Monophasic Action Potential Mapping in Swine and Humans Using Modified-tip Ablation Catheter and Electroanatomic Mapping System

OBJECTIVE: To evaluate the feasibility of monophasic action potential (MAP) mapping using a modified-tip NaviStar catheter in swine and humans. METHODS: MAP mapping was performed using the modified-tip catheter at 71 +/- 21 atrial and 60 +/- 16 ventricular sites in 10 healthy pigs and at 56 ventricular sites in one patient, and using an ordinary Navi-Star catheter at 30 atrial sites in one patient and 50 +/- 14 ventricular sites in four patients. In an additional 20 patients, MAPs were also recorded at 9 +/- 2 atrial sites using the modified-tip catheter or at 12 +/- 9 atrial sites using the ordinary catheter. RESULTS: In pigs, the plateau amplitudes of the MAPs recorded using the modified-tip catheter were 4.1 +/- 3.2 mV for the atrial and 9.5 +/- 4.3 mV for the ventricular MAPs. In patients, both the ventricular and atrial MAPs recorded using the modified-tip catheter were significantly higher than using the ordinary catheters, 15.7 +/- 8 and 3.0 +/- 0.9 mV vs 9.5 +/- 3.9 and 2.0 +/- 0.6 mV for the ventricular and atrial MAPs, respectively (p < 0.0001). The baseline disturbances were <10% of the MAP amplitude in 95% of the pig and 96% of the patient MAPs. CONCLUSION: A modified-tip Navi-Star catheter could be used in swine and in humans for prompt recording of MAPs with acceptable amplitudes and baselines. MAP mapping using the modified-tip catheter is safe and feasible for clinical use.