Estimation Of Ejection Fraction Research Articles

Letter by Nagueh et al Regarding Article, “Tissue Doppler Imaging in the Estimation of Intracardiac Filling Pressure in Decompensated Patients With Advanced Systolic Heart Failure”

To the Editor: We read with interest the article by Mullens et al,1 which reported that, in patients with decompensated systolic heart failure, the early transmitral velocity to tissue Doppler mitral annular early diastolic velocity (E/Ea) ratio may not be reliable in predicting filling pressures, especially in patients with larger left ventricular volumes, lower cardiac indices, and cardiac resynchronization therapy pacing. We want to express caution in interpreting these results because they contradict abundant data previously published and validated.2 Our concern is that the conclusions proffered may convey the wrong message about the use of E/Ea as a noninvasive estimate of filling pressures in patients with heart failure and left ventricular systolic dysfunction, in whom the ratio generally works well. The first major issue is the composition of …

Echocardiographic validation of the layer of maximum count method in the estimation of the left ventricular EF using gated myocardial perfusion SPECT: correlation with QGS, ECTb, and LVGTF

Quantitative gated single-photon emission computed tomography (SPECT) (QGS), Emory Cardiac toolbox (ECTb), layer of maximum count (LMC), and left ventricular global thickening fraction (LVGTF) are four different methods designed to estimate the LV ejection fraction (EF). The third method (LMC) is relatively new and achieved good results in preliminary investigations. Thus, the objective of the study was to further assess the performance of the LMC versus two-dimensional echocardiography in the estimation of the LVEF in comparison with other methods. Data for 38 patients were analyzed retrospectively (27 males) with a mean age of 51+/-10 years. All patients underwent gated myocardial perfusion gated SPECT and two-dimensional echocardiography. EF estimated by the four methods and echocardiography were recorded and analyzed with paired t-test, Pearson's correlation coefficient, analysis of variance, and Bland-Altman plot. The mean EF by echocardiography was significantly higher than QGS and LMC (P<0.0001 and P = 0.003, respectively), whereas it was significantly lower than ECTb and LVGTF methods (P = 0.02 and 0.001, respectively). QGS, ECTb, and LMC correlated significantly in the measurements of the EF with echocardiography (r = 0.844, 0.825, and 0.700, respectively); however, a lower correlation was found between LVGTF and echocardiography (r = 0.595). The agreement limits were (-7.6, 16.1) and (10.5, -15.7) for QGS and ECTb, respectively, whereas it was (-11.6, 19.6) and (-27.9, 15.7) for LMC and LVGTF, respectively. Pair-wise comparison has shown that the EF calculated by QGS was significantly lower than ECTb (P = 0.009) and LVGTF (P<0.0001), whereas it was not different from LMC (P = 0.928). For ECTb, the EF was significantly higher than LMC (P = 0.011), but was not different from LVGTF method (P = 0.173). Further, the EF by LMC was significantly lower than LVGTF method (P<0.0001). The quantitative gated SPECT methods showed a significant correlation with echocardiography in the calculation of the EF. LMC method showed close results to those obtained by QGS and ECTb with similar variability versus the measurements made by echocardiography. This study has investigated the utility of using LMC method in clinical practice; however, it will be more feasible when it becomes independent and extensively validated with other accurate techniques and in different patient conditions.

Optimal phase for coronary interpretations and correlation of ejection fraction using late-diastole and end-diastole imaging in cardiac computed tomography angiography: implications for prospective triggering

