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1.
Left ventricular (LV) systolic function in hypertrophic cardiomyopathy (HCM) is usually normal. Late in the disease, however, LV systolic dysfunction and dilatation are recognized. Although abnormalities in cardiac sympathetic nerve activity in patients with HCM have been demonstrated using (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, the changes of cardiac sympathetic nerve activity throughout the clinical course from typical to end-stage HCM are unclear. The objective of this study was to evaluate the relationship between abnormalities on (123)I-MIBG myocardial scintigraphy and pathophysiologic changes in patients with HCM. METHODS: We performed (123)I-MIBG scintigraphy on 46 patients with HCM and 18 age-matched control subjects. The patients were categorized into 3 groups: 28 patients with normal LV systolic function (group A), 9 patients with LV systolic dysfunction (group B), and 9 patients with LV systolic dysfunction and dilatation (group C). With planar (123)I-MIBG imaging, the heart-to-mediastinum ratio for early and delayed acquisitions and the washout rate were calculated. With SPECT, polar maps of the LV myocardium were divided into 20 segments. The regional uptake and washout rate were calculated from semiquantitative 20-segment bull's-eye analysis. RESULTS: The early uptake was significantly lower in group C than in the control group (P < 0.01). The washout rate was progressively higher in group A, group B, and group C (P < 0.01). Reduced regional early uptake was found in 2.9 +/- 3.4 (group A), 4.1 +/- 4.7 (group B), and 7.4 +/- 4.3 (group C) segments, respectively. In group C, regional early uptake was significantly reduced, predominantly in the interventricular septal wall, and regional washout rate was increased in the apex and lateral wall. CONCLUSION: These results suggest that cardiac sympathetic nerve abnormalities in patients with HCM may advance with development of LV systolic dysfunction and dilatation and that (123)I-MIBG myocardial scintigraphy may be a useful tool for the evaluation of pathophysiologic changes in HCM.  相似文献   

2.
Although autonomic function has been investigated in panic disorder, previous studies have not yet revealed a consistent autonomic change in this disease. The purpose of this study was to evaluate the cardiac sympathetic function in panic disorder using (123)I-metaiodobenzylguanidine ((123)I-MIBG). METHODS: Myocardial imaging using (123)I-MIBG was performed on 9 patients with panic disorder (7 men, 2 women; mean age, 37.4 +/- 13.2 y) and 11 control subjects (11 men; mean age, 37.6 +/- 9.3 y). Early (30 min) and delayed (4 h) planar images were taken after the injection of 111 MBq (123)I-MIBG. The mean counts in the whole heart and the mediastinum were obtained from the early and delayed images to calculate the heart-to-mediastinum count ratios (H/M ratios) and the myocardial washout rate. RESULTS: The (123)I-MIBG H/M ratios of the patients with panic disorder were 1.80 +/- 0.16 for the early images and 1.86 +/- 0.30 for the delayed images, which were significantly lower than those of the control subjects (2.15 +/- 0.15 [P = 0.001] and 2.26 +/- 0.21 [P = 0.009], respectively). The (123)I-MIBG washout rate from the heart in the patients with panic disorder (33.8% +/- 6.9%) was significantly higher than that in the control subjects (27.8% +/- 3.5%) (P = 0.02). CONCLUSION: (123)I-MIBG myocardial scintigraphy demonstrated impairment of cardiac sympathetic function in panic disorder. The results suggest that (123)I-MIBG imaging could become a useful tool for analyzing the pathophysiology of panic disorder.  相似文献   

3.
Cardiac (123)I-metaiodobenzylguanidine ((123)I-MIBG) uptake is reduced in chronic heart failure, and its reduction is reported to relate to the decrease in exercise capacity. Reduced (123)I-MIBG uptake may predict an inadequately reduced adrenergic drive to the heart during cardiac sympathetic stimulation, including exercise. However, there is little information about the relationship between cardiac (123)I-MIBG uptake at rest and norepinephrine (NE) release during exercise in relation to the exercise capacity in the failing heart. The aim of this study was to examine whether cardiac (123)I-MIBG uptake at rest can predict cardiac sympathetic activity during exercise in patients with chronic heart failure. We determined how cardiac (123)I-MIBG uptake at rest relates to NE overflow from the heart during symptom-limited graded exercise in such patients. METHODS: Twelve patients (mean +/- SD, 52 +/- 12 y) with chronic stable heart failure performed symptom-limited graded exercise tests under catheterizations with a 4-min stage using a supine bicycle ergometer within 2 wk after (123)I-MIBG imaging. NE concentrations in the arterial and coronary sinus blood (NE(A) and NE(CS), respectively) were measured at each exercise stage, and NE overflow was approximated by the difference between NE(CS) and NE(A) (NE(CS-A)). RESULTS: The left ventricular ejection fraction at rest was 47% +/- 16% and peak oxygen uptake was 17.7 +/- 5.1 mL/kg/min. The heart-to-mediastinum uptake ratio of the delayed (123)I-MIBG image (1.00 - 1.72; mean +/- SD, 1.30 +/- 0.19) correlated with NE(CS-A) at peak exercise (r = 0.80, P < 0.01) and peak heart rate (r = 0.73, P < 0.01) but not with peak oxygen uptake. CONCLUSION: Cardiac (123)I-MIBG uptake of the delayed image can predict the degree of the increase in adrenergic drive to the heart during sympathetic stimuli induced by exercise in patients with chronic heart failure.  相似文献   

