Fundamento: A comparação do rigor diagnóstico da TCMD e da USIV foi pouco descrita, estando restrita principalmente a estudos que avaliaram segmentos com placas ateroscleróticas já documentadas. Objetivos: Este estudo objetiva avaliar o desempenho diagnóstico da tomografia computadorizada com 64 colunas de detectores (tomografia computadorizada multidetector- TCMD) e da ultrassonografia intravascular (USIV) em escala de cinza na verificação das dimensões da luz coronária, em um contexto mais amplo, incluindo também segmentos coronários sadios e com patologia leve. Métodos: A TCMD foi realizada em todos os pacientes antes da realização da USIV, com um intervalo < 72 horas entre os dois exames. Imagens de USIV foram obtidas de pelo menos uma coronária, independente da presença de estenose luminal durante a angiografia. Um total de 21 pacientes foram incluídos, com imagens de 70 vasos (comprimento total 114,6 ± 38.3 mm por paciente). Placas coronárias foram diagnosticada em segmentos com carga de placas > 40%. Resultados: Uma alta correlação entre as medidas de TCMD e USIV para área luminar média, área luminar mínima e diâmetro luminar mínimo foi encontrada no nível de paciente, vaso e segmento (p-valor < 0,01 para todas as correlações). A TCMD, no entanto, tendeu a subestimar o tamanho luminar com uma dispersão de diferenças relativamente ampla. A comparação entre as medidas da luz por TCMD e USIV não foi substancialmente afetada pela presença ou ausência de placa subjacente. Além disso, a TCMD mostrou boa precisão geral na detecção de parâmetros associados a lesões limitantes de fluxo. Conclusão: Em uma análise compreensiva e multi-focal da luz coronária, demonstramos bom desempenho diagnóstico da TCMD, quando comparada a USIV, independente da presença de placas ateroscleróticas adjacentes.

Background: The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives: We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods: The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. Results: At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions: In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

OBJETIVO: Análise comparativa dos resultados hospitalares em pacientes infartados reperfundidos por meio de uma intervenção coronariana percutânea de resgate ou primária. MÉTODOS: Selecionados pacientes consecutivos, submetidos a uma intervenção percutânea no infarto do miocárdio (< 24h), entre 1997 e 2000, incluídos no registro nacional multicêntrico CENIC, comparando os resultados hospitalares, entre aqueles submetidos ao procedimento de resgate (n=840) ou primário (n=8.531). RESULTADOS: Os pacientes que realizaram intervenção de resgate eram significativamente mais jovens, com infarto anterior, associado à presença de disfunção ventricular, porém com menor porcentual de doença coronariana multiarterial, comparados aos primários. As taxas de implante de stents foram similares (56,9% vs. 54,9%; p=0,283), mas o sucesso do procedimento foi menor nos casos de resgate (88,1% vs. 91,2%; p<0,001), cursando com maior mortalidade (7,4% vs. 5,6%; p=0,034), comparado à intervenção primária; nova revascularização (< 0,5%), cirurgia de emergência (< 0,3%) e reinfarto (< 2,6%) foram similares. A análise multivariada identificou o procedimento de resgate como preditor de mortalidade ao final da fase hospitalar [RC (IC=95%) = 1,60 (1,17-2,19); p=0,003]. CONCLUSÃO: Neste registro nacional, a intervenção de resgate apresentou uma maior mortalidade hospitalar, comparada ao procedimento primário.

OBJECTIVE: To perform a comparative analysis of in-hospital results obtained from AMI patients who underwent rescue or primary PTCA. METHODS: From the Brazilian Interventional National Registry (CENIC), we selected all consecutive patients who underwent a percutaneous coronary intervention for myocardial infarction (< 24 hours), between 1997 and 2000, analyzing those undergoing a rescue (n=840) or a primary (n=8,531) procedure, and comparing their in-hospital results. RESULTS: Rescue patients were significantly younger males with anterior wall infarctions, associated with left ventricular dysfunction, but had less multivessel disease, compared with those treated with primary intervention. Coronary stents were implanted in at similar rates (56.9% vs. 54.9%; P=0.283). Procedural success were lower for rescue cases (88.1% vs. 91.2%; P<0.001), with higher mortality (7.4% vs. 5.6%; P=0.034), compared with the primary intervention group; target vessel revascularization (< 0.5%), emergency bypass surgery (< 0.3%) and reinfarction (< 2.6%) rates were similar for both strategies. Multivariate analysis identified the rescue procedure as a predictor of in-hospital death [OR(CI=95%) = 1.60 (1.17-2.19); P=0.003]. CONCLUSION: Patients who underwent a rescue coronary intervention had higher in-hospital death rates compared with those who underwent a primary coronary intervention.

We intend to divulge an easy experiment that permits the determination of molar masses of various compounds by cryoscopy. The major advantage of this is the use of the tert-butyl alcohol as a solvent, which requires simple apparatus and easy procedures. The melting point of this alcohol is around 25 ºC, which makes it easy to freeze and then melt the solutions. This solvent has a high cryoscopic constant and is miscible with both polar and non-polar compounds. The molar masses of acetone, water, chloroform, dichloro-methane, ethanol, hexane, carbon tetrachloride and toluene were determined. The results were good except for water. Even though there are reliable techniques of molar mass determination nowadays, this method is still frequently taught in undergraduate courses.