A typical acquisition protocol for multi-row detector computed tomography (MDCT) angiography is to obtain all phases of the cardiac cycle, allowing calculation of ejection fraction (EF) simultaneously with plaque burden. New MDCT protocols scanner, designed to reduce radiation, use prospectively acquired ECG gated image acquisition to obtain images at certain specific phases of the cardiac cycle with least coronary artery motion. These protocols do not we allow acquisition of functional data which involves measurement of ejection fraction requiring end-systolic and end-diastolic phases. We aimed to quantitatively identify the cardiac cycle phase that produced the optimal images as well as aimed to evaluate, if obtaining only 35% (end-systole) and 75% (as a surrogate for end-diastole) would be similar to obtaining the full cardiac cycle and calculating end diastolic volumes (EDV) and EF from the 35th and 95th percentile images. 1,085 patients with no history of coronary artery disease were included; 10 images separated by 10% of R–R interval were retrospectively constructed. Images with motion in the mid portion of RCA were graded from 1 to 3; with ‘1’ being no motion, ‘2’ if 0 to <1 mm motion, and ‘3’ if there is >1 mm motion and/or non-interpretable study. In a subgroup of 216 patients with EF > 50%, we measured left ventricular (LV) volumes in the 10 phases, and used those obtained during 25, 35, 75 and 95% phase to calculate the EF for each patient. The average heart rate (HR) for our patient group was 56.5 ± 8.4 (range 33–140). The distribution of image quality at all heart rates was 958 (88.3%) in Grade 1, 113 (10.42%) in Grade 2 and 14 (1.29%) in Grade 3 images. The area under the curve for optimum image quality (Grade 1 or 2) in patients with HR > 60 bpm for phase 75% was 0.77 ± 0.04 [95% CI: 0.61–0.87], while for similar heart rates the area under the curve for phases 75 + 65 + 55 + 45% combined was 0.92 ± 0.02. LV volume at 75% phase was strongly correlated with EDV (LV volume at 95% phase) (r = 0.970, P < 0.001). There was also a strong correlation between LVEF (75_35) and LVEF (95_35) (r = 0.93, P < 0.001). Subsequently, we developed a formula to correct for the decrement in LVEF using 35–75% phase: LVEF (95_35) = 0.783 × LVEF (75_35) + 20.68; adjusted R2 = 0.874, P < 0.001. Using 64 MDCT scanners, in order to acquire >90% interpretable studies, if HR < 60 bpm 75% phase of RR interval provides optimal images; while for HR > 60 analysis of images in 4 phases (75, 35, 45 and 55%) is needed. Our data demonstrates that LVEF can be predicted with reasonable accuracy by using data acquired in phases 35 and 75% of the R–R interval. Future prospective acquisition that obtains two phases (35 and 75%) will allow for motion free images of the coronary arteries and EF estimates in over 90% of patients.

Left ventricular apical cystic thrombus mimicking a hydatid cyst

A 69-year-old man was admitted to the emergency department with dyspnea. His medical history was remarkable for smoking (75 pack-years), chronic obstructive pulmonary disease and ischemic cardiomyopathy. On physical examination, his blood pressure was 100/80 mmHg, his pulse rate was 104 beats/min and he had bilateral moderate pretibial edema. Cardiac auscultation revealed a 2/6 systolic murmur at the apex with distant heart sounds. Auscultation of the lungs revealed bilateral rales with diffuse rhonchi in the lower lobes. On a 12-lead electrocardiogram, poor progression of the pre-cordial R wave and P mitrale were noticed. Two-dimensional echocardiography displayed diffuse left ventricular hypokinesia with an estimated ejection fraction of 15%. A cystic thrombus that did not have a germinative membrane was found at the apex of the left ventricle (Figure 1). Pulmonary computed tomography angiography showed a filling defect in the left ventricle. Tests for Echinococcus granulosus were negative. Heparin, warfarin and heart failure treatment were started. One week later, echocardiography showed that the size of the thrombus had decreased by 25%. The patient did not have any complication related to the thrombus. Figure 1) Left ventricular apical cystic thrombus Left ventricular thrombus is a common complication of severe heart failure. Therapeutic options for such thrombi include anti-thrombotics, anticoagulant therapy, thrombolysis or surgical removal of the thrombus. Clinicians should also consider hydatid cysts in the differential diagnosis, when history and laboratory tests could be used to confirm the diagnosis. But overall, until the diagnosis is established, treatment should also be initiated for a probable diagnosis of thrombus (1,2).

An Australian risk prediction model for 30-day mortality after isolated coronary artery bypass: The AusSCORE

