Effect of abnormal K+ concentration on pacemaker activity of rabbit sinoatrial node and its control by computer simulation

AIM:To study the effect of different potassium ion concentrations on the electrophysiological activity of the sinoatrial node (SAN) and the control of Na+ and Ca2+ on the pacemaker activity of SAN under the condition of abnormal K+ concentration. METHODS: We used the Zhang model of the rabbit SAN. By changing the conductance of K+, Na+ and Ca2+, as well as their concentration, numerical calculations were then performed on the differential equations for this dynamic model. RESULTS: The effect of abnormal K+ concentration on electrophysiology of SAN was confirmed. It was found that under the hyperkalemia condition, changes in serum Na+ induced a significant regulating effect on pacing activity. Under the condition of abnormal K+ concentration, it restored pacemaker and conduction activity of SAN when increasing the L- and T-type Ca2+ current. CONCLUSION: Elevating Na+ concentration can enhance the activity of the SAN. Furthermore, pacemaker activity of SAN with abnormal K+ concentration can be effectively improved by increasing the activity of Ca2+ channels.