Feasibility of assessing cardiac systolic function using longitudinal fractional shortening calculated by two-dimensional speckle tracking echocardiography

Background: The left ventricular longitudinal fractional shortening (LVLFS) evaluated by the speckle tracking method reflects the longitudinal contraction of left ventricle (LV). We aimed to evaluate the accuracy of LVLFS as an index of LV systolic function. Methods: Two hundred thirty‐three patients with or without heart failure (HF) were divided into four groups according to the progress of HF. Conventional echocardiography and two‐dimensional speckle tracking echocardiography (2DSTE) were performed in all subjects. Besides, cardiac magnetic resonance (CMR) images were acquired in a subgroup of 30 patients with poor echo image quality. LVEF was measured using the biplane Simpson's method by two‐dimensional echocardiography and CMR, respectively. LVLFS was calculated using QLAB 7.0, which performed speckle tracking analysis automatically. Results: Generally, LVLFS declined accordingly with the progression of HF (P < 0.05). In a liner regression model, LVLFS correlated well with conventional LVEF (r = 0.856, P < 0.001). In the subgroup study performed in patients with poor acoustic windows, LVLFS correlated better with LVEF measured by CMR than conventional LVEF measured using biplane Simpson's method (r = 0.899 vs. 0.848). As for the reproducibility, better intra‐ and interobserver variability was observed in LVLFS than in conventional LVEF (6.2 ± 3.5% vs. 8.5 ± 4.7% and 7.8 ± 5.6% vs. 11.3 ± 6.2%, P < 0.05), especially for patients with poor image quality. Besides, measurement of LVLFS is much less time‐consuming than conventional LVEF. Conclusions: The results of this study suggest a linear relationship between LVLFS and LVEF. LVLFS may provide sensitive and accurate assessment of LV systolic function, and its measurement reproducibility is better than that of LVEF. (Echocardiography 2011;28:402‐407)     

Assessment of left ventricular mechanical dyssynchrony using real time three-dimensional echocardiography: a comparative study to Doppler tissue imaging

Purpose: To assess left ventricular mechanical dyssynchrony (LVMD) using real time three‐dimensional echocardiography (RT3DE) and comparing it with the different dyssynchrony indices derived from Doppler tissue imaging (DTI) for the same patient. Methods: The study included 60 consecutive patients who were considered candidates for CRT, i.e., having ejection fraction ≤35%, NYHA class III or ambulatory class IV, QRS duration ≥120 msec, on optimal pharmacological therapy. Apical RT3DE full volumes were obtained and analyzed to generate the systolic dyssynchrony index (SDI‐16), which is the standard deviation of the time to minimal systolic volume of the 16 segments of LV. Color‐coded DTI was performed for the three standard apical views with estimation of the mechanical dyssynchrony index (12 Ts‐SD), which is the standard deviation of the time to peak systolic velocity at 12 segments of LV. Results: SDI‐16 was 10.96 ± 3.9% (cutoff value: 8.3%), while Ts‐SD was 38 ± 10.2 msec (cutoff value: 32.6 msec). The concordance rate for both indices was 75%; however, there was no correlation between both indices (r = 0.14, P = 0.3). SDI‐16 showed good correlation with QRS duration (r = 0.45, P < 0.001) and inverse correlation with left ventricular ejection fraction (LVEF) calculated by RT3DE (r =?0.37, P = 0.004), while 12 Ts‐SD index showed no correlation with QRS duration (r =?0.0082, P = 0.51) or 2D LVEF (r =?0.26, P = 0.84). Conclusions: RT3DE can quantify LVMD by providing the SDI‐16 and it may prove to be more useful than DTI as it shows increasing dyssynchrony with increased QRS duration and decreased LVEF. (Echocardiography 2012;29:173‐181)     

Rapid and accurate measurement of LV mass by biplane real-time 3D echocardiography in patients with concentric LV hypertrophy: comparison to CMR.

