Left Ventricular Volumes And Ejection Fraction Research Articles

Diagnostic accuracy for CZT gamma camera compared to conventional gamma camera technique with myocardial perfusion single-photon emission computed tomography: Assessment of myocardial infarction and function

BackgroundThe solid-state cadmium-zinc-telluride (CZT) gamma camera for myocardial perfusion single-photon emission computed tomography (MPS) has theoretical advantages compared to the conventional gamma camera technique. This includes more sensitive detectors and better energy resolution. We aimed to explore the diagnostic performance of gated MPS with a CZT gamma camera compared to a conventional gamma camera for detection of myocardial infarct (MI) and assessment of left ventricular (LV) volumes and ejection fraction (LVEF), using cardiac magnetic resonance (CMR) as the reference method. MethodsSeventy-three patients (26% female) with known or suspected chronic coronary syndrome were examined with gated MPS using both a CZT gamma camera and a conventional gamma camera as well as with CMR. Presence and extent of MI on MPS and late gadolinium enhancement (LGE) CMR was evaluated. For LV volumes, LVEF and LV mass, gated MPS images and cine CMR images were evaluated. ResultsMI was found in 42 patients on CMR. The overall sensitivity, specificity, positive and negative predictive values for the CZT and the conventional gamma camera were the same (67%, 100%, 100% and 69%). For infarct size > 3% on CMR, the sensitivity was 82% for the CZT and 73% for the conventional gamma camera, respectively. LV volumes were significantly underestimated by MPS compared to CMR (P ≤ .002 for all measures). The underestimation was slightly less pronounced for the CZT compared to the conventional gamma camera (2-10 mL, P ≤ .03 for all measures). For LVEF, however, accuracy was high for both gamma cameras. ConclusionDifferences between a CZT and a conventional gamma camera for detection of MI and assessment of LV volumes and LVEF are small and do not appear to be clinically significant.

Progressive left ventricular electro-mechanical remodelling in presence of left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders (FWO) Introduction Recent cross-sectional studies suggest a relationship between persisting left bundle branch block (LBBB) and the extent of left ventricular (LV) electro-mechanical remodelling over time. However, when patients are referred for cardiac resynchronization therapy (CRT), temporal data during the sub-clinical phase of disease are often missing. A longitudinal study using an animal model would improve our understanding of the relationship between the onset of LBBB and the electro-mechanical remodelling. Purpose To investigate the progressive remodelling that develops over time in an animal model of LBBB. Methods Fifteen sheep were subjected to rapid DDD pacing (180 bpm; leads on right atrium and right ventricular free wall) in order to induce a LBBB-like conduction delay. All animals underwent an 8-week pacing protocol, whereas 5 of them were subjected to 16 weeks of pacing in total. Echocardiographic speckle tracking was used to assess circumferential strain of the septal and lateral wall. Septal and lateral wall thickness were measured at end-diastole. Cardiac magnetic resonance imaging was used to determine LV volumes and ejection fraction (LVEF). Examinations took place at baseline (before and after start of pacing), and after 8 and 16 weeks of pacing. All examinations were performed at a physiologic heart rate of 110 bpm. Results At baseline, DDD pacing induced an increase in QRS duration (+83%, p < 0.0001) and LBBB-like mechanical dyssynchrony, with mild early-systolic notching and preserved systolic shortening of the septal wall. Early lateral wall pre-stretch was followed by increasing systolic shortening. No acute changes in LV end-diastolic volume, LVEF or septal or lateral wall thickness were observed (all p > 0.05). After 8 weeks of DDD pacing, mechanical dyssynchrony worsened: septal notching increased, followed by reduced systolic shortening. After 16 weeks, the initial septal shortening was followed by profound stretching throughout systole. Lateral wall shortening was reduced compared to baseline (p < 0.05). QRS duration progressively increased by +15% (week 8) and +26% (week 16) (all p < 0.001). End-diastolic volumes had increased by +38% (week 8) and +74% (week 16), whereas LVEF had decreased by –35% (week 8) and –55% (week 16) (all p < 0.001). Septal wall thickness had reduced by –18% (week 8) and –29% (week 16), while lateral wall thickness had increased by +13% (week 8) and +24% (week 16) (all p < 0.05). Conclusion A persisting LBBB induces progressive changes in LV deformation patterns, and triggers morphological and electrical remodelling, strengthening the concept of LBBB-induced cardiomyopathy. In the clinic, patients with mild dysfunction should be closely monitored for potential disease progression in order to treat dyssynchrony as soon as guideline indications are reached. Further studies need to show if earlier CRT-implantation might prevent further LV deterioration. Abstract Figure. Abstract Figure.

