Evaluation of right ventricular volume and mass using retrospective ECG-gated cardiac multidetector computed tomography: comparison with first-pass radionuclide angiography

The purposes of this study were to evaluate the right ventricular (RV) volume and mass using cardiac multidetector computed tomography (MDCT) and to compare the cardiac MDCT results with those from first-pass radionuclide angiography (FPRA). Twenty patients were evaluated for the RV end-diastolic volume (RVEDV), the RV end-systolic volume (RVESV), the RV ejection fraction (RVEF), and RV mass using cardiac MDCT with a two-phase reconstruction method based on ECG. The end-diastolic phase was reconstructed at the starting point of the QRS complex on ECG, and the end-systolic phase was reconstructed at the halfway point of the ascending T-wave on ECG. The RV mass was measured for the end-systole. The RVEF was also obtained by FPRA. The mean RVEF (47±7%) measured by cardiac MDCT was well correlated with that (44±6%) measured by FPRA (r=0.854). A significant difference in the mean RVEF was found between cardiac MDCT and FPRA (p=0.001), with an overestimation of 2.9±5.3% by cardiac MDCT versus FPRA. The interobserver variability was 4.4% for the RVEDV, 6.8% for the RVESV, and 7.9% for the RV mass, respectively. Cardiac MDCT is relatively simple and allows the RV volume and mass to be assessed, and the RVEF obtained by cardiac MDCT correlates well with that measured by FPRA.     

实时三维超声心动图结合二维斑点追踪技术评价运动负荷前后对肥厚型非梗阻性心肌病患者右心室功能的影响

目的探讨应用实时三维超声心动图(RT-3DE)结合二维斑点追踪技术(2D-STI)评价运动前后肥厚型非梗阻性心肌病(HNCM)患者右心室功能。方法选取32例HNCM患者和与之性别、年龄相符的35例对照组。分别于运动前后测量右心室参数:三尖瓣舒张早、晚期血流峰值速度E峰、A峰(TV-E峰、TV-A峰);组织多普勒显像测得三尖瓣环收缩期峰值速度、舒张早期速度(TV-Sm、TV-Em);2D-STI方法测量右心室整体长轴应变(RVGLS);RT-3DE技术测得右心室舒张末期容积(RVEDV)、右心室收缩末期容积(RVESV)、右心室每搏量(RVSV)、右心室射血分数(RVEF)以及三尖瓣环收缩期位移(TAPSE)、右心室面积变化率(RVFAC)。并将容积参数结合体表面积(BSA)进行标化得到右心室舒张末期容积指数(RVEDVi)、右心室收缩末期容积指数(RVESVi)、右心室每搏量指数(RVSVi)。结果运动后对照组与HNCM组常规参数TAPSE、RVFAC、TV-E峰、TV-A峰、三维参数RVEDVi、RVESVi、RVEF差异均无统计学意义(P>0.05);运动后对照组与HNCM组...     

81mKr equilibrium radionuclide ventriculography for the assessment of right heart function

Right heart^81mKr equilibrium radionuclide ventriculography was used to derive right ventricular ejection fraction (RVEF) in 12 healthy male volunteers. Anatomical lung subtraction using^99mTc-MAA perfusion scintigraphy was compared with conventional background correction and the effect of imaging projection on the techniques of image analysis evaluated. Both intra and inter observer variability were reduced by anatomical lung subtraction when compared to conventional background correction. In the right anterior oblique (RAO) projection, background corrected RVEF was lower than lung subtracted RVEF - 0.544 ±0.05 and 0.612±0.08 (mean ± SD) (P<0.02). Lung subtracted RVEF in the anterior projection was lower than that with background correction (P<0.05) and lower than lung subtracted RVEF in the RAO projection (P < 0.001). We conclude that optimal separation of right heart structures is achieved in the RAO projection and that reproducibility of the analytical technique is improved by anatomical lung subtraction.     

