Evaluating the peak frequency electrograms has the potential to differentiate near-field from far-field components. This study examined how peak frequency analyses of electrograms preceding idiopathic ventricular arrhythmias (VAs) impact catheter ablation outcomes. A retrospective analysis was conducted on 111 VAs from 104 patients. Electrograms at the earliest activation site, detected using high-density activation maps, were analyzed to assess the association with successful elimination following a single radiofrequency delivery. In outflow tract VAs (n=77), the first deflection timing was similar for VAs with and without successful elimination. The peak frequency timing was earlier (RVOT: -21 ms -32--16 ms vs. -11 ms -20-0 ms, p=0.002, LVOT: -26 ms -33--4 ms vs. 0 ms -6-10 ms, p=0.005) and the difference between the first deflection and peak frequency timing (delta F-P) shorter (RVOT: 7 ms 5-13 ms vs. 17 ms 11-24 ms, p22 ms achieved successful elimination. For non-outflow tract VAs (n=34), no parameters were associated with successful elimination. The first component of the EGM at the earliest activation site may reflect a far-field recording from the site of origin of idiopathic VAs. A novel delta F-P electrogram index may predict quick successful endocardial ablation of outflow tract VAs.
Nishimura et al. (Mon,) studied this question.