Análise da modulação autonômica do coração em repouso e atividade eletromiográfica relacionada à variabilidade da frequência cardíaca durante o exercício dinâmico em cicloergômetro

Abstract

SILVA, C. S. Analysis of the autonomic modulation of the heart in rest and activity electromyographic related the heart rate variability during dynamic exercise in cicle ergometer. Sao Carlos, 2002, 81p. Dissertacao (Mestrado) – Escola de Engenharia de Sao Carlos / Faculdade de Medicna de Ribeirao Preto / Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo. Heart rate variability (HRV) has been used as a physiological marker of heart autonomic control, while surface electromyography (SEMG) has shown to be a useful analysis tool for evaluating muscular response to physical exercise. Therefore, the purpose of the present research was to evaluate heart autonomic control beginning from heart rate (HR) answers and its variability (HRV) in rest conditions, in supine and seating positions, and during test of dynamic physical exercise continuous of ramp type (TDPEC-R). We also intended to evaluate electromyographic activity during TDPEC-R and analyze correlation between HRV and SEMG during test of dynamic physical exercise continuous of ramp type (TDPEC-R). Methodology: Ten men; young (23,7 ± 3,02 years), healthy and with an active life style; were followed up during TDPEC-R in rest, supine and seating positions, with 20 W increments per minute. The HR and R-R intervals (R-RI) data were recorded on a beat-to-beat basis in real time during rest and exercise. Integrated SEMG was collected from vastus lateralis muscle captured during the last 20 seconds of each minute during TDPEC-R. Analysis of the data: HR average values were calculated [in beats per minute (bpm)] and R-RI, in rest condition for 15 minutes. RMSSD temporal index of R-RI and HR were calculated in both conditions. During TDPEC-R, the average HR and RMSSD of R-RI was achieved in the last 20 s of each minute of exercise in parallel with SEMG analysis by RMS index of signal width in microvolts. Statistics Methodology: Wilcoxon nonparametric tests were used for paired samples, Friedman’s for repeated measures followed by multiple comparisons techniques with Dunn test and correlation analysis of Spearman. α=0.05 was the considered level of significance. Results: the data presented statistic significance (p<0,05) in the following analyses: 1) lower HR (bpm) and R-RI (ms) average values in supine than in seating position; 2) higher HRV values in supine in comparison to seating position; 3) average HR (bpm) and