Automated determination of the right ventricular ejection fraction by digital processing of 81mKr scintigrams

A method is presented for the automated determination of the right ventricular ejection fraction (RVEF) by digital image processing of scintigrams obtained by intravenous infusion of Krypton 81m (^81mKr) dissolved in a glucose solution. End-diastolic and end-systolic sum pictures were computed by the addition of approximately 30–40 frames selected from the time-activity curve of a preliminary, manually drawn, right ventricular region of interest. After processing these two images with an adaptive Wiener filter, the right ventricular contour was determined by a recently developed algorithm using morphological and functional criteria. The RVEF was calculated for a series of 51 patients from the counts in the detected right ventricular regions in the end-diastolic and end-systolic sum images. In 16 patients without evidence of cardiopulmonary disease, the mean RVEF was 50±6.1%. RVEF was significantly reduced in 18 patients with obstructive pulmonary disease (42±6.5%) and in 17 patients with congestive cardiomyopathy (36±7.1%). The correlation coefficient between two determinations of the RVEF was r=0.94. Through digital image processing, the determination of the RVEF by radioimage processing, the determination of the RVEF by radioventriculography with ^81mKr showed high reliability and reproducibility.     

Radionuclide ejection fraction: Comparison of response to treadmill and bicycle exercise

Most exercise radionuclide studies utilise the supine bicycle ergometer during imaging, although exercise on a treadmill results in greater cardiovascular stress. Twenty-three patients were studied to compare the radionuclide left ventricular ejection fraction (LVEF) estimated immediately following treadmill exercise with that obtained at peak supine bicycle exercise in patients with coronary artery disease (CAD) and patients with normal coronary arteries.In 14 patients with CAD the rest LVEF was 47±7% (mean±SD) by first pass and 49±10% by equilibrium blood pool techniques. Immediately following maximum treadmill exercise, 13 of the 14 patients with coronary artery disease showed either no change or a decrease in LVEF, the LVEF was 49±7% (P=NS) and 47±8% (P=NS) by first pass and equilibrium determinations respectively. In comparison the LVEF during peak supine bicycle exercise decreased significantly to 42±12% (P<0.01). In nine patients with angiographically normal coronary arteries the rest LVEF was 51±4% by first pass and 54±6% by equilibrium, increasing to 67±7% (P<0.01) and 64±7% (P<0.01) respectively following treadmill exercise. During peak bicycle exercise LVEF increased in the normal patients to 61±7% (P<0.05).These data suggest that quantitative radionuclide angiography following either maximum treadmill exercise or during peak bicycle exercise can discriminate between patients with coronary artery disease and normal subjects, although the magnitude of left ventricular functional changes are greater during bicycle stress.     

Evaluation of right and left ventricular function by quantitative blood-pool SPECT (QBS): Comparison with conventional methods and quantitative gated SPECT (QGS)

Though quantitative ECG-gated blood-pool SPECT (QBS) has become a popular tool in research settings, more verification is necessary for its utilization in clinical medicine. To evaluate the reliability of the measurements of left and right ventricular functions with QBS, we performed QBS, as well as first-pass pool (FPP) and ECG-gated blood-pool (GBP) studies on planar images in 41 patients and 8 healthy volunteers. Quantitative ECG-gated myocardial perfusion SPECT (QGS) was also performed in 30 of 49 subjects. First, we assessed the reproducibility of the measurements of left and right ventricular ejection fraction (LVEF, RVEF) and left and right ventricular end-diastolic volume (LVEDV, RVEDV) with QBS. Second, LVEF and RVEF obtained from QBS were compared with those from FPP and GBP, respectively. Third, LVEF and LVEDV obtained from QBS were compared with those from QGS, respectively. The intra- and inter-observer reproducibilities were excellent for LVEF, LVEDV, RVEF and RVEDV measured with QBS (r = 0.88 to 0.96, p < 0.01), while the biases in the measurements of RVEF and RVEDV were relatively large. LVEF obtained from QBS correlated significantly with those from FPP and GBP, while RVEF from QBS did not. LVEF and LVEDV obtained from QBS were significantly correlated with those from QGS, but the regression lines were not close to the lines of identity. In conclusion, the measurements of LVEF and LVEDV with QBS have good reproducibility and are useful clinically, while those of RVEF and RVEDV are less useful compared with LVEF and LVEDV. The algorithm of QBS for the measurements of RVEF and RVEDV remains to be improved.     

