926 resultados para Bundle-Branch Block


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In this longitudinal study 5,710 people were included. The inclusion criteria were two positive serological results for Trypanosoma cruzi infection, 15 and 50 years old and no other demostrable diesease at the time of study. In the five year follow up 1,117 patients were lost. The follow up involved yearly evaluation of serology, clinical examination, X-ray of torax, and ECG, for 4,593 patients and 263 were contacted at home because they did not assist for their clinical consultant. Time average of follow up was 5.3 years. Eighty nine (1.5%) of the 4,593 patients died during the follow-up period, 63 (71%) by cardiac insufiency (CI) and 26 (29%) by severe ventricular arrithmias. Diagnosis of cardiomegaly was present in all the patients with diagnosis of CI and in 15 (5%) of the patients with diagnosis of arrithmias.The ECG alterations of these pacients show 61 right bundle brunch block (RBBB), associated or not with left anterior hemiblock (LAHB), 47 pathological Q wave and 70 primary repolarization alterations; 61 had polyfocal ventricular arrithmia. The death rate was similar in the sexes and was more frequent between 40 and 50 years of age. Information on 1,380 recuperated patients shows that 15 died with no previous symptoms and without medical assistance and were interpretate as sudden death. The latest ECG in three follow-up of these pacients indicates (before death) that only one had normal study and 14 presented 12 RBBB; 9 LAHB; 7 isolated ventricular arrithmia; 10 repolariz alterations; 2 patological Q wave, 10 patients of them with RBBB and repolariz alterations. In all the cases we had people between 35 and 43 years old, 9 men and 6 women. This study shows that in Chagas disease is possible to differenciate two risk groups. A low risk death group that have normal ECG and clinical evaluation during the follow up, and a high risk group associate ECG with RBBB and primary alterations of repolarization and/or inactivation zones with not anual clinical evaluation.

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OBJECTIVES: ,,,,,The prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease according to disease severity has not yet been established. The aim of this study was to assess the prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease patients according to disease severity. ,,,, ,,,, ,,,,,METHODS: ,,,,,The study included 25 mild/moderate chronic obstructive pulmonary disease patients and 25 severe/very severe chronic obstructive pulmonary disease patients. All participants underwent clinical evaluation, spirometry and electrocardiography/echocardiography. ,,,, ,,,, ,,,,,RESULTS: ,,,,,Electrocardiography and echocardiography showed Q-wave alterations and segmental contractility in five (10%) patients. The most frequent echocardiographic finding was mild left diastolic dysfunction (88%), independent of chronic obstructive pulmonary disease stage. The proportion of right ventricular overload (p<0.05) and blockage of the anterosuperior division of the left bundle branch were higher in patients with greater obstruction. In an echocardiographic analysis, mild/moderate chronic obstructive pulmonary disease patients showed more abnormalities in segmental contractility (p<0.05), whereas severe/very severe chronic obstructive pulmonary disease patients showed a higher prevalence of right ventricular overload (p<0.05), increased right cardiac chamber (p<0.05) and higher values of E-wave deceleration time (p<0.05). Age, sex, systemic arterial hypertension, C-reactive protein and disease were included as independent variables in a multiple linear regression; only disease severity was predictive of the E-wave deceleration time [r2 = 0.26, p = 0.01]. ,,,, ,,,, ,,,,,CONCLUSION: ,,,,,Chronic obstructive pulmonary disease patients have a high prevalence of left ventricular diastolic dysfunction, which is associated with disease severity. Because of this association, it is important to exclude decompensated heart failure during chronic obstructive pulmonary disease exacerbation.

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A doença de Chagas causada pelo T. cruzi é transmitida, principalmente, por insetos vetores e está distribuída na Argentina, no Chile, na Venezuela e no Brasil. O cão, além de ser um importante reservatório, também é vítima da doença e a única espécie capaz de desenvolver manifestações clínicas iguais a do homem. O presente trabalho teve como objetivo descrever as alterações clínicas encontradas em quatro cães infectados naturalmente pelo T. cruzi e alertar para a possibilidade de que a ocorrência dessa enfermidade em cães de Mato Grosso do Sul possa estar sendo subestimada. Os animais foram selecionados a partir de exames sorológicos de reação de imunofluorescência indireta (RIFI), ensaio imunossorvente ligado à enzima (ELISA) e immunoblotting com antígeno secretado e excretado da forma tripomastigota do T. cruzi (TESA-blot) e submetidos a xenodiagnóstico, exame físico, radiografia torácica, eletrocardiografia, ecocardiografia e bioquímica sérica. As alterações encontradas foram aumento de ventrículo direito, presença de arritmias do tipo bloqueio átrio ventricular, sinus arrest e bloqueio de ramo direito, além de disfunção sistólica e diastólica. Três animais apresentaram hiperproteinemia e as dosagens das enzimas CK e CK-MB revelaram valores indicativos de uma miocardite ativa. Esses são os primeiros casos descritos de cães com evidências consistentes de infecção natural pelo T. cruzi em Mato Grosso do Sul e ressalta-se o alerta aos médicos veterinários para a importância clínica e o papel dessa espécie como reservatório da doença.

