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.     

Influence of the postexercise acquisition delay on the detection of functional abnormalities in sestamibi-gated SPECT.

BACKGROUND: Gated single photon emission computed tomography (SPECT) identifies functional changes produced by ischemia, but the influence of acquisition delay on their detection is not established. METHODS AND RESULTS: In 80 patients with known or suspected coronary artery disease, gated SPECT was acquired twice: first, less than 30 minutes after peak exercise (stress 1), and second, more than 45 minutes after peak exercise (stress 2). End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were compared with perfusion. The relationship between the DeltaEF (stress EF - resting EF) and the summed difference score (SDS) was -0.443 (P < .0001) for stress 1 and -0.416 (P < .0001) for stress 2. In stress 1, EF increased in patients without inducible ischemia (SDS = 0) (57% +/- 10% vs 54% +/- 9% at rest, P < .02) and decreased in those with an SDS of 1 or greater (53% +/- 10.8% vs 55% +/- 9.6% at rest, P < .05). In stress 2, EF was unchanged in patients without ischemia (55.8% +/- 9.7%, P = .06) and decreased in the other patients (52.8% +/- 10.2%, P < .01). In patients without ischemia, both the EDV and ESV decreased significantly in stress 1 and were unchanged in stress 2. In patients with an SDS of 1 or greater, the EDV remained unchanged and the ESV minimally decreased in stress 1, whereas both volumes clearly and significantly increased in stress 2. CONCLUSIONS: The early acquisition of postexercise gated SPECT is slightly more effective in detecting ischemia-related functional changes; however, a delayed acquisition within 60 minutes still permits the detection of functional abnormalities in most patients.     

Diagnostic value of left ventricular function after stress and at rest in the detection of multivessel coronary artery disease as assessed by electrocardiogram-gated SPECT.

BACKGROUND: Although transient left ventricular (LV) dilation is a well-known marker for extensive coronary artery disease (CAD), few studies have performed quantitative analysis of LV function after stress and at rest to detect extensive CAD. METHODS AND RESULTS: Poststress and resting gated single photon emission computed tomography (SPECT) was performed in 175 patients with suspected CAD. All of the patients underwent coronary angiography within 3 months of gated SPECT. In the 83 patients with multivessel CAD, the summed difference score was greater (9.2 +/- 7.0 vs 3.3 +/- 4.0, P < .0001), the poststress increase in end-systolic volume (ESV) was larger (7.0 +/- 8.0 mL vs -0.8 +/- 4.7 mL, P < .0001), and the poststress increase in ejection fraction (EF) was less (-4.7% +/- 5.4% vs -0.4% +/- 4.5%, P < .0001) than in the 92 patients with insignificant or single-vessel CAD. In the detection of multivessel CAD, a summed difference score of 9 or greater showed a sensitivity of 46% and specificity of 90%, whereas an increase in ESV of 5 mL or greater and a decrease in EF of 5% or greater after exercise had a sensitivity of 66% and 52%, respectively, and specificity of 87% and 83%, respectively. The multivariate discriminant analysis revealed that the combination of poststress increase in ESV, summed difference score, and diabetes mellitus best identified multivessel CAD, with a sensitivity of 72% and specificity of 84% (chi(2), 81.7). CONCLUSIONS: The addition of poststress and at-rest LV functional analysis by use of gated SPECT to conventional perfusion analysis helps to better identify patients with multivessel CAD.     

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.     

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.     

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.     

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.     

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.     

Chronic monotherapy with rosuvastatin prevents progressive left ventricular dysfunction and remodeling in dogs with heart failure.

OBJECTIVES: This study examined the effects of long-term monotherapy with rosuvastatin (RSV) on the progression of left ventricular (LV) dysfunction and remodeling in dogs with heart failure (HF). BACKGROUND: 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors or "statins" possess other noncholesterol-lowering properties that include inhibiting proinflammatory cytokines, attenuating LV hypertrophy, and stimulating the release of bone marrow-derived stem cells (BMSCs). METHODS: Twenty-one dogs with microembolization-induced HF were randomized to 3 months oral monotherapy with low-dose (LD) RSV (0.5 mg/kg once daily, n = 7), high-dose (HD) RSV (3.0 mg/kg once daily, n = 7), or to no therapy (control group, n = 7). The change (Delta) from pre- to post-therapy (treatment effect) in LV end-diastolic volume (EDV) and end-systolic volume (ESV) and ejection fraction (EF) was measured. Protein level of tumor necrosis factor (TNF)-alpha in LV tissue and the number of circulating Sca-1-positive BMSCs was also determined. Blood and LV tissue from 6 normal dogs was obtained and used for comparison. RESULTS: There were no differences in DeltaEDV, DeltaESV, and DeltaEF between control group and LD RSV. In contrast, DeltaEDV and DeltaESV were significantly lower, and DeltaEF was significantly higher in HD RSV compared with control group. High-dose, but not LD, RSV also normalized protein levels of TNF-alpha and was associated with a significant increase in the number of circulating BMSCs. CONCLUSIONS: In dogs with HF, chronic therapy with HD RSV prevents progressive LV dysfunction and dilation. This benefit may be partly derived from normalization of TNF-alpha expression and partly from increased mobilization of BMSCs.     