Factors influencing the variations of ejection fraction during exercise in chronic aortic regurgitation

The influence of left ventricular volume variations and regurgitant fraction variations upon left ventricular ejection fraction, during exercise was examined using equilibrium radionuclide angiography in patients suffering from aortic regurgitation. Ejection fraction (EF), regurgitant fraction (RF), end diastolic volume (EDV) and end systolic volume (ESV) variations from rest to peak exercise were determined in 44 patients suffering from chronic aortic regurgitation (AR) and in 8 healthy volunteers (C). In C, EF increased (+0.10±0.03, P<0.01) and ESV decreased significantly (-23%±12%, P<0.01) RF and EDV did not vary significantly. In AR patients, EF, EDV and ESV did not vary significantly because of important scattering of individual values. Changes in EF and ESV were inversely correlated (r=-0.79, P<0.01) and RF decreased significantly (-0.12±0.10, P<0.01). Volumes and EF changes during exercise occurred in three different ways. In a 1st subgroup of 7 patients, EF increased (+0.09±0.03, P<0.05) in conjunction with a reduction of ESV (-24%±12%, P<0.05) without a significant change in EDV. In a 2nd group of 22 patients. EF decreased (-0.04±0.07, P<0.01) in association with an increase in ESV (+17%±16%, P<0.01) and no change in EDV. In a 3rd subgroup of 15 patients, EF decreased (-0.02±0.06, P<0.01) despite a reduction in ESV (-7%±6%, P<0.01) because of a dramatic EDV decrease (-10%±6%, P<0.05). In this subgroup, changes in EF were inversely correlated with changes in ESV (r=-0.55, P<0.01) and positively related to EDV variations (r=0.42, P=0.02). EDV related to EDV variations (r=0.42, P=0.02). EDV changes were weakly, but significantly, correlated to RF decrease (r=0.39, P<0.05). We conclude that changes in left ventricular ejection fraction during exercise in patients with chronic aortic regurgitation are significantly related in some patients to changes in ventricular loading conditions as well as contractile state. Therefore, a correct interpretation of EF changes during exercise requires the simultaneous determination of changes in LV volumes.Abbreviations EDV end diastolic volume - EF ejection fraction - ESV end systolic volume - LV left ventricle - RV right ventricle     

Diagnosis of exercise-induced left bundle branch block at rest by scintigraphic phase analysis

Accurate diagnosis of diseases of the ventricular conducting system is essential for their appropriate therapy. some conduction abnormalities, such as exercise-induced left bundle branch block (EX-LBBB), are not apparent on resting electrocardiograms. Phase analysis of rest and exercise radionuclide ventriculograms (RVG's) was used to compare four EX-LBBB patients with six normal controls. All patients had normal resting electrocardiograms, ejection fractions, and visually normal wall motion. First harmonic phase images were generated reflecting the timing of ventricular contraction. Dynamic phase displays were reviewed and graded in a blinded fashion by three independent experienced observers. Phase angle histograms of the right and left ventricle were determined for both resting and exercise images. The mean phase angle and standard deviation were also calculated for each ventricle. Visual grading of the resting phase images failed to show a significant difference between normal patients and patients with EX-LBBB. Quantitative analysis, however, revealed a significant difference in mean phase angle differences (LV-RV) in resting studies: 0.8° (±1.9° SEM) in normals versus 9.3° (±2.3° SEM) in EX-LBBB patients (P<0.03). Exercise accentuated the phase angle differences: 1.8° in normals vs. 31.2° in EX-LBBB patients (P<0.001). Quantitative phase analysis of resting RVG's permits the diagnosis of cardiac conduction disease that is not apparent on the resting EKG and may result in better monitoring and treatment.     

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole (P <0.0005). Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses: anterior percentage uptakes, 0.785%±0.230% with exercise versus 0.870%±0.217% with dipyridamole (NSD). Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise (1.587±0.408 versus 1.446±0.518, P <0.02; 1.78±0.479 versus 1.46±0.502, P <0.002; 2.598±0.788 versus 1.265 ± 0.386, P < 0.001, respectively). High right and left lung uptakes with dipyridarnole were strongly correlated with high exercise values (r =0.756, P <0.001; r =0.809, P < 0.001). The liver uptake was weakly correlated between the 2 different stress tests (r =0.483, P < 0.02). These results demonstrate that dipyridamole, at 0.56 mg/kg over 4 min, induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise.     

Evaluation of right ventricular volume and ejection fraction by gated 18F-FDG PET in patients with pulmonary hypertension: Comparison with cardiac MRI and CT

Background

Right ventricular (RV) function is a powerful predictor of survival in patients with pulmonary hypertension (PH), but noninvasively assessing RV function remains a challenge. The aim of this study was to prospectively compare gated ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) myocardial imaging (gated PET), cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT) for the assessment of RV volume and ejection fraction in patients with PH.

