Explore the vast range of titles available.

The purpose of the present study was to compare the blood pressure, heart rate, and rate pressure product behavior during interval and continuous aerobic exercise in physically active women. Eight physically active women with prior indoor cycling experience were recruited for the present study. Participants visited the laboratory for three sessions, the first visit was used for familiarization and the remaining two visits were to perform the experimental protocols in a randomized order: 1) Twenty-one minutes of continuous indoor cycling at 70% of maximum heart rate (CONT), and 2) Twenty-one minutes of interval indoor cycling, alternating one minute at 90% and two minutes at 60% of maximum heart rate (INT). To assess the hemodynamic behavior, blood pressure, heart rate, and rate pressure product were also measuring at 6-minute (During-6), 12-minute (During-12), 18-minute (During-18), and 21-minute (During-21) intervals. Both protocols (continuous and interval) showed significant increases in blood pressure, heart rate, and rate pressure product in three out of four moments (During-6, During-12, and During-21), with the interval protocol showing higher values compared to the continuous protocol. The results of this study have practical implications for both prescription and cardiac rehabilitation and may be used in an athletic and non-athletic population, since a hypotension effect and lower cardiac workload is advantageous to one’s fitness.  Resumen. El propósito del presente estudio fue comparar lo comportamiento de la presión arterial, la frecuencia cardíaca y doble producto durante el ejercicio aeróbico continuo y a intervalos en mujeres físicamente activas. Para el presente estudio se reclutaron ocho mujeres físicamente activas con experiencia previa en ciclismo indoor. Los participantes visitaron el laboratorio durante tres sesiones, la primera visita se utilizó para familiarizarse y les das visitas restantes fueron para realizar los protocolos experimentales en un orden aleatorio: 1) Veintiún minutos de ciclismo indoor continuo al 70% de la frecuencia cardíaca máxima (CONT), y 2) Veintiún minutos de ciclismo indoor a intervalos, alternando un minuto al 90% y dos minutos al 60% de la frecuencia cardíaca máxima (INT). Para evaluar el comportamiento de la presión arterial, la frecuencia cardíaca y doble producto también se midieron a los 6 minutos (Durante-6), 12 minutos (Durante-12), 18 minutos (Durante-18) y 21 minutos (durante-21) durante la actividad. Ambos los protocolos (CONT y INT) mostraron aumentos significativos en la presión arterial, la frecuencia cardíaca, y el doble producto en tres de cuatro momentos (Durante-6, Durante-12 y durante-21), con el protocolo INT que muestra los valores más altos en comparación al protocolo CONT. Los resultados de este estudio tienen implicaciones prácticas tanto para la prescripción médica como para la rehabilitación cardíaca y pueden usarse en una población atlética y no atlética, ya que un efecto de hipotensión y una menor carga de trabajo cardíaco son ventajosos para la aptitud física.

Patent ductus arteriosus (PDA) is characterized by the failure of complete closure of the communication between the aorta and the pulmonary trunk during the early stages of life and is frequently observed in young animals. This vascular connection originates from pulmonary non-functionality during the fetal period and should close shortly after birth. In the absence of complete closure, the patient becomes a carrier of PDA, often with hemodynamic consequences. The aim of the present case report is to describe a case of PDA in an elderly mixed-breed dog. A mixed-breed dog, approximately 12 years old, was referred for cardiological evaluation due to a history of excessive fatigue reported over the previous 60 days. Clinical and laboratory examinations revealed a continuous murmur localized over the pulmonary area. Additional diagnostic tests were requested for further investigation. On Doppler echocardiographic examination, the following findings were observed: continuous turbulent flow at the site of the ductus arteriosus in the pulmonary trunk (left-to-right shunting); a minimal ductal diameter ranging from approximately 4.3 to 5.7 mm; and no abnormalities in other cardiac structures. These findings confirmed the diagnosis of PDA. Given the presence of flow reversal, routine clinical monitoring was recommended. A persistência do ducto arterioso (PDA) é caracterizada pela falha no fechamento completo da comunicação entre a artéria aorta e o tronco pulmonar durante os estágios iniciais de vida, sendo frequentemente observada em animais jovens. A ligação entre os vasos é derivada da afuncionalidade pulmonar no período fetal, que deveria ser ocluída logo após o nascimento e, na ausência de oclusão completa, o paciente se torna portador de PDA, geralmente com repercussão hemodinâmica. O objetivo do presente relato é descrever um caso de PDA em paciente sem raça definida idoso. Um cão, sem raça definida, com aproximadamente 12 anos de idade, foi encaminhado para avaliação cardiológica mediante histórico de cansaço excessivo, identificado há 60 dias. Ao exame clínico-laboratorial, constatou-se sopro contínuo em foco pulmonar. Exames complementares foram solicitados para maiores investigações. Ao exame ecodopplercardiográfico, notou-se: fluxo turbulento e contínuo em topografia do canal arterial no tronco pulmonar (direção esquerda-direita); diâmetro ductal mínimo de aproximadamente 4,3 – 5,7mm; demais estruturas sem alterações. Os achados foram conclusivos de PDA, e mediante a presença de reversão de fluxo, foi indicado apenas o monitoramento clínico rotineiro.