4.
OBJECTIVE: To evaluate the sensitivity of 123I-labeled metaiodobenzylguanidine (123I-MIBG) scintigraphy in detecting diabetic autonomic nervous system disorders. MATERIALS AND METHODS: Thirty-one-week-old male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of spontaneous non-insulin-dependent diabetes mellitus, were maintained for 8 weeks with or without 30% sucrose solution as a drinking water (n = 3 each). Long-Evans Tokushima Otsuka (LETO) rats (n = 3), served as controls. Plasma glucose and insulin levels were measured, and 123I-MIBG scintigraphy was performed with a gamma camera equipped with a pinhole collimator for animals. Plasma and cardiac tissue cathecolamine levels were also determined. RESULTS: Plasma glucose levels of OLETF rats with and without sucrose loading (554+/-106 and 141+/-1.5 mg/dl respectively) were significantly higher than those of LETO rats (116+/-3.7 mg/dl). Norepinephrine concentrations in heart and plasma tended to be lower in diabetic rats. The washout rate of 123I-MIBG in diabetic rats was significantly higher than the rate in control rats. Cardiac uptake of 123I-MIBG, calculated as % dose/g of tissue, was significantly lower in diabetic rats than in control rats. CONCLUSION: These results suggest that myocardial 123I-MIBG scintigraphy is suitable for assessing cardiac sympathetic activity noninvasively in diabetic states, even in the early stages.  相似文献   

5.
Sympathetic cardiopulmonary nerves arise from the cervical sympathetic trunks and travel alongside the great arteries to innervate the ventricles. Because of the proximity of the nerve and artery, cardiac sympathetic denervation may occur in patients who have just undergone surgery for the repair of an ascending aortic aneurysm. METHODS: To evaluate the cardiac sympathetic activity in aortic aneurysm, we performed cardiac 123I-metaiodobenzylguanidine (MIBG) imaging on 12 patients (mean age +/- SD, 47 +/- 17 y) before and after the surgical repair of an aneurysm. Seven patients scheduled for coronary artery bypass grafting also underwent 123I-MIBG imaging as controls for open-chest surgery. Planar images were obtained at 15 min (early) and 4 h (delayed) after injection of 111 MBq 123I-MIBG, and the cardiac 123I-MIBG uptake was graded quantitatively and visually. The quantitative evaluation was based on the heart-to-mediastinum ratio (H/M), and visual evaluation was performed by assigning a score of 0-3 (0 = absent, 1 = severely reduced, 2 = reduced, and 3 = normal). Heart rate variability using 24-h Holter electrocardiography was analyzed before and after the operation to generate a time-domain index of heart rate variability as an index of autonomic balance. RESULTS: In patients with aortic aneurysms, both early and delayed H/Ms were significantly decreased after the operation (early H/M: 1.84 +/- 0.16 before vs. 1.40 +/- 0.16 after, P = 0.001; delayed H/M: 1.79 +/- 0.38 before vs. 1.27 +/- 0.18 after, P = 0.004). Visual analysis of 123I-MIBG accumulation in early images showed absence of 123I-MIBG accumulation in 3 of 12 patients, a score of 1 in 7 patients, and a score of 2 in 2 patients. In contrast, no significant difference between H/M before surgery and H/M after surgery was seen in patients who underwent coronary artery bypass grafting. The time-domain index of heart rate variability was significantly lower after the operation than before (135 +/- 40 after vs. 96 +/- 27 before, P < 0.05). CONCLUSION: Cardiac sympathetic nerves are totally or partially denervated after the surgical repair of ascending aortic aneurysm.  相似文献   