Sequential left ventricular electro-mechanical changes in presence of left bundle branch block

Abstract Introduction Recent cross-sectional studies suggest a relationship between persisting left bundle branch block (LBBB) and the extent of left ventricular (LV) electro-mechanical alterations over time. When patients are referred for cardiac resynchronization therapy (CRT), temporal data during the sub-clinical phase of disease is often missing. A longitudinal study using an animal model would provide a better understanding of the relationship between the onset of LBBB and the electro-mechanical changes. Purpose To investigate the sequential alterations in LV structure and function that develop over time in an animal model of LBBB. Methods Thirteen sheep were subjected to rapid DDD pacing (180 bpm; leads on right atrium and right ventricular free wall) in order to induce a LBBB-like conduction delay. All animals underwent an 8-week pacing protocol, whereas 4 of them were subjected to 16 weeks of pacing in total. Echocardiographic speckle tracking was used to assess circumferential strain of the septal and lateral wall. Septal and lateral wall thickness were measured at end-diastole. Cardiac magnetic resonance imaging was used to determine LV volumes and ejection fraction (LVEF). Examinations took place at baseline (before and after start of pacing), and after 8 and 16 weeks of pacing. All examinations were performed at a physiologic heart rate of 110 bpm. Results At baseline, DDD pacing induced an increase in QRS duration (+85%, p<0.0001) and LBBB-like mechanical dyssynchrony, with mild early-systolic notching and preserved systolic shortening of the septal wall. The lateral wall demonstrated early pre-stretch followed by increasing systolic shortening. No acute changes in LV end-diastolic volume, LVEF or septal or lateral wall thickness were observed (all p>0.05). After 8 weeks of DDD pacing, mechanical dyssynchrony worsened: septal notching increased, followed by reduced systolic shortening. After 16 weeks, the initial septal shortening was followed by profound stretching throughout systole. Lateral wall systolic shortening was reduced compared to baseline. QRS duration increased further by +12% (week 8) and +20% (week 16) (all p<0.001). End-diastolic volumes had increased by +39% (week 8) and +72% (week 16), whereas LVEF had decreased by −48% (week 8) and −56% (week 16) (all p<0.001). Septal wall thickness had reduced by −24% (week 8) and −33% (week 16), while lateral wall thickness had increased by +21% (week 8) and +30% (week 16) (all p<0.05). Conclusion A persisting LBBB-like conduction delay induces sequential changes in LV deformation patterns, and triggers morphological and electrical remodelling. These changes are similar to those observed in patients with LBBB and different degrees of LV dysfunction. Our data suggest a continuum due to the progression of LBBB-induced LV disease. In the clinic, patients with mild dysfunction should be closely monitored in order to treat dyssynchrony as soon as guideline indications are reached. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): This work was supported by a KU Leuven research grant

3-D Echocardiography Is Feasible and More Reproducible than 2-D Echocardiography for In-Training Echocardiographers in Follow-up of Patients with Heart Failure with Reduced Ejection Fraction