El modelo computacional tridimensional idealizado de un aneurisma cerebral sacular se utiliza para estudiar la hemodinámica vascular bajo el efecto de campos electromagnéticos externos. Los campos analizados son emitidos por resonadores magnéticos con diferentes direcciones de aplicación sobre el paciente en posición decúbito dorsal. La simulación computacional de dos configuraciones de resonadores permite evaluar el efecto de la dirección del campo magnético en la velocidad de la sangre y en el tiempo de permanencia de partículas. Los resultados muestran que bajo la acción de un resonador abierto, el fluido entra con mayor velocidad al saco del aneurisma y aumenta el tiempo de permanencia de las partículas dentro del dominio.  

Introducción: en los pacientes con neurofibromatosis tipo 1 (NF!) la prevalencia de feocromocitoma es alta. El riesgo de tener feocromocitoma es 10 veces mayor que en la población general. Objetivo: describir el caso de un paciente con patologías poco frecuentes que requiere del concurso de expertos para su manejo previo y para el seguimiento después de la cirugía. Presentación del caso: paciente masculino de 38 años con antecedente de NF1, evaluado por 4 meses de cefalea, dolor abdominal e hipertensión arterial de difícil control. Se hace diagnóstico de feocromocitoma y se define adrenalectomía con hospitalización perioperatoria para control de cifras tensionales con alfa y beta bloqueadores. Discusión: el manejo del feocromocitoma es la resección quirúrgica. Para el procedimiento quirúrgico los pacientes deben recibir bloqueo alfa por lo menos 10 días antes del procedimiento y betabloqueadores 3 días antes. Las crisis de catecolaminas pueden ocurrir en un intraoperatorio por estrés mecánico del tumor al ser manipulado, y estrés psicológico y por medicamentos. Conclusión: el tratamiento quirúrgico es la elección y se debe realizar por un grupo interdisciplinario para garantizar un adecuado control de las cifras tensionales en el perioperatorio y así evitar complicaciones.

