RESUMO
Introducción: El estrés mental agudo, así como los estados de ansiedad inducidos para influenciar la reactividad psicofisiológica en jóvenes sanos, aportan cambios en los patrones nerviosos que pueden ser medidos mediante la variabilidad de la frecuencia cardiaca. Objetivo: Determinar las diferencias en los parámetros lineales del balance autonómico cardiovascular en individuos jóvenes en estado basal y durante la prueba de cálculo aritmético. Métodos: Se realizó un estudio cuasi-experimental, sin grupo control de tipo antes y después, en el Laboratorio de Ciencias Básicas Biomédicas de la Universidad de Ciencias Médicas de Santiago de Cuba. Población y muestra de 10 sujetos. Se registró el trazado electrocardiográfico (5 min) durante el reposo y luego durante la prueba de cálculo aritmético. Resultados: Existieron diferencias significativas entre ambos estados en las variables frecuencia cardiaca (p = 0,005); mínima (p = 0,007); máxima (p = 0,005); intervalo RR (p = 0,005); stress index (p = 0,028); índice simpático (p = 0,005); bajas frecuencias (p = 0,005); relación LF/HF (p = 0,005); RMSSD (p = 0,007); NN50 (p = 0,008); pNN50 (p = 0,005); índice parasimpático (p = 0,005) y altas frecuencias (p = 0,005). El estrés mental provocó una disminución parasimpática y un predominio simpático uniforme en todos los sujetos participantes en el estudio. Conclusiones: Durante el estrés mental inducido por la prueba de cálculo aritmético la dinámica lineal de la respuesta autonómica cardiovascular experimenta un aumento en la actividad simpática y una disminución del tono parasimpático, traduciendo una respuesta adaptativa en la regulación de la función cardiovascular por el sistema nervioso autónomo(AU)
Introduction: Acute mental stress and states of anxiety induced to influence psychophysiological reactivity in healthy young people, result in changes in nervous patterns which may be measured in terms of heart rate variability. Objective: Determine the differences in linear parameters for autonomic cardiovascular balance in young individuals at baseline and during the arithmetic computation test. Methods: A non-observational quasi-experimental before-after study without a control group was conducted at the Basic Biomedical Sciences Laboratory of the University of Medical Sciences of Santiago de Cuba. The study population and sample was 10 subjects. The electrocardiographic tracing (5 min) was recorded at rest and then during the arithmetic computation test. Results: Significant differences were found between the two states as to the variables heart rate (p = 0.005), minimum (p = 0.007), maximum (p = 0.005), RR interval (p = 0.005), stress index (p = 0.028), sympathetic index (p = 0.005), low frequencies (p = 0.005), LF/HF ratio (p = 0.005), RMSSD (p = 0.007), NN50 (p = 0.008), pNN50 (p = 0.005), parasympathetic index (p = 0.005) and high frequencies (p = 0.005). Mental stress caused a parasympathetic reduction and uniform sympathetic predominance in all the subjects participating in the study. Conclusions: During the mental stress induced by the arithmetic computation test, the linear dynamic of the autonomic cardiovascular response experiences an increase in sympathetic activity and a reduction in parasympathetic tone, displaying an adaptive response in cardiovascular function regulation by the autonomous nervous system(AU)
Assuntos
Humanos , Masculino , Feminino , Estresse Psicológico/etiologia , Escala de Ansiedade Frente a Teste/normas , Frequência Cardíaca/fisiologia , Ensaios Clínicos Controlados não Aleatórios como AssuntoRESUMO
OBJECTIVE: To the objective of the study was to determine accuracy and predictive values of a symptoms scale for diagnosing reflux esophagitis (RE). STUDY DESIGN AND SETTING: Standard criterion study. All recruited patients from two centers in Chile underwent both digestive endoscopy (reference standard) and a symptoms scale known to be valid and reliable for diagnosing gastroesophageal reflux disease. The RE variable was dealt with dichotomously. A receiver operating characteristic curve was constructed. Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of the scale were calculated. RESULTS: Two hundred and thirty eight (238) subjects (57.6% female), with an average age of 44.2+/-13.0 years were included. Of these, 57.1% presented with RE. With a cut-off score of six, association was confirmed between the symptoms scale and RE with an odds ratio of 7.26 and a correct classification i.e. diagnostic accuracy of 73.1%. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, of 74.3%, 71.6%, 77.7%, 67.6%, 2.61, and 0.36 respectively, were obtained. CONCLUSION: A seven-item symptoms scale when compared to endoscopy as gold standard was useful for diagnosing RE. Using a cutoff of six points, the diagnostic accuracy of the scale was 73.1%.