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.     

Pre- and postoperative assessment of left ventricular function by magnetic resonance imaging and 2-D-echocardiography in patients undergoing left ventricular aneurysmectomy

BACKGROUND: Left ventricular (LV) aneurysms may complicate myocardial infarctions. Reliable quantification of LV functional parameters is mandatory to predict clinical outcome in patients undergoing LV aneurysmectomy. We compared global LV function measured by magnetic resonance (MR) and 2-D-echocardiography in patients before and after aneurysmectomy. METHODS: 31 patients (23 male), mean age 64 (range 35 - 85) years with an LV aneurysm (25/31 anterior MI, 5/31 inferior MI, 1/31 both) were enrolled. MR and echocardiography were performed directly before and 3 - 65 (median 8) days after surgery. MR studies were performed on a 1.5 Tesla scanner. End-diastolic and end-systolic volumes and diameters (EDV/ESV, EDD/ESD), ejection fraction (EF) and stroke volume (SV) were determined. Echocardiography was performed to determine EF, EDD and ESD. NYHA class was assessed before and 3 months after surgery. RESULTS: After aneurysmectomy MR analysis showed a decrease in EDV (255 +/- 68 ml to 202 +/- 59 ml) ( p < 0.001) and ESV (186 +/- 71 ml to 134 +/- 53 ml; p < 0.001); EF increased (28 +/- 10 % to 35 +/- 12 %; p < 0.001); EDD/ESD decreased ( p < 0.01). Compared to echocardiography, a low correlation was found in EF before/after surgery r = 0.76/r = 0.69 and ESD r = 0.43/r = 0.60, respectively. In EDD a good correlation was found before surgery (r = 0.81), and a lower correlation after surgery (r = 0.72). NYHA class improved from 3.0 +/- 0.5 before to 1.8 +/- 0.8 after operation ( p < 0.001). CONCLUSION: Resection of an LV aneurysm results in a mean improvement of 25 % in LV function, and improved clinical outcome. In asymmetric ventricles with aneurysms MR proved to be superior as a sensitive and non-invasive tool compared to conventional 2-D-echocardiography.     

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.     

Quantitation of right ventricular volumes and ejection fraction by three-dimensional echocardiography in patients: comparison with magnetic resonance imaging and radionuclide ventriculography

Three-dimensional echocardiography (3DE) provides volumetric measurements without geometric assumptions. Volume-rendered 3DE has been shown to be accurate for the measurement of right ventricular (RV) volumes in vitro and in animal studies; however, few data are available regarding its accuracy in patients. This study examined the accuracy of 3DE for quantitation of RV volumes and ejection fraction (EF) in patients, compared to magnetic resonance imaging (MRI) and radionuclide ventriculography (RNV). Twenty patients underwent MRI, gated equilibrium RNV, and 3DE using rotational acquisition from both the transesophageal and transthoracic approaches. RV volumes and EF were calculated from the 3DE data using multislice analysis (true Simpson's rule). RV volumes calculated by MRI (end-diastolic volume (EDV) 109.4 +/- 34.3 mls, end-systolic volume (ESV) 59.6 +/- 31.0 mls, and EF 47.7 +/- 17.1%) agreed closely with 3DE. For transesophageal echocardiography, EDV was 108.1 +/- 29.7 mls (r = 0.86, mean difference 1.3 +/- 17.8 mls); ESV was 62.5 +/- 23.8 mls (r = 0.85, mean difference 2.8 +/- 15.1 mls); and EF was 43.2 +/- 11.7% (r = 0.84, mean difference 4.5 +/- 9.7%). For transthoracic echocardiography, EDV was 107.7 +/- 27.5 mls (r = 0.85, mean difference 1.6 +/- 18.2 mls); ESV was 59.7 +/- 22.1 mls (r = 0.93, mean difference 3.2 +/- 19.6 mls); and EF was 45.2 +/- 11.5% (r = 0.86, mean difference 2.0 +/- 9.4%). There were close correlations, small mean differences and narrow limits of agreement between RNV-derived EF (43.4 +/- 12.1%) and both transesophageal (r = 0.95 mean difference 0.2 +/- 3.7%) and transthoracic 3DE (r = 0.95, mean difference 1.8 +/- 5.4%). Three-dimensional echocardiography is a promising new method of calculating RV volumes and EF, comparing well with MRI and RNV. The accuracy of transthoracic 3DE was comparable to that of the transesophageal approach. Three-dimensional echocardiography has the potential to be useful in the clinical assessment of RV disorders.     