6.
Abnormalities of norepinephrine uptake have been found to reflect impairment of cardiac adrenergic neuronal function in adults with heart failure. To our knowledge, no data on childhood dilated cardiomyopathy (DCM) are available. The aim of this study was to assess the cardiac neuronal function using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in children with idiopathic DCM. METHODS: We studied 26 patients (mean age, 44+/-50 mo) with DCM and left ventricular dysfunction and 12 control subjects (mean age, 49+/-65 mo) with normal left ventricular function. All subjects underwent planar cardiac imaging after intravenous injection of 20-75 MBq 123I-MIBG. A static anterior view was acquired 4 h after injection. The heart-to-mediastinum count ratio was measured as described previously. RESULTS: On the basis of a reduction of the heart-to-mediastinum count ratio, cardiac neuronal uptake of 123I-MIBG was significantly decreased in patients with DCM compared with cardiac uptake in control subjects (172%+/-34% versus 277%+/-14%; P<0.0001). A significant correlation was found between left ventricular ejection fraction and 123I-MIBG cardiac uptake in patients with DCM (y = 2.5x + 113.3; r = 0.80; P<0.0001). CONCLUSION: Cardiac adrenergic neuronal function is impaired in children with idiopathic DCM. 1231-MIBG cardiac scintigraphy is a useful tool to assess cardiac neuronal function in childhood DCM.  相似文献   

7.
The clinical characteristics of reversible left ventricular dysfunction due to "takotsubo" cardiomyopathy have been described, but the origin of this condition remains unclear. This study investigated (123)I-metaiodobenzlguanidine ((123)I-MIBG) myocardial scintigraphy in patients with takotsubo cardiomyopathy. METHODS: Eight consecutive patients with takotsubo cardiomyopathy were studied. Left ventricular wall motion was monitored by echocardiography until wall motion normalized. (123)I-MIBG myocardial scintigrams were performed within 3 d of admission (0 mo) and after the improvement of left ventricular dysfunction (3 mo). Early images were obtained at 30 min after radioisotope injection and delayed images were obtained after 4 h. The heart-to-mediastinum ratio (H/M ratio) and the washout rate were calculated. RESULTS: The mean left ventricular ejection fraction improved significantly (from 42.8% +/- 8.7% to 66.5% +/- 7.9%; P < 0.0001) and normalized after 19.4 +/- 5.4 hospital days. The early H/M ratio was significantly higher than the late ratio at 0 mo (2.16 +/- 0.25 vs. 1.89 +/- 0.24, respectively; P < 0.05), but not at 3 mo. The washout rate was significantly greater at 0 mo than at 3 mo (39.1% +/- 10.2% vs. 25.4% +/- 6.3%, respectively; P < 0.05). CONCLUSION: In patients with takotsubo cardiomyopathy, initial (123)I-MIBG myocardial scintigraphy depicted a unique pattern of ventricular asynergy and indicated the existence of cardiac sympathetic hyperactivity, although coronary blood flow was maintained. These findings strongly suggest that takotsubo cardiomyopathy could be caused by neurogenic myocardial stunning.  相似文献   

8.
Meta-[123I]iodobenzylguanidine (123I-MIBG) is currently used to assess myocardial sympathetic innervation by single photon emission tomography (SPET). In recent studies, an enhanced cardiac uptake of 123I-MIBG with high specific activity has been reported, suggesting the clinical potential of no-carrier-added (n.c.a.) 123I-MIBG in the assessment of abnormalities in cardiac sympathetic function. This paper describes the preparation of n.c.a. 123I-MIBG by non-isotopic Cu(I)-assisted [123I]iododebromination and by [123I]iododestannylation, both resulting in n.c.a. 123I-MIBG with radiochemical yields of 88 +/- 6% and high specific activity (> or = 6.3 TBq.mumol-1) in a total synthesis time of less than 50 min. The diagnostic potential of n.c.a. 123I-MIBG (> 6.3 TBq.mumol-1) was studied in 13 patients (nine patients with malignant ventricular arrhythmias and four patients suspected of phaeochromocytoma) and compared to commercial 123I-MIBG (approximately 75 MBq.mumol-1) using a dual-headed SPET camera (MULTISPECT II). High specific activity results in higher 123I-MIBG uptake in the heart and in the liver in all patients. The calculated heart-to-lung and heart-to-liver count ratios 4.5 h post-injection increased by 22 +/- 6% and 10 +/- 5% with n.c.a. 123I-MIBG compared to commercial 123I-MIBG respectively. In contrast, no significant correlation between the specific activity of 123I-MIBG and lung uptake could be established in this study. Analysis of radioactivity in blood after the intravenous injection of n.c.a. and commercially available 123I-MIBG showed an initial rapid clearance of radioactivity from blood, followed by a plateau from 60 min onwards. Within the first 24 h, more than 85% of the plasma activity was unchanged 123I-MIBG. The free 123I-iodide concentration determined 24 h post-injection was 2 +/- 1% with commercial 123I-MIBG and 3 +/- 2% with n.c.a. 123I-MIBG. In conclusion, the results of this investigation indicate that n.c.a. 123I-MIBG is a promising clinical tool for imaging myocardial sympathetic dysfunction by SPET. High specific activity n.c.a. 123I-MIBG can now be prepared by simple one-step methods giving high radiochemical yields and high purity suitable for clinical application. This encourages the further clinical validation of n.c.a. 123I-MIBG on a large scale.  相似文献   