AIMS: To evaluate the accuracy of real-time three-dimensional echocardiography (RT3DE) using a biplane and multiplane method in determining left ventricular (LV) mass compared to cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS: LV mass was measured in 18 adult patients with congenital aortic stenosis using CMR and echocardiography (M-mode, two-dimensional echocardiography (2DE), and RT3DE). RT3DE data were analysed using a biplane and multiplane method. No geometric assumptions were necessary using the multiplane RT3DE method. With regard to biplane or multiplane RT3DE, no tendency of over- or underestimation of LV mass was observed. Pearson's correlation coefficients for RT3DE versus CMR were 0.84 and 0.90 for the biplane and multiplane method, respectively. In addition, the accuracy of both RT3DE methods were comparable (Fisher's R-to-Z transformation: Z = 0.69, P = NS). Finally, off-line analysis using biplane RT3DE was significantly faster than multiplane RT3DE (3.8 +/- 1.2 vs. 7.8 +/- 1.7 minutes, P < 0.001). CONCLUSIONS: Biplane RT3DE provided an accurate estimate of LV mass in patients with concentric left ventricular hypertrophy, which was not improved by multiplane RT3DE. The accuracy and speed of analysis renders biplane RT3DE an attractive tool in daily clinical practice for assessing the degree of LV hypertrophy.     

Quantitative assessment of left ventricular volume and ejection fraction using two-dimensional speckle tracking echocardiography

Aims: Two-dimensional speckle tracking echocardiography (2DSTE) allowsmeasurements of left ventricular (LV) volumes and LV ejectionfraction (LVEF) without manual tracings. Our goal was to determinethe accuracy of 2DSTE against real-time 3D echocardiography(RT3DE) and against cardiac magnetic resonance (CMR) imaging. Methods and results: In Protocol 1, 2DSTE data in the apical four-chamber view (iE33,Philips) and CMR images (Philips 1.5T scanner) were obtainedin 20 patients. The 2DSTE data were analysed using custom software,which automatically performed speckle tracking analysis throughoutthe cardiac cycle. LV volume curves were generated using thesingle-plane Simpson's formula, from which end-diastolic volume(LVEDV), end-systolic volume (LVESV), and LVEF were calculated.In Protocol 2, the 2DSTE and RT3DE data were acquired in 181subjects. RT3DE data sets were acquired, and LV volumes andLVEF were measured using QLab software (Philips). In Protocol1, excellent correlations were noted between the methods forLVEDV (r = 0.95), ESV (r = 0.95), and LVEF (r = 0.88). In Protocol2, LV volume waveforms suitable for analysis were obtained from2DSTE images in all subjects. The time required for analysiswas <2 min per patient. Excellent correlations were notedbetween the methods for LVEDV (r = 0.95), ESV (r = 0.97), andLVEF (r = 0.92). However, 2DSTE significantly underestimatedLVEDV, resulting in a mean of 8% underestimation in LVEF. Intra-and inter-observer variabilities of 2DSTE were 7 and 9% in LVvolume and 6 and 8% in LVEF, respectively. Conclusions: Two-dimensional speckle tracking echocardiography measurementsresulted in a small but significant underestimation of LVEDVand EF compared with RT3DE. However, the accuracy, low intra-and inter-observer variabilities and speed of analysis make2DSTE a potentially useful modality for LV functional assessmentin the routine clinical setting.     

The Impacts of Transcatheter Occlusion for Congenital Atrial Septal Defect on Left Ventricular Systolic Synchronicity: A Three‐Dimensional Echocardiography Study

Objectives: To investigate the impacts of transcatheter occlusion for congenital atrial septal defect (ASD) on left ventricular (LV) systolic synchronicity using a real time three‐dimensional echocardiography (RT3DE). Methods: Thirty patients with ASD closure were recruited for the study. Realtime three‐dimensional echocardiographic data sets were acquired for the measurement of LV volumes LV ejection fractions and LV three‐dimensional systolic synchronicity before and at 6 months after transcatheter occlusion for ASD. M‐mode echocardiography and RT3DE were performed to characterize interventricular septal (IVS) motion. Results: There were no differences in LV systolic synchronicity between before and after transcatheter closure of ASD (Tmsv‐16SD%: 5.6%± 1.4% vs 5.8%± 1.8%, P > 0.05; Tmsv—12SD%: 5.2 ± 1.1% vs 5.4 ± 1.2%, P > 0.05). But the abnormal IVS motion was found before device closure and normalized after transcatheter occlusion for ASD using M‐mode echocardiography and the excursion‐time figure (bull's‐eye derived from RT3DE); At the same time, LV ejection fraction (59.8 ± 2.6 vs 66.7 ± 5.9, P < 0.05) stroke volume (49 ± 14 vs 63 ± 11, P < 0.05) was improved significantly as well as normalization of IVS motion after transcatheter occlusion for ASD. The correlation between ASD diameter and change of LVEF is significant (r = 0.85, P < 0.001). Conclusion: Although transcatheter occlusion did not significantly impact on intrinsic LV systolic synchronicity in patients with ASD, LV systolic function can be improved through normalization of IVS abnormal motion after transcatheter ASD occlusion. (Echocardiography 2010;27:324‐328)     

