 5%; REF1), and used to interpret RMSE and bias. Results The cohort comprised of patients undergoing treatment for breast cancer, lymphoma, and myeloma. Similar body mass indices were seen between groups (median [IQR]: 26.5 [6.7] kg/m2; Kruskall-Wallace test, p = 0.320), but breast cancer patients were younger (55.0 [14.5], 58.5 [23], 60 [9], respectively; p = 0.034). For estimates of LV volumes and function, statistical equivalence, RMSE, and bias are presented in Table1. Average estimates (mean [SD]) of EDV, ESV, and EF were 121 [33] vs. 112 [33] mL, 50 [23] vs. 44 [19] mL, and 60 [9] vs. 61 [8]%, for MAN-CON and AUTO-NON respectively. Comparing between MAN-CON and AUTO-NON in breast cancer patients, all variables were statistically equivalent (Figure1), and while bias was lower than equivalence bounds, RMSE was only lower for EDV and ESV, not EF. For lymphoma patients, estimates of EDV were statistically equivalent, but not EF and ESV. Bias was lower than equivalence bounds for all variables, whereas RMSE was lower for ESV, but not EDV or EF. For myeloma patients, estimates of ESV and EF were statistically equivalent, but not EDV. While bias was lower than equivalence bounds for all variables, RMSE was not lower for any variable. Conclusions: Estimates of LV function from automated contouring of non-contrast TTE are similar to contrast-enhanced TTE (manually contoured), despite poorer image quality. Automated contouring using ML reduces variability, therefore increasing TTE sensitivity, which is critical when clinical management relies on accurate assessment of LV function. Abstract Table1 Abstract Figure1

Non-Invasive Myocardial Infarction Ischemic Area Estimation Through Four-Dimensional Ultrasound

Background/Objective: Following myocardial infarction, infarct size and cardiac function are significant predictors of long-term prognosis. Most echocardiography studies rely on two-dimensional analysis for estimation of left ventricular function and electrical activity analysis for estimation of infarct area. Other imaging modalities, such as cardiac magnetic resonance imaging, are limited by time, cost, availability, patient tolerance, and incompatible implantable devices. Using an experimental mouse model of myocardial infarction, we hypothesize that four-dimensional ultrasound offers a possible alternative for easy, quick, and reliable estimation of infarct size. &#x0D; Methods: A cohort of 10 mice underwent four-dimensional cardiac imaging at baseline using a small animal high frequency ultrasound. A thoracotomy was subsequently performed, and a suture placed to ligate the left coronary artery approximately midway down the left ventricle. Sequential four-dimensional ultrasound was performed at six time points over 28 days, following which the mice were euthanized. The hearts were then removed and sent for embedding and sectioning into seven uniform segments stained using both H&amp;E and Masson’ s Trichrome.&#x0D; Results: Thus far, we have segmented the imaging and collected end diastolic volume, peak systolic volume, stroke volume, ejection fraction, transmural thickness, and circumferential strain. Additionally, four-dimensional models of the left ventricles have been rendered. Histological embedding, sectioning, and staining is still in progress, and therefore validation against the gold standard is still in process.&#x0D; Conclusion and Impact: Treatment and monitoring of myocardial infarction patients is reliant upon accurate assessment of patient status and prognosis. This study provides initial evidence for the validity of four-dimensional ultrasound as a tool for estimation of myocardial infarction size, providing an alternative to current two-dimensional methods that are less accurate and a more accessible alternative to highly specialized and costly equipment. Improved and accessible imaging methods have the potential to enhance patient care, ultimately improving overall health outcomes.