Left ventricular volumes (LVVs) and ejection fraction (LVEF) are key elements in the evaluation and follow-up of patients with heart failure with reduced ejection fraction (HFrEF). Therefore, a feasible and reproducible imaging method to be used by both experienced and in-training echocardiographers is mandatory. Our aim was to establish if, in a large echo lab, echocardiographers in-training provide feasible and more reproducible results for the evaluation of patients with HFrEF when using 3-dimensional echocardiography (3-DE) versus 2-dimensional echocardiography (2-DE). Sixty patients with HFrEF (46 males, age: 58 ± 17 y) underwent standard transthoracic 2-D acquisitions and 3-D multibeat full volumes of the left ventricle. One expert user in echocardiography (expert) and three echocardiographers with different levels of training in 2-DE (beginner, medium and advanced) measured the 2-D LVVs and LVEFs on the same consecutive images of patients with HFrEF. Afterward, the expert performed a 1-mo training in 3-DE analysis of the users, and both the expert and trainees measured the 3-D LVVs and LVEF of the same patients. Measurements provided by the expert and all trainees in echo were compared. Six patients were excluded from the study because of poor image quality. The mean end-diastolic LVV of the remaining 54 patients was 214 ± 75 mL with 2-DE and 233 ± 77 mL with 3-DE. Mean LVEF was 35 ± 10% with 2-DE and 33 ± 10% with 3-DE. Our analysis revealed that, compared with the expert user, the trainees had acceptable reproducibility for the 2-DE measurements, according to their level of expertise in 2-DE (intra-class coefficients [ICCs] ranging from 0.75 to 0.94). However, after the short training in 3-DE, they provided feasible and more reproducible measurements of the 3-D LVVs and LVEF (ICCs ranging from 0.89–0.97) than they had with 2-DE. 3-DE is a feasible, rapidly learned and more reproducible method for the assessment of LVVs and LVEF than 2-DE, regardless of the basic level of expertise in 2-DE of the trainees in echocardiography. In echo labs with a wide range of staff experience, 3-DE might be a more accurate method for the follow-up of patients with HFrEF.

P311 Morpho-functional myocardial alteration during trastuzumab therapy: anything beyond cardiotoxicity?

Abstract Background Trastuzumab (TZ) has a primary role in the therapy of HER-2 positive breast cancer but has potential negative effect on left ventricular (LV) function that define cardiotoxicity (CT). Decrease in LV longitudinal strain (GLS) and in left atrial (LA) function observed by peak atrial longitudinal strain (PALS), besides LA remodeling, has already been described as predictors of TZ-related CT. However these parameters haven’t been observed together and regardless of CT. Purpose to describe overall atrial and ventricular morpho-functional variations during TZ therapy. Methods HER-2 positive metastasis-free breast cancer patientsreferring to our Echo-lab were prospectively recruited. Trans-thoracic echocardiography was performed before starting TZ and every 3 up to 12 months. LV volumes and ejection fraction (LVEF), indexed LA volume (LAVI), LA deformation parameters, and multiple diastolic parameters were collected. 2D-Speckle tracking analysis was performed at baseline and at each examination using Philips’ QLAB software. Results Eligible patients were 64. 53 of these (82,8%) had a complete follow-up at 12 months and were included in the analysis. 42 patients (79,3%) were treated with both TZ and anthracyclines. During follow-up CT occurred in 7 patients (10,9%). Mean baseline parameters were: age 54 ± 13 years,LVEF 63,3 ±3,2%, GLS -21,2 ± 2,1%, LAVI 24,4 ±6,9 ml/mq, peak atrial contraction strain (PACS) 22,9 ±6,5%, PALS 51,1 ± 11,5%. Deformation analysis was feasible in 95% of patients. None of the echocardiographic parameters regarding diastolic function and LV volumes showed significant variations. Analyzing overall populations data during the 1 year of follow-up, we reported a decrease trend of GLS (p for time <0.0001) with an early drop during the first 6 months of TZ therapy with a subsequent "plateau" phase, and a reductionof LVEFover time (p for time <0.0001) with a continuous gradual decreasefor the whole follow-up (but still within the normal value span). On top LA functional parameters showed a decreasing trend: PALS (p for time <0.0001) and PACS (p for time <0.0001) showed both decrease trend since the first months of therapy, lasting for the entire follow-up. Also we reported a notable LAVI dilation during the first 6 months of TZ therapy (p for time <0.0001) followed by a plateau phase, and combining LAVI and PALS (LAVI/PALS) we noted an increase trend (p for time <0.0001). These data are showed in Figure I. Conclusions Our results suggest that deformation analysis is useful to study LV and LA functional remodeling during TZ therapy. Actual recommendations for the identification of CT are based upon a joint evaluation of LVEF and GLS, but our study show significant variations of other morpho-functional parameters regardless of CT. These changes could be used as indicators of subclinical damage involving the entire heart and the analysis of different deformation indexes could improve the early detection of CT. Abstract P311 Figure. Morpho-functional variations

Three-dimensional full automated software in the evaluation of the left ventricle function: from theory to clinical practice.