Real time three-dimensional echocardiographic assessment of left ventricular function in heart failure patients: underestimation of left ventricular volume increases with the degree of dilatation

Background: Accurate quantification of left ventricular (LV) volumes and ejection fraction (EF) is of critical importance. Cardiac magnetic resonance (CMR) is considered as the reference and three-dimensional echocardiography (3DE) is an accurate method, but only few data are available in heart failure patients. We therefore sought to compare the accuracy of real time three-dimensional echocardiography (RT3DE) and two-dimensional echocardiography (2DE) for quantification of LV volumes and EF, relative to CMR imaging in an unselected population of heart failure patients. Methods and Results: We studied 24 patients (17 men, age 58 ± 15 years) with history of heart failure who underwent echocardiographic assessment of LV function (2DE, RT3DE) and CMR within a period of 24 hours. Mean LV end-diastolic volume (LVEDV) was 208 ± 109 mL (121 ± 64 mL/m(2) ) and mean LVEF was 31 ± 12.8%. 3DE data sets correlate well with CMR, particularly with respect to the EF (r: 0.8, 0.86, and 0.95; P < 0.0001 for LVEDV, LVESV, and EF, respectively) with small biases (-55 mL, -44 mL, 1.1%) and acceptable limits of agreement. RT3DE provides more accurate measurements of LVEF than 2DE (z= 2.1, P = 0.037) and lower variability. However, 3DE-derived LV volumes are significantly underestimated in patients with severe LV dilatation. In patients with LVEDV below 120 mL/m(2) , RT3DE is more accurate for volumes and EF evaluation. Conclusion: Compared with CMR, RT3DE is accurate for evaluation of EF and feasible in all our heart failure patients, at the expense of a significant underestimation of LV volumes, particularly when LVEDV is above 120 mL/m(2) .     

Assessment of left ventricular ejection fraction: comparison of two dimensional echocardiography, cardiac magnetic resonance imaging and 64-row multi-detector computed tomography

Objectives To compare left ventricular ejection fraction (LVEF) determined from 64-row multi-detector computed tomography (64-row MDCT) with those determined from two dimensional echocardiography (2D echo) and cardiac magnetic resonance imaging (CMR). Methods Thirty-two patients with coronary artery disease underwent trans-thoracic 2D echo, CMR and contrast-enhanced 64-row MDCT for assessment of LVEF within 48 hours of each other. 64-row MDCT LVEF was derived using the Syngo Circulation software; CMR LVEF was by Area Length Ejection Fraction (ALEF) and Simpson method and 2D echo LVEF by Simpson method. Results The LVEF was 49.13±15.91 % by 2D echo, 50.72±16.55% (ALEF method) and 47.65±16.58%(Simpson method) by CMR and 50.00±15.93% by 64-row MDCT. LVEF measurements by 64-row MDCT correlated well with LVEF measured with CMR using either the ALEF method (Pearson correlation r = 0.94, P <0.01) or Simpson method (r = 0.92, P<0.01). It also correlated well with LVEF measured using 2D echo (r = 0.80, P < 0.01). Conclusion LVEF measurements by 64-row MDCT correlated well with LVEF measured by CMR and 2D echo. The correlation between 64-row MDCT and CMR was better than the correlation between 2D echo with CMR. Standard data set from a 64-row MDCT coronary study can be reliably used to calculate the LVEF. (J Geriatr Cardiol 2006;3(1): 2-8)     

Fast Data Acquisition and Analysis with Real Time Triplane Echocardiography for the Assessment of Left Ventricular Size and Function: A Validation Study