Depressed systemic arterial compliance and impaired left ventricular midwall performance in aortic stenosis with concomitant type 2 diabetes: a retrospective cross-sectional study

BackgroundDegenerative aortic stenosis (AS), a disease of the elderly, frequently coexists with concomitant diseases, including type 2 diabetes (T2DM) which amplifies the cardiovascular (CV) risk. T2DM affects left ventricular (LV) structure and function via hemodynamic and metabolic factors. In concentric LV geometry, typical for AS, indices of LV midwall mechanics are better estimates of LV function than ejection fraction (EF). Effects of T2DM coexisting with AS on circumferential LV midwall systolic function and large artery properties have not been reported so far. Our aim was to compare characteristics of AS patients with and without T2DM, with a focus on LV midwall systolic function and arterial compliance.MethodsMedical records of 130 electively hospitalized patients with moderate or severe isolated degenerative AS were retrospectively analyzed. Exclusion criteria included clinical instability, atrial fibrillation, coronary artery disease and relevant non-cardiac diseases. From in-hospital echocardiography and blood pressure, we calculated LV midwall fractional shortening (mwFS), circumferential end-systolic LV wall stress (cESS) and valvulo-arterial impedance (Zva), estimates of LV afterload, as well as systemic arterial compliance.ResultsPatients with (n = 50) and without T2DM (n = 80) did not differ in age, AS severity, LV mass and LV diastolic diameter. T2DM patients exhibited elevated cESS (247 ± 105 vs. 209 ± 84 hPa, p = 0.025) and Zva (5.8 ± 2.2 vs. 5.1 ± 1.8 mmHg per mL/m2, p = 0.04), and lower stroke volume index (33 ± 10 vs. 38 ± 12 mL/m2, p = 0.01) and systemic arterial compliance (0.53 ± 0.16 vs. 0.62 ± 0.22 mL/m2 per mmHg, p = 0.01). mwFS (11.9 ± 3.9 vs. 14.1 ± 3.7%, p = 0.001), but not EF (51 ± 14 vs. 54 ± 13%, p = n.s.), was reduced in T2DM. mwFS and cESS were inversely interrelated in patients both with (r = − 0.59, p < 0.001) and without T2DM (r = − 0.53, p < 0.001) By multiple regression, higher cESS (p < 0.001) and T2DM (p = 0.02) were independent predictors of depressed mwFS.ConclusionsIn AS, coexistent T2DM appears associated with reduced systemic arterial compliance and LV dysfunction at the midwall level, corresponding to slightly depressed myocardial contractility.

Learning curve-cumulative summation analysis of visual estimation of left ventricular function in novice practitioners: A STROBE-compliant article.

The aim of the present study was to determine the value of cumulative summation (CUSUM) analysis in assessing the proficiency of novice practitioners in estimating the left ventricular ejection fraction (EF).Seven novice practitioners with no echocardiography experience were recruited in this observational study. Each practitioner assessed EF from echocardiographic video files of 100 cases, one by one, and received feedback and teaching. We obtained a CUSUM score through comparison of the gold standard values of EF and the EF values determined by the practitioners. Then, the practitioners underwent the same test 4 weeks later, except without feedback and teaching, using echocardiographic video files from 100 other cases.The mean number of visual estimation cases required to pass the learning curve (LC)-CUSUM test was 56.3 ± 9.1 (95% CI 47.8–64.7). The LC-CUSUM average of the 7 novice practitioners showed improvement in visual estimation skill, with an average acceptable level achieved after a mean experience of 55 cases. In the test performed after 4 weeks, 5 of the 7 novice practitioners showed significantly good overall agreement. All novice practitioners had a kappa coefficient greater than .8, and significant and almost perfect agreement was observed. All the participants exhibited a percentage of correct answers greater than 81%.We found that the novice practitioners could acquire an acceptable level of skill for estimating EF with short-term, self-learning-focused echocardiographic training.

Cardiac abnormalities in children with thalassemia major: correlation of echocardiographic parameters with serum ferritin levels

Background: Thalassemias are a group of inherited disorders of haemoglobin synthesis, with significant morbidity and mortality. The leading cause of death in transfused thalassemia major children is myocardial haemosiderosis. Echocardiographic estimation of left ventricular function may reveal abnormalities before there is any clinical evidence of cardiac disease. The aim of the study was to determine the magnitude and nature of cardiac involvement in children with thalassemia major with respect to various serum ferritin levels. Methods: A prospective study was done on 30 cases of Thalassemia major attending our tertiary referral centre for a period of two yrs. The relationship of blood transfusion and serum ferritin with the parameters PWT-d, PWT-s, LViedd, LViesd, septal thickness, E/A and ES were studied. Results: Out of 30 patients studied, mean age was 4.02 yrs, mean number of transfusions was 28.97 and mean serum ferritin level was 1475. Mean serum ferritin levels of the patients receiving transfusions were estimated in various groups, ferritin levels were higher (2610 ±115.33) in patients who had received more than 50 transfusions.3 of our patients had features of left ventricular hypertrophy in ECG, rest were normal and none of them had evidence of cardiac arrhythmia. Echo parameters were compared; an increase in LViesd was noted in cases when compared to controls which was statistically significant (0.006). Conclusions: Persistent ferritin levels greater than 2500 mcg/ml and assessment of annual blood requirement can assist in prediction of development of cardiac disease. Thus, regular monitoring for cardiac dysfunction and arrhythmias with annual echocardiogram and ECG is extremely important.