Left ventricular systolic function evaluation is an essential part of all transthoracic echocardiographic (TTE) studies. 3D echocardiography (3DE) is superior to 2D and is recommended as the method of choice. However, since it is time consuming and requires training, it is rarely performed. Different automatic analysis software tries to overcome these limitations but they need to be accurate and reproducible before they can be used clinically. The aim of this study was to test the accuracy and reproducibility of new 3D automatic quantitative software in everyday clinical practice. 69 patients referred to our Echo Lab for a clinically indicated echocardiographic examination were included. All patients underwent a full TTE with 3D image acquisition. Left ventricular volumes and ejection fraction (LVEF) were obtained using Heart Model software, and compared with conventional 3D volumetric data. Automated analysis was performed using three different sliders setting, with or without regional editing if necessary. 20 patients underwent a cardiac magnetic resonance (CMR) study the same day of the echo and automated measurements were also compared with a CMR reference. Intra- and inter-technique comparisons including linear regression with Pearson correlation coefficients and Bland-Altman analyses were calculated. Mean age of the patients was 59years, with 49.3% male. The automated 3DE model demonstrated excellent correlation with the conventional 3DE measurements of LVEF, using three different sliders settings (r = 0.906; r = 0.898 and r = 0.940). Correlations with CMR values were very good as well (r = 0.888; r = 0.869; r = 0.913). Similarly, no significant differences were noted between the values of EDV and ESV, measured with the automated model or CMR, with excellent correlation (EDV: r = 0.892, r = 0.842, 0.910; ESV: r = 0.925, r = 0.860, r = 0.907). Finally, volumes calculated with the automated software were significantly greater than those obtained manually, but they showed a very good correlation (EDV: r = 0.875, r = 0.856, r = 0.891; ESV: r = 0.929, r = 0.879, r = 949). 3D automatic software for LV quantification is feasible and shows excellent correlations with both CMR and 3D echocardiography, considered the gold standard. No clinically relevant differences were noted when applying different border settings. This technique holds promise to facilitate the integration of 3D TTE into clinical practice.

Rational and design of EuroCRT: an international observational study on multi-modality imaging and cardiac resynchronization therapy.

Assessment of left ventricular (LV) volumes and ejection fraction (LVEF) with cardiac imaging is important in the selection of patients for cardiac resynchronization therapy (CRT). Several observational studies have explored the role of imaging-derived LV dyssynchrony parameters to predict the response to CRT, but have yielded inconsistent results, precluding the inclusion of imaging-derived LV dyssynchrony parameters in current guidelines for selection of patients for CRT. The EuroCRT is a large European multicentre prospective observational study led by the European Association of Cardiovascular Imaging. We aim to explore if combing the value of cardiac magnetic resonance (CMR) and echocardiography could be beneficial for selecting heart failure patients for CRT in terms of improvement in long-term survival, clinical symptoms, LV function, and volumes. Speckle tracking echocardiography will be used to assess LV dyssynchrony and wasted cardiac work whereas myocardial scar will be assessed with late gadolinium contrast enhanced CMR. All data will be measured in core laboratories. The study will be conducted in European centres with known expertise in both CRT and multimodality cardiac imaging.

Improvement in Strain Concordance between Two Major Vendors after the Strain Standardization Initiative

Disagreement of strain measurements among different vendors has provided an obstacle to the clinical use of strain. A joint standardization task force between professional societies and industry was initiated to reduce intervendor variability of strain. Although feedback from this process has been used in software upgrades, little is known about the effects of efforts to improve conformity. The aim of this study was to assess whether intervendor agreement for global longitudinal strain (GLS) has improved after standardization initiatives. Eighty-two subjects (mean age, 52±21years; 55% men) prospectively underwent two sequential examinations using two most common ultrasound systems (Vivid E9 and iE33). GLS was calculated using proprietary software (EchoPAC-PC BT12 [E12] and BT13 [E13] vs QLAB version 8.0 [Q8], QLAB version 9.0 [Q9], and QLAB version 10.0 [Q10]). Agreements in GLS were evaluated with Bland-Altman plots. Coefficients of variation (CVs) were compared using the Friedman test and compared with CVs of left ventricular volumes and ejection fraction (LVEF). Median GLS using E12 was -19.2% (interquartile range [IQR], -15.2% to -23.2%), compared with -19.3% (IQR, -14.9% to -23.7%) for E13, -15.7% (IQR, -11.4% to -20%) for Q8, -19% (IQR, -15.7% to -22.3%) for Q9, and -18.7% (IQR, -15.7% to -21.7%) for Q10. The CVs of prestandardization GLS (12 ± 8% [E12/Q8] and 14±8 [E13/Q8]) were significantly larger than that of LVEF (5±5) (P<.001). Since standardization, the CVs of GLS have shown improvement (6±4 [E12/Q9], 7±4 [E12/Q10], 6±4 [E13/Q9], and 7±4 [E13/Q10]) and are similar to those of LVEF. Subsequent to the joint standardization task force, there has been improvement in between-vendor concordance in GLS between two leading ultrasound manufactures, the variability of which is now analogous to that of LVEF. The removal of concerns about measurement variability should allow wider use of GLS.

