Carotid artery atherosclerotic profile as a predictor of the aorta atherosclerotic profile in patients with cerebrovascular events

Background: It is well known that the presence of atheroma of the thoracic aorta is a risk factor for cerebrovascular events. We sought to evaluate whether the presence and the morphology of atherosclerotic plaque in the carotid artery detected by duplex ultrasonography is associated with disease in the proximal aorta visualized by transesophageal echocardiogram in patients with a cerebrovascular event. Methods: We carried out a cross-sectional prospective study including 147 consecutive patients with prior stroke or transient ischemic attack (TIA). Neurological evaluations were performed by an expert neurologist using clinical and tomographic diagnostic criteria including the definition of etiology and whether the patient suffered from stroke or TIA. Transthoracic and transesophageal echocardiograms and carotid artery duplex ultrasonography were performed by the same examiner. Patients with and without plaque in the carotid artery were compared using Student's t test or the χ2 test. Regression analysis was used to determine whether the presence of plaque in the carotid artery was predictive of the presence of plaque in the proximal aorta and to analyze the relationship between the echogenicity of carotid and aortic plaques. The significance level was set at p < 0.05. Results: All 147 patients (95 men) were included in the analysis. Patients' ages ranged from 23 to 85 years (65 ± 12.4 years). Most of the patients (58.5%) were Caucasian, while 41.5% were African-Brazilian. Arterial hypertension, diabetes and tobacco use were more frequent among patients with atherosclerotic plaque in the aorta. A normal carotid intima-media thickness halved the risk of atherosclerotic plaque in the aorta [odds ratio (OR) 0.46, 95% confidence interval (CI) 0.23-0.91; p = 0.026]. The presence of carotid plaque increased the risk of aortic plaque by 70-fold (OR 73.2, 95% CI 25.6-2,018.6; p < 0.001) in univariate analysis. The absence of atherosclerotic plaque in the carotid artery reduced the risk of plaque in the aorta to almost 0 (OR 0.014, 95% CI 0.004-0.041; p < 0.001). Considering the 86 patients with both aortic and carotid plaques, the presence of hypoechoic plaque in the carotid artery was a predictor of hypoechoic plaque in the aorta (OR 10.1, 95% CI 3.3-31.2; p < 0.001). Conclusions: The carotid artery atherosclerotic profile defined by ultrasonography is a strong predictor of the atherosclerotic profile of the proximal aorta. This should be taken into consideration before referring patients with acute cerebrovascular events for transesophageal echocardiogram. © 2013 S. Karger AG, Basel.

Ultrasound evaluation of common carotid artery blood flow in the Labrador retriever

Background: Doppler ultrasound (DUS) examination provides quantitative and qualitative information concerning the blood flow in veins and arteries, enabling their morphological evaluation and the collection of hemodynamic data. Dogs and cats as well as humans may display neurological signs of brain hypoperfusion secondary to common carotid alterations. Hence, DUS examination might aid in the differential diagnosis of neurological disorders of ischemic origin, among other causes. The objective of this study was to register normal values for systolic peak velocity, minimum diastolic velocity, diameter and resistance index of both common carotid arteries of 12 healthy Labrador retriever dogs between 2 and 5 years of age. By gathering these values, we might be able to improve the sensitivity of hemodynamic studies in clinically important brain disorders. Results: There were no statistical differences between the values for the right and left vessels: the systolic peak velocity was 75.8 ± 16 cm/s, minimum diastolic velocity was 12.2 ± 4 cm/s, common carotid diameter was 0.545 ± 0.063 cm, and resistance index was 0.83 ± 0.07. Conclusions: The results of this study might be used to establish normal parameters for Labrador retriever dogs and thus help in the diagnosis of neurological disorders associated with alterations of the carotid arteries. Similar studies must be performed to evaluate the same parameters in other dog breeds of different sizes and skull conformations. © 2013 Svicero et al.; licensee BioMed Central Ltd.

