Success of different techniques to induce regular changes in RR-intervals and systolic blood pressure levels

This study investigated different protocols to induce regular changes in RR-intervals and systolic blood pressure by considering the success of inducing changes, the variability in following the protocols and the variability of the changes. Twelve subjects had their ECG and continuous noninvasive blood pressure (Finapres) recorded while following four breathing, and four action protocols. All the protocols were designed to induce changes in heart rate and blood pressure at 8 times a minute (0.133 Hz). Induction success was 92% for the breathing protocols and 47% for the action protocols. Both sets of protocols were performed equally well. With RR-interval changes, variability was 3.1 times lower for breathing protocols than action protocols, and for SP level changes it was 3.4 times lower. Breathing protocols more successfully induced changes in RR-intervals and SP levels.