Our objective was to identify risk factors associated with 30-day mortality after isolated coronary artery bypass grafting in the Australian context and to develop a preoperative model for 30-day mortality risk prediction. Preoperative risk associated with cardiac surgery can be ascertained through a variety of risk prediction models, none of which is specific to the Australian population. Recently, it was shown that the widely used EuroSCORE model validated poorly for an Australian cohort. Hence, a valid model is required to appropriately guide surgeons and patients in assessing preoperative risk. Data from the Australasian Society of Cardiac and Thoracic Surgeons database project was used. All patients undergoing isolated coronary artery bypass grafting between July 2001 and June 2005 were included for analysis. The data were divided into creation and validation sets. The data in the creation set was used to develop the model and then the model was validated in the validation set. Preoperative variables with a P value of less than .25 in chi(2) analysis were entered into multiple logistic regression analysis to develop a preoperative predictive model. Bootstrap and backward elimination methods were used to identify variables that are truly independent predictors of mortality, and 6 candidate models were identified. The Akaike Information Criteria (AIC) and prediction mean square error were used to select the final model (AusSCORE) from this group of candidate models. The AusSCORE model was then validated by average receiver operating characteristic, the P value for the Hosmer-Lemeshow goodness-of-fit test, and prediction mean square error obtained from n-fold validation. Over the 4-year period, 11,823 patients underwent cardiac surgery, of whom 65.9% (7709) had isolated coronary bypass procedures. The 30-day mortality rate for this group was 1.74% (134/7709). Factors selected as independent predictors in the preoperative isolated coronary bypass AusSCORE model were as follows: age, New York Heart Association class, ejection fraction estimate, urgency of procedure, previous cardiac surgery, hypercholesterolemia (lipid-lowering treatment), peripheral vascular disease, and cardiogenic shock. The average area under the receiver operating characteristic was 0.834, the P value for the Hosmer-Lemeshow chi(2) test statistic was 0.2415, and the prediction mean square error was 0.01869. We have developed a preoperative 30-day mortality risk prediction model for isolated coronary artery bypass grafting for the Australian cohort.

Transverse strain predicts exercise capacity in systemic right ventricle patients

Because transposition of great arteries (TGA) patients who underwent atrial switch repair (AS) remain asymptomatic for decades before development of symptomatic heart failure, there may be some clinical value to preclinical detection of ventricular dysfunction. Detection of systemic right ventricular (RV) dysfunction in patients who are asymptomatic may prompt early initiation of heart failure therapy and more frequent clinical follow-up. The objective of this study was to characterize longitudinal and transverse systolic function of the systemic RV using two-dimensional (2D) strain in patients with TGA after AS repair and to correlate these parameters with their exercise capacity. The study population consisted of 26 patients (20±6 years) with TGA after AS operation. Conventional echocardiography and bidimensional strain were performed on consecutive patients reporting to the out patient congenital heart disease clinic. Twenty-four healthy, age-matched individuals were used as control subjects. Analysis was performed on the non-systemic RVs of the control group. All the studied patients underwent treadmill exercise testing according to the Bruce II protocol. RV longitudinal 2D-strain in controls showed a base to apex gradient, while in patients was homogeneously reduced. Also RV transverse strain (i.e the radial deformation assessed by the apical 4 chamber view) showed a base to apex gradient in controls, while in patients was significantly increased in the mid and apical segments. In the systemic RV free wall, transverse strain was greater than longitudinal strain (p<0.0001), opposite from findings in the normal RV free wall (p: NS). Of interest, in AS-TGA patients we found a strong correlation between RV transverse 2D strain and exercise capacity (p<0.0001; R: 0.80). At multivariate analysis (including age, degree of tricuspid regurgitation, TAPSE, RV area fractional change, RV visually estimated ejection fraction, RV global longitudinal strain and RV global transverse strain) the best predictor of exercise capacity in AS-TGA patients was transverse 2D strain (p<0.0001). In AS-TGA patients there is a shift from a predominant longitudinal shortening to a predominant transverse thickening. The transverse thickening assessed by 2D transverse strain is correlated to exercise capacity of these patients. In the follow up of AS-TGA patients the monitoring of RV transverse myocardial deformation properties should be considered more than the simple evaluation of RV longitudinal function.

Factors affecting the measurement of left ventricular ejection fraction in myocardial perfusion imaging

Estimation of the left ventricular ejection fraction (LVEF) using myocardial perfusion imaging is increasingly used in the evaluation of coronary artery disease. This study aims to compare the effect of (i) two commercially available software packages: quantitative gated single-photon emission computed tomography (SPECT) (QGS) and 4DM-SPECT, and (ii) prereconstruction filtering, on LVEF quantification. Images from 101 patients were reconstructed using AutoCardiac and processed using QGS and 4DM-SPECT. Filtering was performed before reconstruction using Hermes FBP SPET on a group of 32 consecutive patients using Butterworth filters (orders 5 and 10; cut-off frequency 0.5-1.2 cycles/cm). Good correlation was observed between QGS and 4DM-SPECT (r=0.88), with an average difference of 2.1%. The difference in LVEF between the two packages ranged from 21 to -28%. The LVEF was overestimated at cut-off frequencies < or = 0.8 cycles/cm compared with higher cut-off frequencies in 26 of 30 (87%) patients. There was a clinically significant difference between the LVEF calculated by QGS and 4DM-SPECT and consequently the two packages should not be used interchangeably. The effect of cut-off frequency on LVEF estimation was found to be very patient specific. Changing the cut-off frequency by as little as 0.1 cycles/cm can cause clinically significant differences in LVEF estimation.

