Imagem por ressonância magnética na cardiopatia chagásica crônica. Correlação com biopsia endomiocárdica / Magnetic resonance imaging in chronic chagas' heart disease. Correlation with endomyocardial biopsy findings

PURPOSE: To study the correlation between magnetic resonance imaging of the heart and right ventricle endomyocardial biopsy results in chronic Chagas' heart disease. METHODS: Ten patients with Chagas' disease, mean age 47 +/- 7 years, all males, in congestive heart failure with New York Heart Association class II (2 patients), III (6) and IV (2) were studied. Mean left ventricular ejection fraction was at echocardiogram 36 +/- 6. The patients were submitted to right ventricular endomyocardial biopsy and magnetic resonance imaging of the heart. The results of this group were compared with a control group of patients with idiopathic dilated cardiomyopathy, with mean age of 46 +/- 10 years and left ventricular ejection fraction of 30 +/- 4, in heart failure with functional class II (1 patient), III (5) and IV (1). RESULTS: All patients with Chagas' heart disease presented an increase in magnetic ressonance imaging signal of the heart after gadolinium use. The septal signal intensity changed from 0.87 +/- 0.06 to 1.54 +/- 0.16 (p < 0.001). In the control group the mean septal signal intensity was 0.93 +/- 0.07 before and 0.89 +/- 0.06 after the gadolinium (p = ns). Eight patients of the Chagas' disease group had biopsy proven myocarditis and two had borderline myocarditis. However, only one patient of the control group had diagnosis of borderline myocarditis. CONCLUSION: Myocarditis is frequently found in Chagas' heart disease patients and who unlike controls present a significant increase in myocardial signal intensity after gadolinium infusion. The magnetic resonance imaging of the heart seems a promising alternative method for the diagnosis of an inflammatory process in Chagas' heart disease.

Objetivo - Estudar a correlação entre a imagem por ressonância magnética e a biopsia endomiocárdica do ventrículo direito (VD) na cardiopatia da doença de Chagas. Métodos - Comparação de 10 pacientes com cardiopatia da doença de Chagas, idade média de 47 ± 7 anos, todos do sexo masculino, com insuficiência cardíaca em classe funcional (CF) II NYHA (2 pacientes), III (6) e IV (2); fração de ejeção do ventrículo esquerdo (FEVE) média pelo ecocardiograma 36 ± 6%; e 6 pacientes com cardiomiopatia dilatada idiopática, idade média de 46 ± 10 anos, FEVE média pelo ecocardiograma 30 ± 4% e insuficiência cardíaca CF II (1 paciente), III (5) e IV (1). Todos os pacientes foram submetidos a biopsia endomiocárdica do VD e exame do coração através de ressonância magnética (RM) com e sem uso do contraste gadolíneo. Resultados - Todos os pacientes com cardiopatia chagásica apresentaram aumento da intensidade de sinal na imagem pela RM após o uso de gadolíneo. A intensidade média do sinal variou de 0,87 ± 0,06 antes a 1,54 ± 0,16 após o uso do contraste (p < 0,001). No grupo controle, antes do uso do gadolíneo a intensidade média septal foi de 0,93 ± 0,07 e, após, o valor médio foi de 0,89 ± 0,06 (p = ns). Oito pacientes no grupo de cardiopatia chagásica tiveram biopsia provando miocardite e 2 com resultado bordeline, contudo no grupo controle, somente um teve diagnóstico duvidoso para miocardite. Conclusão - A miocardite é freqüentemente encontrada na doença de Chagas, os pacientes com cardiomiopatia chagásica, ao contrário do grupo controle, apresentam aumento significativo da intensidade de sinal de ressonância após o uso do gadolíneo. A imagem por RM parece ser método alternativo e com boa acurácia para diagnóstico de processo inflamatório cardíaco na doença de Chagas

Valor da ressonância nuclear magnética na detecção da perviabilidade da artéria coronária após trombólise / Role of the Magnetic Resonance Imaging to Detect Artery Patency After Thrombolysis

PURPOSE--To determine the value of magnetic resonance imaging (MRI) in the noninvasive detection of infarct related coronary artery patency after thrombolysis. METHODS--We studied 26 patients with acute myocardial infarction submitted to thrombolysis underwent MRI studies before and after 0.1mmol/kg gadolinium-DTPA injection within the first 48 h of MI. Signal intensity was assessed by circumferential profile analysis techniques. RESULTS--The average ratio of signal intensity of infarcted tissue over normal myocardium (I/N) was significantly higher in patients with patent arteries (1.3 +/- 0.13 vs 1.12 +/- 0.07, p < 0.02). Compared to coronariography MRI, sensitivity of 81 and specificity of 100 for the diagnosis of coronary patency. CONCLUSION--Gadolinium infusion increased infarcted and normal myocardium differentiation. The study of gadolinium kinetics at MRI is a promising technique for noninvasive diagnosis of coronary patency.

A revascularizaçäo precoce das artérias näo relacionadas ao infarto melhora a funçäo regional e global do ventrículo esquerdo após o infarto agudo do miocárdio / Early Noninfarct Related Arteries Revascularization Improves Regional Wall Motion Post Myocardial Infarction

PURPOSE--To evaluate if early interventions which increase flow in the non-infarct related arteries (NRA) could improve long-term ventricular function in the non-infarct (NI) area after an acute myocardial infarction (MI). METHODS--We studied regional wall motion analyzed by the center-line method in two groups of patients with significant stenoses (> or = 70 per cent ) in the NRA after successful coronary reperfusion (chemical or mechanical thrombolysis). Group I (GI) consisted of 21 patients that were submitted to early (mean 14 days) complete surgical revascularization of both NRA and infarct related artery (IRA); the 12 group II (GII) patients underwent successful revascularization of the IRA only, with percutaneous transluminal coronary angioplasty (mean 6 days). Paired ventriculograms were obtained within 48 hours of the infarction and a mean of 17 months later. RESULTS--NI area contractility in GI patients improved from -0.35 +/- 2.16 to +0.62 +/- 1.6sd/chord (p < 0.05), whereas in GII decreased from +0.54 +/- 1.78 to -0.66 +/- 1.72 sd/chord (p < 0.05), p < 0.05 between the groups at follow-up. Mean infarct area wall motion did not differ between the two groups: from -3.04 +/- 2.43 to 2.61 +/- 2.49 sd/chord in GI (p = NS), and from -2.68 +/- 2.54 to -2.93 +/- 2.35 sd/chord in GII (p = NS). Mean global left ventricular (LV) ejection fraction did not change in GII patients (0.72 +/- 0.09 and 0.67 +/- 0.12, p = NS), but significantly increased from 0.63 +/- 0.12 to 0.72 +/- 0.11 in GI patients (p < 0.01). CONCLUSION--These data suggest that early revascularization of NRA with significant stenoses can improve not only the NI area regional contractility, but also the global LV function in the long-term follow-up of post MI patients treated with thrombolytic therapy