Enhanced prognostic stratification of CAD patients with low ejection fraction by stress-rest Tc99m tetrofosmin gated-spect

OBJECTIVE: This study was performed to assess whether post-stress and rest functional parameters, as measured by gated-SPECT, provide additional predictive value for long-term prognosis, over clinical and perfusion data in patients (pts.) with low left ventricular ejection fraction (LVEF). METHODS: 647 consecutive pts. underwent stress/rest gated-SPECT, and 497 were followed for a mean period of 516 +/- 264 days. Segmental perfusion and motion/thickening (post-stress and rest) were analysed visually, while EF and LV volumes were calculated using an automatic algorithm (QGS). The post-stress and rest ratio were determined for both end-diastolic (EDV) and end-systolic volume (ESV), while the post-stress LVEF change was calculated subtracting rest-EF from stress-EF. RESULTS: 84/497 pts. showed rest EF < 40%, and 15/84 (18%) experienced a cardiac event (3 cardiac deaths, 1 infarction, 3 hospitalized angina and 9 late revascularizations). The perfusion and functional parameters were not significantly more compromised in pts. with cardiac events compared with pts. without events. Post-stress ESV was the only index significantly higher in pts. with low EF and events compared with pts. with low EF without events (150 +/- 72 ml vs. 123 +/- 53 ml, P = 0.02). Univariate Cox analysis of clinical, perfusion and functional data showed that the best predictor of cardiac events was stress-ESV (score 6.5, P = 0.01), followed by rest-ESV, rest-EDV, stress-EDV and stress-LVEF. Multivariate analysis demonstrated that the addition of stress-ESV to stress-EF, yielded a significant increase in the global chi2 in the prediction of hard events (cardiac death/infarction) (score 4.634, P = 0.03). CONCLUSION: In patients with depressed LVEF, stress-ESV was the only independent predictor of long-term outcome.     

Electrocardiogram-gated single-photon emission computed tomography versus cardiac magnetic resonance imaging for the assessment of left ventricular volumes and ejection fraction: a meta-analysis

OBJECTIVES: The purpose of this study was to evaluate the accuracy of electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) for assessment of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) compared with the gold standard of cardiac magnetic resonance imaging (MRI). BACKGROUND: Several comparisons of ECG-gated SPECT with cardiac MRI have been performed for evaluation of LV volumes and EF, but each has considered few subjects, thus leaving uncertainty about the frequency of discrepancies between the two methods. METHODS: We performed a meta-analysis of data on 164 subjects from nine studies comparing ECG-gated SPECT versus cardiac MRI. Data were pooled in correlation and regression analyses relating ECG-gated SPECT and cardiac MRI measurements. The frequency of discrepancies of at least 30 ml in EDV, 20 ml in ESV and 5% or 10% in EF and concordance for EF < or =40% versus >40% were determined. RESULTS: There was an overall excellent correlation between ECG-gated SPECT and cardiac MRI for EDV (r = 0.89), ESV (r = 0.92) and EF (r = 0.87). However, rates of discrepancies for individual subjects were considerable (37% [95% confidence interval [CI], 26% to 50%] for at least 30 ml in EDV; 35% [95% CI, 23% to 49%] for at least 20 ml in ESV; 52% [95% CI, 37% to 63%] for at least 5% in EF; and 23% [95% CI, 11% to 42%] for at least 10% in EF). The misclassification rate for the 40% EF cutoff was 11%. CONCLUSIONS: Electrocardiogram-gated SPECT measurements of EDV, ESV and EF show high correlation with cardiac MRI measurements, but substantial errors may occur in individual patients. Electrocardiogram-gated SPECT offers useful functional information, but cardiac MRI should be used when accurate measurement is required.     

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.     