Localization and Segmentation of Left Ventricle in Cardiac Cine-MR Images

Accurate delineation of the left ventricular myocardial boundaries on cardiac cine magnetic resonance (MR) images is essential for volumetric and functional cardiac analysis. Automated myocardial contour delineation often suffers from misalignment of slices, nonuniform coil sensitivity, blood-flow-related inter- and intraslice intensity inhomogeneities, blurring due to motion, partial voluming, and a need to circumscribe the papillary muscles and the trabeculae. In this paper, we propose a novel method for data-driven localization and segmentation of the left ventricle in the cine-MR images toward automated computation of ejection fraction (EF). Our hybrid segmentation method combines intensity- and texture-based fuzzy affinity maps obtained from a novel multiclass, multifeature fuzzy connectedness method with dynamic-programming-based boundary detection to delineate the myocardial contours. Bland-Altman analysis indicates that the mean biases of the end-diastolic volume, end-systolic volume, and EF estimates of our method are comparable to the interobserver variability when compared with the annotations from two experts.

Assessment of left ventricular function with single breath-hold highly accelerated cine MRI combined with guide-point modeling

Purpose To prospectively assess the performance of highly accelerated cine MRI in multi-orientations combined with a new guide-point modeling post-processing technique (GPM approach) for assessment of left ventricular (LV) function compared to the standard summation of slices method based on a stack of short axis views (SoS approach). Materials and methods 33 consecutive patients were examined on a 1.5 T scanner with a standard steady state free precession (SSFP) sequence (TR, 3.0 ms; TE, 1.5 m; flip angle (FA), 60°; acceleration factor (AF), 2) analyzed with the SoS method and a highly accelerated, single breath-hold temporal parallel acquisition SSFP sequence (TR, 4.6 ms; TE, 1.1 ms; AF, 3) post-processed with the GPM method. LV function values were measured by two independent readers with different experience in cardiac MRI and compared by using the paired t-test and F-test. Inter- and intraobserver agreements were calculated using Bland–Altman-Plots. Results Mean acquisition and post-processing time was significantly shorter with the GPM approach (15 s/3 min versus 360 s/6 min). For all LV function parameters interobserver agreement between the experienced and non-experienced reader was significantly improved when the GPM approach was used. However, end-diastolic and end-systolic volumes were larger for the GPM technique when compared to the SoS method ( P < 0.001), whereas ejection fraction estimation yielded equivalent results ( P > 0.121). In both readers and for all parameters variances did not differ significantly ( P ≥ 0.409) and the two approaches showed an excellent linear correlation ( r > 0.951). Conclusion Due to its accurate, fast and reproducible assessment of LV function parameters highly accelerated MRI combined with the GPM technique may become the technique of first choice for assessment of LV function in clinical routine.

Impact of Contrast Echocardiography on Evaluation of Ventricular Function and Clinical Management in a Large Prospective Cohort

The aim of this study was to evaluate the impact of echocardiographic contrast utilization on patient diagnosis and management. Contrast echocardiography (CE) has improved visualization of endocardial borders. However, its impact on patient management has not been evaluated previously. We prospectively enrolled 632 consecutive patients with technically difficult echocardiographic studies who received intravenous contrast (Definity, Lantheus Medical Imaging, Billerica, Massachusetts). Quality of studies, number of left ventricular (LV) segments visualized, estimated ejection fraction, presence of apical thrombus, and management decisions were compared before and after contrast. After CE, the percent of uninterpretable studies decreased from 11.7% to 0.3% and technically difficult studies decreased from 86.7% to 9.8% (p < 0.0001). Before contrast, 11.6 +/- 3.3 of 17 LV segments were seen, which improved after CE to 16.8 +/- 1.1 (p < 0.0001). An LV thrombus was suspected in 35 patients and was definite in 3 patients before CE. After contrast, only 1 patient had a suspected thrombus, and 5 additional patients with thrombus were identified (p < 0.0001). A significant impact of CE on management was observed: additional diagnostic procedures were avoided in 32.8% of patients and drug management was altered in 10.4%, with a total impact (procedures avoided, change in drugs, or both) observed in 35.6% of patients. The impact of contrast increased with worsening quality of nonenhanced study, the highest being in intensive care units. A cost-benefit analysis showed a significant savings using contrast ($122/patient). The utilization of CE in technically difficult cases improves endocardial visualization and impacts cardiac diagnosis, resource utilization, and patient management.

