A meta-analysis of the effect of exercise training on left ventricular remodeling in heart failure patients: the benefit depends on the type of training performed.

OBJECTIVES: The aim of this study was to determine the effect of exercise training and type of exercise (aerobic vs. strength vs. combined training) on left ventricular (LV) remodeling in heart failure (HF). BACKGROUND: A number of randomized controlled trials have examined the effect of exercise training on LV remodeling in individuals with HF. However, the results of these trials have been inconclusive. METHODS: The authors searched MEDLINE (1966 to 2006), Cochrane Central Register of Controlled Trials (issue #3, 2006), CINAHL (1982 to 2006), EMBASE (1988 to 2006), PubMed (1966 to 2006), and reference lists of identified studies for randomized controlled trials examining the effects of exercise training on ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) in clinically stable patients with HF. Primary study authors were also contacted if appropriate. Studies were selected and data were extracted independently by 2 reviewers. Weighted mean differences (WMD) were calculated using a random effects model. RESULTS: Fourteen trials reported EF data (n = 812 patients). Seven trials reported both EDV and ESV data (n = 569). Aerobic training significantly improved EF (9 trials, 538 patients, WMD = 2.59%; 95% confidence interval [CI] 1.44% to 3.74%), EDV (371 patients; WMD = -11.49 ml; 95% CI -19.95 to -3.02 ml) and ESV (371 patients; WMD = -12.87 ml; 95% CI -17.80 to -7.93 ml). Combined aerobic and strength training was not associated with significant improvements in EF, EDV, or ESV. CONCLUSIONS: Aerobic training reverses LV remodeling in clinically stable individuals with HF. This benefit was not confirmed with combined aerobic and strength training.     

Cardiac MRI assessment of left and right ventricular parameters in healthy Australian normal volunteers

Cardiac magnetic resonance imaging (MRI) is being utilised increasingly for the purposes of cardiovascular imaging. Limited data suggest a high degree of reproducibility for parameters such as left ventricular (LV) ejection fraction (EF), mass, end-diastolic and end-systolic volumes (EDV and ESV). We sought to investigate reproducibility and establish means for these parameters in a selected normal non-Aboriginal Australian population, using cardiac MRI. Sixty normal volunteers underwent cardiac MRI investigation using a 1.5 T MRI system. Steady state free precession imaging was performed with short axis cine images through the left ventricle obtained. All images were acquired with cardiac gating. Two independent observers then analysed the data set. Data were collected for assessment of left ventricular EF, EDV, ESV, mass and right ventricular volumes. Data are presented as mean+/-S.D. Total imaging time was approximately 15 min. All patients were able to complete the full protocol. Left ventricular parameters: EF 58.5+/-8.0%, LV mass 114.2+/-40.6g, EDV 117.3+/-33.4 mls and ESV 50.0+/-22.2 mls. Right ventricular parameters: EF 45.6+/-11.6%, EDV 163.5+/-52.2 mls and ESV 89.5+/-34.3 mls. Intraclass correlation coefficients for LV: EF 0.84, LV mass 0.84, EDV 0.85 and ESV 0.89. Cardiac MRI provides high quality information about cardiac function with a high level of reproducibility. Cardiac MRI parameters in a normal non-Aboriginal Australian population are provided.     

Differences in left ventricular ejection fraction and volumes measured at rest and poststress by gated sestamibi SPECT.

BACKGROUND: Some studies suggested that the poststress left ventricle ejection fraction (LV EF) is lower than rest LV EF in patients with stress-induced ischemia. METHODS AND RESULTS: By using a 2-day protocol and 30 mCi Tc-99m sestamibi, LV EF, end-systolic volume (ESV), and end-diastolic volume (EDV) were measured with gated SPECT. Of 99 eligible patients, 91 had technically adequate studies. Poststress LV EF minus rest LV EF was defined as DeltaLV EF. DeltaEDV and DeltaESV were similarly defined. Rest and poststress LV EF (r = 0.89), EDV (r = 0.78), and ESV (r = 0.93) were highly correlated (P <.001). Rest LV EF, EDV, and ESV were not significantly different between patients with and without stress-induced ischemia. DeltaLV EF was significantly lower in patients with stress-induced ischemia (-3.5% +/- 4.5% vs -1.1% +/- 4.7%, P = .02). Mean LV EF poststress in ischemic patients was 55.0% +/- 10.5% vs 61.2% +/- 10.0% in nonischemic patients (P = .008). However, only 1 patient (3%) with ischemia had DeltaLV EF that exceeded the 95% confidence limit of DeltaLV EF for normal patients. Ischemia was significantly associated with increased DeltaEDV and DeltaESV (P < .01). CONCLUSIONS: Stress-induced ischemia is associated with poststress reduction in LV EF and increased poststress EDV and ESV. However, the effect of ischemia on the difference between poststress and rest EF measurements is modest and rarely exceeds the confidence limits in normal patients undergoing 2-day protocols. In most patients, poststress LV EF is an accurate reflection of rest LV EF.     