磁共振电影成像评价左右心室整体收缩功能

目的对照超声心动图研究磁共振(MR)电影成像评价左右心室功能的应用价值。方法应用屏气真实稳定进动快速成像(TrueFISP)电影序列和右室改良定位方法对36名健康成人志愿者进行MRI检查,以及超声心动图左心功能对照检查。MRI图像经Argus心脏功能软件进行左右室功能的分析及评价。结果(1)MRI测量正常组的左心室整体收缩功能各指标:舒张末期容积(EDV)为(101.3±19.2)ml,收缩末期容积(ESV)为(42.1±13.3)ml,每搏输出量(SV)(69.2±9.8)ml,射血分数(EF)(59.1±7.2)%;右心室整体收缩功能EDV(118.9±27.1)ml,ESV(57.6±16.1)ml,SV(61.2±12.7)ml,EF(51.9±4.5)%。(2)MRI测量左心功能与超声心动图检查结果对照:EDV与超声心动图测值[(97.2±17.6)ml]比较,差异无统计学意义;ESV测值大于超声心动图测值[(33.2±9.4)ml],其余指标均低于超声检查[SV为(64.0±11.3)ml,EF为66.1%±6.2%,P<0.01]。两种方法各指标测量值相关性良好(r=0.66～0.80,P<0.05)。(3)右心室短轴定位改良前后心功能指标测值比较:除ESV测值与改良前差异无统计学意义外,EDV、SV、EF均明显大于改良前(P<0.05)。结论MRI是综合准确无创的心脏检查技术。其电影成像技术结合改良定位对左右心室功能测量准确,兼获心脏解剖和形态信息,可以用于心脏疾病的功能评价及疗效监测。     

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.     

Intravenous left ventriculography utilizing digital subtraction technique

To detect the left ventricular boundary in the intravenous ventriculography, we used a subtraction technique for background suppression. Images containing contrast medium and reference mask images were transferred to a computer through a flying spot scanner and stored on the digital disc. Stored reference mask images were subtracted from the digitized contrast images. The resulting images were then electronically enhanced to extract the left ventricular (LV) image. The LV boundary was delineated with an algorithm we have developed and the volume of the LV cavity was calculated automatically. The validity of this method was compared with data obtained from conventional left ventriculogram (LVG). In 11 patients, values for end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) calculated from the intravenous LVG were correlated closely with those from the conventional LVG (128 +/- 38 (SD) vs 133 +/- 39 ml, r = 0.95; 50 +/- 28 vs 53 +/- 30 ml, r = 0.98; 63 +/- 10 vs 62 +/- 12%, r = 0.96, respectively). Nine patients with valvular regurgitation were followed up serially after valve replacement. EDV index fell significantly after corrective surgery (145 +/- 50 to 81 +/- 33 ml/m2, p less than 0.02), whereas, EF was affected variably depending upon the preoperative state (58 +/- 13 to 61 +/- 11%, not significant). Thus, this method is less invasive than conventional LVG and has successfully allowed for sequential determination of ventricular function on an outpatient basis.     

The diagnostic utility of the Heston index in gated SPECT to detect multi-vessel coronary artery disease

OBJECTIVES: Although the Heston index, derived left ventricular (LV) volumetric analysis, is reported to best represent transient LV dilation on non-gated single-photon emission computed tomography (SPECT), its diagnostic performance has not been proven to identify extensive coronary artery disease (CAD) as assessed by coronary angiogram. Accordingly, we sought to evaluate the diagnostic utility of Heston index to detect multi-vessel CAD. METHODS: Post-stress and resting electrocardiogram-gated 99mTc-sestamibi SPECT was performed in 223 patients with suspected or known CAD. All of the patients underwent coronary angiography within 3 months of gated SPECT. The summed stress, summed rest, and summed difference scores were calculated using a 20-segment model. The left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were calculated automatically with the QGS program. In addition, stress-to-rest ratios of EDV, ESV, and (ESVx5+EDV) were calculated; the latter was defined as Heston index. RESULTS: In the 104 patients with multi-vessel CAD, the summed stress score (17.5+/-10.0 vs. 11.7+/-9.2, p<0.001), the summed difference score (9.1+/-6.3 vs. 4.3+/-4.2, p<0.0001), the Heston index (1.17+/-0.15 vs. 1.02+/-0.13, p<0.0001), the stress-to-rest ratio of EDV (1.05+/-0.10 vs. 0.99+/-0.09; p<0.0001), and that of ESV (1.23+/-0.21 vs. 1.04+/-0.17; p<0.0001, respectively) were greater than in the 119 patients with one-vessel CAD or insignificant lesion. The best cut-off value was determined as 1.09 for Heston index, giving a sensitivity of 76%, specificity of 77% for detection of multi-vessel CAD. Multiple stepwise logistic regression analysis showed that Heston index >or =1.09, summed stress score > or =14, and summed difference score > or =9 were the independent predictors of detecting multi-vessel CAD, yielding a sensitivity of 76% and specificity of 77% (global chi 2, 88.8). CONCLUSIONS: The Heston index is simple and achieves higher diagnostic value in the detection of multi-vessel CAD, compared with conventional analysis alone.