Peak frequency analysis and functional substrate mapping to predict critical isthmus of atypical atrial tachycardia: Findings from a novel automated annotation algorithm to detect near-field signals.

Abstract

Background: Atypical atrial tachycardia (AT) is a commonly encountered rhythm disorder, especially in patients with underlying atrial scar. Peak frequency (PF) annotation of bipolar electrograms is a novel method that mainly aims to discriminate near-field and far-field signals.

Objective: This study aimed to evaluate the PF annotation of low-voltage zones and deceleration zones during sinus/paced rhythm and their role in predicting the critical isthmus (CI) and termination sites of atypical ATs.

Methods: We retrospectively included a total of 25 patients (mean age, 60 ± 12 years; 13 [52%] male) who underwent high-density mapping during both sinus/paced rhythm and AT. Omnipolar voltage and isochronal late activation maps of the left atrium were created on the basis of PF annotation. The CI of the AT was defined on the basis of both activation mapping and successful termination site/change in AT during ablation.

Results: A total of 30 ATs were mapped in the left atrium (22 [73.3%], localized reentry; 8 [26.7%], macroreentry). Median PF of the termination site was significantly higher compared with low-voltage zones alone (345 [209-530] Hz vs 235 (47-417] Hz; P < .001). PF had a significant predictive value for the termination site (area under the curve, 0.83; 95% confidence interval, 0.719-0.950; P < .001). When the cutoff value for PF was taken as 280 Hz, the sensitivity of the test was determined to be 80.0% and the specificity was determined to be 78.3%.

Conclusion: A PF annotation algorithm with a cutoff of 280 Hz accurately detects the CI of atypical ATs and accurately predicts deceleration zones during isochronal late activation mapping.