Variabilidade da frequência cardíaca em cães com endocardiose valvar submetidos a treinamento físico

Abstract

Valvular endocardiosis is the most prevalent cardiopathy in canine specie. This disease is able to change autonomic balance, which is related to sudden death and worse prognostic, through chronic activation of sympathetic nervous system. Looking at heart rate variability, various walk training plans were efficient for the autonomic balance reestablishment in cardiophats people. In this way, this study focused on evaluate the effect of 8 weeks walking plan on cardiac autonomic function of dogs with valvular endocardiosis. These walking plans were consisted of moderated intensity walking (reaching from 60 to 80% of maximum heart rate) during 30 to 50 minutes, three times a week. Heart rate variability was analyzed by utilizing time and frequency domain as a tool. Thus, 20 dogs with valvular endocardiosis were divided into two groups: Control group, with no training (CG, n=9), and Training group (TG, n=11). They were evaluated at basal moment (T0), 4 weeks (T1), and 8 weeks (T2). At time domain, only the medium variable rMSSD (the root mean square of successive differences between the square NN intervals) was higher in the TG in four (155.5+42.07) and eight weeks (199.8+83.54) than CG (91.17+35.79 and 88.17+57.51) (p<0.05). At frequency domain, the high frequency variable was the most representative and after four weeks, it showed higher on TG (30950+25810) than CG (19090+23210) (p<0.05). After eight weeks, within TG there was higher frequency (40300+33870) when compared to basal evaluation (29340+20950) (p<0.05). The proposed training program did not affect the other variables. These results suggest that the physical training with utilization of walking plans were able to change the heart rate variability what indicated a higher parasimpathetic participation of dogs with valvular endocardiosis.