Sympathetic Dysautonomia in Heart Failure by 123I-MIBG: comparison between Chagasic, non-Chagasic and heart transplant patients / Disautonomia Simpática na Insuficiência Cardíaca pela 123I-MIBG: Comparação entre Pacientes Chagásicos, não-Chagásicos e Transplantados Cardíacos

Abstract Background: Heart failure (HF) is a severe public health problem because of its high morbidity and mortality and elevated costs, thus requiring better understanding of its course. In its complex and multifactorial pathogenesis, sympathetic hyperactivity plays a relevant role. Considering that sympathetic dysfunction is already present in the initial phases of chronic Chagas cardiomyopathy (CCC) and frequently associated with a worse prognosis, we assumed it could be more severe in CCC than in cardiomyopathies of other etiologies (non-CCC). Objectives: To assess the cardiac sympathetic dysfunction 123I-MIBG) of HF, comparing individuals with CCC to those with non-CCC, using heart transplant (HT) patients as denervated heart parameters. Methods: We assessed 76 patients with functional class II-VI HF, being 25 CCC (17 men), 25 non-CCC (14 men) and 26 HT (20 men), by use of cardiac 123I-metaiodobenzylguanidine 123I-MIBG) scintigraphy, estimating the early and late heart-to-mediastinum ratio (HMR) of 123I-MIBG uptake and cardiac washout (WO%). The 5% significance level was adopted in the statistical analysis. Results: The early and late HMR values were 1.73 ± 0.24 and 1.58 ± 0.27, respectively, in CCC, and 1.62 ± 0.21 and 1.44 ± 0.16 in non-CCC (p = NS), being, however, higher in HT patients (p < 0.001). The WO% values were 41.65 ± 21.4 (CCC), 47.37 ± 14.19% (non-CCC) and 43.29 ± 23.02 (HT), p = 0.057. The late HMR values showed a positive weak correlation with left ventricular ejection fraction (LVEF) in CCC and non-CCC (r = 0.42 and p = 0.045; and r = 0.49 and p = 0.015, respectively). Conclusion: Sympathetic hyperactivity 123I-MIBG) was evidenced in patients with class II-IV HF, LVEF < 45%, independently of the HF etiology, as compared to HT patients.

Resumo Fundamentos: A insuficiência cardíaca (IC) representa um grave problema de saúde pública pela alta morbimortalidade e custos envolvidos, exigindo uma melhor compreensão de sua evolução. Em sua patogênese, complexa e multifatorial, a hiperatividade simpática ocupa relevante papel. Considerando que a disfunção simpática está presente já nas fases iniciais da cardiopatia chagásica crônica (CCC), frequentemente associando-se a um pior prognóstico, supomos que pudesse ser mais grave na CCC que nas demais etiologias (não-CCC). Objetivos: Avaliar a disfunção simpática cardíaca (123I-MIBG) da IC, comparando-se os portadores de CCC aos não-CCC, utilizando os pacientes transplantados cardíacos (TC) como parâmetro de coração desnervado. Métodos: Estudamos 76 pacientes com IC classe funcional II-VI, sendo 25 CCC (17 homens), 25 não-CCC (14 homens) e 26 TC (20 homens), pela cintilografia cardíaca (123I-MIBG), estimando-se a captação (HMR) precoce e tardia e o washout cardíaco (Wc%). Nas análises estatísticas, o nível de significância foi de 5%. Resultados: Os valores da HMR precoce e da tardia foram 1,73 ± 0,24 e 1,58 ± 0,27, respectivamente, na CCC, e 1,62 ± 0,21 e 1,44 ± 0,16 na não-CCC (p = NS), sendo, porém, mais elevados nos TC (p < 0,001). Os valores de Wc% foram 41,65 ± 21,4 (CCC), 47,37 ± 14,19% (não-CCC) e 43,29 ± 23,02 (TC), p = 0,057. Os valores de HMR tardia apresentaram correlação positiva fraca com a fração de ejeção de ventrículo esquerdo (FEVE) na CCC e na não-CCC (r = 0,42 e p = 0,045; e r = 0,49 e p = 0,015, respectivamente). Conclusão: Evidenciou-se a presença de hiperatividade simpática (123I-MIBG) em pacientes com IC classe II-IV, FEVE < 45%, independentemente da etiologia da IC, quando comparados aos pacientes TC.