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The role of gap junction channels on cardiac impulse propagation is complex. This review focuses on the differential expression of connexins in the heart and the biophysical properties of gap junction channels under normal and disease conditions. Structural determinants of impulse propagation have been gained from biochemical and immunocytochemical studies performed on tissue extracts and intact cardiac tissue. These have defined the distinctive connexin coexpression patterns and relative levels in different cardiac tissues. Functional determinants of impulse propagation have emerged from electrophysiological experiments carried out on cell pairs. The static properties (channel number and conductance) limit the current flow between adjacent cardiomyocytes and thus set the basic conduction velocity. The dynamic properties (voltage-sensitive gating and kinetics of channels) are responsible for a modulation of the conduction velocity during propagated action potentials. The effect is moderate and depends on the type of Cx and channel. For homomeric-homotypic channels, the influence is small to medium; for homomeric-heterotypic channels, it is medium to strong. Since no data are currently available on heteromeric channels, their influence on impulse propagation is speculative. The modulation by gap junction channels is most prominent in tissues at the boundaries between cardiac tissues such as sinoatrial node-atrial muscle, atrioventricular node-His bundle, His bundle-bundle branch and Purkinje fibers-ventricular muscle. The data predict facilitation of orthodromic propagation.

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Los electrocardiogramas (ECG) registran la actividad eléctrica del corazón a través de doce señales principales denominadas derivaciones. Estas derivaciones son analizadas por expertos médicos observando aquellos segmentos de la señal eléctrica que determinan cada una de las patologías que pueden afectar al corazón. Este hecho en general, es un condicionante muy importante para el diseño de sistemas expertos de diagnóstico médico, ya que es preciso conocer, delimitar y extraer de la señal eléctrica aquellos segmentos que determinan la patología. Dar solución a estos problemas, sería fundamental para facilitar el diseño de sistemas expertos para el diagnóstico de enfermedades cardiacas. El objetivo de este trabajo es demostrar que es posible identificar patologías cardiacas analizando la señal completa de las diferentes derivaciones de los ECGs, y determinar puntos concretos que determinan la patología en lugar de segmentos de la señal. Para ello se ha utilizado una BBDD de electrocardiogramas y se ha determinado mediante un algoritmo, los puntos de la señal que determinan la patología. Se ha aplicado a la patología de bloqueos de rama y los puntos obtenidos con el algoritmo se han utilizado para el diseño de un clasificador automático basado en redes neuronales artificiales, obteniendo un coeficiente de sensibilidad del 100% y de especificad del 99.24%, demostrando su validez para el diseño de sistemas expertos de clasificación.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Eighteen Cebus apella monkeys, (juvenile and adult of both sexes) were inoculated five years ago, with three Trypanosoma cruzi strains (CA1, n = 10; Colombian, n=4 and Tulahuen, n=4), either by conjunctival or intraperitoneal route, once or repeatedly. Parasitological, hematological, serological, enzymatic, radiographic, electro and echocardiographic findings have been peviously published15 and they are similar to those observed in human pathology. The most frequent electrocardiographic alteration was right branch bundle block. Six animals, chosen at random, were sacrificed. Those sacrificed 20 to 25 months post-first inoculation showed focal accumuli of leukocytes with myocytolysis. Foci of diffuse interstitial fibrosis with mild infiltrate of leukocytes among fibers were observed in the animals sacrificed 36 to 47 months post-inoculation. No parasites were seen. The lesions were more prominent in the ventricular walls and the septum. The fact that the infiltrates were predominant in the animals sacrificed at a shorter time after first inoculation and that fibrosis was more severe in those sacrificed at a longer time suggests that there is a progression of the infiltrative lesions to fibrosis, with a leukocytic activity indicative of a chronic phase. These lesions are similar to those described in human chronic Chagas' disease. This would demonstrate that this model is useful in evaluating a progress in the knowledge of the pathogenesis which is still a controversial issue, immunology, immunogenesis and chemotherapeutic agents of the chronic and indeterminate phases of this disease.

