P-wave body surface potential distribution in rats.

The aim of this study was to investigate body surface potential distribution during the P wave in Wistar rats. We performed body surface potential mapping by means of a 64-channel synchronous electrocardiotopography. The positive area covered the caudal part of the thorax, and the negative one covered the cranial part of the thorax. During the P wave, we observed 1 maximum and 1 minimum on the body surface. The dynamics of the P-wave body surface potential distribution in rats was characterized by minor movement of the positive and negative areas, and a counterclockwise shift of the extrema on the ventral body surface. The obtained results are discussed in comparison with those in dogs and humans.