实时三维超声心动图与磁共振对比评价左心室射血分数≥45%患者的左心室容量

目的:评价实时三维超声心动图(RT3D)测量左心室射血分数(LVEF)≥45% 成年人左心室容量的准确性和重复性.方法:选取因各种不同原因进行心脏磁共振(MRI)检查显示 LVEF ≥45%的患者37例,同时进行RT3D检查.RT3D检查采用Philips iE-33型超声心动图仪,左心室容量及左心室功能的分析通过TomTec工作站用人工描记法完成,并与MRI所得结果相比较.结果:MRI测量的左心室舒张末期容量(EDV)为:60～208.76(110.48±33.50)ml,左心室收缩末期容量(ESV)为:19～102.4(45.80±17.84 )ml,LVEF为:45.40～71.10(59.13±7.24)%.RT3D测量的EDV为:42.8～ 211.9(100.64±34.48)ml,ESV为:14.30 ～94.54(44.08 ±17.62)ml,LVEF为:35.1～73.4(56.70±7.02)%.与MRI相比,RT3D低估EDV(P＜0.01,r=0.842,y=0.867x+4.88,SEE=18.86ml),二者平均相差(-9.84±38.26) ml.RT3D同时低估ESV,二者相比差异无统计学意义(P＞0.05,r=0.846,y=0.835x+5.82,SEE=9.53 ml),二者平均相差(-1.71±19.68)ml.RT3D所测的LVEF稍小于MRI所测得的LVEF,二者相比差异有统计学意义(P＜0.05,r=0.616,y=0.597x+21.38,SEE=5.61%),平均相差(-2.42±12.5 )%.在不同观察者间及观察者自身不同时间内测量的RT3D,结果显示良好的重复性.结论:与MRI相比,RT3D测量成人患者的左心室容量及LVEF有较好的准确性和重复性.     

Comparison of gated blood pool SPECT and multi-detector row computed tomography for measurements of left ventricular volumes and ejection fraction in patients with atypical chest pain: validation with radionuclide ventriculography

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare GBPS, multi-row detector spiral computed tomography (MDCT), and PRNV for the determination of left ventricular ejection fraction (LVEF) and left ventricular volumes (LV) in subjects with atypical chest pain. METHOD: Twenty-three consecutive patients (14 men, 9 women; mean age 56.2 +/- 9.5 years) referred for MDCT for evaluation of atypical chest pain. All patients underwent PRNV, GBPS, and MDCT at the same day. RESULTS: The mean LVEFs calculated with PRNA (57.3 +/- 8.6%), GBPS (55.2 +/- 6.6%), and MDCT (56 +/- 9.1%) were not statistically different (F value 0.3374, p = 0.715). Comparison of LVEFs from GBPS and MDCT yielded correlation coefficients of 0.5238 (p = 0.0178, 95% CI = 0.1057-0.7845). The correlation of LVEFs between GBPS and PRNV showed a correlation coefficient of 0.8073 (p < 0.0001, 95% CI = 0.5676-0.9209) and 0.6190 (p = 0.0036, 95% CI = 0.2431-0.8333) between MDCT and PRNV. The mean LV end-diastolic volume (EDV) calculated with GBPS (82.7 +/- 17.5 ml) was significantly lower than MDCT (106.8 +/- 18.5 ml) (p = 0.0001). The mean LV end-systolic volume (ESV) calculated with GBPS (37.2 +/- 9.6 ml) was also significantly lower than MDCT (48.1 +/- 15.8 ml) (p = 0.012). Comparison of EDV from GBPS and MDCT yielded a correlation coefficient of 0.5220 (p = 0.0182, 95% CI = 0.1033-0.7835). The correlation of ESV between GBPS and MDCT showed a correlation coefficient of 0.6642 (p = 0.0014, 95% CI = 0.3140-0.8553). CONCLUSION: In conclusion, the LVEF, EDV, and ESV calculated by GBPS correlated significantly with those of obtained with 16-MDCT. In addition, there were no statistical differences of LVEF calculated from PRNV, GBPS, and MDCT. However, with regard to LV, EDV and ESV from GBPS revealed statistically significantly lower than those of MDCT. Also, these results should be addressed whether similar results could also be found in patients with cardiac diseases by the consequent larger population-based study.     

New generation 3-dimensional echocardiography for left ventricular volumetric and functional measurements: comparison with cardiac magnetic resonance.