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This paper formally derives a new path-based neural branch prediction algorithm (FPP) into blocks of size two for a lower hardware solution while maintaining similar input-output characteristic to the algorithm. The blocked solution, here referred to as B2P algorithm, is obtained using graph theory and retiming methods. Verification approaches were exercised to show that prediction performances obtained from the FPP and B2P algorithms differ within one mis-prediction per thousand instructions using a known framework for branch prediction evaluation. For a chosen FPGA device, circuits generated from the B2P algorithm showed average area savings of over 25% against circuits for the FPP algorithm with similar time performances thus making the proposed blocked predictor superior from a practical viewpoint.

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A Scots pine (Pinus sylvestris) progeny trial was established in 1990, in the southwestern part of Sweden. The offspring was from 30 plus trees. The trial is located on abandoned agricultural land and has a single tree block design with a variation in spacing. The trial has been damaged by voles. At a tree age of ten years, growth, damages and branch properties were estimated. An analysis of variance on height, diameter and stem volume shows significant difference between spacing and progenies as well as interactions between these factors. As indicated by a better annual height increment and fewer and thinner branches at each whorl the densest spacing has the highest potential to produce quality logs.There were also differences between progenies in growth and quality traits. Some progenies combined good growth and branch characters with low mortality, straight stems and few damages. Other progenies had superior volume production.

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We consider the management branch model where the random resources of the subsystem are given by the exponential distributions. The determinate equivalent is a block structure problem of quadratic programming. It is solved effectively by means of the decomposition method, which is based on iterative aggregation. The aggregation problem of the upper level is resolved analytically. This overcomes all difficulties concerning the large dimension of the main problem.

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The authors describe a modification of the medial branch kryorhizotomy technique for the treatment of lumbar facet joint syndrome using a fluoroscopy-based laser-guided method. A total of 32 patients suffering from lumbar facet joint syndrome confirmed by positive medial nerve block underwent conventional or laser-guided kryorhizotomy. The procedural time (20.6 +/- 1.0 vs 16.3 +/- 0.9 minutes, p < 0.01), fluoroscopy time (54.1 +/- 3.5 vs 28.2 +/- 2.4 seconds, p < 0.01), radiation dose (407.5 +/- 32.0 vs 224.1 +/- 20.3 cGy/cm(2), p < 0.01), and patient discomfort during the procedure (7.1 +/- 0.4 vs 5.2 +/- 0.4 on the visual analog scale, p < 0.01) were significantly reduced in the laser-guided group. There was a tendency for a better positioning accuracy when the laser guidance method was used (3.0 +/- 0.3 vs 2.2 +/- 0.3 mm of deviation from the target points, p > 0.05). No difference in the outcome was observed between the 2 groups of patients (visual analog scale score 3.5 +/- 0.2 vs 3.3 +/- 0.3, p > 0.05). This improved minimally invasive surgical technique offers advantages to conventional fluoroscopy-based kryorhizotomy.

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REASONS FOR PERFORMING STUDY: Evidence-based information is limited on distribution of local anaesthetic solution following perineural analgesia of the palmar (Pa) and palmar metacarpal (PaM) nerves in the distal aspect of the metacarpal (Mc) region ('low 4-point nerve block'). OBJECTIVES: To demonstrate the potential distribution of local anaesthetic solution after a low 4-point nerve block using a radiographic contrast model. METHODS: A radiodense contrast medium was injected subcutaneously over the medial or the lateral Pa nerve at the junction of the proximal three-quarters and distal quarter of the Mc region (Pa injection) and over the ipsilateral PaM nerve immediately distal to the distal aspect of the second or fourth Mc bones (PaM injection) in both forelimbs of 10 mature horses free from lameness. Radiographs were obtained 0, 10 and 20 min after injection and analysed subjectively and objectively. Methylene blue and a radiodense contrast medium were injected in 20 cadaver limbs using the same techniques. Radiographs were obtained and the limbs dissected. RESULTS: After 31/40 (77.5%) Pa injections, the pattern of the contrast medium suggested distribution in the neurovascular bundle. There was significant proximal diffusion with time, but the main contrast medium patch never progressed proximal to the mid-Mc region. The radiological appearance of 2 limbs suggested that contrast medium was present in the digital flexor tendon sheath (DFTS). After PaM injections, the contrast medium was distributed diffusely around the injection site in the majority of the limbs. In cadaver limbs, after Pa injections, the contrast medium and the dye were distributed in the neurovascular bundle in 8/20 (40%) limbs and in the DFTS in 6/20 (30%) of limbs. After PaM injections, the contrast and dye were distributed diffusely around the injection site in 9/20 (45%) limbs and showed diffuse and tubular distribution in 11/20 (55%) limbs. CONCLUSIONS AND POTENTIAL RELEVANCE: Proximal diffusion of local anaesthetic solution after a low 4-point nerve block is unlikely to be responsible for decreasing lameness caused by pain in the proximal Mc region. The DFTS may be penetrated inadvertently when performing a low 4-point nerve block.