Algoritmo GRASP especializado aplicado ao problema de reconfiguração de alimentadores em sistemas de distribuição radial

Pós-graduação em Engenharia Elétrica - FEIS

Metaheurística particle swarm utilizada para alocação ótima de bancos de capacitores em sistemas de distribuição radial

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Treinamento de uma rede neural de base radial usando computação evolutiva: implementação e aplicações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Perfil radial e uniformidade de precipitação do aspersor NaanDanJain 427, em função do defletor de ajuste

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo experimental da interação fluido-estrutura no escoamento em um difusor radial

Pós-graduação em Engenharia Mecânica - FEIS

Simulação do escoamento bifásico da mistura óleo-refrigerante através da folga radial de compressores rotativos de pistão rolante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Origem, ramificação e distribuição fascicular do nervo radial no braço do gato doméstico (Felis catus domesticus, Linnaeus, 1758)

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

Construção de um dispositivo de simulação do escoamento pulsátil em artérias

Pós-graduação em Engenharia Mecânica - FEIS

Proposta de implementação de redes de base radial em tecnologias CMOS e BiCMOS

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metodologia de discretização espacial para o método radial de interpolação por pontos (RPIM) aplicada para solução numérica das equações de Maxwell

Neste trabalho, foi desenvolvido e implementado um método de discretização espacial baseado na lei de Coulomb para geração de pontos que possam ser usados em métodos meshless para solução das equações de Maxwell. Tal método aplica a lei de Coulomb para gerar o equilíbrio espacial necessário para gerar alta qualidade de discretização espacial para um domínio de análise. Este método é denominado aqui de CLDM (Coulomb Law Discretization Method ) e é aplicado a problemas bidimensionais. Utiliza-se o método RPIM (Radial Point Interpolation Method) com truncagem por UPML (Uniaxial Perfectlly Matched Layers) para solução das equações de Maxwell no domínio do tempo (modo TMz).

An automatic methodology for obtaining optimum shape factors for the radial point interpolation method

In this letter, a methodology is proposed for automatically (and locally) obtaining the shape factor c for the Gaussian basis functions, for each support domain, in order to increase numerical precision and mainly to avoid matrix inversion impossibilities. The concept of calibration function is introduced, which is used for obtaining c. The methodology developed was applied for a 2-D numerical experiment, which results are compared to analytical solution. This comparison revels that the results associated to the developed methodology are very close to the analytical solution for the entire bandwidth of the excitation pulse. The proposed methodology is called in this work Local Shape Factor Calibration Method (LSFCM).

Echobiometrics kidney and renal artery triplex doppler of canine fetuses

O objetivo deste estudo foi avaliar, por meio da ultrassonografia convencional modo B, as características sonográficas e a biometria dos rins de fetos caninos, bem como determinar os índices vasculares da artéria renal dos conceptos ao Doppler Triplex. Foram utilizadas 24 fêmeas Shi-tzu e Pugs pesando de quatro a 10 kg e com idade entre quatro e seis anos. Ao modo B, a ecobiometria renal fetal, a regularidade da superfície renal, a ecotextura e a relação córtico-medular foram avaliadas durante a quinta, sexta, sétima e oitava semanas gestacionais. Ao Doppler Triplex, durante o mesmo período em que se realizou o exame convencional, foram determinados o pico de velocidade sistólica (PVS), a velocidade diastólica final (EDV) e o índice de resistência vascular (RI) e de pulsatividade (PI). Ao modo B, não foram detectadas alterações em rins fetais, e à ecobiometria renal dos fetos, foi possível determinar medidas renais importantes, verificando-se aumento das biometrias no decorrer do desenvolvimento fetal (P<0,0001). Ao Doppler Triplex, determinaram-se os índices vasculares da artéria renal fetal, sendo que os valores para PSV e EDV aumentaram no decorrer das semanas gestacionais (P<0,05) e permaneceram constantes para PI e RI (P>0,05). Concluiu-se que o modo B e o Doppler Triplex são ferramentas importantes para a avaliação do desenvolvimento renal fetal, com a utilização da ecobiometria renal e avaliação dos indices vasculares da artéria renal de fetos caninos.