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.     

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.     

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.     

Prognostic value of poststress left ventricular volume and ejection fraction by gated myocardial perfusion SPECT in women and men: gender-related differences in normal limits and outcomes.

BACKGROUND: Whether there are gender differences in the prognostic application of gated myocardial perfusion single photon emission computed tomography (SPECT) has not been assessed. METHODS AND RESULTS: Gender-specific normal limits of poststress volume and ejection fraction (EF) were obtained in 597 women and 824 men with a low likelihood of coronary artery disease and normal perfusion and were applied in a prognostic evaluation of 6713 patients (2735 women and 3978 men). Patients underwent rest thallium-201/stress technetium-99m sestamibi gated myocardial perfusion SPECT and were followed up for 35 +/- 14 months. The upper limit of the end-systolic volume (ESV) index was 27 mL/m2 in women and 39 mL/m2 in men, and the upper limit of the end-diastolic volume index was 60 mL/m2 in women and 75 mL/m2 in men. The lower limit of the EF was 51% in women and 43% in men. Gated SPECT variables provided incremental prognostic information in both genders. Women with severe ischemia and an EF lower than 51% or an ESV index greater than 27 mL/m2 were at very high risk of cardiac death or myocardial infarction (3-year event rates of 39.8% and 35.1%, respectively), whereas women with severe ischemia but an EF of 51% or greater or an ESV index of 27 mL/m2 or less were at intermediate or high risk (3-year event rates of 10.8% and 15.2%, respectively). CONCLUSION: Poststress EF and ESV index by gated myocardial perfusion SPECT provide comparable incremental prognostic information over perfusion in women and men. After separate criteria for abnormal EF and ESV index in women are used, the combination of severe ischemia and abnormal EF or ESV index identifies women at very high risk of cardiac events.     

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.     

Usefulness of combination post-stress dysfunction and perfusion imaging in technetium-99m-tetrofosmin myocardial scintigraphy

OBJECTIVES: Myocardial perfusion imaging has lower sensitivity for the diagnosis of coronary artery disease in patients with three-vessel disease. The presence of post-stress dysfunction of the left ventricle, evaluated by electrocardiography(ECG) gated single photon emission computed tomography(SPECT) with a quantitative gated SPECT program, was investigated in patients with coronary artery disease, and also whether combining post-stress dysfunction and myocardial perfusion imaging improved the diagnosis of coronary artery disease. METHODS: ECG gated technetium-99m-tetrofosmin SPECT was performed using a one day, stress and rest, protocol in 139 patients. SPECT and coronary angiography were performed within 1 month. The coronary artery disease group consisted of 89 patients: 43 with one-vessel disease(1VD), 28 with two-vessel disease(2VD), and 18 with three-vessel disease(3VD). The group with zero-vessel disease(0VD) consisted of 50 patients. According to post-stress and rest ejection fraction(EF) and end-systolic volume (ESV), post-stress dysfunction is defined as follows: rest EF--post-stress EF > or = 5% and post-stress ESV--rest ESV > or = 5 ml. RESULTS: In the coronary artery disease group, post-stress ESV was larger than rest ESV(37.8 +/- 26.4, 34.0 +/- 24.2 ml, p < 0.001), and post-stress EF was lower than rest EF (61.5 +/- 11.1%, 64.2 +/- 10.8%, p < 0.001). In the 0VD group, ESV and EF were the same for post-stress and rest (25.7 +/- 20.8, 26.2 +/- 21.6 ml, NS; 70.4 +/- 9.5%, 70.0 +/- 9.6%, NS). Post-stress dysfunction was 6.0% in the 0VD group and 30.3% in the coronary artery disease group(p < 0.001). Furthermore, post-stress dysfunction in the 2VD (35.7%) and 3VD(38.9%) groups was higher than that in the 0VD group(p < 0.01, p < 0.01). Sensitivity of coronary artery disease diagnosis by myocardial perfusion imaging was 75%. The combination of post-stress dysfunction and myocardial perfusion imaging improved sensitivity from 75% to 82%(p < 0.05), but reduced the specificity from 92% to 86%(p = 0.08). CONCLUSIONS: Post-stress dysfunction is a useful parameter for clinical diagnosis of coronary artery disease.     

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.     

Performance of thallium-201 electrocardiography-gated myocardial perfusion single photon emission computed tomography to assess left ventricular function

This study evaluated the performance of gated single photon emission computed tomography (SPECT) with thallium-201 (201Tl) in assessing left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) in Taiwanese by determining repeatability and correlation with two-dimensional (2D) echocardiography. A total of 18 patients underwent two sequential gated SPECT acquisitions within 30 minutes in the resting state to assess repeatability. Another 28 patients who underwent gated SPECT and 2D echocardiography within 7 days were included for comparison. The two sequential measurements were well correlated with respect to LVEF, EDV, and ESV (r = 0.97, 0.95, and 0.97, respectively, all p < 0.0001). Bland-Altman analysis revealed that two standard deviations of the absolute difference between the two sequential measurements for LVEF, EDV, and ESV were 6.4%, 16.8 mL, and 8.6 mL, respectively. For LVEF, EDV, and ESV, correlations between redistribution 201Tl-gated SPECT and echocardiography were also excellent (all r = 0.83, p < 0.0001). LVEF was similar with 201Tl-gated SPECT and echocardiography, but EDV and ESV were significantly higher with echocardiography (p < 0.05). Our study revealed that 201Tl-gated SPECT has high repeatability and excellent correlation with echocardiography for the assessment of LVEF and volumes in Taiwanese. These results support the clinical application of gated SPECT in routine 201Tl myocardial perfusion imaging in Taiwanese.     