Intracoronary injection of adenosine before reperfusion in patients with ST-segment elevation myocardial infarction: A randomized controlled clinical trial

BackgroundThe effect of intracoronary adenosine (ADO) on ST-segment elevation myocardial infarction (STEMI) size and adverse remodeling is not well established. MethodsIn a double-blind trial, 201 patients with STEMI were randomized to receive percutaneous coronary intervention (PCI) within 6hours of symptom onset, 4.5mg ADO or saline immediately prior to reperfusion. Primary end-point: percentage of total myocardial necrotic mass by cardiac magnetic resonance (CMR) 2–7days post-reperfusion. Secondary end-points: changes in left ventricular volumes and ejection fraction (LVEF) at baseline and at 6months. ResultsBaseline CMR could not be performed in 20 patients. Overall, no significant differences were observed between ADO and placebo regarding infarct size (20.8% vs. 22.5%; p=0.40). However, infarct size was significantly reduced (19.4% vs. 25.7%; p for interaction=0.031) in those with ischemia duration below the median (200min). CMR at 6months, performed in 138 patients, did not show statistically significant differences between groups in the rate of LVEF increase (3.3units (SD 9.6) in ADO group vs. 1.5units (SD 9) in placebo group; p=0.25). In the subgroup analysis, among patients with ischemia time below 200min, the increase in LVEF was slightly higher with ADO (3.59% vs. 0.43%; p for interaction=0.06). ConclusionsAlthough our study failed to demonstrate that intracoronary administration of ADO prior to PCI limits infarct size, in patients receiving early PCI ADO might enhance myocardial salvage and has a favorable effect on LVEF evolution, which may help to reconcile apparently contradictory results of previous studies. Clinical trial registrationhttp://clinicaltrials.gov (NCT00781404).

The influence of microvascular injury on T1- and T2*-relaxation times after acute myocardial infarction

Background Pre-contrast T1-mapping and Late Gadolinium Enhancement (LGE) imaging offer a detailed characterization of the infarcted myocardium and its severity after acute myocardial infarction (AMI). However, the influence of T2*-effects in infarcts with microvascular injury (MVI) on local T1-mapping values has not yet been elucidated. We evaluate the effect of T2*-decay on T1relaxation times in the infarcted myocardium in patients after AMI. Methods Forty-three patients after AMI, treated with successful primary percutaneous coronary intervention, underwent CMR at 4 (3-5) days, for cine imaging, pre-contrast T1mapping and T2*-mapping, and LGE. MVI was defined as a contrast-devoid area in the core of the infarcted, hyperenhanced myocardium on the LGE images. T1and T2*-mapping was performed in short-axis orientation at the level of the infarcted area. T1- and T2*relaxation time values were determined in a region of interest (ROI) in [1] the core of the infarcted myocardium within the hyperenhanced region incorporating any area with MVI when present, [2] the border zone within the hyperenhanced myocardium but outside any areas of MVI, and [3] remote myocardium without hyperenhancement. Left ventricular volumes and ejection fraction (LVEF) were derived from the cine images and infarct size was determined on the LGE images. Normal distribution of relaxation times was achieved by log-transformation. Results Twenty of the 43 patients (47%) had MVI. Infarct cores with MVI had significantly lower T1-values (MVI 1062 [974-1107]ms, vs. no MVI 1128 [1051-1185]ms, p = 0.02) and lower T2*-values (MVI 20.3 [18.2-23.3]ms vs. no MVI 30.9 [26.0-38.9]ms, p < 0.001) than infarct cores without MVI. Border zone T2*-values did not differ between patients with and without MVI; however, border zone T1-values were significantly longer in patients with MVI than in patients without MVI (MVI 1140 [1096-1174]ms, vs. no MVI 1050 [1007-1089]ms, p = 0.009). As would be expected, remote T1-values did not differ between patients with and without MVI (MVI 1000 [965-1011]ms vs. no MVI 977 [929-993]ms, p = 0.13). A significant correlation was found between T2*values and LVEF (r = 0.60, p < 0.001), and between T2*-values and infarct size (r = -0.60, p < 0.001). For T1-values, however, these relations did not exist. Conclusions Patients with reperfused AMI have shorter T1- and T2*relaxation times in the infarct core when MVI is present. In the adjacent border zone, T1-relaxation times are longer in patients with MVI. This has important implications for the interpretation of pre-contrast T1-mapping values shortly after AMI.

