Abstract: AIM: To investigate the electrophysiology of the atrium and the feasibility of monophasic action potentials (MAP) recording using a common mapping electrode catheter. METHODS: MAPs were recorded at high and low lateral walls of the right atrium using common four-pole mapping electrodes in 12 patients with paroxysmal supraventricular tachycardia. RESULTS: Twenty one satisfactory MAPs signals were recorded. The action time at high right atrium was shorter than at low lateral right atrium and was reversed in action potential duration (APD) and recovery time (RT) (P<0.05 or P<0.01). APD was shorter in S1S1 stimulation than in sinus rhythm (P<0.05). Dispersion of RT was lower than dispersion of APD (P<0.01). CONCLUSION: Repolarization dispersion and electrophysiology stability exist simultaneously in normal right atrium.