Determination of Regional Ejection Fraction in Patients with Myocardial Infarction by Using Merged Late Gadolinium Enhancement and Cine MR: Feasibility Study

To quantify regional ejection fraction (EF) in patients with myocardial infarction (MI) by using merged late gadolinium enhancement (LGE) and cine magnetic resonance (MR) imaging, and compare this method with the standardized 17-segment American Heart Association approach. After institutional review board approval and informed consent, 15 MI patients (14 men, one woman; mean age, 63 years +/- 10 [standard deviation]) were studied at 1 week and at 4 months after MI. Short-axis LGE MR information was used to quantify infarct size, and to divide the left ventricle (LV) on short-axis cine MR images in infarct, periinfarct, and remote regions by using a fixed-center method, yielding information on regional volumes, regional EFs, systolic wall thickening (SWT), and systolic wall motion (SWM). This approach was compared with a floating-center approach and the 17-segment approach. Mean infarct size (normalized to LV mass) was 25% +/- 14 at 1 week and 16% +/- 8 at 4 months (P < .001). At 4 months, LV EF significantly improved (mean, 47.9% +/- 5.9 vs 50.9% +/- 6.6, P = .031), matching an improvement of regional EF (mean, 17.1% +/- 11.5 vs 24.6% +/- 13.1, P = .005) and SWM (mean, 3.2 mm +/- 1.7 vs 3.9 mm +/- 2.1, P = .027) in the infarcted myocardium. No significant changes in regional EF, SWT, or SWM occurred in the remote myocardium. Regional EF estimates correlated well with SWT and SWM (both r = 0.92, P < .001). The floating-center method invariably underestimated regional EF (mean, -20.8% +/- 7.6; 95% confidence interval: -23.7%, -17.9%), especially with increasing infarct size. By using the 17-segment approach, no functional improvement was shown in the infarcted myocardium. Assessment of regional ventricular performance (regional EF) in well-defined areas (eg, infarcted and remote myocardium) is feasible by using merged LGE and cine MR imaging.

Síndrome de Tako-Tsubo em decorrência de bloqueio neuromuscular residual: relato de caso

Tako-Tsubo syndrome is a rare postoperative complication with a 5% mortality rate. The objective of this report was to present residual neuromuscular blockade as a trigger for this syndrome, discuss this disorder, and call attention to the risks of residual neuromuscular blockade.A 61-year old female, physical status ASA I, who underwent general anesthesia associated with paravertebral cervical block for arthroscopic repair of a rotator cuff lesion. Physical exam after extubation detected residual neuromuscular blockade. In the post-anesthetic care unit the patient developed somnolence, tachycardia, hypertension, and severe respiratory acidosis. After reintubation the patient evolved for cardiac arrest with electrical activity without a pulse, which was reverted with the administration of adrenaline and external cardiac massage. In the postoperative period the patient presented elevation of the ST segment, increased troponin, and left ventricular medial-apical akinesia with an estimated ejection fraction of 30%. Cardiac catheterization showed absence of significant atheromatous lesions in the coronary vessels, and severe disruption of the systolic function with inferior and antero-septo-apical akinesia and compensatory basal hypercontractility. The patient had complete functional recovery with the treatment instituted.Residual neuromuscular blockade associated with diaphragmatic paralysis and possible pulmonary atelectasis leading to respiratory failure, hypercapnia, and adrenergic discharge triggered the Tako-Tsubo syndrome with severe clinical repercussion.

Biochemical Markers for Prediction of Chemotherapy-Induced Cardiotoxicity

Chemotherapy is a well-established therapeutic approach for several malignancies, but its clinical efficacy is often limited by its related cardiotoxicity, which leads to cardiomyopathy, possibly evolving into heart failure. To detect cardiac damage, the adopted diagnostic approach is the estimation of left ventricular ejection fraction by echocardiography. This approach shows low sensitivity toward early prediction of cardiomyopathy, when the possibilities of appropriate treatments could still improve the patient's outcome. Cardiac troponins, however, show high diagnostic efficacy as early as 3 months before the clinical onset of cardiomyopathy. The increase in their concentrations is correlated with disease severity and may predict the new onset of major cardiac events during follow-up. Negative troponin concentrations may identify patients with a very low risk of cardiomyopathy (negative predictive value, 99%). Concerning cardiac natriuretic peptides, definitive evidence in regard to a diagnostic or prognostic role in predicting chemotherapy-induced cardiomyopathy is still lacking.