9.
Autonomic disorder is not infrequent in patients with akinetic-rigid syndromes, including idiopathic Parkinson's disease. In the advanced stage of Parkinson's disease, abnormal blood pressure responses, such as orthostatic hypotension and abnormal circadian blood pressure rhythm, may occur. Few cases of reduced 123I-metaiodobenzylguanidine (MIBG) accumulation in the heart or limbs of Parkinson's disease patients have been reported. However, whether reduced accumulation is caused by damage to the postganglionic sympathetic nervous system or by central autonomic failure corresponding to abnormalities in blood pressure regulation is unknown. METHODS: We evaluated sympathetic denervation in 32 Parkinson's disease patients using 123I-MIBG cardiac scintigraphy and compared the findings with those for autonomic dysfunction detected by orthostatic hypotension and diurnal blood pressure variation. Cardiac 125I-MIBG accumulation was also determined in an experimental model of Parkinson's disease using mice pretreated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). RESULTS: Cardiac 123I-MIBG accumulation 15 min after injection and 4 h after injection was markedly reduced in the Parkinson's disease patients (heart-to-mediastinum ratio: 1.58 +/- 0.37 and 1.33 +/- 0.28, respectively) compared with 7 healthy volunteers (2.42 +/- 0.27 and 2.60 +/- 0.15, respectively). This reduction was observed even at the earlier stages of physical activity or disease duration and also in patients with normal blood pressure response and variation, indicating that the marked decrease in cardiac 123I-MIBG accumulation may be a special feature of Parkinson's disease. Pretreatment with a total dose of 100 mg/kg MPTP, which is the standard dose used to destroy the dopaminergic neurons in models of Parkinson's disease, significantly reduced cardiac 125I-MIBG accumulation in C57BL/6 mice. Interestingly, the reduction of 125I-MIBG accumulation was still significant when MPTP was reduced to 5 mg/kg. These findings indicated that the postganglionic sympathetic nerves may be damaged by MPTP or unknown toxic substrates in experimental or human Parkinson's disease during the early stage, because dopaminergic neurons and sympathetic nerves are substantially similar in their plasma membrane transporters. CONCLUSION: Cardiac scintigraphy with 123I-MIBG may be used as a new imaging approach in the diagnosis and characterization of akinetic-rigid syndromes, especially Parkinson's disease.  相似文献   

10.
Primary dysfunction of the autonomic nervous system can be observed in patients with Parkinson's disease and those with multiple system atrophy. However, the fate of the two diseases differs considerably and leads to different strategies for patient management. Differentiation of the two diseases currently requires a combination of several clinical and electrophysiological tests. First studies of myocardial innervation using iodine-123 metaiodobenzylguanidine (MIBG) indicated a possible role of scintigraphy for this purpose. An increase in the pulmonary uptake of 123I-MIBG has been reported in secondary dysautonomias. Whether sympathetic innervation of the lung is affected in primary dysautonomias is currently unknown. Therefore, cardiac and pulmonary uptake of 123I-MIBG was studied in 21 patients with Parkinson's disease, 7 patients with multiple system atrophy and 13 age- and sex-matched controls. Thoracic images were obtained in the anterior view 4 h after intravenous injection of 185 MBq 123I-MIBG, at which time the maximum neuronal uptake is reached. All patients with Parkinson's disease had significantly lower cardiac uptake of 123I-MIBG than patients with multiple system atrophy and controls. Sympathetic innervation of the lung was not affected in either disease. It is concluded that scintigraphy with 123I-MIBG appears to be a useful tool for differentiation between Parkinson's disease and multiple system atrophy early after onset of autonomic dysfunction.  相似文献   

