Cardiac Cycles
Mostrando 1-12 de 39 artigos, teses e dissertações.
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1. Cardiac Autonomic Modulation of Healthy Individuals and Patients with Chronic Obstructive Pulmonary Disease During Spontaneous and Controlled Breathing
Abstract Background: Lung diseases and different forms of breathing may interfere with cardiac autonomic modulation (CAM). Objective: To compare CAM in individuals with chronic obstructive pulmonary disease (COPD) with healthy individuals during spontaneous breathing (SB) and controlled breathing (CB). Methods: Cross-sectional study involving 30 individua
Int. J. Cardiovasc. Sci.. Publicado em: 2020-02
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2. Cardiac Autonomic Modulation of Healthy Individuals and Patients with Chronic Obstructive Pulmonary Disease During Spontaneous and Controlled Breathing
Abstract Background: Lung diseases and different forms of breathing may interfere with cardiac autonomic modulation (CAM). Objective: To compare CAM in individuals with chronic obstructive pulmonary disease (COPD) with healthy individuals during spontaneous breathing (SB) and controlled breathing (CB). Methods: Cross-sectional study involving 30 individua
Int. J. Cardiovasc. Sci.. Publicado em: 24/10/2019
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3. Remote preconditioning, perconditioning, and postconditioning: a comparative study of their cardio-protective properties in rat models
OBJECTIVE: Ischemia reperfusion injury is partly responsible for the high mortality associated with induced myocardial injury and the reduction in the full benefit of myocardial reperfusion. Remote ischemic preconditioning, perconditioning, and postconditioning have all been shown to be cardioprotective. However, it is still unknown which one is the most ben
Clinics. Publicado em: 2013
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4. Detecção e classificação de arritmias em eletrocardiogramas usando transformadas wavelets, máquinas de vetores de suporte e rede Bayesiana
The cardiopathies are currently, according the Ministério da Saúde, the second biggest cause of mortality among the Brazilians, behind only the brain vascular diseases. The motivation for the work here presented is the identification and classification of cardiopathies registered in Electrocardiogram exams, ECG, such as premature contractions, branches blo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/03/2012
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5. Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease
BACKGROUND: A synchronism exists between the respiratory and cardiac cycles. However, the influence of the inspiratory muscle weakness in chronic obstructive pulmonary disease (COPD) on cardiac autonomic control is unknown. The purpose of the present investigation was to evaluate the influence of respiratory muscle strength on autonomic control in these pati
Clinics. Publicado em: 2010
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6. Vasodilation increases pulse pressure variation, mimicking hypovolemic status in rabbits
OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV) amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP)-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory vari
Clinics. Publicado em: 2010
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7. Sistema automÃtico para anÃlise de variabilidade da freqÃencia cardÃaca / Automatic system for analysis of heart rate variability
This dissertation describes a system for analysis of heart rate variability through metrics on time and frequency domain and by non-linear methodology, which is initiated by the process of segmentation of the QRS complex of the electrocardiogram signal. The motivation for this work is the analysis of the influence from the algorithms of beat segmentation and
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/10/2008
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8. Identificação de marcadores moleculares para células T reguladoras humanas com perfil CD4+CD25+ por phage display / Peptide phage display for the identification of novel molecular markers on human thymic regulatory CD4+CD25+ T cells
There are consistent data in literature indicating that thymic CD4+CD25+ cells play an important role in immune regulation and are continuously developed as an independent lineage in the thymus. These cells are known as natural regulatory T cells. Several questions about these cells remain unanswered, such as how they are generated, what is determinant in th
Publicado em: 2008
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9. Electrocardiogram evaluation under a mathematical approach. / Estudo do eletrocardiograma sob uma abordagem matemática.
The electrocardiogram gives information related to the passage of an electric pulse through the heart and, therefore, to his state function. Since the beginning of electrocardiogram utilization, thanks to the work of Willem Einthoven building the first machine capable of measuring the electric pulse non-invasively and with sensitivity enough to be able to pr
Publicado em: 2006
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10. Metodologia para localização de ciclo cardíaco a partir do sinal eletrocardiográfico
This dissertation proposes a cardiac cycle detection algorithm based on digital signals generated by ECG (electrocardiogram) devices. Detection is made through a threshold, seeking R wave occurrences, as represented by its second derivate. A threshold is established dynamically based on the last 10 seconds of the signal and its value is calculated taking the
Publicado em: 2006
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11. Variabilidade da frequencia cardiaca em trabalhadores em turnos / Heart rate variability in shift workers
In industrialized countries approximately 15 to 20% of the workforce is engaged on shift work and this is associated with an increased rate of cardiovascular diseases. It is still not clear but the alterations in circadian rhythms of the cardiac autonomic nervous system could explain this phenomenon. A non-invasive tool to evaluate autonomic nervous system a
Publicado em: 2006
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12. Laser assisted extraction of pacemaker and implantable defibrillator leads
OBJECTIVE: To analyze the results of laser-assisted extraction of permanent pacemaker and defibrillator leads. METHODS: We operated upon 36 patients, whose mean age was 54.2 years, and extracted 56 leads. The reasons for extracting the leads were as follows: infection in 19 patients, elective replacement in 13, and other causes in 4 patients. The mean time o
Arquivos Brasileiros de Cardiologia. Publicado em: 2001-09