Methods

Twenty-three consecutive patients aged more than 16 years diagnosed with PH were included. All patients underwent gated PET, CMR, and CCT within 7 days. Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and right ventricular ejection fraction (RVEF) were calculated by three imaging modalities. RV ¹⁸F-FDG uptake was determined as RV-corrected standardized uptake value (SUV), and the ratio of RV to left ventricular (LV)-corrected SUV (Corrected SUV R/L).

Results

Gated PET showed a moderate correlation (r = 0.680, P < .001) for RVEDV, good correlation for RVESV (r = 0.757, P < .001) and RVEF (r = 0.788, P < .001) with CMR, and good correlation for RVEDV (r = 0.767, P < .001), RVESV (r = 0.837, P < .001), and RVEF (r = 0.730, P < .001) with CCT. Bland-Altman analysis revealed systematic underestimation of RVEDV and RVESV and overestimation of RVEF with gated PET compared with CMR and CCT. The correlation between RVESV (r = 0.863, P < .001), RVESV (r = 0.903, P < .001), and RVEF (r = 0.853, P < .001) of CMR and those of CCT was excellent; Bland-Altman analysis showed only a slight systematic variation between CMR and CCT. There were statistically significant negative correlations between RV-corrected SUV and RVEF-CMR (r = ?0.543, P < .01), Corrected SUV R/L and RVEF-CMR (r = ?0.521, P < .05), RV-corrected SUV and RVEF-CCT (r = ?0.429, P < .05), Corrected SUV R/L and RVEF-CCT (r = ?0.580, P < .01), respectively.

Conclusion

Gated PET had moderate-to-high correlation with CMR and CCT in the assessments of RV volume and ejection fraction. It is an available method for simultaneous assessing of RV function and myocardial glucose metabolism in patients with PH.     

Evaluation of right ventricular function by 64-row CT in patients with chronic obstructive pulmonary disease and cor pulmonale

Purpose

The aim of this study was to investigate the clinical application value of right ventricle (RV) function measured by 64 multi-detector row CT (MDCT) in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale.

Materials and methods

Sixty-three consecutive patients with COPD and cor pulmonale were referred for electrocardiographically gated MDCT for evaluation of suspected or known coronary artery disease. Magnetic resonance imaging (MRI) for cardiac function analysis was performed on the same day. The MDCT and MRI examinations were successfully completed in 58 patients. Forty-six patients with COPD were divided into three groups according to the severity of disease by the pulmonary function test (PFT). Twelve patients diagnosed as cor pulmonale and 32 control subjects were also included. The RV function and myocardial mass (MM) were obtained by 64-MDCT and 1.5 T cardiac MRI in all of the groups. The results were compared among the groups using the Newman–Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and MM with the PFT results in COPD and cor pulmonale patients.

Results

The RVEF was significantly lower in patients with severe COPD and cor pulmonale than it was in those patients with mild or moderate COPD (P < 0.01). There were strong correlations between MDCT and MRI (r = 0.826 for RV MM, r = 0.982 and 0.969 for RV EDV and RV ESV, r = 0.899 for RVEF) and between MDCT results and forced expiratory volume in 1 s (r = 0.787 for RVEF, r = −0.774 for RV MM) in all patients.

Conclusion

MDCT can accurately quantify RV function and MM. The RVEF and RV MM measured by MDCT correlate well with the severity of disease as determined by PFT in patients with COPD and cor pulmonale. The assessment of right ventricular function is clinically important for evaluation of the severity of COPD, which may provide an objective basis for therapeutic strategy.     

Demonstration of disturbed free fatty acid metabolism of myocardium in patients with non-insulin-dependent diabetes mellitus as measured with iodine-123-heptadecanoic acid