11.
We evaluated the diagnostic usefulness of combination studies with a statistical mapping method in N-isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) brain perfusion SPECT, cardiac sympathetic nerve function by (123)I-metaiodobenzylguanidine ((123)I-MIBG), and myocardial function by electrocardiographically gated (99m)Tc-sestamibi ((99m)Tc-MIBI) SPECT for patients with probable or possible dementia with Lewy bodies (DLB). METHODS: Twelve patients with probable DLB (7 male, 5 female; mean age +/- SD, 72.3 +/- 5.63 y; range, 65-82 y) and 9 patients with possible DLB (3 male, 6 female; mean age +/- SD, 73.1 +/- 9.23 y; range, 59-88 y) were enrolled in this study. (123)I-IMP SPECT images were analyzed with 3-dimensional stereotactic surface projections (3D-SSP) and the severity of ischemia was classified objectively using quantitatively analytic and display software; stereotactic extraction estimation (SEE) methods were compared with a normal database. In addition, we evaluated (123)I-MIBG heart-to-mediastinum (H/M) uptake ratios. Moreover, we performed (99m)Tc-MIBI SPECT to evaluate myocardial perfusion and the left ventricular ejection fraction (LVEF) compared with a normal database. RESULTS: 3D-SSP images of group comparison with healthy control subjects showed significantly decreased perfusion in the parietotemporal, occipital cortex, posterior cingulated, and precuneus regions in the probable DLB group but no significant reduction in the possible DLB group. Mean H/M ratios in the probable DLB group were significantly lower than those of the possible DLB group and the control group, respectively. Ten of 12 patients (83.3%) with probable DLB and 1 of 9 patients (11.1%) with possible DLB showed severe reduction in the bilateral occipital lobe and also a low (123)I-MIBG uptake. One patient (8.3%) with probable DLB and 2 patients (22.2%) with possible DLB showed no bilateral occipital hypoperfusion but showed low (123)I-MIBG uptake. One patient (8.3%) with probable DLB and 6 patients (66.7%) with possible DLB showed no occipital hypoperfusion and normal (123)I-MIBG uptake. (99m)Tc-MIBI gated SPECT did not indicate any wall motion abnormality in any subjects. CONCLUSION: These results suggest that combined examination of cerebral blood flow with 3D-SSP and SEE analysis, and cardiac sympathetic nerve function with (123)I-MIBG, would be a useful supporting diagnostic method in patients with DLB-particularly, in possible DLB and when cerebral blood flow does not indicate occipital hypoperfusion.  相似文献   

12.
Little is known about the relation between left ventricular (LV) functional reserve in response to exercise and cardiac sympathetic nervous function in patients with nonobstructive hypertrophic cardiomyopathy (HCM). We investigated whether an assessment of cardiac sympathetic nervous function by myocardial (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy might provide a sign of an abnormal LV functional reserve in response to exercise-induced beta-adrenergic stimulation in patients with HCM. METHODS: Thirty HCM patients underwent (123)I-MIBG scintigraphy and echocardiography at rest and subsequent biventricular cardiac catheterization at rest and during dynamic exercise. LV pressures were measured using a micromanometer-tipped catheter system. The early and delayed (123)I-MIBG images were quantified as a heart-to-mediastinum ratio (H/M). The plasma levels of brain natriuretic peptide (BNP) and norepinephrine (NE) were also measured. RESULTS: Patients were divided into 2 groups according to the delayed (123)I-MIBG H/M: group I consisted of 12 patients with a delayed H/M of < or =1.8 and group II had 18 patients with a delayed H/M of >1.8. Both the percentage increase from rest to exercise in LV isovolumic contraction (LV dP/dt(max)) and the percentage shortening of LV pressure half-time (T(1/2)) as an index of isovolumic relaxation were significantly less in group I than in group II (P < 0.05, respectively). A significant linear correlation was observed between the percentage increase in LV dP/dt(max) and (123)I-MIBG H/Ms (early H/M: r = 0.49, P < 0.01; delayed H/M: r = 0.54, P < 0.005, respectively). A significant linear correlation was also observed between the percentage shortening in T(1/2) and (123)I-MIBG H/Ms (early H/M: r = 0.58, P < 0.001; delayed H/M: r = 0.64, P < 0.0005, respectively). The plasma NE levels were significantly higher in group I than in group II (P < 0.01), whereas the plasma BNP levels were comparable in the 2 HCM groups. CONCLUSION: beta-Adrenergic enhancement of LV function during exercise may depend on the extent of cardiac sympathetic nervous innervation in HCM patients. Resting myocardial (123)I-MIBG scintigraphy can noninvasively evaluate LV functional reserve in response to exercise in patients with nonobstructive HCM.  相似文献   