Objective: the study sought to identify, in national and international publications, the principal Nursing interventions aimed at patients with intracranial hypertension. Materials and Method: integrative literature review with search in LILACS, PubMed, Scopus, Web of Science, Cinahal, and Google Scholar databases, from 2013 to 2018. Results: the sample was comprised of seven articles fulfilling the inclusion criteria. Two thematic categories were established for the Nursing interventions aimed at patients with intracranial hypertension: cognitive skills and clinical reasoning, necessary to control neuro-physiological parameters and prevent intracranial hypertension, and evidence-based practices to improve care for neuro-critical patients. Conclusions: intracranial hypertension is an event of great clinical impact, whose complications can be minimized and control through specific Nursing interventions that encompass control of neuro-physiological and hemodynamic parameters and prevention of increased intracranial pressure related with the performance of procedures by the Nursing staff. Objetivo: este estudo objetiva identificar, nas publicações nacionais e internacionais, as principais intervenções de Enfermagem direcionadas a pacientes com hipertensão intracraniana. Materiais e método: revisão integrativa da literatura com busca nas bases de dados LILACS, PubMed, Scopus, Web of Science, Cinahal e Google Acadêmico, de 2013 a 2018. Resultados: a amostra foi constituída por sete artigos que atenderam aos critérios de inclusão. Elencaram-se duas categorias temáticas para as intervenções de Enfermagem direcionadas ao paciente com hipertensão intracraniana: habilidades cognitivas e raciocínio clínico, necessárias para o controle de parâmetros neurofisiológicos e para a prevenção de hipertensão intracraniana, e práticas baseadas em evidências para a melhoria da assistência ao paciente neurocrítico. Conclusões: a hipertensão intracraniana é um evento de grande repercussão clínica, cujas complicações podem ser minimizadas e controladas mediante intervenções de Enfermagem específicas que abrangem controles de parâmetros neurofisiológicos, hemodinâmicos, bem como prevenção de aumento da pressão intracraniana atrelado à realização de procedimentos pela equipe de Enfermagem. Objetivo: el estudio tiene como objetivo identificar, en publicaciones nacionales e internacionales, las principales intervenciones de Enfermería dirigidas a pacientes con hipertensión intracraneal. Materiales y método: revisión integradora de la literatura con búsqueda en las bases de datos LILACS, PubMed, Scopus, Web of Science, Cinahal y Google Académico, del 2013 al 2018. Resultados: la muestra se conformó de siete artículos que cumplieron con los criterios de inclusión. Se establecieron dos categorías temáticas para las intervenciones de Enfermería dirigidas a pacientes con hipertensión intracraneal: habilidades cognitivas y razonamiento clínico, necesarias para el control de parámetros neurofisiológicos y la prevención de hipertensión intracraneal, y prácticas basadas en evidencias para la mejora de la asistencia al paciente neurocrítico. Conclusiones: la hipertensión intracraneal es un evento de gran repercusión clínica, cuyas complicaciones se pueden minimizar y controlar mediante intervenciones de Enfermería específicas que abarcan controles de parámetros neurofisiológicos, hemodinámicos y prevención de aumento de la presión intracraneal relacionado a la realización de procedimientos por el equipo de Enfermería.

Mujer de 86 años, hipertensa, evaluada por 72 horas de pérdida de la conciencia luego de una caída súbita que no fue precedida por ningún síntoma. Durante el examen físico se encontraba hipotensa, sin respuesta al estímulo doloroso, con reflejos de tallo presentes. Durante la hospitalización permaneció hipotensa y necesitó soporte vasopresor. Despúes de un mes de hospitalización continuó sin respuesta. La IRM cerebral mostró eventos agudos isquémicos bilaterales tanto supra como infratentoriales (Figura 1). En la ecocardiografía se evidenció una fracción de eyección de 55% con un aneurisma del septum atrial con desplazamiento bilateral de 15 mm y un foramen oval permeable de 7 mm. El doppler de miembros inferiores fue normal. Discusión: Los infartos cerebrales limítrofes constituyen aproximadamente el 10% de todos los infartos cerebrales. Dichos infartos se pueden clasificar en externos (corticales) e internos (subcorticales). Cuando ambos se presentan en un mismo paciente, de forma bilateral y con compromiso tanto supratentorial como infratentorial, la causa más probable es la alteración hemodinámica y el pronóstico invariablemente es pobre

The book represents a paradigm shift from the traditional static model of investigation of oxidative biology to the dynamic model of vascular oxidative stress. The investigation of vascular biology and cardiovascular medicine is made possible by the use of fluid dynamics, molecular signaling, genomic approach, tissue engineering, stem cell biology, and microfluidics. This is the first book to target a wide readership from academia to industry and government agencies in the field of cardiovascular diseases.

