Search results for "HEART RATE"
showing 10 items of 887 documents
Assessment of test-meal induced autonomic arousal in anorexic, bulimic and control females
1998
This study attempted to measure three different physiological responses to food intake in eating disordered subjects. Skin conductance level (SCL), heart rate and electroencephalogram were recorded before, during and after a test-meal in 42 females (14 anorexic inpatients, 10 bulimic outpatients and 18 control subjects). Significant increase in SCL during the meal was found in anorexics only. Pre-meal SCL was lower in bulimics than in controls and anorexics. No changes were found on heart rate or electroencephalogram in all groups of subjects. This suggests that anorexic inpatients may display a measurable arousal when confronted with a meal, whereas bulimic outpatients and control subjects…
A method for the time-varying nonlinear prediction of complex nonstationary biomedical signals
2009
A method to perform time-varying (TV) nonlinear prediction of biomedical signals in the presence of nonstationarity is presented in this paper. The method is based on identification of TV autoregressive models through expansion of the TV coefficients onto a set of basis functions and on k -nearest neighbor local linear approximation to perform nonlinear prediction. The approach provides reasonable nonlinear prediction even for TV deterministic chaotic signals, which has been a daunting task to date. Moreover, the method is used in conjunction with a TV surrogate method to provide statistical validation that the presence of nonlinearity is not due to nonstationarity itself. The approach is t…
Visual data mining with self-organising maps for ventricular fibrillation analysis
2012
Detection of ventricular fibrillation (VF) at an early stage is being deeply studied in order to lower the risk of sudden death and allows the specialist to have greater reaction time to give the patient a good recovering therapy. Some works are focusing on detecting VF based on numerical analysis of time-frequency distributions, but in general the methods used do not provide insight into the problem. However, this study proposes a new methodology in order to obtain information about this problem. This work uses a supervised self-organising map (SOM) to obtain visually information among four important groups of patients: VF (ventricular fibrillation), VT (ventricular tachycardia), HP (healt…
Introduction to coronary imaging with 64-slice computed tomography
2005
The aim of this article is to illustrate the main technical improvements in the last generation of 64-row CT scanners and the possible applications in coronary angiography. In particular, we describe the new physical components (X-ray tube-detectors system) and the general scan and reconstruction parameters. We then define the scan protocols for coronary angiography with the new generation of 64-row CT scanners to enable radiologists to perform a CT study on the basis of the diagnostic possibilities.
Assessing Transfer Entropy in cardiovascular and respiratory time series under long-range correlations.
2021
Heart Period (H) results from the activity of several coexisting control mechanisms, involving Systolic Arterial Pressure (S) and Respiration (R), which operate across multiple time scales encompassing not only short-term dynamics but also long-range correlations. In this work, multiscale representation of Transfer Entropy (TE) and of its decomposition in the network of these three interacting processes is obtained by extending the multivariate approach based on linear parametric VAR models to the Vector AutoRegressive Fractionally Integrated (VARFI) framework for Gaussian processes. This approach allows to dissect the different contributions to cardiac dynamics accounting for the simultane…
The role of social processes and decision making on the psychobiological response to social stress
2018
Los humanos, a diario, se enfrentan a diversas interacciones sociales, que pueden ser interpretadas como retos o como amenazas en función del contexto y del individuo que las enfrenta. Es por ello, que el cuerpo humano acaba activando sus mecanismos fisiológicos y conductuales en función de cómo interpreta está situación. Durante toda esta interpretación los humanos deciden un patrón de conducta que les lleva a tomar un tipo de decisiones u otras para adaptarse a estas interacciones sociales. Es por ello que la toma de decisiones puede ser una variable de estudio importante a lo largo de toda una interacción social, tanto como decidimos en función de la interacción y la respuesta fisiológic…
Diferències entre sexes en la resposta cardiovascular, hormonal i psicològica a una competició: Variables moduladores i facilitadors de la victòria
2018
Competition is a social interaction where there is a confrontation between individuals or groups to achieve an objective. In our society competition is present transversally, with consequences for individuals. Therefore, competition is considered a social stressor able to elicit important psychobiological responses. From an evolutionary perspective, it has been suggested that, against stress situations, men would be more likely to fight-and-flight, while women would be more likely to tend-and-befriend strategies. Consequently, different psychobiological response to competition can be described depending on sex. A large proportion of studies on competition were based on the biosocial status …
Heart rate responses during the modified six-minute walk test among Special Olympics athletes
2021
Objective: The construct validity of the modified six-minute walk test (m6MWT) was examined by addressing the following questions: 1) do participants attain a steady state plateau in heart rate (HR) within the range of 110-150 beats per minute? 2) at what percentage of their predicted HR maximum were participants during each minute of the test? Material and Methods: Participants were 36 (male=56%) Special Olympics athletes aged 34.4 years (SD = 12.7). Following familiarization, participants completed the m6MWT while wearing a Polar Team 2 heart rate monitor. Results: By the end of the first minute, average heart rate was 120bpm, and a factorial repeated measures ANOVA revealed that steady s…
Respuesta cardiovascular al estrés en pacientes con epilepsia farmacorresistente: datos preliminares
2021
El estrés es un factor de riesgo para las enfermedades cardiovasculares en la población general. La epilepsia se ha considerado un modelo adecuado de estrés crónico, con mayor incidencia de mortalidad cardiovascular que la población general. Este estudio proporciona datos preliminares sobre la respuesta cardiovascular ante un estresor cognitivo y una evaluación neuropsicológica en pacientes con epilepsia, explorando las relaciones entre la respuesta cardiovascular y el rendimiento cognitivo dependiendo del hemisferio responsable de la epilepsia. Treinta y cinco pacientes con epilepsia farmacorresistente, 17 con el área epileptógena(AE) en el hemisferio izquierdo (LH) y 18 con AE en el hemis…
Correction of the unfavourable effects of vasopressin by nitroglycerin infusion
1982
Nitroglycerin was administered with vasopressin to prevent adverse effects. Vasopressin 0.25U . 70 kg-1 min-1 was infused intravenously in four dogs for 40 minutes, when a venous infusion of nitroglycerin 1.2 micrograms . kg-1 . min-1 was added for 20 minutes. Nitroglycerin 1.2 micrograms . kg-1 . min-1 alone was infused intravenously in another four dogs for 40 minutes. The venous blood pressures (mesenteric and central) and arterial pressures (mesenteric and femoral), the electrocardiogram and arterio-venous difference were recorded. Nitroglycerin was shown to annul the unfavourable effects of vasopressin without altering its efficacy upon portal pressure.