Left Ventricle: Automated Segmentation by Using Myocardial Effusion Threshold Reduction and Intravoxel Computation at MR Imaging

This retrospective analysis of existing patient data had institutional review board approval and was performed in compliance with HIPAA. No informed consent was required. The purpose of the study was to develop and validate an algorithm for automated segmentation of the left ventricular (LV) cavity that accounts for papillary and/or trabecular muscles and partial voxels in cine magnetic resonance (MR) images, an algorithm called LV Myocardial Effusion Threshold Reduction with Intravoxel Computation (LV-METRIC). The algorithm was validated in biologic phantoms, and its results were compared with those of manual tracing, as well as those of a commercial automated segmentation software (MASS [MR Analytical Software System]), in 38 subjects. LV-METRIC accuracy in vitro was 98.7%. Among the 38 subjects studied, LV-METRIC and MASS ejection fraction estimations were highly correlated with manual tracing (R(2) = 0.97 and R(2) = 0.95, respectively). Ventricular volume estimations were smaller with LV-METRIC and larger with MASS than those calculated by using manual tracing, though all results were well correlated (R(2) = 0.99). LV-METRIC volume measurements without partial voxel interpolation were statistically equivalent to manual tracing results (P > .05). LV-METRIC had reduced intraobserver and interobserver variability compared with other methods. MASS required additional manual intervention in 58% of cases, whereas LV-METRIC required no additional corrections. LV-METRIC reliably and reproducibly measured LV volumes. http://radiology.rsnajnls.org/cgi/content/full/248/3/1004/DC1.

Relative Importance of Errors in Left Ventricular Quantitation by Two-Dimensional Echocardiography: Insights From Three-Dimensional Echocardiography and Cardiac Magnetic Resonance Imaging

The accuracy of left ventricular (LV) volumes and ejection fraction (EF) on two-dimensional echocardiography (2DE) is limited by image position (IP), geometric assumption (GA), and boundary tracing (BT) errors. Real-time three-dimensional echocardiography (RT3DE) and cardiac magnetic resonance imaging (CMR) were used to determine the relative contribution of each error source in normal controls (n = 35) and patients with myocardial infarctions (MIs) (n = 34). LV volumes and EFs were calculated using (1) apical biplane disk summation on 2DE (IP + GA + BT errors), (2) biplane disk summation on RT3DE (GA + BT errors), (3) 4-multiplane to 8-multiplane surface approximation on RT3DE (GA + BT errors), (4) voxel-based surface approximation on RT3DE (BT error alone) and (5) CMR. By comparing each method with CMR, the absolute and relative contributions of each error source were determined. IP error predominated in LV volume quantification on 2DE in normal controls, whereas GA error predominated in patients with MIs. Underestimation of volumes on 2DE was overcome by increasing the number of imaging planes on RT3DE. Although 4 equidistant image planes were acceptable, the best results were achieved with voxel-based RT3DE. For EF estimation, IP error predominated in normal controls, whereas BT error predominated in patients with MIs. Nevertheless, one third of the EF estimation error in patients with MIs was due to a combination of IP and GA errors, both of which may be addressed using RT3DE. The relative contribution of each source of LV quantitation error on 2DE was defined and quantified. Each source of error differed depending on patient characteristics and LV geometry.

Evaluation of left ventricular function: does the imaging technique matter?

