Electrophysiologic properties of the adult human sinus node

Electrophysiologic properties of the sinoatrial (SA) node have been studied extensively in various species. Published studies on human SA nodal properties were carried out on fetal SA node preparations; however, the electrophysiologic properties of adult human cardiac tissues have never been examined. In this study we report, for the first time, recordings of transmembrane potentials in the adult human SA node. Our data demonstrate that the electrical behavior of adult human SA node pacemaker cells resemble those of SA nodal tissue of different animal species. We conclude that the latter ideally mimic the former. Furthermore, human SA node preparations could contribute to a better understanding of some sinus arrhythmias.