Aims: To assess accuracy and reproducibility of real time simultaneous triplane echocardiography (RT3PE) for the assessment of left ventricular (LV) volumes and ejection fraction (EF) using cardiac magnetic resonance (CMR) as a reference method. Methods and Results: A total of 24 patients with various degrees of LV dysfunction (EF from 36 to 57%) in sinus rhythm with good image quality were enrolled in the study. Digital loops of apical views were recorded with standard two-dimensional imaging and with RT3PE. Echocardiography and CMR were performed within 1 hour. RT3PE measurements of LV end-diastolic volume, end-systolic volume, and EF resulted closely correlated to CMR (r = 0.95, 0.97, and 0.95, respectively) with small biases (−4 ml, −6 ml, and 1%, respectively) and narrow limits of agreement (SD = 15 ml, 12 ml, and 6%, respectively). Two-dimensional echocardiography ( 2DE) showed a weaker correlation with CMR (r = 0.85, 0.91, and 0.83, respectively; P < 0.06) with similar biases (−4 ml, −10 ml, 5%, respectively), but wider limits of agreement (SD = 28 ml, 21 ml, 10%, respectively, P < 0.007). RT3PE showed lower interobserver variability for the assessment of EF (SD = 2% vs. 5%, P = 0.03) and lower measurement time of LV EF (175 ± 54 sec vs. 241 ± 49 sec, respectively; P < 0.0001), as compared to 2DE. Conclusion: RT3PE allows simple and fast image acquisition and volume calculation. In addition, it allows more accurate and reproducible EF measurements than conventional 2DE.     

Left atrial volume estimation by two-dimensional echocardiography

We examined 12 patients aged six months to 76 years by echocardiography to determine left atrial volume. The results were compared with angiographic left atrial volumes calculated by the biplane Simpson's rule method. Three two-dimensional planes were used: precordial long axis, apical two-chamber, and four-chamber. Area outlines were traced using a light pen computational system providing single plane area length estimates of left atrial volume. The two apical left atrial outlines were combined, and Simpson's rule method was used to calculate left atrial volume. M-mode echocardio-grams performed on these patients were used to estimate left atrial volume. As the resuits of covariance analysis showed that there was no significant difference in the line of regression in systole and diastole, these data were pooled for subsequent comparison with angiography. The closest correlation with angiography was the biplane Simpson rule method with the echocardiographic left atrial volume (Y) = 1.0, angiographic volume (X) + 6.3 ml, r = 0.86. The single plane area length estimates also correlated well with angiography, but correction factors were required. M-mode estimates of left atrial volume could only correlate to angiography using a power function y = 3.7 X^1.80, r = 0.69. We conclude that left atrial volume can be determined by two-dimensional echocardiography and that this technique is superior to M-mode echocardiography.     

Assessment of left ventricular asynchrony using volume-time curves of 16 segments by real-time 3 dimensional echocardiography: comparison with tissue Doppler imaging

BACKGROUND: Recent technical developments with high-resolution real-time 3 dimensional echocardiography (RT3DE) facilitate the acquisition of high quality images and the analysis of segmental volume-time curves (VTCs). AIMS: To assess left ventricular (LV) asynchrony using the VTCs of 16 segments by RT3DE, and to evaluate accuracy compared to tissue Doppler imaging (TDI). METHODS: Twenty-three heart failure (HF) patients (LVEF: 25+/-6%, age: 60+/-13 years) and 16 normal controls underwent TDI and RT3DE. The standard deviation (SD3) of the end systolic time reaching minimal systolic volume for the 16 segments on VTCs was obtained by RT3DE. The standard deviation (SD2) of the electromechanical coupling time for the 8 segments was measured using TDI. RESULTS: SD3 was markedly higher in HF patients than in controls (7.7+/-2.5 vs 1.5+/-1.0%, P<0.01) and increased as LVEF decreased (r=-0.85, P<0.01). SD2 was also significantly higher in HF patients (27.0+/-8.6 vs 12.6+/-5.0 ms, P<0.01) and had a good negative correlation with LVEF (r=-0.72, P<0.01). SD3 was well correlated to SD2 (r=0.66, P<0.01). CONCLUSIONS: We suggest that analysis of VTCs in 16 segments using RT3DE may be a useful alternative to TDI for the evaluation of LV asynchrony.     

Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data.