Measurement of left ventricular ejection fraction is a common procedure in cardiology. This is not without reason. Left ventricular ejection fraction has proven to be an important predictor of mortality in patients with heart failure and after myocardial infarction [1, 2]. It is also frequently used to monitor left ventricular remodelling after myocardial infarction and to select patients for ICD therapy and biventricular pacing [3, 4]. Next to this, measurement of left ventricular ejection fraction is used to detect cardiac toxicity in cancer treatment, especially chemotherapy with anthracyclines and related compounds (doxorubicin, daunorubicin, idarubicin, epirubicin, anthraquinone mitoxantrone) and trastuzumab [5, 6]. Therefore determination of left ventricular ejection fraction has to be correct and reproducible. Fortunately, several techniques are available to measure left ventricular ejection fraction: echocardiography, nuclear imaging, magnetic resonance imaging, CT of the heart and contrast angiography. Echocardiography is the most commonly used technique, particularly because it is a cheap and easy to perform technique, gives no irradiation gives no patient discomfort and can be used anywhere. In addition, the technique can be used in settings where MRI cannot be used and in patient with irregular heart rhythm, which makes radionuclide angiography inaccurate. Unfortunately the technique is highly operator dependent and patient dependent. Left ventricular function is frequently measured with 2D techniques with extrapolation to a 3D structure, assuming, that the four chamber view and two chamber view give a correct display of this 3D structure. In this setting, visual assessment may not always be accurate [7, 8]. Intra observer and inter observer variability improves if quantitative assessment with the Simpson’s rule is used. In some patients echocardiography is technically cumbersome (Patients with pulmonary disease, women with large breasts and patients with deformations of the thorax). Contrast enhancement can improve estimates of left ventricular ejection fraction significantly in this setting [9]. Magnetic resonance imaging gives also no radiation exposure, but is more difficult to perform and more expensive. Because of the high resolution of the images, the high endocardial intrinsic contrast, the absence of foreshortening, the absence of user-dependence, the high reproducibility, the ability to perform 3D images and the moderate to high temporal resolution, MRI has become the gold standard for the last two decades [10]. Nuclear imaging, CT of the heart and contrast angiography give radiation exposure, and are therefore contraindicated in pregnant women, are relative expensive and require contrast agents (CT and contrast angiography) with possible adverse effects. Radionuclide ventriculography was introduced three decades ago and soon became an accepted technique for measurement of left ventricular ejection fraction. This L. H. B. Baur (&) Department of Cardiology, Atrium Medical Centre Parkstad and University of Maastricht, Henri Dunantstreet 5, 6401CX Heerlen, The Netherlands e-mail: l.baur@atriummc.nl

Should All Patients With Asymptomatic but Significant (&gt;50%) Left Main Coronary Artery Stenosis Undergo Surgical Revascularization?

The incidental detection of asymptomatic but significant (>50%) left main coronary artery disease (LMCAD) has become more frequent with the increased use of coronary angiography for acute myocardial infarction. Most would agree that such LMCAD cannot be ignored. Yet, clarity is somewhat lacking as to the best approach to managing such patients. The long-running debate of the best revascularization method of LMCAD has flared up again. However, medical management also may be a viable option for some of these patients. A 64-year-old nondiabetic man without a history of cardiovascular disease is admitted with an acute inferior ST-elevation myocardial infarction. He undergoes successful primary angioplasty of a dominant right coronary artery. Left ventriculography reveals inferior hypokinesis with an estimated ejection fraction of 45% to 50%. However, the patient also has a smooth mid-to-distal 60% LMCAD without any significant lesions in the left anterior descending or left circumflex artery. A month later, a stress echocardiogram reveals no new wall motion abnormalities. On the basis of this presentation, should he be referred for coronary artery bypass graft (CABG) surgery? The American College of Cardiology/American Heart Association (ACC/AHA) 2002 guidelines for stable angina1 discuss the indications for CABG surgery separately for symptomatic and asymptomatic LMCAD, but the recommendations are the same for both: Revascularization with CABG is a class I recommendation with level of evidence B. (Class I recommendations indicate situations for which evidence or general agreement exists that a given procedure or treatment is beneficial, useful, and effective.) An abbreviated version of these same guidelines was published in 2003.2 These guidelines acknowledged that the evidence behind the recommendation for asymptomatic patients is weak, yet the class IB recommendation was not changed. The ACC/AHA 2004 guidelines for use of CABG surgery also separate symptomatic and asymptomatic LMCAD recommendations and propose that CABG …

What a Headache

A 45-year-old male presented with 2 days of nausea, sweating, and abdominal pain. Examination revealed tachycardia, hypertension, diaphoresis, widespread crepitations, and diffuse abdominal tenderness. Profound hypotension developed, despite intravenous fluids, and was treated with noradrenaline and dobutamine; hypoxia required endotracheal intubation, followed by chest radiograph, which demonstrated extensive pulmonary edema. Echocardiography revealed severe global left ventricular systolic impairment, with an estimated ejection fraction of only 10% (Data Supplement Movies I and II). The patient was transferred to our hospital for the consideration of intraaortic balloon counterpulsation or left ventricular assist device support or both. An intraaortic balloon pump was inserted, and inotropic support was changed to adrenaline with modest improvement. Examination revealed a large mobile nonpulsatile mass in the left paraumbilical region, confirmed as a paraganglionoma on computed tomography (Figure 1). α-Blockade with …