Can Emergency Physicians Accurately Identify Complex Abnormalities on Point-of-Care Echocardiogram?

Prior studies have demonstrated the ability of emergency physicians to accurately perform focused bedside echocardiograms. Focused bedside echocardiography has become a valuable tool in the diagnosis of pericardial effusion, assessment of volume status, estimation of left ventricular function, management of shock and cardiac arrest. In the recent years, there is growing interest among emergency physicians to learn advanced echocardiography. To our knowledge, no prior study has shown that emergency physicians can accurately identify complex abnormalities on echocardiograms.

Evaluation of Left Ventricular Function by Bedside Ultrasound in Acute Toxic Myocarditis

BackgroundMyocarditis can be difficult to diagnose in the Emergency Department (ED) due to the lack of classic symptoms and the wide variation in presentations. Poor cardiac contractility is a common finding in myocarditis and can be evaluated by bedside ultrasound. ObjectiveTo demonstrate the utility of fractional shortening measurements as an estimation of left ventricular function during bedside cardiac ultrasound evaluation in the ED. Case ReportA 54-year-old man presented to the ED complaining of 3 days of chest tightness, palpitations, and dyspnea, as well as persistent abdominal pain and vomiting. An electrocardiogram (ECG) showed sinus tachycardia with presumably new ST-segment elevation and signs of an incomplete right bundle branch block. A bedside echocardiogram was performed by the emergency physician that showed poor left ventricular function by endocardial fractional shortening measurements. On further questioning, the patient revealed that for the past 2 weeks he had been regularly huffing a commercially available compressed air duster. Based on these history and examination findings, the patient was given a presumptive diagnosis of toxic myocarditis. A follow-up echocardiogram approximately 7 weeks later demonstrated resolution of the left ventricular systolic dysfunction and his ECG findings normalized. ConclusionCardiac ultrasound findings of severely reduced global function measured by endocardial fractional shortening were seen in this patient and supported the diagnosis of myocarditis. Endocardial fractional shortening is a useful means of easily evaluating and documenting left ventricular function and can be performed at the bedside in the ED.

Performance of emergency physicians in point-of-care echocardiography following limited training

ObjectivesThe aim of this study was to evaluate if emergency medicine trainees with a short duration of training in echocardiography could perform and interpret bedside-focused echocardiography reliably on emergency department...

Estimation of left ventricular function using a novel acoustic-based device

We examined the feasibility of estimating left ventricular ejection fraction (LVEF) by a novel acoustic-based device [vibration response imaging (VRI); Deep Breeze]. One hundred and forty-one subjects (117 patients and 24 healthy volunteers; age 55 ± 15 years, 82% men) were examined by both VRI and echocardiography. LVEF was determined by echocardiography (echo-LVEF) using the biplane Simpson's method. Low-frequency acoustic signals (10-70 Hz) were recorded by VRI from the left posterior thorax by a matrix of 36 microphones during 8 s of breath holding, and an electrocardiogram was recorded simultaneously. The acoustic signals were processed digitally, and an algorithm designed to estimate LVEF was developed (VRI-LVEF), based on a combination of multiple acoustic (systolic and diastolic acoustic signals, beat-to-beat variability of acoustic signals and propagation of acoustic signals throughout the matrix), electrocardiographic and clinical parameters. Mean echo-LVEF was 51 ± 15% (range, 11-76%). Echo-LVEF was reduced (< 50%) in 55 subjects (39%) and severely reduced (< 35%) in 28 subjects (20%). VRI-LVEF calculated by a multivariate algorithm correlated significantly with echo-LVEF (R(2) = 0·59; P < 0·001). VRI-LVEF accurately predicted the presence of reduced (< 50%) or severely reduced (< 35%) echo-LVEF, with sensitivities of 84% and 82%, specificities of 86% and 91%, positive predictive values of 79% and 70% and negative predictive values of 89% and 95%, respectively. LVEF can be estimated using a novel acoustic-based device. This device may assist in triage of patients according to LVEF prior to definitive assessment of LVEF by echocardiography.