AIMS: Determination of left ventricular (LV) volumes and ejection fraction (EF) from two-dimensional echocardiographic (2DE) images is subjective, time-consuming, and relatively inaccurate because of foreshortened views and the use of geometric assumptions. Our aims were (1) to validate a new method for rapid, online measurement of LV volumes from real-time three-dimensional echocardiographic (RT3DE) data using cardiac magnetic resonance (CMR) as the reference and (2) to compare its accuracy and reproducibility with standard 2DE measurements. METHODS AND RESULTS: CMR, 2DE, and RT3DE datasets were obtained in 50 patients. End-systolic and end-diastolic volumes (ESV and EDV) were calculated from the 2DE images using biplane method of disks. ES and ED RT3DE datasets were analysed using prototype software designed to automatically detect the endocardial surface using a deformable shell model and calculate ESV and EDV from voxel counts. 2DE and RT3DE-derived volumes were compared with CMR (linear regression, Bland-Altman analysis). In most patients, analysis of RT3DE data required <2 min per patient. RT3DE measurements correlated highly with CMR (r: 0.96, 0.97, and 0.93 for EDV, ESV, and EF, respectively) with small biases (-14 mL, -6.5 mL, -1%) and narrow limits of agreement (SD: 17 mL, 16 mL, 6.4%). 2DE measurements correlated less well with CMR (r: 0.89, 0.92, 0.86) with greater biases (-23 mL, -15 mL, 1%) and wider limits of agreement (SD: 29 mL, 24 mL, 9.5%). RT3DE resulted in lower intra-observer (EDV: 7.9 vs. 23%; ESV: 7.6 vs. 26%) and inter-observer variability (EDV: 11 vs. 26%; ESV: 13 vs. 31%). CONCLUSION: Semi-automated detection of the LV endocardial surface from RT3DE data is suitable for clinical use because it allows rapid, accurate, and reproducible measurements of LV volumes, superior to conventional 2DE methods.     

Value of real time three-dimensional echocardiography in patients with hypertrophic cardiomyopathy: comparison with two-dimensional echocardiography and magnetic resonance imaging

Real time three-dimensional echocardiography (RT3DE) has been demonstrated to be an accurate technique to quantify left ventricular (LV) volumes and function in different patient populations. We sought to determine the value of RT3DE for evaluating patients with hypertrophic cardiomyopathy (HCM), in comparison with cardiac magnetic resonance imaging (MRI). Methods: We studied 20 consecutive patients with HCM who underwent two-dimensional echocardiography (2DE), RT3DE, and MRI. Parameters analyzed by echocardiography and MRI included: wall thickness, LV volumes, ejection fraction (LVEF), mass, geometric index, and dyssynchrony index. Statistical analysis was performed by Lin agreement coefficient, Pearson linear correlation and Bland-Altman model. Results: There was excellent agreement between 2DE and RT3DE (Rc = 0.92), 2DE and MRI (Rc = 0.85), and RT3DE and MRI (Rc = 0.90) for linear measurements. Agreement indexes for LV end-diastolic and end-systolic volumes were Rc = 0.91 and Rc = 0.91 between 2DE and RT3DE, Rc = 0.94 and Rc = 0.95 between RT3DE and MRI, and Rc = 0.89 and Rc = 0.88 between 2DE and MRI, respectively. Satisfactory agreement was observed between 2DE and RT3DE (Rc = 0.75), RT3DE and MRI (Rc = 0.83), and 2DE and MRI (Rc = 0.73) for determining LVEF, with a mild underestimation of LVEF by 2DE, and smaller variability between RT3DE and MRI. Regarding LV mass, excellent agreement was observed between RT3DE and MRI (Rc = 0.96), with bias of − 6.3 g (limits of concordance = 42.22 to − 54.73 g) . Conclusion: In patients with HCM, RT3DE demonstrated superior performance than 2DE for the evaluation of myocardial hypertrophy, LV volumes, LVEF, and LV mass.     