Reply from Potkin, Siegel, and Chen

LETTERS TO THE EDITORReply from Potkin, Siegel, and ChenRalph Potkin, Robert Siegel, and Victor ChengRalph Potkin, Robert Siegel, and Victor ChengPublished Online:01 May 2008https://doi.org/10.1152/japplphysiol.00101.2008MoreSectionsPDF (27 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: We thank Marabotti and colleagues (1) for their letter addressing the use of subcostal echocardiographic imaging to assess right ventricular systolic function in our recent work regarding glossopharyngeal insufflation. The major concerns raised in the letter were twofold: that radionuclide ventriculography, rather than echocardiography, is the most accurate assessment of right ventricular volume, and that the volumes obtained in our calculations were significantly discordant from those obtained in the left ventricle and much smaller than expected in healthy persons.We considered several factors before selecting echocardiography to evaluate ventricular function in the elite divers. First, our primary interest was the change of ventricular function induced by glossopharyngeal insufflation, rather than a true measure of ventricular size and volume. In this respect, each diver at rest acted as his/her own control, and ventricular volume calculations were strictly used to demonstrate the degree of change in ventricular function. Second, subcostal echocardiographic assessment of right ventricular function has shown good correlation with radionuclide angiography in the past (2). Third, echocardiography allowed rapid, real-time imaging of cardiac function before, during, and after glossopharyngeal insufflation. In our hypothesis-generating investigation, it was the only noninvasive modality that achieves appropriate temporal and visual resolution for the requisite analysis while sparing participating divers ionizing radiation. Despite the known shortcomings of subcostal echocardiographic imaging when studying the geometrically complex right ventricle, it was still a strong modality to detect marked changes in ventricular function, and we firmly believe in the validity of the observed decline in right and left ventricular function during glossopharyngeal insufflation.The principal message in our study was that, for the first time, decrease in biventricular function due to glossopharyngeal insufflation has been demonstrated by direct cardiac imaging. We agree with Marabotti and colleagues that pursuing confirmation of our findings with “gold-standard” evaluation of right ventricular function is worthwhile. Perhaps more importantly, we believe, are future investigations to clarify the underlying mechanisms by which glossopharyngeal insufflation compromises cardiac performance.REFERENCES1 Marabotti C, Bedini R, L'Abbate A. Right ventricular volume determination: not a matter for echocardiography. J Appl Physiol; doi:10.1152/japplphysiol.00065.2008.Link | ISI | Google Scholar2 Panidis IP, Ren JP, Kotler MN, Mintz G, Iskandrian A, Ross J, Kane S. Two-dimensional echocardiographic estimation of right ventricular ejection fraction in patients with coronary artery disease. J Am Coll Cardiol 2: 911–918, 1983.Crossref | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: R. Potkin, Beverly Hills Center for Hyperbaric Medicine, 1125 S. Beverly Dr., Los Angeles, CA 90035 (e-mail: [email protected]) Download PDF Previous Back to Top FiguresReferencesRelatedInformation More from this issue > Volume 104Issue 5May 2008Pages 1548-1548 Copyright & PermissionsCopyright © 2008 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00101.2008History Published online 1 May 2008 Published in print 1 May 2008 Metrics

Exactitud de distintos métodos de segmentación para cuantificar parámetros de función cardiaca y masa ventricular izquierda en un modelo animal

To evaluate accuracy of manual, semiautomatic and automatic segmentation methods to quantify cardiac function parameters, volumes, and left ventricular mass. Ten Goettingen miniature pigs (seven male, three female; mean weight 49.8 kg; SD: 10.65; range: 35-65 kg) were evaluated using a 1.5 Tesla MR scanner and free-breathing SSFP sequences. Short axis images were employed to quantify cardiac parameters. In all animals volumes (end-diastolic volume, end-sisstolic volume, stroke volume), ejection fraction and left ventricular mass was calculated. To quantify these parameters three different segmentation methods (manual, semiautomatic, and automatic) were employed. The correlation of different segmentation methods for each variable was analyzed. No statistically significant differences in left ventricular volume or mass quantification using different segmentation methods was found (p > 0.05). Correlation to estimate ejection fraction and end-diastolic volume was good (r > 0.6) and turned to be excellent for the rest of the variables (r > 0.8). Mean quantification time was less for semiautomatic and automatic methods than for the manual method. SSFP sequences allow to accurately evaluate cardiac function parameters and left ventricular mass in a large animal model with any of the segmentation method described in this report. Non-manual segmentation methods allow rapid quantification of cardiac parameters.