Abstract T-wave alternans (TWA) analysis is one of the main techniques for determining whether an individual is at risk of sudden cardiac death (SCD). Among the existing methods for determining TWA is the adaptive spectral method (SM-Adaptive), which uses time-frequency distributions (TFD) for the analysis. The objective of the study is to apply the method on main public databases in order to detect the presence or absence of alternations, and to obtain quality parameters of the aforementioned method. The method was tested on synthetic signals, 90 signals without TWA and 450 with TWA; on the other hand, 10 signals from Physionet’s TWADB database belonging to healthy patients and 26 signals from patients with risk factors associated to SCD were used. Tests with synthetic signals showed a sensitivity of 94.89%, specificity of 92.22% and accuracy of 94.44%. As for the tests in the database, the method exhibits an accuracy of 80.56%, which indicates that the SM-Adaptive method enables detecting TWA with an acceptable accuracy and, in addition, it shows greater robustness against noise and stationary data.

OBJECTIVE: To evaluate the management of patients complaining of high blood pressure (BP) in a cardiological emergency room. METHODS: Patients referred to the cardiological emergency room with the main complaint of high blood pressure were consecutively selected. The prescriptions and the choice of antihypertensive drugs were assessed. The classification of these patients as hypertensive emergencies or pseudoemergencies, according to the physician who provided initial care, was recorded. RESULTS: From a total of 858 patients presenting to the emergency room, 80 (9.3%) complained of high BP, and 61 (76.3%) received antihypertensive drugs. Sublingual nifedipine was the most commonly used drug (59%). One patient received intravenous medication, one patient was hospitalized and 6 patients (7.5%) were classified as hypertensive emergencies or pseudoemergencies. CONCLUSION: High BP could seldom be classified as a hypertensive emergency or pseudoemergency, even though it was a frequent complaint (9.3% of visits). Currently, the therapeutic approach is not recommended, even in specialized clinics.

Objetivo: Vários estudos têm demonstrado que Radicais Livres de Oxigênio (RLO) contribuem para o dano celular decorrente da isquemia e reperfusão. Este estudo foi desenvolvido como o objetivo de avaliar os efeitos da isquemia e reperfusão renal em ratos, tratados ou não com alopurinol, sobre a lipoperoxidação (LPO) das membranas celulares renais. Método: Foram usados ratos Wistar distribuídos em 4 grupos e submetidos a períodos de isquemia e reperfusão renal ou não, dependendo do grupo. Também foram submetidos ou não a tratamento com alopurinol na dose de 50 e 150 mg/Kg por via intraperitoneal, 5 e 1 horas antes do procedimento. Na avaliação da lipoperoxidação utilizou-se os métodos do TBARS e QL. Resultados: Os resultados demonstraram aumento da LPO nos animais submetidos a isquemia e reperfusão renal. No entanto, estes efeitos deletérios foram reduzidos com o pré-tratamento com alopurinol (p<0,05). Conclusão: O dano causado em animais submetidos a isquemia e reperfusão renal pode ser demonstrado e quantificado pela LPO. Além disso, o alopurinol demonstrou proteção renal contra o dano decorrente desta síndrome, diminuindo a LPO nestes animais. Estes resultados sugerem que a via da xantina oxidase é uma das mais importantes rotas metabólicas envolvidas na geração de RLO, estes responsáveis em parte pelos danos funcionais do rim na síndrome da isquemia e reperfusão deste órgão.

Background: Evidence has accumulated that oxygen free radical (OFR) contribute to the cellular damage induced by ischemia-reperfusion. This study was undertaken to determine the effects of renal ischemia-reperfusion in rats, treated or not with allopurinol evaluating the lipid peroxidation (LPO) of renal cellular membranes. Method: Wistar rats were divided into 4 groups (n=10) and submitted to 50 minutes of renal ischemia and reperfusion and treated or not with allopurinol (50 and 150 mg/Kg of body, 5 and 1 hour before ischemia, respectively). The lipid peroxidation was assessed by TBARS method (Thiobarbituric acid reactives substances) and CL method (Chemiluminescence). Results:The results showed that animals submitted to renal ischemia-reperfusion had renal LPO damage. These effects of ischemia and reperfusion were reduced by treatment with allopurinol (p<0,05). Conclusion: These results suggest that xanthine oxidase is one of the most important pathway envolved in the generation of OFR and chemical reactives elements with injury potencial at the renal cellular membranes due to ischemia-reperfusion syndrome. At least, allopurinol showed benefical effects preventing damage due to renal ischemia-reperfusion injury.