AIMS: Non-invasive assessment of left ventricular (LV) structure and function is important in the evaluation of cardiac patients. This study was designed to test the accuracy and reproducibility of new generation 3-dimensional echocardiography (3DE) in measuring volumetric and functional LV indices as compared with current "gold standard" of non-invasive cardiac imaging, cardiac magnetic resonance (CMR). METHODS AND RESULTS: Sixty-four subjects with good acoustic windows, including 40 cardiac patients with LV ejection fraction (EF)<45%, 14 patients with EF>45% and 10 normal volunteers underwent 3DE using a commercially available Philips Sonos 7500 scanner equipped with a matrix phase-array x4 xMATRIX transducer, and CMR on a 1.5 T Signa CV/i scanner (GE Medical Systems). Volumetric assessment was performed with analytical 4D-LV-Analysis software (TomTec) for 3DE and MRI-Mass software (Medis) for CMR. We found no significant differences in LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF with excellent correlations between the indices measured using 3DE and CMR (r=0.97, r=0.98, and r=0.94, respectively). Bland-Altman analysis showed bias of 7 ml for EDV, 3 ml for ESV and -1% for EF with 3DE with corresponding limits of agreement (2SD) of 28 ml, 22 ml and 10%, respectively. Intraobserver and interobserver variabilities were for EDV: 3% and 4% (3DE) vs 2% and 2% (CMR), for ESV: 3% and 6% (3DE) vs 2% and 3% (CMR), and for EF: 4% and 4% (3DE) vs 2% and 4% (CMR), respectively. CONCLUSION: New generation 3DE provides accurate and reproducible quantification of LV volumetric and functional data in subjects with good acoustic windows as compared with CMR.     

Evaluation of global and regional left ventricular function obtained by quantitative gated SPECT using 99mTc-tetrofosmin for left ventricular dysfunction

OBJECTIVE: The quantitative gated SPECT (QGS) software is able to calculate LV volumes and visualize LV wall motion and perfusion throughout the cardiac cycle using an automatic edge detection algorithm of the left ventricle. We evaluated the reliability of global and regional LV function assessment derived from QGS by comparing it with the results from left ventriculo-cineangiography (LVG). PATIENTS: In 20 patients with left ventricular dysfunction who underwent ECG gated 99mTc-tetrofosmin SPECT, the end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were calculated. The QGS-assessed regional wall motion was determined using the cinematic display. RESULTS: QGS-derived EDV, ESV and LVEF correlated well with those by LVG (p<0.001 for each). There was a good correlation between wall motion score (WMS) derived from the QGS and the LVG (r=0.40, p<0.05). In some patients with extensive myocardial infarction, there was a discrepancy in the regional wall motion results between QGS and LVG. CONCLUSIONS: The ECG-gated SPECT using QGS is useful to evaluate global and regional LV functions in left ventricular dysfunction.     

Freehand three-dimensional echocardiography with rotational scanning for measurements of left ventricular volume and ejection fraction in patients with coronary artery disease

BACKGROUND: Measurement of left ventricular (LV) volumes and ejection fraction (EF) is important in managing patients with coronary artery disease (CAD). Introduction of free-hand three-dimensional echocardiography (3DE) system which is equipped with small magnetic tracking system and average rotational geometry for LV volumes may provide easy and accurate quantification of LV systolic function in CAD patients. PURPOSE: To evaluate the feasibility and accuracy of LV volumes and EF measurement by free-hand 3DE with rotational geometry in patients with CAD. METHODS AND RESULTS: The study subjects consisted of consecutive 25 patients with CAD who were scheduled for quantitative gated single-photon emission computed tomography (QGS). LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF were determined by conventional two-dimensional echocardiography (2DE), 3DE, and QGS. Three-dimensional echocardiography data acquisition and analysis were possible in 22 of 25 subjects (feasibility 88%). In this 3DE system, image acquisition time was 2 minutes, and 5 minutes were needed for off-line analysis of LV volumes and EF. Correlations and the limits of agreement between 3DE and QGS (r = 0.97, 0.0 +/- 9.1 ml for EDV, r = 0.99, 0.0 +/- 5.0 ml for ESV, and r = 0.97, 0.5 +/- 3.3% for EF, respectively) were superior to those between 2DE and QGS (r = 0.85, 12.6 +/- 26.8 ml for EDV, r = 0.85, 9.7 +/- 26.1 ml for ESV, and r = 0.90, -1.3 +/- 6.9% for EF, respectively). Inter- and intra-observer variabilities of 3DE were smaller than that of 2DE (5% vs 10%, 5% vs 10% for EDV, 6% vs 13%, 5% vs 9% for ESV, and 4% vs 11%, 4% vs 6% for EF, respectively). CONCLUSION: Three-dimensional echocardiography using magnetic tracking system and average rotational geometry offered a feasible and accurate method for quantification of LV volumes and EF in patients with CAD.     