CT for Evaluation of Myocardial Cell Therapy in Heart Failure: A Comparison With CMR Imaging

The aim of this study was to use multidetector computed tomography (MDCT) to assess therapeutic effects of myocardial regenerative cell therapies.Cell transplantation is being widely investigated as a potential therapy in heart failure. Noninvasive imaging techniques are frequently used to investigate therapeutic effects of cell therapies in the preclinical and clinical settings. Previous studies have shown that cardiac MDCT can accurately quantify myocardial scar tissue and determine left ventricular (LV) volumes and ejection fraction (LVEF).Twenty-two minipigs were randomized to intramyocardial injection of phosphate-buffered saline (placebo, n = 9) or 200 million mesenchymal stem cells (MSC, n = 13) 12 weeks after myocardial infarction (MI). Cardiac magnetic resonance and MDCT acquisitions were performed before randomization (12 weeks after MI induction) and at the study endpoint 24 weeks after MI induction. None of the animals received medication to control the intrinsic heart rate during first-pass acquisitions for assessment of LV volumes and LVEF. Delayed-enhancement MDCT imaging was performed 10 min after contrast delivery. Two blinded observers analyzed MDCT acquisitions.MDCT demonstrated that MSC therapy resulted in a reduction of infarct size from 14.3 ± 1.2% to 10.3 ± 1.5% of LV mass (p = 0.005), whereas infarct size increased in nontreated animals (from 13.8 ± 1.3% to 16.5 ± 1.5%; p = 0.02) (placebo vs. MSC; p = 0.003). Both observers had excellent agreement for infarct size (r = 0.96; p < 0.001). LVEF increased from 32.6 ± 2.2% to 36.9 ± 2.7% in MSC-treated animals (p = 0.03) and decreased in placebo animals (from 33.3 ± 1.4% to 29.1 ± 1.5%; p = 0.01; at week 24: placebo vs. MSC; p = 0.02). Infarct size, end-diastolic LV volume, and LVEF assessed by MDCT compared favorably with those assessed by cardiac magnetic resonance acquisitions (r = 0.70, r = 0.82, and r = 0.902, respectively; p < 0.001).This study demonstrated that cardiac MDCT can be used to evaluate infarct size, LV volumes, and LVEF after intramyocardial-delivered MSC therapy. These findings support the use of cardiac MDCT in preclinical and clinical studies for novel myocardial therapies.

Comparison of dual-source 64-slice adenosine stress CT perfusion with stress-gated SPECT-MPI for evaluation of left ventricular function and volumes

Evaluation of left ventricular (LV) volumes and ejection fraction (LVEF) represent important components of pharmacologic stress imaging with either myocardial CT perfusion (CTP) or gated single-photon emission CT (SPECT) myocardial perfusion imaging (SPECT-MPI). We compared measurements of left ventricular function and volumes obtained with CTP and SPECT-MPI. Forty-seven patients (mean age, 62 ± 11 years; male, n = 39) underwent stress CTP and SPECT-MPI. LVEF (in %), end-systolic volume (ESV; in mL), and end-diastolic volume (EDV; in mL) derived from stress CTP images were compared with SPECT-MPI. Stress CTP was in good agreement with SPECT-MPI for quantification of LVEF (r = 0.91), EDV (r = 0.75), and ESV (r = 0.83; all P < 0.001). The mean LVEF measured by stress CTP (66% ± 17%) was similar to SPECT-MPI (64% ± 15%). Similar values were also derived for mean EDV (123 ± 30 mL vs 120 ± 34 mL) and ESV (44 ± 28 mL vs 51 ± 34 mL) for CTP and SPECT-MPI, respectively. Good agreement was also shown between both techniques for the assessment of regional wall motion with identical wall motion scores in 95.3% of the segments (κ = 0.79). LVEF and LV volume parameters as determined by dual-source 64-slice adenosine stress CTP show a high correlation with values obtained with stress-gated SPECT-MPI.