Individual rupture risk assessment of intracranial aneurysms is a major issue in the clinical management of asymptomatic aneurysms. Aneurysm rupture occurs when wall tension exceeds the strength limit of the wall tissue. At present, aneurysmal wall mechanics are poorly understood and thus, risk assessment involving mechanical properties is inexistent. Aneurysm computational hemodynamics studies make the assumption of rigid walls, an arguable simplification. We therefore aim to assess mechanical properties of ruptured and unruptured intracranial aneurysms in order to provide the foundation for future patient-specific aneurysmal risk assessment. This work also challenges some of the currently held hypotheses in computational flow hemodynamics research. A specific conservation protocol was applied to aneurysmal tissues following clipping and resection in order to preserve their mechanical properties . Sixteen intracranial aneurysms (11 female, 5 male) underwent mechanical uniaxial stress tests under physiological conditions, temperature, and saline isotonic solution. These represented 11 unruptured and 5 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a 3-parameter ( C 10, C 01, C 11) Mooney–Rivlin hyperelastic model. Each aneurysm was classified according to its biomechanical properties and (un)rupture status. Tissue testing demonstrated three main tissue classes: Soft, Rigid, and Intermediate. All unruptured aneurysms presented a more Rigid tissue than ruptured or pre-ruptured aneurysms within each gender subgroup. Wall thickness was not correlated to aneurysmal status (ruptured/unruptured). An Intermediate subgroup of unruptured aneurysms with softer tissue characteristic was identified and correlated with multiple documented risk factors of rupture. There is a significant modification in biomechanical properties between ruptured aneurysm, presenting a soft tissue and unruptured aneurysms, presenting a rigid material. This finding strongly supports the idea that a biomechanical risk factor based assessment should be utilized in the to improve the therapeutic decision making.

NOABSTRACTAdvanced heart failure (HF) represents a clinical entity encompassing severely symptomatic HF with severely dysfunctional left ventricles (LV). The single most important parameter for defining severe LV dysfunction and indicating the prescription of evidence-based therapies is LV ejection fraction (EF). We sought to investigate the hemodynamics by echocardiography in a cohort of advanced HF patients during a hospitalization for HF decompensation and assess the relevant differences when compared to a control cohort of asymptomatic patients with minor structural/functional cardiac abnormalities.In this prospective study we selected 18 advanced HF patients and 12 asymptomatic pre-HF patients with only minor structural/functional abnormalities. The 2 groups were clearly delineated by size parameters (end -systolic and -diastolic diameters and volumes respectively, with very low p values p<0.0001). Hemodynamic parameters were significantly different as well in the advanced HF group vs the ‘pre-HF’ group, including: ventricular-arterial coupling 1.745 vs. 0.895, p=0.0007; cardiac power output 0.762 vs. 0.932, p=0.044, systolic times ratio 0.406 vs. 0.200, p=0.0001. There were no significant differences for neither effective arterial elastance (Ea) and nor for cardiac index. Inside the advanced HF group, no correlation between LVEF and other parameters were found and none of these parameters could predict outcome. We observed a highly skewed variation of Ea in advanced HF patients.Among the most severe HF patients, the hemodynamic interaction between the dysfunctional LV and the compensatory response of the peripheral system is heterogenous and cannot predict outcome by single parameters. In these patients, assessment of cardiac performance should no longer rely on LEVF alone.

We relate vascular network structure to hemodynamics after vessel obstructions. We consider tree-like networks with a viscoelastic fluid with the rheological characteristics of blood. We analyze the network hemodynamic response, which is a function of the frequencies involved in the driving, and a measurement of the resistance to flow. This response function allows the study of the hemodynamics of the system, without the knowledge of a particular pressure gradient. We find analytical expressions for the network response, which explicitly show the roles played by the network structure, the degree of obstruction, and the geometrical place in which obstructions occur. Notably, we find that the sequence of resistances of the network without occlusions strongly determines the tendencies that the response function has with the anatomical place where obstructions are located. We identify anatomical sites in a network that are critical for its overall capacity to supply blood to a tissue after obstructions. We demonstrate that relatively small obstructions in such critical sites are able to cause a much larger decrease on flow than larger obstructions placed in non-critical sites. Our results indicate that, to a large extent, the response of the network is determined locally. That is, it depends on the structure that the vasculature has around the place where occlusions are found. This result is manifest in a network that follows Murray's law, which is in reasonable agreement with several mammalian vasculatures. For this one, occlusions in early generation vessels have a radically different effect than occlusions in late generation vessels occluding the same percentage of area available to flow. This locality implies that whenever there is a tissue irrigated by a tree-like in vivo vasculature, our model is able to interpret how important obstructions are for the irrigation of such tissue.