High-resolution transthoracic real-time three-dimensional echocardiography: quantitation of cardiac volumes and function using semi-automatic border detection and comparison with cardiac magnetic resonance imaging

OBJECTIVES: We sought to validate high-resolution transthoracic real-time (RT) three-dimensional echocardiography (3DE), in combination with a novel semi-automatic contour detection algorithm, for the assessment of left ventricular (LV) volumes and function in patients. BACKGROUND: Quantitative RT-3DE has been limited by impaired image quality and time-consuming manual data analysis. METHODS: Twenty-four subjects with abnormal (n = 14) or normal (n = 10) LVs were investigated. The results for end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) obtained by manual tracing were compared with the results determined by the semi-automatic border detection algorithm. Moreover, the results of the semi-automatic method were compared with volumes and EF obtained by cardiac magnetic resonance imaging (CMRI). RESULTS: Excellent correlation coefficients (r = 0.98 to 0.99) and low variability (EDV -1.3 +/- 8.6 ml; ESV -0.2 +/- 5.4 ml; EF -0.1 +/- 2.7%; p = NS) were observed between the semi-automatically and manually assessed data. The RT-3DE data correlated highly with CMRI (r = 0.98). However, LV volumes were underestimated by RT-3DE compared with CMRI (EDV -13.6 +/- 18.9 ml, p = 0.002; ESV -12.8 +/- 20.5 ml, p = 0.005). The difference for EF was not significant between the two methods (EF 0.9 +/- 4.4%, p = NS). Observer variability was acceptable, and repeatability of the method was excellent. CONCLUSIONS: The RT-3DE, in combination with a semi-automatic contour tracing algorithm, allows accurate determination of cardiac volumes and function compared with both manual tracing and CMRI. High repeatability suggests applicability of the method for the serial follow-up of patients with cardiac disease.     

Semiautomatic Quantification of Left Ventricular Function by Two‐Dimensional Feature Tracking Imaging Echocardiography. A Comparison Study with Cardiac Magnetic Resonance Imaging

Objective: To evaluate the accuracy of a semiautomatic quantification of left ventricular (LV) volumes and ejection fraction (EF) using two‐dimensional (2D) feature tracking imaging (FTI). Methods: Thirty‐four consecutive subjects (11 patients with dilated cardiomyopathy, 13 with hypertrophic cardiomyopathy, and 10 subjects with no cardiac disease) underwent, on the same day, trans‐thoracic echocardiography (TTE) examination, FTI, and cardiac magnetic resonance imaging (MRI), as gold standard, in order to quantify LV volumes and EF. The echocardiographic quantification of LV volumes and EF was determined from four‐ and two‐chamber views using both standard TTE Biplane Simpson's method and a semiautomatic border detection based on FTI. Furthermore, the time for data analysis for each method was measured. Results: The time required for semiautomatic analysis of volumes and EF was significantly lower (P < 0.0001) by FTI (71 seconds) in comparison with standard biplane Simpson's method (93 seconds). LV volumes obtained by FTI were significant underestimated (P < 0.001) in comparison with MRI. Bland‐Altman analysis of EDV and ESV using FTI and cardiac MRI showed a low level of agreement for EDV (mean difference = 40.8; SD = 39) and ESV (mean difference = 38.1; SD = 42). On the contrary, no significant difference between FTI and MRI in assessing the LVEF was found; furthermore, a very low bias (2 ± 12) by Bland‐Altman analysis was found between FTI and cardiac MRI for the quantification of EF. Conclusion: Semiautomatic quantification of LV volumes using FTI allows an accurate, rapid, easy and reliable assessment of LV EF and a rough estimation of LV volumes. (Echocardiography 2010;27:791‐797)     

Verification of the left ventricular ejection fraction from gated myocardial perfusion studies (GSPECT)

