RESUMO
Although Takotsubo cardiomyopathy (TCM) knowledge is increasing, the exact pathophysiology remains unclear. TCM represents 1%-2% of all troponin positive acute coronary syndromes, affects predominantly postmenopausal women, and is commonly preceded by exposure to severe physical or emotional stress. Transient wall motion abnormalities mimicking ST-elevation myocardial infarction is expected as well as increase of troponin levels and echocardiography alterations. This case report is about a patient that as far as we know is the first case that shows the use of myocardial perfusion imaging in the acute phase of TCM. In general, the TCM Mayo Clinic diagnostic criteria have been very helpful in the clinical setting. In this specific case, however, the presence of reduced myocardial perfusion in the acute phase combined with increased troponin levels seemed to be in contradiction with the exclusion of obstructive coronary artery disease.
Assuntos
Dor no Peito/diagnóstico por imagem , Cardiomiopatia de Takotsubo/diagnóstico por imagem , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Ecocardiografia , Feminino , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio , Isquemia Miocárdica/patologia , Imagem de Perfusão do Miocárdio , Perfusão , Cintilografia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Troponina/análiseRESUMO
A avaliação da atividade adrenérgica cardíaca através de exames de imagem apresenta grande potencial em uma ampla variedade de aplicações clínicas. A cintilografia miocárdica com 123I-mIBG desempenha papel importante na avaliação de insuficiência cardíaca crônica (ICC) ao estratificar o risco de pacientes para eventos cardíacos. A mIBG, um análogo da norepinefrina (NE), pode ser utilizada para avaliar a atividade simpática cardíaca ao se analisar a diminuição da expressão do adrenorreceptor (AR) ß na ICC. Além disso, a cintilografia miocárdica com 123I-mIBG em combinação com outros parâmetros de função ventricular esquerda pode ser usada para identificar o melhor respondedor a dispositivos cardíacos implantáveis, assim como avaliar cardiotoxicidade oncológica. Ainda que útil, a cintilografia miocárdica com 123I-mIBG não é amplamente realizada devido à falta de padronização entre as diferentes instituições. Portanto, sua padronização e validação podem contribuir para sua aceitação na prática clínica
Assuntos
Humanos , Masculino , Feminino , 3-Iodobenzilguanidina , Insuficiência Cardíaca , Miocárdio , Diabetes Mellitus , Diagnóstico por Imagem , Isquemia , Perfusão/métodos , Cintilografia/métodos , Sistema Nervoso Simpático/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
PURPOSE: The goal of this study was to evaluate late cardiotoxic effects of anthracyclines (ATC) by evaluating cardiac sympathetic activity in a cohort of asymptomatic patients previously treated with ATC for childhood cancers. METHODS: We studied 89 asymptomatic patients previously treated with ATC with a normal echocardiogram (49 men and 40 women) and a control group of 40 healthy individuals (26 men and 14 women). Both groups underwent planar myocardial 123I-meta-iodobenzylguanidine scintigraphy (123I-mIBG). From these images, the early and late heart-to-mediastinum (H/M) ratio and washout rate (WR) were assessed. RESULTS: The mean survival at the time of the 123I-mIBG scintigraphy was 5.3 ± 3.4 years. Patients treated with ATC had a lower but clinical normal left ventricular ejection fraction (LVEF) compared to controls (60.44 ± 6.5 vs 64.1 ± 6.0%, P < 0.01). Both the late H/M ratio and WR were not able to discriminate ATC treated patients from controls. The cumulative ATC dose was the only independent predictor of the LVEF, explaining approximately 12% of the variation in LVEF (P = 0.01). CONCLUSIONS: Although the pathophysiology behind ATC cardiotoxicity is most likely multifactorial, myocardial sympathetic activity is not associated with a reduction in LVEF 5-years after completion of chemotherapy.
Assuntos
Antraciclinas/uso terapêutico , Doenças do Sistema Nervoso Autônomo/diagnóstico por imagem , Doenças do Sistema Nervoso Autônomo/mortalidade , Neoplasias/tratamento farmacológico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/mortalidade , 3-Iodobenzilguanidina , Adolescente , Adulto , Antineoplásicos/efeitos adversos , Brasil/epidemiologia , Cardiotoxicidade/diagnóstico por imagem , Cardiotoxicidade/mortalidade , Causalidade , Criança , Pré-Escolar , Comorbidade , Feminino , Humanos , Masculino , Neoplasias/mortalidade , Prevalência , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Taxa de Sobrevida , Resultado do TratamentoRESUMO
PURPOSE: Myocardial perfusion imaging (MPI) with 99mTc-sestamibi (sestamibi) SPECT and rubidium-82 (82Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose. MATERIALS AND METHODS: A group of 221 consecutive patients (65.2 ± 10.4 years, 52.9% male) underwent consecutive sestamibi and 82Rb MPI after a single dipyridamole stress dose. Sestamibi and 82Rb summed rest (SRS), stress (SSS) and difference (SDS) scores, and LV end-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were compared. RESULTS: Bland-Altman analysis showed that with increasing ESV and EDV the difference between the two perfusion tracers increased both at rest and post-stress. The mean difference in EDV and ESV between the two perfusion tracers at rest could both be independently explained by the 82Rb SDS and the sestamibi SRS. The combined models explained approximately 30% of the variation in these volumes between the two perfusion tracers (R2 = 0.261, p = 0.005; R2 = 0.296, p < 0.001, for EDV and ESV respectively). However, the mean difference in LVEF between sestamibi and 82Rb showed no significant trend post-stress (R2 = 0.001, p = 0.70) and only a modest linear increase with increasing LVEF values at rest (R2 = 0.032, p = 0.009). CONCLUSIONS: Differences in left ventricular volumes between sestamibi and 82Rb MPI increase with increasing volumes. However, these differences did only marginally affect LVEF between sestamibi and 82Rb. In clinical practice these results should be taken into account when comparing functional derived parameters between sestamibi and 82Rb MPI.