Regulation of pacing rate by variations of mixed venous oxygen saturation.

Right ventricular oxygen saturation (SO2) may be an ideal sensor for determining the rate of an implanted pacemaker. In order to prove this hypothesis, the obtained signals were optimally analyzed; determinations of SO2 at rest and during exercise were made in healthy volunteers and in patients with pacemakers; and an algorithm was developed for varying pacing rate as a function of measured SO2. The results suggest that this method may be applicable to the long-term implantee.