Real-time 3-dimensional echocardiography evaluation of intracardiac masses

The size of an intracardiac mass (vegetation, tumor, or thrombus) is an important predictor for embolic events and for response to treatment. Maximum diameter measurements from two-dimensional (2D) echocardiography are routinely used to determine mass size. However, most masses are irregularly shaped, making it difficult to accurately image or select the largest diameter. The selection of a diameter that is not truly the largest may lead to underestimation of the true size of the mass and a misrepresentation of the patients' prognosis. Three-dimensional (3D) echocardiography images the entire volume of a mass allowing for accurate measurements in multiple planes. We tested the hypothesis that measurements of the maximum diameter of a mass by 3D echocardiography are larger than those obtained by 2D echocardiography. METHODS: Patients with findings of an intracardiac mass by 2D transthoracic (TTE) or transesophageal (TEE) echocardiogram were imaged using real-time three-dimensional echocardiography (RT3DE) within 24 hours. The complete mass was acquired on RT3DE. Maximum mass diameter was measured on 2D and RT3DE. Comparison of measurements between RT3DE and 2D was performed using correlation coefficients and Bland-Altman analyses. RESULTS: In 19 masses evaluated in 17 patients, there was a strong correlation between 2D TTE and RT3DE maximum diameter measurements (R2 = 0.88, P < 0.01) but correlation was fair for 2D TEE (R2 = 0.48, P = 0.02). In addition, 2D maximum diameter also correlated with 3D volumes (R2 = 0.72, P < 0.01 for TTE and R2 = 0.56, P < 0.01 for TEE). However, there was a consistent underestimation of maximum diameter measured by 2D (TTE and TEE) regardless of the size, location, and etiology of the mass. 2D TTE underestimates cardiac mass size by 24.6% (P < 0.001) compared to RT3DE and 2D TEE underestimated size by 19.8% (P = 0.01). CONCLUSION: These findings suggest that RT3DE may be the technique of choice for the noninvasive evaluation of intracardiac mass size.     

Evaluation of right ventricular regional volume and systolic function in patients with pulmonary arterial hypertension using three-dimensional echocardiography

Objective: To evaluate right ventricular (RV) regional volume and systolic function in patients with pulmonary arterial hypertension (PAH) using real time three‐dimensional echocardiography (RT3DE), and to explore the relationship between parameters measured by RT3DE and right heart catheterization (RHC). Methods: RT3DE images were acquired from 24 patients with PAH and 27 normal controls for evaluation and analysis to obtain RV regional end‐diastolic volume (EDV), end‐systolic volume (ESV), ejection fraction (EF) in three compartments (inflow, body, and outflow). Conventional echocardiographic parameters were calculated and recorded. RHC was performed in 17 patients to obtain pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR). Results: RV regional EDV and ESV were significantly higher while regional EF was significantly lower in the PAH patients when compared with controls (P < 0.001). In the PAH group, EDV was similar in the inflow and body compartment, both higher than that in the outflow compartment (P < 0.05); EF was the highest in the inflow compartment and the lowest in the body compartment (P < 0.05). RV regional EF in the inflow compartment and global EF were negatively correlated with PASP (r =–0.766, –0.816, P < 0.001) and PVR (r =–0.529, –0.656, P < 0.05). Conclusions: In patients with PAH, RV regional volume was enlarged and systolic function was impaired with distinct characteristics; regional EF in the inflow compartment and global EF were inversely correlated with PASP and PVR. Evaluation of RV regional systolic function using RT3DE may play a potential role in the noninvasive assessment of the severity of PAH. (Echocardiography 2012;29:706‐712)     

Global and regional left ventricular function assessment with 16-detector row CT: comparison with echocardiography and cardiovascular magnetic resonance.

AIMS: To compare multidetector row computed tomography (MDCT) global and regional left ventricular (LV) function assessment with echocardiography and cardiovascular magnetic resonance (CMR). METHODS AND RESULTS: In 25 patients, who were referred for noninvasive angiography with 16-detector row CT, LV function assessment was also performed. A subsequent echocardiogram was performed, and in a subgroup of patients, CMR examination was completed to evaluate LV function. For global function assessment, the LV ejection fraction (LVEF) was calculated. Regional LV function was scored using a 17-segment model and a 4-point scoring system. MDCT agreed well with echocardiography for the assessment of LVEF (r=0.96; bias 0.54%; p<0.0001) and regional LV function (kappa=0.78). Eight patients had no contra-indications and gave informed consent for CMR examination. A fair correlation between MDCT and CMR was demonstrated in the assessment of LVEF (r=0.86; bias -1.5%; p<0.01). Regional LV function agreement between MDCT and CMR was good (kappa=0.86). CONCLUSION: MDCT agreed well with both echocardiography and CMR in the assessment of global and regional LV function. Global and regional LV function may accurately be evaluated by 16-detector row CT, and can be added to a routine CT image analysis protocol without need for additional contrast or imaging time.     

