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1.
J Nucl Cardiol ; 29(6): 3166-3176, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34981413

RESUMO

BACKGROUND: Regional myocardial sympathetic denervation is a conspicuous and early disorder in patients with chronic Chagas' cardiomyopathy (CCC), potentially associated to the progression of myocardial dysfunction OBJECTIVE: To evaluate in a longitudinal study the association between the presence and the progression of regional myocardial sympathetic denervation with the deterioration of global and segmental left ventricular dysfunction in CCC. METHODS: 18 patients with CCC were submitted at initial evaluation and after 5.5 years to rest myocardial scintigraphy with 123Iodo-metaiodobenzylguanidine and 99mTc-sestamibi and to two-dimensional echocardiography to assess myocardial sympathetic denervation, extent of fibrosis, and the left ventricular ejection fraction (LVEF) and wall motion abnormalities. RESULTS: In the follow-up evaluation, compared to the initial one, we observed a significant decrease in LVEF (56 ± 11 to 49% ± 12; P = .01) and increased summed defects scores in the myocardial innervation scintigraphy (15 ± 10 to 20 ± 9; P < .01). The presence of regional myocardial sympathetic denervation in ventricular regions of viable non-fibrotic myocardium presented an odds ratio of 4.25 for the development of new wall motion abnormalities (P = .001). CONCLUSION: Regional and global myocardial sympathetic denervation is a progressive derangement in CCC. In addition, the regional denervation is topographically associated with areas of future development of regional systolic dysfunction in patients with CCC.


Assuntos
Cardiomiopatia Chagásica , Doença de Chagas , Disfunção Ventricular Esquerda , Humanos , Cardiomiopatia Chagásica/diagnóstico por imagem , Cardiomiopatia Chagásica/complicações , Volume Sistólico , Estudos Longitudinais , Função Ventricular Esquerda , Miocárdio , Simpatectomia , Doença de Chagas/complicações
2.
J Nucl Cardiol ; 25(1): 75-83, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-27381340

RESUMO

BACKGROUND: To investigate the correlation between the extent of myocardial sympathetic denervation and fibrosis and the presence of degrees of severity of ventricular arrhythmias in chronic Chagas cardiomyopathy (CCC). METHODS: Forty-three CCC patients with left ventricular ejection fraction (LVEF) ≥ 35% were divided into three groups: SVT group-presenting Sustained Ventricular Tachycardia (SVT) (n = 15), NSVT group-exhibiting episodes of non-SVT (NSVT) on 24-h Holter monitoring (n = 11), and Control group-exhibiting neither SVT nor episodes of NSVT (n = 17). The patients underwent SPECT imaging for myocardial sympathetic innervation with 123Iodine-MIBG (MIBG) and myocardial perfusion with 99mTc-Sestamibi (MIBI) for the evaluation of regional myocardial fibrosis. RESULTS: The summed rest perfusion scores were similar in the three groups. The summed difference score between MIBG and MPI images, which evaluated the extent of denervated but viable myocardium, was significantly higher in SVT group (20.0 ± 8.0) as compared with the control group (2.0 ± 5.0, P < .0001) and with the NSVT group (11.0 ± 8.0, P < .05). CONCLUSIONS: The occurrence of ventricular arrhythmias of different degrees of severity correlates quantitatively with the extent of cardiac sympathetic denervation, but not with the extent of fibrosis, suggesting that myocardial sympathetic denervation plays a major role in triggering ventricular arrhythmia in CCC.


Assuntos
Arritmias Cardíacas/diagnóstico por imagem , Cardiomiopatia Chagásica/diagnóstico por imagem , Imagem de Perfusão do Miocárdio , Simpatectomia , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Ecocardiografia , Eletrocardiografia , Feminino , Fibrose , Coração/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Perfusão , Estudos Prospectivos , Índice de Gravidade de Doença , Sístole , Tecnécio Tc 99m Sestamibi
4.
J Nucl Cardiol ; 9(3): 294-303, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12032477

RESUMO

BACKGROUND: This investigation tested the application of low-dose dobutamine (LDD) gated single photon emission computed tomography (SPECT) with thallium 201 for myocardial viability detection early after acute myocardial infarction (AMI). METHODS AND RESULTS: Thirty-two hemodynamically stable post-AMI patients (aged 55 +/- 5 years [mean +/- SEM]; 20 men) who were exhibiting regional left ventricular dysfunction underwent stress-redistribution Tl-201 scanning within 4 to 8 days, followed by 2 additional gated SPECT acquisitions after Tl-201 reinjection, at rest and during LDD. A visual 5-point score was computed for segmental radiotracer uptake (0, normal; 4, absent) and a 4-point score for left ventricular wall motion (1, normal; 4, dyskinesis). Predominant viable myocardium in dyssynergic regions was predicted by a mean Tl-201 uptake score of 2 or less or ischemic area of 30% or greater. These indices showed a significant association with wall motion improvement in follow-up echocardiographic studies (overall accuracy = 0.69, sensitivity = 0.93, and specificity = 0.50). Regarding the response to LDD stimulus, an increase in mean wall motion score of 30% or greater was predictive of predominant viable myocardium. Contractile reserve assessment yielded a significant increment in the predictive accuracy for function recovery (overall accuracy = 0.84, sensitivity = 0.71, and specificity = 0.94). CONCLUSIONS: Evaluation of contractile reserve by means of LDD gated SPECT with Tl-201 is safely feasible early after AMI, with incremental value over perfusion assessment alone for myocardial viability detection.


Assuntos
Dobutamina , Coração/diagnóstico por imagem , Infarto do Miocárdio/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular Esquerda/fisiologia , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Estudos Prospectivos
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