Change of Cardiovascular Variability During a Stepwise Paced Breathing Procedure

To investigate the effect of paced breathing on cardiovascular system, the cardiovascular variables of heart rate, blood pressure and pulse transit time (PTT) were measured during a stepwise paced breathing procedure (six different breathing rates at14, 12.5, 11, 9.5, 8, 7BPM). Respiratory sinus arrhythmia (RSA) was estimated by using autoregressive (AR) model based power spectral analysis. The ensemble empirical mode decomposition (EEMD) was applied to PTT to decompose the signal into different intrinsic mode function, and respiration-derived oscillation and trend component (baseline) in PTT were extracted for further analysis. The results clearly indicate that the stepwise paced breathing procedure can induce increased oscillations in RSA, blood pressure and PTT, meanwhile, reduce blood pressure and lengthen PTT baseline. It was demonstrated that this stepwise paced breathing procedure can lead to blood pressure reduction significantly (p<0.05), and PTT can be used as a maker for the effect of paced breathing on cardiovascular system.