INTRODUCTION: The perfusion study (which may be obtained using SPECT or GSPECT technology within six hours of administration of the radionuclide Tc-99m-MIBI) reflects the regional blood supply to the left ventricular [LV] myocardium at the time of radionuclide administration (i.e. at rest, at peak exercise, or at peak vasodilatation), while the values of EF, EDV, and ESV measured using GSPECT are parameters of LV contractility at the time of image acquisition (i.e. at rest or in a nearresting state following exercise or vasodilatation). Planar radionuclide ventriculography [RNV] is, however, considered to be the most accurate method for calculating LVEF. AIMS: The main goal of the study was to compare the values of EF obtained by the most frequently used method, GSPECTQGS, and the reference method, RNV - taking into consideration various clinical scenarios (presence or absence of LV dilatation) and various conditions under which GSPECT was recorded (at rest, post-exercise, or post-dipyridamole). METHODS: Two hundred patients (145 males) aged 58+/-11 (18-80) with previously confirmed (n=166, of whom 108 had a history of myocardial infarction) or suspected (n=34) coronary artery disease were included in the study. Ranges of normal values for EF, EDV, and ESV were established based on a group of 26 'normal' subjects. LV dilatation was defined as an EDV >127 ml (at rest, measured by QGS) - this was present in 88 patients. Myocardial perfusion studies were obtained using GSPECT following administration of Tc-99m-MIBI at rest (all patients), as well as one hour after treadmill exercise (138 patients) or dipyridamole administration (48 patients). The resting RNV was conducted within three weeks of the GSPECT exam. The EF values obtained by QGS and RNV were compared for patients with and without LV dilatation. EF, EDV, and ESV values obtained by QGS were compared for resting patients, post-exercise, and post-dipyridamole. RESULTS: 1. The GSPECT EF values calculated using QGS software, at rest or one hour after treadmill exercise or dipyridamole administration, demonstrated, for the study population as a whole, a significant, strong correlation with the results obtained by the reference method, RNV (correlation coefficient, r> or =0.86). The correlation was stronger in patients with LV dilatation than in those without. Both in patients with and without LV dilatation the correlation of EF with RNV was slightly weaker for postexercise (relative to resting) and post-dipyridamole (relative to post-exercise) measurements. 2. QGS tended to underestimate the absolute values of EF, as compared to RNV. 3. In post-exercise and post-dipyridamole measurements, relative to the resting measurements (in patients with previously diagnosed or suspected coronary artery disease) the mean values of EF were lower while EDV and ESV were higher. CONCLUSIONS: In order to complement data on myocardial perfusion, the GSPECT-QGS technique should be optimally used to calculate LV contractility parameters at rest (as opposed to post-exercise or post-dipyridamole), and include a range of normal values for EF, EDV, and ESV, obtained using QGS. Of note, EF measurements by GSPECT are more accurate for dilated than non-dilated ventricles.     

Unbiased and efficient estimation of left ventricular volumes by three-dimensional echocardiography with coaxial sections. Validation with magnetic resonance imaging

The objective of this study was to investigate the degree of bias with coaxial three-dimensional echocardiography in an experimental animal setup and to establish the minimum number of sections needed for estimation of left ventricular (LV) volume. Epicardial coaxial echocardiography and magnetic resonance imaging (MRI) was used to measure LV volume in 14 pigs, with chronic remodeled left ventricles induced by repeated intracoronary microembolizations. In addition, six animals underwent serial MRI at baseline, immediately after intracoronary microembolization, and after 119–165 days (mean 129 days). Coaxial echocardiography was performed by rotational acquisition of long-axis sections starting from an arbitrary angle. Planimetered MRI contours of LV endocardial borders were analyzed to investigate the relationship between the number of coaxial sections, and the precision of volume estimates. The mean ± 2SD of the differences between coaxial epicardial echocardiography with six sections and MRI were −2.5 ± 16.4 ml, 0.8 ± 13. 1 ml, and 2% ± 14% for end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF), respectively. Numerical analysis conducted on MRI contours of LV endocardial borders showed that with six coaxial sections the average coeffi-cient of error was <1% for the EDV and ESV. Three-dimensional echocardiography with six coaxial sections provides unbiased LV volume estimation with minimal geometric error. Received: February 10, 2000 / Accepted: May 23, 2000     

Evaluation of left ventricular contractile pattern by intravenous digital subtraction ventriculography: Comparison with cineangiography and assessment of interobserver variability

The accuracy and reproducibility of measurements of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and regional wall motion obtained by digital subtraction ventriculography (DSV) were compared with values of direct cineangiography in 40 patients, 21 of whom were ambulatory. DSV was performed with a 1-second, 30-ml contrast injection, which yielded real-time fluoroimages composed of 512 × 512 pixels at 30 frames/s. Single-plane right anterior oblique LV volumes were calculated by area-length methods for both DSV and cineangiography. Wall motion was assessed as percent area shortening for 12 equal myocardial segments, with results classified as abnormal if greater than 2 standard deviations below the mean of 20 normal values. DSV exhibited close correlation with angiography for EDV (r = 0.88), ESV (r = 0.92) and EF (r = 0.93). Intravenous DSV and direct cineangiography were concordant in classification of LV contractile pattern in 436 of 480 (91%) myocardial segments. Measurements of DSV obtained by 2 observers showed close correlations for EDV (r = 0.88), ESV (r = 0.95) and EF (r = 0.94), and wall motion classification was in agreement in 434 of 480 (90%) LV segments. Artifacts induced by respiratory motion, persistence of contrast in the right ventricle or left atrium, or low cardiac output may have contributed to the discrepancies observed. These data indicate that DSV is accurate in assessing LV volume and EF, correlates well with cineangiography and exhibits good interobserver reproducibility.     