Myocardial free fatty acid metabolism and left ventricular function were evaluated in 15 middle-aged patients with non-insulin-dependent diabetes mellitus (NIDDM) and in 8 healthy control subjects. The study subjects had no evidence of coronary heart disease on the basis of clinical history, exercise ECG or myocardial perfusion scintigraphy. During peak exercise, iodine-123 hepatadecanoic acid (HDA) was intravenously injected. Myocardial activity distribution of ¹²³I-HDA was measured 10, 30, and 50 min after exercise using single-photon emission tomography (SPET); and then further corrected by free ¹²³I-iodine. Venous blood samples were drawn for detecting the plasma activity of ¹²³I. The net extraction of ¹²³I-HDA into the myocardium was obtained by dividing the corrected tissue ¹²³I concentration by the integral of the plasma time activity curve. The net extraction was 0.40 ± 0.06 min^–1 (mean ± SD) patients with NIDDM and 0.38 ± 0.06 min^–1 in control subjects (P>0.1), respectively. The faster elimination rate of ¹²³I-HDA was found in patients with NIDDM (0.029±0.008 min^–1) than in control subjects (0.022±0.004 min^–1; P<0.01). There was no statistically significant difference in left ventricular ejection fraction (LVEF) at rest between patients with NIDDM (53±9%) and control subjects (56±2%), whereas the increase of LVEF during exercise remained lower in patients with NIDDM (3.4±8.2%) than in control subjects (11.8±5.8%; P<0.025). A significant correlation (r=0.64; P < 0.01) was found between the net extraction of ¹²³I-HDA and the change of LVEF, as well as with exercise load (r=0.68; P<0.01). In conclusion, evidence of an increased fatty acid utilization and triglyceride synthesis rate was observed in the diabetic myocardium. Offprint requests to: J.T. Kuikka     

Left ventricular dysfunction during exercise in patients with angina pectoris and angiographically normal coronary arteries (syndrome X)

Left ventricular function during exercise and recovery was investigated in patients with angina pectoris, ST segment depression during exercise and angiographically normal coronary arteries (syndrome X) using a continuous left ventricular function monitor with cadmium telluride detector (CdTe-VEST). Fourteen patients with syndrome X and 14 patients with atypical chest pain without ST segment depression during exercise and normal coronary arteries (control group) performed supine ergometric exercise after administration of 740–925 MBq of technetium-99m labelled red blood cells, and left ventricular function was monitored every 20 s using CdTe-VEST. Left ventricular ejection fraction (EF) response was impaired (55% increase from rest to peak exercise) in 11 or 14 patients with syndrome X but in none of the control patients. Resting EF was similar in the two groups (62.1%±6.7% in patients with syndrome X, 61.9%±6.2% in controls); however, EF increase from rest to peak exercise was lower in syndrome X (–3.1±9.5% vs 14.7%±7.4%, P <0.001). After cessation of exercise, all patients showed rapid EF increase over baseline and this EF overshoot was lower (19.3%±8.3% vs 26.4%±7.3%, P <0.001) with the time to EF overshoot longer (114±43 s vs 74±43 s, P<0.05) in patients with syndrome X. Thus, in patients with syndrome X, left ventricular dysfunction was frequently observed during exercise in spite of normal epicardial coronary arteries. Correspondence to: J. Taki     

Effect of partial left ventriculectomy on left and right ventricular volumes and function as assessed with electron beam tomography: preliminary results

Our objective was to determine if left ventricular reduction surgery affects left and right ventricular volumes and function. Twenty-three patients with end-stage heart failure underwent contrast-enhanced electron beam tomographic function studies before and twice after partial left ventriculectomy (PLV). The PLV was combined with other cardiosurgical procedures in 20 of 23 patients. Left and right ventricular enddiastolic volume (LVEDV, RVEDV), stroke volume (LVSV, RVSV), ejection fraction (LVEF, RVEF), and enddiastolic diameter (LVEDD, RVEDD) were determined by manual tracing of endo- and epicardial borders at enddiastole and endsystole. Patients were scanned 31 days (±34) before and 18 days (±13) and 8 months (±4) after PLV. Mean pre- and early and late postoperative values for LVEDV, LVSV, LVEF, and LVEDD were 387.9 ml (±125.5 ml), 255.6 ml (±79.3 ml; p<0.01), and 253.7 ml (±97.8 ml; p<0.05), 79.7 ml (±25.2 ml), 74.8 ml (±17.9; n.s.), and 79.1 ml (±26.5 ml; n.s.), 21.6% (±7.3%), 31.9% (±13.4%; p<0.05), and 34.1% (±14.1%; p<0.05), and 72.0 mm (±10.6 mm), 64.3 mm (±8.5 mm; p<0.05), and 63.5 mm (±9.4 mm; p<0.05), respectively. Mean pre- and postoperative values for RVEDV, RVSV, RVEF, and RVEDD were 177.7 ml (±72.8 ml), 172.4 ml (±59.2 ml; n.s.), and 178.9 ml (±60.8 ml; n.s.), 60.3 ml (±21.6 ml), 68.8 ml (±19.9 ml; n.s.), and 78.3 ml (±25.3 ml; n.s.), 38.1% (±15.4%), 43.7% (±16.3%; p<0.05), and 45.1% (±11.2%; n.s.), and 50.4 mm (±10.9 mm), 48.1 mm (±8.7 mm; n.s.), and 48.5 mm (±9.8 mm; n.s.), respectively. The PLV may induce a significant early reduction of left ventricular volumes and improvement of biventricular function; however, our results must be judged carefully as the majority of patients in this study underwent additional cardiosurgical procedures, the contributory effect of which on the overall outcome remains unclear. Electronic Publication     