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.     

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.     

Evaluation of left ventricular function in chronic pulmonary disease by exercise gated equilibrium radionuclide angiography

To assess left ventricular (LV) response to supine bicycle exercise, we studied 10 normals (group 1), 10 patients with coronary artery disease (CAD) (group 2), 12 patients with severe obstructive lung disease (COPD) (group 3), and eight patients with both CAD and COPD (group 4) by gated equilibrium radionuclide angiography. Most individuals in all groups also had pulmonary catheter-obtained measurements of LV filling pressures during exercise. Normal individuals increased their ejection traction (EF) during exercise by increasing stroke volume (SV) and reducing end-systolic volume (ESV) without changing end-diastolic volume (EDV); pulmonary artery (PAP) and wedge (PAW) pressures were unaltered. CAD patients (group 2) showed no change in EF with increased EDV, ESV, SV, and PAW. COPD patients (group 3) exhibited decreases in EDV, ESV, and SV, accounting for abnormal EF responses in 6 of 12; PAW was unchanged and the marked elevation of PAP correlated with reduced EDV. Group 4 patients (CAD plus COPD) had abnormal EF responses with increased EDV and ESV without change in SV. Thus an abnormal LV function response to exercise in COPD patients may be multifactorial, thereby indicating the possible need for therapeutic modalities in addition to those employed in alleviating pulmonary parenchymal disease.     

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.     

Left ventricular volume curve analysis using gated blood pool emission computed tomography

Analysis of the left ventricular volume curve was performed using gated blood pool emission computed tomography (SPECT) in six patients with old myocardial infarction (MI), five with hypertrophic cardiomyopathy (HCM), three with dilated cardiomyopathy (DCM), and five normal controls (N). Image collection was synchronized with the QRS complex, and each cardiac cycle was divided into nine to 10 frames. In each frame, left ventricular volume was determined based on the number of voxels above the threshold level (50% cut-off level), and the volume curve was fitted to the third harmonics of Fourier analysis. From the fitted curve, the peak ejection rate (PER), the peak filling rate (PFR), end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated. 1. There were good correlations between SPECT and the conventional gated blood pool (MUGA) for PER (r = 0.694, p less than 0.005), PFR (r = 0.527, p less than 0.025) and EF (r = 0.682, p less than 0.005). 2. PER in MI (2.21 +/- 0.55, mean +/- SD) was lower than in N (3.68 +/- 0.80, p less than 0.05) and HCM (4.85 +/- 2.39, p less than 0.05), and EF in MI (36.6 +/- 6.4) was lower than in HCM (68.7 +/- 23.7, p less than 0.05). 3. There were good correlations between EDVs (y = 1.11x + 5.71, r = 0.877, p less than 0.01), and ESVs (y = 1.05x - 3.88, r = 0.876, p less than 0.01) estimated by MUGA and SPECT.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Use of intravenous digital subtraction ventriculography in the evaluation of left ventricle volumes and ejection fraction

Although intravenous digital subtraction ventriculography (IDSV) is increasingly used to estimate end-diastolic left ventricular volume (EDV), end-systolic left ventricular volume (ESV) and left ventricular ejection fraction (EF), its ability to reproduce the precise estimates provided by left ventricle cineangiography (LVCA) and its role in clinical cardiology have not been unequivocally established. In 32 patients subjected to cardiac catheterization for a variety of cardiac disorders and a normal or reduced left ventricular function the EDV, ESV and EF provided by a 30 degrees right anterior oblique LVCA were compared with those provided by a 30 degrees right anterior oblique IDSV. The mean EDV, ESV and EF obtained by IDSV in the 32 patients were superimposable on those obtained by LVCA. The individual EDV, ESV and EF values provided by the two methods were all related in a close linear fashion. For EF the correlation coefficient was 0.98 and the 90% confidence interval of the mean difference between the two series of values was +/- 6.1%, i.e. +/- 10% error compared to the mean EF provided by LVCA. Thus IDSV is a reliable and not too invasive method for estimating left ventricle volumes and ejection fraction. It might provide serial estimations with a better assessment of the evolution of a patient's disease and the effect of treatment.     

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。     

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.     

Prognostic value of normal stress myocardial perfusion imaging in Japanese population.

BACKGROUND: In Japan, Diagnosis Procedure Combination (DPC) of hospitalization health-care costs has been introduced since 2004, and its introduction has been recently expanded also to general hospitals. In such situations, the role of nuclear cardiology as a gatekeeper for the diagnosis of ischemic heart disease is increasingly important. Thus, the present study was designed to determine which clinical risk for hard events after normal single-photon emission computed tomography (SPECT) images, identify the predictors of increased risk in patients with normal SPECT images based on the J-ACCESS study. METHODS AND RESULTS: A total of 4,629 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at hospitals in Japan were included in the study. Based on SPECT image data, 1,862 participants had a summed stress score of or=49% in men, EF >or=55% in women), which is defined as selection criteria III (normal perfusion, ESV and EF). During the 3-year follow-up period, there was a total of 211 cardiac events (11.3%) in patients grouped in selection criteria I, 196 cardiac events (11.0%) in patients grouped in selection criteria II, and 189 cardiac events in patients grouped in selection criteria III (10.8%). The annual hard event rates were 0.81%, 0.67% and 0.63% in selection criteria I, II and III, respectively. Cox proportional hazard analysis showed that diabetes mellitus, age and hypertension were independent predictors of all cardiac events in all selection criteria. CONCLUSION: Normal stress myocardial perfusion imaging in the Japanese population is associated with a low cardiac event risk. The prognosis results of a normal SPECT scan would be useful for better patient management.     

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.