Semiautomatic quantification of left and right ventricular function in cardiac magnetic resonance imaging: A preliminary study

ObjectivesThe aim of this study was to compare a semiautomatic segmentation method to quantify the function of both ventricles in magnetic resonance imaging (MRI) with the manual tracing method. Material and methodsWe examined 17 patients with diverse cardiovascular diseases on a 1.5 Tesla MRI unit (Magnetom Symphony Quantum; Siemens Medical Systems, Erlangen, Germany) using the following parameters: maximum gradient, 30 mT/m; and slew rate, 125 T/m/s. In all studies, we acquired images in cine mode in the short axis (SSFP, 6mm slice thickness, from the base to the ventricular apex) with breath holding. To reduce the user interaction, we used only one image per patient to initiate the semiautomatic method. The semiautomatic method was based on a specifically designed algorithm of regional growth and border detection. We quantified the end-diastolic volume (EDV), end-systolic volume (ESV), and the ejection fraction (EF) for both ventricles in all patients. ResultsNo significant differences between the two segmentation techniques were found in the quantification of either ventricle (p>0.05). The difference in the volumes, although nearly significant, are clinically irrelevant. The correlation for the estimation of left ventricular function was excellent (r>0.9), and the correlation for the estimation of right ventricular function was good (r>0.7). ConclusionsOur semiautomatic segmentation method enables the function of both ventricles to be quantified as accurately as the conventional method.

Cuantificación semiautomática de la función ventricular izquierda y derecha en resonancia magnética cardíaca. Estudio preliminar

Objectives The aim of this study was to compare a semiautomatic segmentation method to quantify the function of both ventricles in magnetic resonance imaging (MRI) with the manual tracing method. Material and methods We examined 17 patients with diverse cardiovascular diseases on a 1.5 Tesla MRI unit (Magnetom Symphony Quantum; Siemens Medical Systems, Erlangen, Germany) using the following parameters: maximum gradient, 30 mT/m; and slew rate, 125 T/m/s. In all studies, we acquired images in cine mode in the short axis (SSFP, 6 mm slice thickness, from the base to the ventricular apex) with breath holding. To reduce the user interaction, we used only one image per patient to initiate the semiautomatic method. The semiautomatic method was based on a specifically designed algorithm of regional growth and border detection. We quantified the end-diastolic volume (EDV), end-systolic volume (ESV), and the ejection fraction (EF) for both ventricles in all patients. Results No significant differences between the two segmentation techniques were found in the quantification of either ventricle (p > 0.05). The difference in the volumes, although nearly significant, are clinically irrelevant. The correlation for the estimation of left ventricular function was excellent (r > 0.9), and the correlation for the estimation of right ventricular function was good (r > 0.7). Conclusions Our semiautomatic segmentation method enables the function of both ventricles to be quantified as accurately as the conventional method.

Tissue Doppler imaging describes diastolic function in men prone to develop hypertension over twenty years