Measurements of the effects of percutaneous nitroglycerin on left ventricular performance in patients with coronary artery disease with a cardiac probe

Left ventricular function was measured after percutaneous nitroglycerin in ten patients with coronary artery disease under double blind random control. The elevation of LVEF after percutaneous nitroglycerin paste (containing 10 mg nitroglycerin) was 8.3%±1.3% (P0.001) at 30 min, 8.5%±1.8% (P0.001) at 60 min, 10.1%±1.8% (P0.001) at 90 min and 8.7%±2.2% (P0.01) at 120 min respectively, but the change of LVEF after nitroglycerin ointment (containing 5 mg nitroglycerin) was not significant. The elevation of ER and RCO after nitroglycerin paste were 0.448±0.088 (EDV/s) (P0.001), 6.73±1.47 (EDV/s) (P0.01) at 30 min, 0.376±0.078 (P0.001), 6.64±1.36 (P0.001) at 60 min, 0.456±0.089 (P0.001), 8.02±2.11 (P0.001) at 90 min and 0.358±0.076 (P0.01), 6.18±2.05 (P0.01) respectively. It was demonstrated that percutaneous nitroglycerin paste (10 mg nitroglycerin) can improve the left ventricular function of patients with coronary artery disease.     

肺心病患者左右心功能的MRI研究

目的探讨MRI评价肺心病患者左、右心功能的应用价值。资料与方法前瞻性研究18例经肺功能实验、临床检查、X线、心电图、超声心动图等影像学检查证实为合并慢性阻塞性肺病(COPD)的肺心病患者,另选取18名健康志愿者作为对照组。采用1.5 T MRI仪测量两组左、右室心功能及右室心肌质量。采用独立样本t检验测量两组间差异是否有统计学意义。结果 2例肺心病患者MRI检查时由于屏气时间长、不能配合而排除。与对照组比较,16例肺心病患者右室(right ventricle,RV)舒张末期容积(end-diastolic volume,EDV)、右室收缩末期容积(end-systolic volume,ESV)及右室心肌质量(myocardial mass,MM)明显增加(P<0.05),而右室射血分数(ejec-tion fraction,EF)明显减低(P<0.01)。左室EDV及EF显著减低(P<0.01)。结论肺心病患者随着肺动脉压升高,超过右心室的代偿能力,促使右心室扩大和右心功能衰竭,同时左心功能损伤。MRI左右心功能的测量可以评价肺心病的严重程度,为临床提供治疗的客观依据。     

Serial evaluation of left ventricular function by radionuclide ventriculography at rest and during exercise after orthotopic heart transplantation

Discrepant results have previously been reported concerning long-term left ventricular function in the human transplanted heart as assessed by radionuclide ventriculography. In this study, radionuclide ventriculograms were obtained at rest and during exercise in 19 patients <6 months, 7–12 months, 13–24 months and >24 months after transplantation. Ejection fraction decreased significantly from <6 months to 13–24 months after transplantation (rest: 69.1%±9.7% to 56.7%±8.3%, P<0.05; exercise: 70.4%±11.3% to 59%±8%, P<0.05). Heart rate increased significantly during exercise after >2 years (90.2±10.5 beats/min to 103.5±15 beats/min, P<0.05) but not within 6 months after transplantation (98.5±12.8 beats/min to 99.07±15.8 beats/min). Left ventricular end-diastolic volume remained unchanged. Peak filling rate at rest decreased significantly from 4.2±0.96 edv/s <6 months after transplantation to 3.3±0.66 edv/s (P<0.05) 13–24 months and 3.3±0.64 edv/s (P<0.05)>24 months after cardiac transplantation. Exercise peak filing rate did not change significantly. It is concluded that radionuclide ventriculography demonstrates a decrease in systolic left ventricular function in the long-term course after cardiac transplantation. A significant increase in exercise peak heart rate may be due to autonomic reinnervation. Differences in the literature concerning left ventricular function may be due to different observation intervals following cardiac transplantation.     