13.
In order to clarify the characteristics of myocardial ischemia in patients with chronic renal failure (CRF), we performed exercise stress myocardial perfusion imaging with 99mTc-MIBI in 36 patients with CRF. In 18 patients myocardial imaging with 123I-MIBG (MIBG) and 201Tl was performed at rest to evaluate myocardial sympathetic activities: cardiac uptake of MIBG normalized by myocardial perfusion (Uptake Ratio, UR) and myocardial washout rate of MIBG (WO). Exercise-induced perfusion abnormality was observed in 25 patients, and coronary angiography was performed in 19 of them. Among 25 diseased coronary arteries, 18 developed perfusion abnormalities in the myocardial segments which were supplied by each coronary artery. However in 5 patients without coronary artery stenosis and 2 patients with left anterior descending coronary artery disease, transient perfusion abnormalities were observed in the inferior segments. In 6 of them, MIBG imaging was obtained (Group A). MIBG imaging was also performed in 5 patients with transient inferior perfusion abnormality with coronary artery stenosis which supplied the inferior wall (Group B), and 7 patients without perfusion abnormality (Group C). In the patients of Group B, inferior UR was significantly lower than in Group C (0.58 +/- 0.07 vs. 0.68 +/- 0.08, p = 0.0485) and inferior WO was more accelerated than in Group C (18.6 +/- 7.7 vs. 12.1 +/- 6.0%, NS). However anterior UR and Wo levels were identical with those in Group C. In Group A, inferior UR (0.43 +/- 0.05) was significantly lower than in Group B and C, and WO in Group A (27.2 +/- 8.3%) was accelerated significantly compared to that in Group C. Besides in Group A, anterior UR was significantly smaller and WO was greater than in Group B and C. These findings suggested that in some patients with CRF, myocardial ischemia could arise without coronary artery stenosis, and this phenomenon might be related to abnormalities of cardiac sympathetic activity.  相似文献   

14.
123I-Metaiodobenzylguanidine (MIBG) is expected to be useful agent for functional evaluation of the myocardial sympathetic innervation. The aim of this paper is to investigate serial change of 123I-MIBG myocardial concentration in patients (pts) with dilated cardiomyopathy (DCM) as compared with 201Tl uptake. Eight pts with DCM and six non-cardiac subjects (controls) were examined. After injection of 111 MBq (3mCi) 201Tl and 111 MBq (3 mCi) 123I-MIBG, simultaneous myocardial imaging in anterior view was performed for both tracers in every 30-60 minutes during 5 hours (6 images). Myocardial uptake ratio per pixel to the injected dose was calculated for each tracer with background and cross-talk correction on each image. In pts with DCM, myocardial uptake ratio of 123I-MIBG did not differ significantly from that of controls. The washout of 123I-MIBG from the myocardium, however, was significantly increased in pts with DCM as compared with controls. The % decrease of the radioactivity in 3 hours was 46.9 +/- 13.8% in DCM, whereas 18.0 +/- 7.7% in controls (p less than 0.05). Especially, the decrease in the early phase (less than 1 hour) was significantly larger in DCM than controls (21.2 +/- 7.5% vs 5.3 +/- 4.0%, p less than 0.01). For 201Tl, on the other hand, neither uptake ratio nor washout rate, differed significantly between the two. In conclusion, the rapid washout of 123I-MIBG in the early phase may reflect some sympathetic dysfunction in pts with DCM.  相似文献   

15.
Sympathetic denervation and reinnervation after the maze procedure.   总被引:2,自引:0,他引:2  
We evaluated serial changes in cardiac sympathetic nerve distribution using 123I-metaiodobenzylguanidine (123I-MIBG) after the Maze procedure. The Maze procedure, in which multiple incisions are made in the atrium, has been concomitantly performed with mitral valve (MV) surgery in an attempt to eliminate atrial fibrillation (AF). Although attenuation of the sinoatrial node response to exercise and a reduction of left ventricular function (left ventricular ejection fraction [LVEF]) in early stages after the Maze procedure have been suggested, factors leading to these changes have not been clarified. METHODS: Thirteen patients with MV disease were enrolled in this study. Six of them had undergone MV surgery and the Maze procedure (Maze+), and 7 had undergone MV surgery without the Maze procedure (Maze-). All patients underwent cardiac 123I-MIBG imaging preoperatively and 10 d and 1 y after surgery to assess 123I-MIBG uptake (heart-to-mediastinum count ratio of early planar images [H/M]) and the washout rate (WR). Radionuclide ventriculography was also performed to calculate LVEF 3 d after each 123I-MIBG imaging. RESULTS: The LVEF of the Maze+ group significantly decreased 10 d after surgery (44.2 +/- 4.8; mean +/- SD) compared with that before surgery (60.3 +/- 6.9; P < 0.05) and significantly increased at 1 y (65.2 +/- 2.9) compared with that at 10 d (P < 0.05). In the Maze- group, there was no significant change 10 d (53.0 +/- 12.3) and 1 y (58.6 +/- 4.8) after surgery compared with that before surgery (60.4 +/- 4.6) (P = not significant, each). In the Maze+ group, the H/M (1.51 +/- 0.18) was significantly lower at 10 d after than that at the preoperative stage (1.90 +/- 0.25; P < 0.05) but significantly recovered at 1 y (2.23 +/- 0.18; P < 0.05) with a similar transient increase in the WR (36.7% +/- 6.1% at preoperative stage; 46.9% +/- 3.4% at 10 d; 39.9% +/- 6.5% at 1 y; P < 0.05, each). On the other hand, the Maze- group did not show a significant change in the H/M (1.94 +/- 0.32, 2.06 +/- 0.18, and 2.13 +/- 0.17, respectively; P = not significant, each) but did exhibit a significant decrease in the WR (40.4% +/- 5.1%, 37.0% +/- 5.1%, and 32.9% +/- 2.5%, respectively; P < 0.05, each). Changes in the H/M of both groups significantly correlated with the change in LVEF (r = 0.82; P < 0.05), and the WR showed a significant inverse correlation with changes in the LVEF (r = -0.81; P < 0.05). CONCLUSION: Cardiac sympathetic nerves were denervated at early stage and reinnervated at late stage after the Maze procedure. Such adrenergic nerve changes may be correlated, at least in part, with changes in left ventricular function after this procedure.  相似文献   