Cardiac 123I-Metaiodobenzylguanidine Scintigraphy in Patients with Parkinson's Disease and Parkinson's Disease with Dementia

BACKGROUND: Because patients with idiopathic Parkinson's disease (PD) may exhibit patterns of cognitive impairment, it is difficult to distinguish from patients with Parkinson's disease dementia (PDD). Recently, cardiac 123I-metaiodobenzylguanidine (MIBG) scinti-graphy has been used to help distinguish PD from atypical Parkinsonism. This study investigated the relations between cardiac 123I-MIBG scintigraphy and these diseases. METHODS: Cardiac 123I-MIBG scintigraphy was conducted on 18 patients with PD, 18 patients with PDD and 13 normal controls matched for age, disease duration and severity of symptoms. The heart to mediastinum (H/M) ratio was calculated. RESULTS: The mean values of H/M ratio were significantly lower for PDD and PD than for normal controls but there was no difference between the disease groups. CONCLUSION: Unfortunately, cardiac 123I-MIBG scintigraphy did not distinguish PDD from PD in our study. We suggest further research with larger study populations be done to clarify the use of cardiac 123I-MIBG scintigraphy in differentiating other Lewy body diseases from dementia with PD features.

Clinical Implications of Cardiac-MIBG SPECT in the Differentiation of Parkinsonian Syndromes

BACKGROUND AND PURPOSE: 123I cardiac meta-iodobenzylguanidine (MIBG), an analogue of norepinephrine, has been used to estimate myocardial sympathetic nerve function. We investigate whether cardiac-MIBG SPECT is clinically applicable in the differentiation of Parkinson's disease (PD) from parkinsonian syndromes. METHODS: Cardiac-MIBG scintigraphy was performed in 27 controls, in 40 patients with PD and in 52 patients with other parkinsonian syndromes comprising 23 with multiple system atrophy (MSA), 26 with drug-induced parkinsonism (DIP), and 3 with corticobasal degeneration (CBD). The heart to mediastinum (H/M) uptake ratio was calculated for each subjects. Patients who either had medical conditions that confused the MIBG SPECT results or who took medications that interfere with MIBG accumulation were excluded from the study. RESULTS: Both early and delayed H/M ratios were in patients with PD significantly lower than in controls (early, 1.34+/-0.15 vs 1.79+/-0.19; delayed, 1.29+/-0.15 vs 2.06+/-0.29, p<0.001). In patients with PD, both early and delayed H/M ratios were significantly lower than those in patients with MSA (early, 1.68+/-0.23; delayed, 1.80+/-0.34, p<0.001), DIP (early, 1.83+/-0.24; delayed, 2.07+/-0.4, p<0.001), or CBD (early, 1.85+/-0.01; delayed, 1.99+/-0.19, p<0.001). Two patients with DIP, who were within the range of patients with PD, showed clinically similar courses of PD. CONCLUSIONS: This study demonstrates that cardiac-MIBG is a clinically powerful tools to differentiate PD from other parkinsonian syndromes.

The diagnosis and therapy of pheochromacytoma / 中国实用内科杂志

The definition of pheochromacytoma is the tumor derived from the adrenal chromaffin cell excessive producing catecholamines.Until now,the urine and plasma metanephrines(MNs) determined by HPLC-ED is considered as the first choice for the biochemical diagnosis of pheochromacytoma.According to the clinical pathway,the location of pheochromocytoma is determined by imaging methods including CT,MRI and PET,however,123I-MIBG is a more specific method for location of the tumor.The candidate genes screening including RET,VHL,SDHD,SDHB and NF1 have been recommended.The surgery to remove the tumor is the first choice for curing of pheochromacytoma.