Myocardial perfusion imaging with real-time respiratory triggering: Impact of inspiration breath-hold on left ventricular functional parameters

The latest gamma-camera generation with cadmium-zinc-telluride (CZT) detectors allows myocardial perfusion imaging (MPI) with respiratory triggering at breath-hold. We assessed its impact on functional left ventricular (LV) parameters. Twenty-eight consecutive patients underwent a one-day (99m)Tc-tetrofosmin pharmacologic stress/rest imaging protocol on a novel CZT camera. Electrocardiogram-gated high-dose (rest) MPI was performed without and with real-time respiratory triggering by intermittent scanning confined to breath-hold at deep inspiration. We studied the effect of respiratory triggering at deep inspiration levels on LV wall motion, wall thickening, LV volumes and ejection fraction (LVEF) compared to regular MPI without respiratory triggering. Compared to regular MPI without respiratory triggering, systolic and diastolic LV volumes and stroke volumes decreased significantly (P<0.05) when respiratory triggering was applied. By contrast, there was no significant change in LVEF, with a high correlation (r=.939, P<0.001) between the two measurements. Furthermore, respiratory triggering introduced a significant change (P<0.05) in regional LV wall motion. Respiratory-triggered MPI with breath-hold at deep inspiration levels introduces significant changes to the measured LV volumes, stroke volumes and regional wall motion but does not significantly affect global LVEF when compared to regular MPI with normal breathing.

Clinical evaluation of a fully automated model-based algorithm to calculate left ventricular volumes and ejection fraction using multidetector computed tomography

To evaluate feasibility and accuracy of a fully automatic algorithm (FAA) for calculating left ventricular volumes and ejection fraction (LVEF) from multidetector computed tomography (MDCT) studies versus a previously validated method based on Simpson's method serving as our reference standard (RS), and left ventriculography (LVG), in patients with acute chest pain (ACP). 23 patients admitted with ACP underwent ECG-gated MDCT, as well as LVG during their hospitalization. MDCT based end-diastolic, end-systolic and stroke volumes (EDV, ESV, SV) and LVEF were calculated using the RS and the FAA. One patient was excluded after FAA failure to detect contours. In the remaining 22 patients, mean+/-SD LVEF measurements were RS 61+/-11%, FAA 59+/-11% (r = 0.91 versus RS), LVG 57+/-16% (r = 0.6 versus RS). In comparison to RS, FAA overestimated EDV by 10.1+/-8.5 ml, ESV by 7.3+/-6.4 ml and SV by 3.6+/-8.6 ml, and underestimated LVEF measurements by 2.7+/-4.6%, related to contour smoothing. LVEF by FAA was within 8% of RS for all patients except one. In contrast, LVG differed significantly from RS. The evaluated FAA obtained accurate, clinically relevant results for left ventricular volumes and LVEF relative to the RS.

Evaluation of new automated gated-SPECT and echocardiographic methods for calculating left ventricular volumes and ejection fraction