Left ventricular volume and ejection fraction determination by cross-sectional echocardiography in patients with coronary artery disease: A prospective study

In a prospective study the accuracy of cross-sectional echocardiography for determination of left ventricular (LV) volume and ejection fraction (EF) was analyzed in 53 patients with coronary artery disease and compared to that of cineangiocardiography (angio). From the apex of the heart phased-array wide-angle (84°) electronic echocardiograms were received in the RAO-equivalent view. Angios were obtained in a 30° RAO view. Using Simpson's rule, end-diastolic (EDV) and end-systolic (ESV) LV volumes were calculated, and the EF derived. Left ventricular long axis was transected in eight segments, yielding seven diameters. In 50 of the 53 patients cross-sectional echocardiograms could be recorded. The correlation between cineangiocardiography and cross-sectional echocardiography for EDV was highly significant: r = 0.936, y = 0.667x + 27.1, standard error of estimate (syx) ± 22.2 ml; for ESV: r = 0.970, y = 0.699x + 14.7, syx ± 14.5 ml; for stroke volume: r = 0.721, y = 0.503x + 11.3, syx ± 15.3 ml; for EF: r = 0.909, y = 0.740x + 11.3, syx ±6.0%. Angio mean long axis was 10.2± 1.2 cm, cross-sectional echocardiographic long axis 8.7 ± 1.3 cm. Mean LV diameter determined by cineangiocardiography was longer than when determined by cross-sectional echocardiography. The mean difference reached 2.0 cm in the middle of the LV. Our prospective comparative study revealed that LV volumes and EF were underestimated by cross-sectional echocardiography compared to cineangiocardiography because of a methodological systematic error caused by a tangential cut of the heart. In the RAO-equivalent view the “true” long axis was missed. The high correlation coefficients, however, indicate that the “true” LV volume and EF can be calculated from the given regression equations. Serial measurements should be legitimated.     

Accuracy of three-dimensional echocardiography with unrestricted selection of imaging planes for measurement of left ventricular volumes and ejection fraction

BACKGROUND: Accurate, reproducible, noninvasive determination of left ventricular (LV) volumes and ejection fraction (EF) is important for clinical assessment, risk stratification, selection of therapy, and serial monitoring of patients with cardiovascular disease. Three-dimensional echocardiography (3DE) approaches have demonstrated significantly greater accuracy than current clinical 2DE, but the clinical utility of 3DE has been limited because of the need for substantial modifications to scanning technique (eg, all image acquisition from a single acoustic window) or cumbersome additional hardware. We describe a novel 3DE system without these limitations and its application to patients. METHODS AND RESULTS: Twenty-five patients were examined by 3DE, 2DE, and magnetic resonance imaging (MRI). The 3DE system used a magnetic scanhead tracking device, and volumes were computed with a novel deformable shell model. End-diastolic volumes and EF by MRI ranged from 96 to 375 mL and 18% to 73%, respectively. There was excellent correlation, without statistically significant differences, between MRI and 3DE for end-systolic volume (ESV) (r(2) = 0.99) and end-diastolic volume (EDV) (r(2) = 0.98), ventricular stroke volume (SV) (r(2) = 0.93), and EF (r(2) = 0.97), with standard error estimates less than 10 mL for volumes and 3% for EF. Conventional 2DE consistently underestimated volumes (EDV, P <.01; ESV, P <.01; SV, P <.05); correlations with MRI were r(2) = 0.91 for ESV, r(2) = 0.88 for EDV, r(2) = 0.62 for SV, and r(2) = 0.72 for EF. Standard error estimates ranged from 16 to 20 mL for ventricular volumes and 9% for EF. Interobserver variability was reduced 3-fold with use of 3DE. CONCLUSIONS: The novel 3DE system allows unrestricted selection and combination of acoustic windows in a single examination, improves accuracy of estimates of LV volumes and EF 3-fold compared with 2DE, and is practical for routine clinical assessment of LV size and function in patients with a wide range of cardiac pathology.     