Real time three-dimensional stress echocardiography: a new approach for assessing diastolic function

Objective: To assess the feasibility of utilizing real time three‐dimensional echocardiography (RT3DE) for assessment of diastolic function during stress. Methods: Rest and stress volumes were acquired in 24 patients and parameters of diastolic function—peak ventricular filling rate (PFR) and time to peak filling rate (TPFR)—were calculated. Results: Calculation of diastolic parameters was feasible in all patients. Resting PFR correlated with end‐diastolic (EDV) and stroke volumes and inversely with TPFR (r = 0.53, 0.66, –0.5). With stress, PFR increased by 93% and TPFR decreased by 23% (P < 0.001). Stress PFR correlated with stress heart rate, EDV and stroke volume (r = 0.52, 0.50, 0.62) while TPFR correlated inversely with heart rate (r =–0.71). The change in PFR with stress correlated with the change in stroke volume (r = 0.42), while the change in TPFR correlated with the change in end‐systolic volume (ESV) (r = 0.43) and inversely with the change in diastolic blood pressure (r =–0.41). Rest and stress PFR and TPFR are independent of age, gender and blood pressure and the change in PFR is independent of stress heart rate or blood pressure. E/E′ correlated with stress TPFR (r = 0.72) and change in TPFR (r = 0.67) and inversely with change in PFR (r =–0.67). Conclusions: RT3DE can assess diastolic function during stress by detecting changes in PFR and TPFR, independent of gender, age, and blood pressure. The changes in these parameters with stress are influenced by baseline filling pressures. Larger studies are required to validate the clinical significance of these observations. (Echocardiography 2011;28:676‐683)     

A pilot study of systolic dyssynchrony index by real time three-dimensional echocardiography and Doppler tissue imaging parameters predicting the hemodynamic response to biventricular pacing in the early postoperative period after cardiac surgery

Objective: To evaluate systolic dyssynchrony index (SDI) measured by real time three‐dimensional echocardiography (RT3DE) and Doppler tissue imaging (DTI) dyssynchrony parameters in predicting the hemodynamic response to biventricular (BIV) pacing in the early postoperative period after cardiac surgery. To compare right ventricular (RV) and BIV pacing using invasively measured hemodynamic values. Methods: A prospective randomized clinical study enrolling 11 patients with ischemic heart disease, concomitant valvular heart disease, and left ventricular ejection fraction (LVEF) ≤ 35% comparing preoperative SDI by RT3DE and DTI LV dyssynchrony parameters to hemodynamic values obtained during RV or BIV sequential (DDD) epicardial pacing in the first 72 hours after cardiac surgery. Results: BIV pacing produced a statistically significant higher cardiac output (CO) (6.27 ± 1.55 L/min) and cardiac index (CI) (3.44 ± 0.93 L/min per m²) than RV pacing (CO 5.44 ± 0.97 L/min, CI 3.03 ± 0.83 L/min per m², P < 0.05). We found a statistically moderate correlation between preoperative SDI by RT3DE and CO (r = 0.596, P < 0.05) and a nonsignificant correlation to CI (r = 0.535, P < 0.10) during BIV pacing. No correlation was observed between DTI dyssynchrony parameters and measured hemodynamic values. BIV pacing reduced the ICU stay and inotropic support requirements of patients after heart surgery. Conclusions: SDI measured preoperatively using RT3DE can predict CO during BIV pacing in the early postoperative period after cardiac surgery. BIV pacing is more hemodynamically effective than RV pacing in patients with LV dysfunction after coronary artery bypass grafting with or without a valve procedure.     

Validation of real-time three-dimensional echocardiography for quantifying left ventricular volumes in the presence of a left ventricular aneurysm: in vitro and in vivo studies

OBJECTIVES: To validate the accuracy of real-time three-dimensional echocardiography (RT3DE) for quantifying aneurysmal left ventricular (LV) volumes. BACKGROUND: Conventional two-dimensional echocardiography (2DE) has limitations when applied for quantification of LV volumes in patients with LV aneurysms. METHODS: Seven aneurysmal balloons, 15 sheep (5 with chronic LV aneurysms and 10 without LV aneurysms) during 60 different hemodynamic conditions and 29 patients (13 with chronic LV aneurysms and 16 with normal LV) underwent RT3DE and 2DE. Electromagnetic flow meters and magnetic resonance imaging (MRI) served as reference standards in the animals and in the patients, respectively. Rotated apical six-plane method with multiplanar Simpson's rule and apical biplane Simpson's rule were used to determine LV volumes by RT3DE and 2DE, respectively. RESULTS: Both RT3DE and 2DE correlated well with actual volumes for aneurysmal balloons. However, a significantly smaller mean difference (MD) was found between RT3DE and actual volumes (-7 ml for RT3DE vs. 22 ml for 2DE, p = 0.0002). Excellent correlation and agreement between RT3DE and electromagnetic flow meters for LV stroke volumes for animals with aneurysms were observed, while 2DE showed lesser correlation and agreement (r = 0.97, MD = -1.0 ml vs. r = 0.76, MD = 4.4 ml). In patients with LV aneurysms, better correlation and agreement between RT3DE and MRI for LV volumes were obtained (r = 0.99, MD = -28 ml) than between 2DE and MRI (r = 0.91, MD = -49 ml). CONCLUSIONS: For geometrically asymmetric LVs associated with ventricular aneurysms, RT3DE can accurately quantify LV volumes.     

