Regional differences in rabbit atrial action potential properties: mechanisms, consequences and pharmacological implications.

Regional differences in electrical action potential (AP) properties can provide a substrate for atrial arrhythmias. We quantify such differences by developing detailed AP models for the left (LA) and right (RA) rabbit atrial cells in order to study the underlying electrophysiological mechanisms, as well as their impacts on vulnerable properties of the atrial tissue. The transient outward current, Ito, is identified as the major factor contributing to the AP differences between the LA and RA cells, which suggests a potential pharmacological target for reducing heterogeneity and vulnerability of the atria.