Measurement of left ventricular ejection fraction with ionic 113mIn and a cardiac probe

Left ventricular ejection fraction (LVEF) was measured with a cardiac probe (Nuclear Stethoscope, Bios Inc., Valhalla, New York) and ^113mIn in 28 normal subjects and 86 patients with coronary artery disease (CAD). In 20 normal subjects ^99mTC-RBCs were compared with ^113mIn which binds to transferrin after IV injection. With ^99mTc-RBCs, average LVEF was 57±7% (1 SD); with ^113mIn, average LVEF was 55±8% (N.S.). Sequential measurements at different times over 60 min revealed good reproducibility.Comparison of LVEFs obtained using ^99mTc-RBCs with a gamma camera and cardiac probe revealed a good correlation. The correlation coefficients were 0.92 in 25 patients with CAD and 0.95 in 10 patients with LV wall motion abnormalities.The LVEF obtained using a cardiac probe and ^113mIn increased in 28 normals from 57±9% to 64±13% (P<0.001) during handgrip exercise, while the LVEF decreased from 45±9% to 41±10% (P<0.01) in patients with acute myocardial infarction 4–7 weeks after episode, from 48±11 to 40±12% (P<0.001) in patients with old myocardial infarction, and from 52±9 to 42±9% (P<0.001) in patients with angina pectoris.The cardiac probe and ^113mIn provide a useful alternate means of determining left ventricular dysfunction in facilities where ^99mTc and a gamma camera computer system are not readily available.This work supported in part by USPHS Grant No. GM10548.     

Assessment of right ventricular afterload in mitral valve diseases with radionuclide angiography

Right ventricular function at rest and during exercise was studied in 33 patients with mitral valve disease by equilibrium gated radionuclide angiography using 99mTc in vivo labeled red blood cells. Radionuclide measurements of right ventricular ejection fraction (RVEF) were correlated with mean pulmonary arterial pressure (mPAP). RVEF decreased significantly with exercise. There was no significant correlation between RVEF at rest and mPAP. However, mPAP showed significant negative correlation with RVEF during exercise and with the changes of RVEF from rest to exercise. It is concluded that RVEF during exercise in mitral valve disease is affected by right ventricular afterload, and the measurements of RVEF at rest and during exercise by equilibrium gated radionuclide angiography is useful to assess right ventricular afterload.     

Effects of perindopril on cardiac sympathetic nerve activity in patients with congestive heart failure: comparison with enalapril

Purpose The production of aldosterone in the heart is suppressed by the angiotensin-converting enzyme (ACE) inhibitor perindopril in patients with congestive heart failure (CHF). Moreover, perindopril has been reported to have more cardioprotective effects than enalapril.Materials and methods Forty patients with CHF [left ventricular ejection fraction (LVEF) <45%; mean 33±7%] were randomly assigned to perindopril (2 mg/day; n=20) or enalapril (5 mg/day; n=20). All patients were also treated with diuretics. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate (WR) were determined from ¹²³I-meta-iodobenzylguanidine (MIBG) images, and plasma brain natriuretic peptide (BNP) concentrations were measured before and 6 months after treatment. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and LVEF were also determined by echocardiography.Results After treatment, in patients receiving perindopril, TDS decreased from 39±10 to 34±9 (P<0.01), H/M ratios increased from 1.62±0.27 to 1.76±0.29 (P<0.01), WR decreased from 50±14% to 42±14% (P<0.05) and plasma BNP concentrations decreased from 226±155 to 141±90 pg/ml (P<0.0005). In addition, the LVEDV decreased from 180±30 to 161±30 ml (P<0.05) and the LVESV decreased from 122±35 to 105±36 ml (P<0.05). Although the LVEF tended to increase, the change was not statistically significant (from 33±8% to 36±12%; P=NS). On the other hand, there were no significant changes in these parameters in patients receiving enalapril.Conclusion Plasma BNP concentrations, ¹²³I-MIBG scintigraphic and echocardiographic parameters improved after 6 months of perindopril treatment. These findings indicate that perindopril treatment can ameliorate the cardiac sympathetic nerve activity and the left ventricular performance in patients with CHF.