Morphological analysis of sinus and retrograde atrial waves detected through a permanent pacemaker atrial lead

The main objective of this study was to characterize morphological differences between sinus and retrograde atrial waves.

We collected intracardiac atrial signals through a DDDR pacemaker to characterize their morphologies and discriminate retrograde from sinus atrial waves off-line. Intracardiac unipolar and bipolar signals were collected at an 800-Hz sampling rate through a 0.4-Hz high-pass filter. Sinus and retrograde atrial waves during ventricular pacing were recorded in the supine and upright positions.

Eleven different form parameters (FPs) were applied to describe atrial wave morphology. Data from 14 patients were collected and analyzed. Atrial signals differed markedly between the two body postures. However, it was possible to discriminate retrograde from sinus atrial waves on the basis of at least one FP in 12 of 14 (86%) patients when unipolar and bipolar atrial signals recorded in both body postures were analyzed separately. When body postures were pooled together to mimic natural conditions, discrimination was successful in nine of 14 patients with either configuration of the atrial signal.

The results indicate that retrograde atrial waves can be discriminated from sinus waves by using high sampling rate, digital signal processing, and specific FPs incorporated in these pacemakers.