Hypertension is one of several risk factors of cardiovascular disease and is associated with left ventricular (LV) systolic and diastolic dysfunction. A method for reliably detecting the onset of LV dysfunction before transition to irreversible damage of the myocardium would be of crucial importance in subjects with essential hypertension. Subjects with clear differences in BP level, development and duration of the hypertensive disease were examined at the age of 60 yrs: normotensives (n = 17), new hypertensives who developed hypertension over a 20 year period (n = 15) and hypertensives (n = 19). Relationships between conventional echocardiographic and tissue velocities imaging (TVI) parameters compared to LV parameters, and TVI as an estimate of LV function were explored. E'(Lat) (TVI peak early diastolic velocity) (P = 0.006) and E/E'(Lat) (P = 0.002) demonstrated differences in diastolic function between the groups. There were no significant differences regarding systolic myocardial velocities. E'(Lat) correlated to S'(Lat) (TDI peak systolic velocity) (r = 0.32, P = 0.026) and was independently predicted by S'(Lat) (R(2) = 0.24, P = 0.025) in multivariate analysis. E'(Lat) correlated negatively to LV mass index (r = -0.34, P = 0.012), also in multivariate regression analysis (R(2) = 0.12, P = 0.032). Myocardial diastolic velocities and mitral flow to annulus velocity ratio differentiated LV function between the hypertensive and normotensive groups. The parameters probably reflect changes in relaxation, recoil and contraction and parallel changes in LV mass index.

Comparing Cardiac Ejection Fraction Estimation Algorithms Without a Gold Standard

Imaging and estimation of left ventricular function have major diagnostic and prognostic importance in patients with coronary artery disease. It is vital that the method used to estimate cardiac ejection fraction (EF) allows the observer to best perform this task. To measure task-based performance, one must clearly define the task in question, the observer performing the task, and the patient population being imaged. In this report, the task is to accurately and precisely measure cardiac EF, and the observers are human-assisted computer algorithms that analyze the images and estimate cardiac EF. It is very difficult to measure the performance of an observer by using clinical data because estimation tasks typically lack a gold standard. A solution to this "no-gold-standard" problem recently was proposed, called regression without truth (RWT). Results of three different software packages used to analyze gated, cardiac, and nuclear medicine images, each of which uses a different algorithm to estimate a patient's cardiac EF, are compared. The three methods are the Emory method, Quantitative Gated Single-Photon Emission Computed Tomographic method, and the Wackers-Liu Circumferential Quantification method. The same set of images is used as input to each of the three algorithms. Data were analyzed from the three different algorithms by using RWT to determine which produces the best estimates of cardiac EF in terms of accuracy and precision. In performing this study, three different consistency checks were developed to ensure that the RWT method is working properly. The Emory method of estimating EF slightly outperformed the other two methods. In addition, the RWT method passed all three consistency checks, garnering confidence in the method and its application to clinical data.

Effect of temporal resolution on the estimation of left ventricular function by cardiac MR imaging

The aim of this study was to investigate the effect of temporal resolution on the estimation of left ventricular (LV) function by cardiac magnetic resonance (MR) imaging using a steady-state free precession (SSFP) sequence. Left ventricular function was assessed by cine MR imaging using a segmented SSFP sequence in 10 healthy volunteers. Views per segment (VPS) were set at 8 and 20, resulting in high and low true temporal resolution, respectively. Irrespective of VPS, images were reconstructed at 40 cardiac phases, providing high apparent temporal resolution. Data were analyzed using 40, 20 and 10 phases to simulate different apparent temporal resolutions. Increasing the cardiac phases used for analysis slightly decreased mean end-systolic volume (ESV) and slightly increased mean ejection fraction (EF). No substantial difference in estimates of end-diastolic volume (EDV) was found between VPSs of 8 and 20. Imaging with a VPS of 20 yielded a larger ESV and smaller EF than imaging with a VPS of 8 when 40 phases were used. In conclusion, low true temporal resolution causes overestimation of ESV and underestimation of EF. Improvement of apparent temporal resolution mildly reduces but does not eliminate the errors caused by low true temporal resolution.

Impact of gender on risk stratification by exercise and dobutamine stress echocardiography: long-term mortality in 4234 women and 6898 men