Background Left ventricular (LV) volumes and ejection fraction (LVEF) are assessed using ECG-gated myocardial perfusion scintigraphy (MPS) and echocardiography. We have developed CAFU, a new automated method for the quantification of MPS images. AutoEF software is a new automated method for quantifying echocardiograms (Tomtec research arena). The aim of the study was to compare these new methods with standard methods. Methods Patients undergoing clinical MPS were invited to an echocardiographic examination. Eighty-eight patients were included, mean age 64 ± 10 years, 50% men. LV volumes and LVEF from the echocardiographic examinations were calculated using the AutoEF software and calculations according to Simpson's rule. The LV volumes and LVEF from the MPS images were calculated using CAFU, Quantitative gated-SPECT (QGS) and Emory Cardiac Toolbox (ECT). Results The MPS methods revealed larger LV volumes and LVEF compared with the echocardiographic methods. CAFU showed an excellent correlation with QGS and ECT (0.91–0.99). The correlations between the MPS and the echocardiographic methods (0.47–0.88), as well as between the AutoEF-assessed values and Simpson's method (0.57–0.87), were lower, however statistically significant. The correlations between the methods were higher for LV volumes than for LVEF. Conclusion There was better agreement between LV volumes and LVEF values from the three MPS methods than between those from the two echocardiographic methods. The echocardiographic methods produced significantly lower LV volumes and LVEF compared with the MPS methods. In the clinical situation, LV volumes and LVEF values from different types of examination or different software packages should be treated with caution.

Improved Assessment of Left Ventricular Volumes and Ejection Fraction by Contrast Enhanced Harmonic Color Doppler Echocardiography

Test the accuracy of contrast enhanced harmonic color Doppler technique (CHCD) to determine left ventricular volumes and ejection fraction (LVEF) compared to equilibrium radionuclide ventriculography (MUGA). A total of 35 patients were enrolled (male 74.3%) with the mean age of 64.5 +/- 10 years and 6.8 +/- 4.9 days between echo and MUGA scans. The correlation of LVEF by CHCD with MUGA was better (R2 = 0.89) than that of harmonic 2D (H2D) and of contrast enhanced harmonic 2D (CH2D) (R2 = 0.74, R2 = 0.82, respectively). The RMS residual of CHCD (0.056) was smaller than that of H2D and CH2D (0.079, 0.067, respectively). The LVED and LVES volumes by H2D, CH2D and CHCD correlate well with MUGA but there was a significant over estimation of LVED and LVES volumes by H2D and CH2D as compared to MUGA. Also, the RMS residuals were the lowest for the CHCD method. The CHCD had the highest mean inter-observer agreement (90.9%) for LVEF compared with H2D and CH2D (78.9% and 88.1%, respectively). CHCD has been feasible in all patients in the present study and it has shown a good concordance with ejection fraction and volumes provided by MUGA.

Persistent Preload Defect in Severe Sepsis Despite Fluid Loading: A Longitudinal Echocardiographic Study in Patients With Septic Shock

To investigate the rate of recovery from septic shock in patients with suspected left ventricular (LV) preload deficiency and LV systolic dysfunction. A monitoring period was defined by the need for inotropic/vasopressor support, and LV function was assessed daily during this period by bedside two-dimensional echocardiography (2D-ECHO). University hospital ICU. During a 5-year period, 90 patients with an episode of septic shock (60% with gram-positive bacteria as the causative agent) were consecutively enrolled in the study (mean age, 55 +/- 18 years). Standard volume resuscitation combined with inotropic/vasopressor support was used to maintain systolic arterial pressure > 90 mm Hg. All patients received mechanical ventilation because of associated respiratory failure. The average duration of hemodynamic support was 4.4 +/- 1.6 days. Thirty-four patients were weaned from hemodynamic support during the monitoring period and ultimately recovered (group I). Twenty-eight patients died from refractory circulatory failure during the monitoring period, and 28 died later from ARDS or multiple organ dysfunction syndrome, leading to a 62% overall mortality rate (group II). Daily bedside LV volumes and ejection fraction (LVEF) were recorded using 2D-ECHO. Data obtained at the start (day 1 and day 2) and end of the monitoring period (day n) were compared. LV end-diastolic volume was within the normal range of our laboratory values in all patients, but was initially smaller in group II than in group I, and remained so despite fluid loading. LVEF was significantly depressed in all patients, resulting in severe reduction in LV stroke volume (LVSV), which was initially more marked in group I. In group I patients, LVEF significantly improved during the monitoring period, resulting in an increase in LVSV. 2D-ECHO changes during hemodynamic support in 90 septic patients confirmed defective LV preload with a propensity to worsen despite fluid loading in nonsurvivors (62% in the present study). Our results are also in agreement with previous studies reporting depressed LV systolic function at the initial phase of septic shock. Since LV dysfunction was more marked in patients who recovered, we suggest that the exact significance of this finding should be reevaluated.