Effects of long-term therapy with bosentan on the progression of left ventricular dysfunction and remodeling in dogs with heart failure

OBJECTIVES: In this study, we examined the effects of long-term therapy with bosentan on the progression of LV dysfunction and remodeling in dogs with moderate HF. BACKGROUND: Acute intravenous administration of bosentan, a mixed endothelin-1 type A and type B receptor antagonist, was shown to improve left ventricular (LV) function in patients and dogs with heart failure (HF). METHODS: Left ventricular dysfunction was induced by multiple, sequential intracoronary microembolizations in 14 dogs. Embolizations were discontinued when LV ejection fraction (EF) was between 30% and 40%. Dogs were randomized to three months of therapy with bosentan (30 mg/kg twice daily, n = 7) or no therapy at all (control, n = 7). RESULTS: In untreated dogs, EF decreased from 35 +/- 1% before initiating therapy to 29 +/- 1% at the end of three months of therapy (p = 0.001), and LV end-diastolic volume (EDV) and end-systolic volume (ESV) increased (EDV: 71 +/- 3 vs. 84 +/- 8 ml, p = 0.08; ESV: 46 +/- 2 vs. 60 +/- 6 ml, p = 0.03). By contrast, in dogs treated with bosentan, EF tended to increase from 34 +/- 2% before initiating therapy to 39 +/- 1% at the end of three months of therapy (p = 0.06), and EDV and ESV decreased (EDV: 75 +/- 3 vs. 71 +/- 4 ml, p = 0.05; ESV: 48 +/- 2 vs. 43 +/- 3 ml, p = 0.01). Furthermore, compared with untreated dogs, dogs treated with bosentan showed significantly less LV cardiomyocyte hypertrophy and LV volume fraction of interstitial fibrosis. CONCLUSIONS: In dogs with moderate HF, long-term therapy with bosentan prevents the progression of LV dysfunction and attenuates LV chamber remodeling. The findings support the use of mixed endothelin-1 receptor antagonists as adjuncts to the long-term treatment of HF.     

Long-term effects of non-excitatory cardiac contractility modulation electric signals on the progression of heart failure in dogs

OBJECTIVE: We previously showed that acute delivery of non-excitatory cardiac contractility modulation (CCM) electric signal during the absolute refractory period improved LV function in dogs with chronic heart failure (HF). In the present study we examined the long-term effects of CCM signal delivery on the progression of LV dysfunction and remodeling in dogs with chronic HF. METHODS: Chronic HF was produced in 12 dogs by multiple sequential intracoronary microembolizations. The CCM signal was delivered using a lead implanted in the distal anterior coronary vein. A right ventricular and a right atrial lead were implanted and used for timing of CCM signal delivery. In six dogs, CCM signals were delivered continuously for 6 h daily with an average amplitude of 3.3 V for 3 months. Six HF dogs did not have leads implanted and served as controls. RESULTS: In control dogs, LV end-diastolic volume (EDV) and LV end-systolic volume (ESV) increased (64+/-5 ml vs. 75+/-6 ml, P=0.003; 46+/-4 ml vs. 57+/-4 ml, P=0.003; respectively), and ejection fraction (EF) decreased (28+/-1% vs. 23+/-1%, P=0.001) over the course of 3 months of follow-up. In contrast, CCM-treated dogs showed a smaller increase in EDV (66+/-4 vs. 73+/-5 ml, P=0.01), no change in ESV, and an increase in EF from 31+/-1 to 34+/-2% (P=0.04) after 3 months of therapy. CONCLUSIONS: In dogs with HF, long-term CCM therapy prevents progressive LV dysfunction and attenuates global LV remodeling. These findings provide compelling rationale for exploring the use of CCM for the treatment of patients with chronic HF.     

Reproducibility of measurements of left ventricular function with gated myocardial perfusion SPECT and comparison with blood pool radionuclide ventriculography

INTRODUCTION AND OBJECTIVE: This study was designed to evaluate the reproducibility of ejection fraction (EF) and ventricular volume measurements obtained with single photon emission computed tomography (gated-SPECT), and to assess the correlation between EF values obtained with this method and blood pool planar radionuclide ventriculography. PATIENTS AND METHOD: A total of 55 patients were included (37 men, mean age 61.3 years) upon referral to two nuclear cardiology units for diagnosis (50%) or follow-up of known coronary artery disease. In a standard 2-day protocol, patients received a dose of [99mTc]tetrofosmin (800 MBq) at stress and at rest. Two resting gated-SPECT studies were performed. QGS software was used to obtain left ventricular EF, end-diastolic volume (EDV) and end-systolic volume (ESV). Forty-nine patients agreed to undergo blood pool ventriculography on the third day. RESULTS: Interobserver variability was 0.5 (2.6)% (r=0.99) for EF, 1.9 (10.7) mL for EDV (r=0.98) and 0.5 (5.4) mL for ESV (r=0.99). Interassay variability was 2 (5.1)% (r=0.94) for EF, 4.5 (8.6) mL for EDV (r=0.99) and 3.4 (6.6) mL for ESV (r=0.99). The correlation between gated-SPECT EF and blood pool EF was suboptimal (r=0.75, 95%CI, 0.59-0.85). CONCLUSIONS: There was excellent interobserver and interassay reproducibility for left ventricular functional parameters measured with gated-SPECT and QGS software, and this method can be used for serial evaluations of ventricular function. Although the correlation between values obtained with gated-SPECT and blood pool ventriculography was acceptable, the differences show that the two techniques cannot be considered equivalent.     

