Comparison of far-field and peak frequency electrogram characteristics at the earliest activation sites during idiopathic ventricular arrhythmias: A novel index to predict ablation success.

BACKGROUND

Evaluating the peak frequency electrograms (EGMs) has the potential to differentiate near-field from far-field components.

OBJECTIVE

This study examined how peak frequency analyses of EGMs preceding idiopathic ventricular arrhythmias (VAs) affect catheter ablation outcomes.

METHODS

A retrospective analysis was conducted on 111 VAs from 104 patients. EGMs at the earliest activation site, detected using high-density activation maps, were analyzed to assess the association with a successful elimination after a single radiofrequency delivery.

RESULTS

In outflow tract VAs (n = 77), the first deflection timing was similar for VAs with and without a successful elimination. The peak frequency timing was earlier (right ventricular outflow tract -21 ms [-32 to -16 ms] vs -11 ms [-20 to 0 ms], P = .002; left ventricular outflow tract -26 ms [-33 to -4 ms] vs 0 ms [-6 to 10 ms], P = .005) and the difference between the first deflection and peak frequency timing (delta F-P) shorter (right ventricular outflow tract 7 ms [5-13 ms] vs 17 ms [11-24 ms], P < .001; left ventricular outflow tract 10 ms [6-19 ms] vs 22 ms [20-27 ms], P = .001) for VAs with a successful elimination than for those without. The delta F-P correlated with the time to elimination of outflow tract VAs (P = .01; r = 0.45). None of the outflow tract VAs with a delta F-P of >22 ms achieved a successful elimination. For non-outflow tract VAs (n = 34), no parameters were associated with a successful elimination.

CONCLUSION

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 EGM index may predict quick, successful endocardial ablation of outflow tract VAs.