A new method of estimation of the optimal AV delay by using pulse oximetry in DDD paced patients

The paper gives a detailed description of a new method for estimating the optimal AV delay in dual chamber paced patients, which is non-invasive, not dependent on the examinator, not time consuming and inexpensive. In principle, the pulse oximetry signal obtained by common finger probe was used to measure the change in its time course after changes in pacemaker stimulation. The Eagle 4000 monitor, manufactured by Marquette USA, was used for measurements and digitizing the data and then this data was analyzed using a portable personal computer with original programs developed in Famulus v. 3.5. Our results were compared to the standard method for optimizing AV delay which uses the direct measurement of blood pressure in the ascending aorta. Twenty-four patients with Physios pacemakers were enrolled in the pilot study. Measurements showed a positive correlation (r = 0.982, N = 432) between the changes in the pulse oximetry amplitude and changes in the pressure pulse amplitude measured in the ascending aorta by a catheter-tip manometer. These results indicated that this new method could be a possible alternative to the currently used techniques for AV interval optimization.