Prior research is limited with regard to the diagnostic and prognostic accuracy of commonplace cardiac imaging modalities in women. The aim of this study was to examine 5-year mortality in 4234 women and 6898 men undergoing exercise or dobutamine stress echocardiography at three hospitals. Univariable and multivariable Cox proportional hazards models were used to estimate time to cardiac death in this multi-centre, observational registry. Of the 11 132 patients, women had a greater frequency of cardiac risk factors (P<0.0001). However, men more often had a history of coronary disease including a greater frequency of echocardiographic wall motion abnormalities (P<0.0001). During 5 years of follow-up, 103 women and 226 men died from ischaemic heart disease (P<0.0001). Echocardiographic estimates of left ventricular function (P<0.0001) and the extent of ischaemic wall motion abnormalities (P<0.0001) were highly predictive of cardiac death. Risk-adjusted 5-year survival was 99.4, 97.6, and 95% for exercising women with no, single, and multi-vessel ischaemia (P<0.0001). For women undergoing dobutamine stress, 5-year survival was 95, 89, and 86.6% for those with 0, 1, and 2-3 vessel ischaemia (P<0.0001). Exercising men had a 2.0-fold higher risk at every level of worsening ischaemia (P<0.0001). Significantly worsening cardiac survival was noted for the 1568 men undergoing dobutamine stress echocardiography (P<0.0001); no ischaemia was associated with 92% 5-year survival as compared with death rates of >/=16% for men with ischaemia on dobutamine stress echocardiography (P<0.0001). Echocardiographic measures of inducible wall motion abnormalities and global and regional left ventricular function are highly predictive of long-term outcome for women and men alike.

Accuracy of emergency physician–directed focused echocardiography in the evaluation of the critically III pediatric patient

Study objectives: Echocardiography can be a rapid, noninvasive, objective tool in the assessment of ventricular function and preload during resuscitation of a critically ill or injured child. We seek to determine the accuracy of bedside limited echocardiography by the emergency physician (BLEEP) in estimation of left ventricular function (LVF) and inferior vena cava (IVC) volume as an indirect measure of preload. Methods: We conducted a prospective observational study of a convenience sample of patients admitted to our ICU. A single emergency physician investigator performed all BLEEP examinations using a Sonosite Titan ultrasonographic machine with a variable frequency convex probe. All patients underwent an independent formal echocardiogram by an experienced pediatric echocardiography provider within 60 minutes of the BLEEP examination. IVC volume was assessed by measurement of the maximal diameter of the IVC just caudad to the hepatic vein confluence on the subxiphoid transverse view. LVF was determined by calculating the shortening fraction using M mode measurements on the parasternal short axis view at the level of the papillary muscle. An independent blinded pediatric cardiologist reviewed all images for accuracy and quality. Estimates of shortening fraction obtained on the BLEEP examination were compared with those obtained by the pediatric echocardiography provider. Concordance or agreement between the emergency physician and pediatric echocardiography provider for the measurement of the shortening fraction and IVC diameter was determined using the Pearson correlation coefficient. A P value less than .05 was considered statistically significant. Paired t test was used to compare the magnitude of the difference in measurement of the shortening fraction and IVC by the emergency physician and pediatric echocardiography provider. The proportion of images obtained by the emergency physician (2-dimensional image, M mode, and IVC) that were assessed to be of quality by the cardiologist was determined. A comparison between the proportions of unacceptable images between the groups was estimated using the McNemar test. Results: Thirty-one patients were enrolled. The mean age was 5.1 years (range 23 days to 16 years); 48.4% (15/31) were female patients; 58.1% (18/31) were on mechanical ventilatory support at their study. There was good agreement between the emergency physician and the pediatric echocardiography provider for estimation of shortening fraction ( r =0.78, P P =.003). Similarly, there was good agreement between the emergency physician and pediatric echocardiography provider for estimation of IVC volume ( r =0.8, P P =.14). All the parasternal short axis 2-dimensional images obtained by the emergency physician were of acceptable or higher quality. The proportion of M mode and IVC images that were of quality was 9.6% (3/31) and 3.2% (1/31), respectively. This difference in proportions was not statistically significant ( P =.32). Conclusion: Our study suggests that pediatric emergency physician sonographers are capable of obtaining images that permit accurate assessment of LVF and IVC volume. BLEEP can be performed with focused training and oversight by a pediatric cardiologist.