16.
Cardiac involvement of systemic sclerosis (SSc) is associated with a poor prognosis. Arrhythmias and conduction disturbances are a known feature of SSc. From histopathological examinations, it is known that the conducting system is secondarily involved as a result of focal fibrosis of the myocardium. Fibrotic changes are believed to be related to vasospasms, such as Raynaud's phenomenon. The sympathetic nervous system is very sensitive to ischaemia, impairing the energy-dependent uptake of intraneuronal norepinephrine. 123I-metaiodobenzylguanidine (123I-MIBG) is a metabolic analogue of norepinephrine and can therefore be used as a marker of norepinephrine depletion. The aim of the study was to evaluate the incidence and extent of SSc-associated ischaemic damage due to primary cardiac involvement by assessing intraneuronal 123I-MIBG uptake and distribution. Supplementary myocardial stress and rest perfusion scintigraphy, together with cardiological examinations (including an exercise stress test, Holter ECG and echocardiography), were performed in 18 patients. None of the patients showed evidence of ischaemia upon myocardial perfusion stress SPET or exercise stress. ECG at rest detected pathological conductance disturbances in one patient (6%). Holter ECG evoked pathological arrhythmias in three patients (17%). The echocardiograms of four patients (22%) showed a slight impairment of left ventricular diastolic function. 123I-MIBG scintigraphy revealed an inhomogeneous reduction of norepinephrine content in 15 patients (83%). It would appear that 123I-MIBG scintigraphy is able to detect cardiac SSc involvement prior to cardiological investigations.  相似文献   

17.
Uptake of (123)I-meta-iodobenzylguanidine ((123)I-MIBG) is markedly reduced in the hearts of patients with Parkinson's disease. Although the mechanism of this reduction is unclear, (12)(5)I-MIBG uptake is similarly reduced in the hearts of mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP)-induced parkinsonism. Three groups of ten 15-week-old C57BL6 mice received intraperitoneal injections of (1) saline (control), (2) 10 mg/kg MPTP or (3) 40 mg/kg MPTP. After 0.185 MBq of (125)I-MIBG was injected, the percent injected dose of (125)I-MIBG per gram of tissue (%ID/g) was determined and cardiac concentrations of norepinephrine were measured. Cardiac concentrations of norepinephrine transporter (NET) were measured in three groups of twenty 15-week-old C57BL6 mice receiving these same treatments. The %ID/g in mice receiving 10 or 40 mg/kg MPTP (5.7 +/- 1.1 and 4.4 +/- 1.2%/g) was significantly lower than that in control mice (11.3 +/- 2.2%/g; P < .00001 and P < .0000001, respectively). The norepinephrine concentration in mice receiving 10 or 40 mg/kg MPTP (7.86 +/- 0.67 x 10(5) and 7.50 +/- 0.89 x 10(5) pg/wet g) was significantly lower than that in control mice (9.21 +/- 0.97 x 10(5) pg/wet g; P < .01 and P < .001, respectively). The NET density in mice receiving 10 or 40 mg/kg MPTP (81 +/- 12, 61 +/- 7 fmol/mg protein) was significantly lower than that in control mice (126 +/- 7 fmol/mg protein; P < .000001 and P < .0000001, respectively). The %ID/g of (125)I-MIBG and NET density decreased as the dose of MPTP increased. This study clearly shows that reduced cardiac (12)(5)I-MIBG uptake in mice with MPTP-induced parkinsonism is closely related to the reduced NET density in postganglionic cardiac sympathetic nerve terminals.  相似文献   