Comparison of contrast agent-enhanced versus non-contrast agent-enhanced real-time three-dimensional echocardiography for analysis of left ventricular systolic function

Ultrasound contrast has shown to improve endocardial border definition. The purpose of this study was to evaluate the value of contrast agent-enhanced versus non-contrast agent-enhanced real-time 3-dimensional echocardiography (RT3DE) for the assessment of left ventricular (LV) volumes and ejection fraction. Thirty-nine unselected patients underwent RT3DE with and without SonoVue contrast agent enhancement and magnetic resonance imaging (MRI) on the same day. An image quality index was calculated by grading all 16 individual LV segments on a scale of 0 to 4: 0, not visible; 1, poor; 2, moderate; 3, good; and 4, excellent. The 3-dimensional data sets were analyzed offline using dedicated TomTec analysis software. By manual tracing, LV end-systolic volume, LV end-diastolic volume, and LV ejection fraction were calculated. After contrast agent enhancement, mean image quality index improved from 2.4 +/- 1.0 to 3.0 +/- 0.9 (p <0.001). Contrast agent-enhanced RT3DE measurements showed better correlation with MRI (LV end-diastolic volume, r = 0.97 vs 0.86; LV end-systolic volume, r = 0.96 vs 0.94; LV ejection fraction, r = 0.94 vs 0.81). The limits of agreement (Bland-Altman analysis) showed a similar bias for RT3DE images with and without contrast agent but with smaller limits of agreement for contrast agent-enhanced RT3DE. Also, inter- and intraobserver variabilities decreased. In a subgroup, patients with poor to moderate image quality showed an improvement in agreement after administration of contrast agent (+/-24.4% to +/-12.7%) to the same level as patients with moderate to good image quality without contrast agent (+/-10.4%). In conclusion, contrast agent-enhanced RT3DE is more accurate in assessment of LV function as evidenced by better correlation and narrower limits of agreement compared with MRI, as well as lower intra- and interobserver variabilities.     

Measurement of Left Ventricular Ejection Fraction by Real Time 3D Echocardiography in Patients with Severe Systolic Dysfunction: Comparison with Radionuclide Angiography

Aim: Measurement of left ventricular ejection fraction (LVEF) using real time 3D echocardiography (3DE) has been performed in subjects with preserved or modestly reduced systolic function. Our aim was to evaluate this technique in the subset of patients with severe systolic dysfunction. Methods and results: Consecutive patients with LVEF less than 0.35 at two-dimensional echocardiography were included. LVEF obtained by 3DE was compared to the value measured by radionuclide angiography (RNA). Real time full-volume 3DE was performed, with offline semiautomated measurement of LVEF using dedicated software (Cardioview RT, Tomtec) by a single observer blinded to the results of RNA. A total of 50 patients were evaluated, of whom 38 (76%, 27 males, age 69 ± 13 years) had a 3DE of sufficient quality for analysis. LVEF for this group was 0.21 ± 0.07 using 3DE and 0.27 ± 0.08 using RNA. The agreement between the two techniques was rather poor (r = 0.49; P < 0.001; 95% limits of agreements of −0.20 to 0.09). Truncation of the apex was observed in 6 of 38 (16%) patients. Conclusion: In patients with severe systolic dysfunction, 3DE shows poor agreement for measurement of LVEF as compared to RNA. There may be underestimation of up to 20% in absolute terms by 3DE. Accordingly, the two methods are not interchangeable for the follow-up of LV function. A limitation of 3DE may, at least in part, be related to the incomplete incorporation of the apical region into the pyramidal image sector in patients with dilated hearts. (Echocardiography 2010;27:58-63)