Comparison of electrogram waveforms between a multielectrode mapping catheter and a linear ablation catheter

BACKGROUND: Smaller low-voltage areas (LVAs) obtained by multielectrode catheters were reported than those by linear ablation catheters. However, the underlying electrogram difference has not been elucidated. This study aimed to compare the two mapping catheters' measurements of electrogram waveforms and LVAs. METHODS: This prospective observational study included 17 consecutive patients undergoing ablation for persistent atrial fibrillation. Following pulmonary vein isolation, voltage mapping during sinus rhythm was performed once using the ablation catheter, and once using the multielectrode catheter. Approximately 20 pairs of mapping points at approximately the same position between the two voltage maps were manually selected evenly throughout the left atrium. RESULTS: Voltage mapping with the multielectrode catheter demonstrated smaller LVAs, defined as <0.50 mV (5.9 [3.3, 11.0] vs 9.7 [6.6, 16.9] cm2 ) than those mapped with the ablation catheter. The two mapping catheters' voltage amplitudes of all pairs of mapping points correlated well (r = 0.81, P < 0.0001) overall, but they did not correlate within diseased areas (either voltage <0.50 mV). The voltage amplitude difference between the two catheters ([VolMulti  - VolAbl ]/VolAbl × 100) was greater in the diseased areas (37.4% [-9.8%, 147%]) than in the healthy areas (both voltages ≥0.50 mV, 26.2% [-13.0%, 92.8%], P = 0.014). The electrogram waveform of the multiple electrode catheter displayed a higher voltage amplitude, shorter duration, greater number of peaks, and lower dull peak ratio (number of dull peaks/total peaks) than that of the ablation catheter. CONCLUSION: The multielectrode catheter produced smaller LVA measurements with sharper and higher voltage electrograms compared to the ablation catheter, specifically in diseased areas.