Evidence for left ventricular remodeling after percutaneous coronary intervention: effect of percutaneous coronary intervention on left ventricular ejection fraction and volumes

BACKGROUND: Post-stress ejection fraction (EF), end-diastolic (EDV) and end-systolic (ESV) volumes by gated myocardial perfusion SPECT (MPS) are well validated, reproducible and of prognostic significance. However, little is known about the impact of percutaneous coronary intervention (PCI) on left ventricular volumes and remodeling. METHODS: Thirty-eight patients who underwent MPS before and 6 months after PCI were evaluated. MPS were interpreted deriving summed stress (SSS), rest (SRS) and difference (SDS = SSS-SRS; extent of ischemia) scores. EF, EDV and ESV were generated by QGS trade mark. Pre-PCI MPS were compared to post-PCI MPS. RESULTS: Single vessel disease was present in 63% of patients. PCI of one vessel was performed in 82% of patients. After 6 months, SSS (10.6 +/- 6.3 vs. 2.8 +/- 4.3, p < 0.001) and SDS (8.2 +/- 5.6 vs. 1.4 +/- 2.3, p < 0.001) had improved; however, EF did not change significantly (55 +/- 10 vs. 57 +/- 13, p = ns). Still, EDV (105 +/- 25 ml vs. 96 +/- 25 ml, p = 0.006) and ESV (49 +/- 19 ml vs. 41 +/- 18 ml, p = 0.001) were significantly reduced. CONCLUSION: Results of MPS documented the beneficial effect of PCI on symptoms and extent of ischemia. In addition, the findings showed a significant decrease in ESV and EDV after PCI as compared to pre-PCI findings which points to a positive effect on left ventricular remodeling even in the absence of significant changes in EF.     

Assessment of regional and global left ventricular function by reinjection T1-201 and rest Tc-99m sestamibi ECG-gated SPECT: comparison with three-dimensional magnetic resonance imaging

OBJECTIVES: The purpose of this study was to test the ability of reinjection thallium-201 and rest technetium-99m sestamibi ECG (electrocardiographic)-gated SPECT (i.e., reinjection-g-SPECT [single-photon emission computed tomography] and MIBI-g-SPECT) to determine regional and global functional parameters. BACKGROUND: The ECG-gated perfusion SPECT was reported to provide accurate left ventricular ejection fraction (LVEF) using an automated algorithm. We hypothesized that other various functional data may be obtained using reinjection-g-SPECT and MIBI-g-SPECT. METHODS: Reinjection-g-SPECT, MIBI-g-SPECT, and three-dimensional magnetic resonance imaging (3DMRI) were conducted in 20 patients with coronary artery disease. Regional wall motion (RWM) and wall thickening (RWT) were analyzed using semiquantitative visual scoring by each g-SPECT and 3DMRI. The left ventricular end-systolic and end-diastolic volumes (EDV, ESV) and LVEF estimated by reinjection- and MIBI-g-SPECT were compared with the results of 3DMRI. RESULTS: A high degree of agreement in RWM and RWT assessment was observed between each g-SPECT and 3DMRI (kappa >.70, p < .001). The LVEF values by reinjection- and MIBI-g-SPECT correlated and agreed well with those by 3DMRI (reinjection: r = .92, SEE = 5.9%, SD of differences = 5.7%; sestamibi: r = .94, SEE = 4.4%, SD of differences = 5.1%). The same also pertained to EDV (reinjection: r = .85, SEE = 18.7 ml, SD of differences = 18.4 ml; sestamibi: r = .92, SEE = 13.1 ml, SD of differences = 13.0 ml) and ESV (reinjection: r = .94, SEE = 10.3 ml, SD of differences = 10.3 ml; sestamibi: r = .97, SEE = 6.7 ml [p < .05 vs. reinjection by F test], SD of differences = 6.6 ml [p < .05 vs. reinjection by F test]). CONCLUSIONS: Reinjection- and MIBI-g-SPECT provide clinically satisfactory various functional data. These functional data in combination with the perfusion information will improve diagnostic and prognostic accuracy without an increase in cost or the radiation dose to the patients.