EFFECT OF BREATHING RATE ON HEART RATE VARIABILITY

摘要

: Tn order to investigate relationship between sympatho-vagal modulation of cardiac function, expressed by heart rate variability (HRV), and spontaneous (as well as paced) breathing rate, this study was performed on 6 young females, characterized at rest by different heart rates (HRs) and different spontaneous breathing rates (8 and 15 breathing rate/min).The RR intervals, registered during spontaneous and paced respiratory rates, were elaborated and the power spectral densities in very-low (VLF), low (LF) and high (HF) frequency bands were evaluated as well as the LF/HF ratio, the two standard deviations (SDi and SD2) of the Poincare plot, the beta values and the fractal dimension (FD). The results indicate no correlation between RR intervals and HRV parameters. On the other hand, an evident correlation between breathing rate, spontaneous or paced, and HRV parameters exists. In particular, we observed higher total power (absolute units), higher SD| and SD_2 (n. u.) parameters and lower FD values at lower breathing rate (8 br. r./min), independently from spontaneous breathing rate. In conclusion, the respiratory rate seems to be correlated to linear and non-linear parameters of HRV.