18.
The purpose of this study was to assess the regional cardiac sympathetic reinnervation late (> or = 1 year) after heart transplantation (HTX) by means of 123I-MIBG (MIBG) scintigraphy. Eight patients with a pretransplantation diagnosis of idiopathic dilated cardiomyopathy underwent MIBG scintigraphy more than one year after HTX. The presence or absence of regional MIBG uptake was evaluated in each SPECT image, and global MIBG uptake was semi-quantitatively assessed by the heart to mediastinum ratio (H/M). Five of 8 patients had visible MIBG uptake in both planar and SPECT images (PU group), whereas 3 of 8 patients had no uptake, 2 of them after a period of 2 years, and one of them as long as 5 years after HTX, respectively (NU group). Positive regional MIBG uptake involved the basal anterior region in all 5 patients, the basal septal region in 4 patients, the basal lateral region in 3 patients and the basal posterior region in 1 patient. The H/M value was 1.24+/-0.10 in the PU group and 1.09+/-0.03 in the NU group. In conclusion, MIBG SPECT can detect regional sympathetic reinnervation, indicating that basal septal and lateral regions next to the basal anterior are more likely to be reinnervated, but reinnervation is much less likely to occur in the midventricular and apical regions.  相似文献   

19.
Primary dysfunction of the autonomic nervous system can be observed in patients with Parkinson’s disease and those with multiple system atrophy. However, the fate of the two diseases differs considerably and leads to different strategies for patient management. Differentiation of the two diseases currently requires a combination of several clinical and electrophysiological tests. First studies of myocardial innervation using iodine-123 metaiodobenzylguanidine (MIBG) indicated a possible role of scintigraphy for this purpose. An increase in the pulmonary uptake of 123I-MIBG has been reported in secondary dysautonomias. Whether sympathetic innervation of the lung is affected in primary dysautonomias is currently unknown. Therefore, cardiac and pulmonary uptake of 123I-MIBG was studied in 21 patients with Parkinson’s disease, 7 patients with multiple system atrophy and 13 age- and sex-matched controls. Thoracic images were obtained in the anterior view 4 h after intravenous injection of 185 MBq 123I-MIBG, at which time the maximum neuronal uptake is reached. All patients with Parkinson’s disease had significantly lower cardiac uptake of 123I-MIBG than patients with multiple system atrophy and controls. Sympathetic innervation of the lung was not affected in either disease. It is concluded that scintigraphy with 123I-MIBG appears to be a useful tool for differentiation between Parkinson’s disease and multiple system atrophy early after onset of autonomic dysfunction. Received 2 December 1999 and in revised form 17 February 2000  相似文献   

20.
123I-Metaiodobenzylguanidine (123I-MIBG) is used for lung scintigraphy to assess pulmonary endothelial cell integrity, but its processing at the cellular level has not been investigated to date. We thus characterized the mechanisms that mediate 123I-MIBG transport in pulmonary endothelial cells and investigated the effects of stimuli associated with pulmonary dysfunction. METHODS: Calf pulmonary artery endothelial (CPAE) cells were examined for 123I-MIBG uptake and efflux rates and evaluated for the presence of norepinephrine (NE) transporters by Western blotting. The specificity of 123I-MIBG uptake was investigated with inhibitors of the uptake 1 and uptake 2 transport systems. In addition, we tested the effects of hypoxia (1% O2), phorbol 12-myristate 13-acetate (PMA, a protein kinase C [PKC] activator), and NG-nitro-L-arginine methyl ester (L-NAME) (a nitric oxide synthase inhibitor) treatments on CPAE cell 123I-MIBG uptake. RESULTS: CPAE cells demonstrated a time-dependent increase in 123I-MIBG uptake that reached a relative plateau (mean +/- SD) at 4 h of 375.6% +/- 5.9% the 30-min level. When the culture medium was changed after 30 min of uptake, 123I-MIBG gradually was eluted from the cells at an efflux rate of 43.8% over 2 h. Western blotting confirmed the presence of NE transporters in CPAE cells. The uptake 1 inhibitors desipramine, imipramine, and phenoxybenzamine at 50 micromol/L reduced 123I-MIBG uptake to 55.3% +/- 2.7%, 62.4% +/- 3.5%, and 48.0% +/- 2.2% control levels, respectively, whereas none of the uptake 2 inhibitors had an effect. Exposure to hypoxia resulted in a reduction in 123I-MIBG uptake to 77.5% +/- 0.2% and 50.0% +/- 3.4% control levels at 0.5 and 4 h, respectively. PMA (10 ng/mL) and L-NAME (2 nmol/L) decreased 123I-MIBG uptake to 76.7% +/- 9.0% and 86.5% +/- 5.6% control levels, respectively. CONCLUSION: Pulmonary endothelial cells express NE transporters and actively take up 123I-MIBG through the specific uptake 1 system. Furthermore, 123I-MIBG transport can be reduced by hypoxia, PKC activation, and nitric oxide deficiency, which may contribute partly to the lower levels of lung uptake observed in diseases that compromise pulmonary endothelial cell integrity.  相似文献   

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