Objective: To investigate the feasibility of monophasic action potential (MAP) mapping using an electroanatomical mapping system (CARTO) in obtaining information on global dispersion of atrial repolarization and to evaluate the role of dispersion of repolarization in the genesis of paroxysmal atrial fibrillation (PAF).
Methods and results: Right atrial MAPs were recorded from 53 +/- 18 sites in 10 healthy pigs and 33 +/- 21 sites in 6 patients with and 4 patients without history of PAF. In pigs, the global dispersions of activation time (AT), MAP duration and end of repolarization time (EOR), 70 +/- 8, 95 +/- 18 and 121 +/- 28 ms, respectively, were significantly greater than those among 10, 20 and 30 sites. In patients with PAF, the global dispersions of MAP duration and EOR (128 +/- 10 and 149 +/- 31 ms) were significantly greater than those in patients without PAF (84 +/- 10 and 91 +/- 17 ms).
Conclusion: MAP mapping using the CARTO system was feasible in experimental and clinical settings in obtaining information on global dispersion of atrial repolarization. The number of recording sites could significantly affect repolarization parameters. The dispersions of atrial repolarization were significantly greater in patients with PAF than those without, suggesting the involvement of an increased dispersion of repolarization in the genesis of PAF.