Anesthetic myocardial protection with sevoflurane

Objective: To examine the role of sevoflurane in myocardial protection in patients undergoing coronary artery bypass graft (CABG) surgery. Design: Prospective, randomized, controlled, double-blinded study. Setting: Veterans Administration Medical Center (VAMC), Buffalo, New York. Subjects: Twenty-one patients undergoing CABG were included in the study. Eleven patients were randomized to receive sevoflurane, and 10 patients served as controls. Intervention: Total intravenous anesthesia was provided for both study and control groups by infusion of propofol, fentanyl, and midazolam. Sevoflurane 2% was added to the cardioplegia solution in the experimental group. Measurements and Main Results: Neutrophil beta-integrins (CD11b/CD18), tumor necrosis factor α (TNF-α), and interleukin (IL)-6 were measured as indicators of the inflammatory response to myocardial ischemia-reperfusion injury. Blood samples were obtained from the aorta and coronary sinus before (T1) and immediately after cardiopulmonary bypass (CPB) (T2) and, in addition, from a peripheral artery 6 hours (T3) after CPB. Myocardial function was determined in all patients at each time point. Left ventricular stroke work index (LVSWI) was calculated as an estimation of left ventricular function. Left ventricular regional wall motion abnormality (RWMA) was assessed by transesophageal echocardiography at T1 and T2 time points. TNF-α was detectable only in the control group in arterial samples at T3. IL-6 levels (pg/mL) were found to be lower in the sevoflurane group compared with controls at T2 arterial circulation (38.2 ± 21.1 v 60.6 ± 19.1, p < 0.05) as well as in the coronary circulation (38.4 ± 19.9 v 118.2 ± 23.5, p < 0.01) at T2. CD11b/CD18 increased 79% after CPB in the control group while only increasing 36% in the sevoflurane group ( p < 0.05). The post-CPB LVSWI was back to its baseline values in the sevoflurane group, whereas it was still significantly depressed in the control group. Eight of 10 patients in the control group showed a transient new-onset RWMA in either the septal or anteroseptal regions. Only 2 of 11 patients in the sevoflurane group showed transient RWMA of the LV. Conclusions: Sevoflurane decreases the inflammatory response after CPB, as measured by the release of IL-6, CD11b/CD18, and TNF-α. Myocardial function after CPB, as assessed by RWMA and LVSWI, was also improved with sevoflurane. The role of sevoflurane in myocardial protection and the inflammatory response to myocardial reperfusion should be considered.

Bestimmung linksventrikulärer Funktionsparameter mittels EKG-gesteuerter Mehrschicht-Computertomographie im Vergleich mit der invasiven Ventrikulographie

To evaluate the accuracy of left ventricular function using a multidetector CT (MDCT) with retrospective ECG-gating and to compare the results with conventional ventriculography. In 26 patients, retrospectively ECG-gated MDCT of the heart (Volume Zoom, Siemens, Germany) as well as conventional coronary angiography including ventriculography was performed to exclude or follow coronary artery disease. CT examination (120 KV, 400 mAs) was carried out with 4 x 1 mm collimation (500 ms gantry rotation time). For CT angiography, 150 ml of contrast media was injected intravenously at a flow rate of 4 ml/s. All data sets of the functional cardiac parameters were reconstructed in end-systolic and end-diastolic phase. End-systolic volume (ESV), end-diastolic volume (EDV) and ejection fraction (EF) were determined from multiplanar reformations orthogonally through the cardiac short axis and analyzed using special evaluation software (ARGUS, Siemens). The results were compared with ESV, EDV and EF obtained from invasive ventriculography. In all cases, a sufficient quality of the MDCT images was achieved. EDV (150.1 +/- 16.2 ml MDCT vs. 138.7 +/- 16.9 ml ventriculography; mean difference 11.4 +/- 12.7 ml; r = 0.51) had an acceptable correlation to conventional ventriculography, and ESV (58.1 +/- 14.6 ml vs. 50.2 +/- 13.4 ml; mean difference 7.9 +/- 8.8 ml; r = 0.81) and EF (60.9 +/- 13.6 % vs. 64.9 +/- 12.7 %; mean difference 4.0 +/- 6.2 %; r = 0.79) showed a good correlation. In comparison with invasive ventriculography, MDCT tended to overestimate significantly EDV (p = 0.008) and ESV (p = 0.003) and to underestimate EF (p = 0.001). MDCT of the heart with retrospective ECG-gating enables efficient estimation of left ventricular function, providing important additional information of non-invasive cardiac imaging using MDCT. However, EDV and EVS were significantly overestimated and EF was underestimated in MDCT compared to ventriculography.