Electrophysiological parameters of action potentials of latent pacemaker cells of rabbit and mouse heart under the influence of lidocaine

The effects of lidocaine on the latent pacemaker cells of sinoatrial (SP) node of rabbit and mouse were studied using standard microelectrode technique. Experiments have shown that lidocaine dose-dependently slows down the AP fast depolarization phase (dV/dtmax) in rabbit and mouse. The results obtained testifyto considerable contribution of Na+-channels in formation of cells fast depolari-zation phase of sinoatrial area.