Effect of Deep Breathing on Interaction between Sympathetic and Parasympathetic Activities

Cardiac autonomic regulation is affected by respiratory training, which has been demonstrated in the linear analysis of heart rate variability (HRV). The two most important bands in frequency domain analysis of HRV, the low frequency (LF) and high frequency (HF) analysis, which respectively represent parasympathetic and sympathetic activity, have been widely used in deep breathing research. However, the interaction between the LF and HF in deep breathing has not been well studied. In this sense, we recruited 12 healthy young subjects (7 males and 5 females) for deep breathing experiment. Transfer entropy (TE) of HRV was applied to analyze the changes in information transmission between HF and LF at baseline and deep breathing. The results demonstrated that the mean TE(LF→ HF) value was significantly lower during deep breathing than at baseline. Compared with the mean TE(HF→ LF) value, the mean TE(LF→ HF) value was significantly higher at baseline. The results also showed a significant increase in the LF/HF ratio in deep breathing. Our results demonstrated that deep breathing attenuates the information transmission from the sympathetic nervous system (SNS) to the parasympathetic nervous system (PNS).