Caracteriza??o da variabilidade de freqüência cardíaca e sensibilidade do barorreflexo em indivíduos sedentários e atletas do sexo masculino

摘要

INTRODUCTION: The capacity to vary the heart rate represents important physiologic role in the daily life. The variations of the RR intervals is dependent of biological modulators as the autonomic nervous system. Those variations constitute the heart rate variability (HRV). METHODS: 10 athletes (Atl) and 10 sedentary (Sed) male individuals (20-35 age) were submitted to digital electrocardiography, in rest, before, during and after the maneuver. The values of RR were analyzed (software Matlab 6.1), in the time domain. RESULTS: Both Sed and Atl presented mean heart rate of 73.5 bpm ± 2,5 and 51 bpm ± 2,4, respectively. Related to the RR intervals, the group of Sed presented average of 826.58 bad ± 5.3 and the group Atl, 1189.18 ± 6.9. The return time of sympathetic system after the maneuver was 72 ± 12 s (Sed) 37 ± 6 s (Atl). The return time of parasympathetic system was 80 ± 11 s (Sed) and 40 ± 8 s (Atl). The pNN50 was of 10 ± 3,3 (Sed) and 42,10 ± 6,9 (Atl). The value of RR variation above the average of the whole sign was 343 ± 40 (Sed) and 175 ± 39 (Atl). The RR variation below the average of the whole sign was 281 ± 27 (Sed) and 425 ± 26 (Atl). CONCLUSIONS: The analysis of HRV associated to the Valsalva maneuver can represent a simple, but important tool, for possible inferences on physical aptitude.