# High-density “APLE” Mapping—Activation, Propagation, Low Voltage, and Electrogram Evaluation with the HD Grid for Atrioventricular Nodal Re-entry Tachycardia Ablation

## TL;DR

This study introduces a new high-density mapping technique using the HD Grid to guide ablation for heart rhythm disorders, showing success in five patients without complications.

## Contribution

The paper presents a novel high-density mapping approach integrating activation, propagation, low-voltage signals, and electrogram evaluation for slow-pathway ablation.

## Key findings

- The HD Grid technique successfully localized and ablated the slow pathway in five patients with no recurrences.
- Mapping the triangle of Koch with the HD Grid was completed in a median of 3 minutes per patient.
- The procedure used no radiation and resulted in successful outcomes with a median of 3 cryotherapy lesions at the success site.

## Abstract

This is the first case series to evaluate high-density mapping of the triangle of Koch (TOK) using the HD Grid to guide slow-pathway ablation integrating activation, propagation (with wave collision), low-voltage signals, and atrial electrogram appearance. We will describe our technique and the results in this case series. Using three-dimensional mapping and the HD Grid, patients underwent high-density voltage mapping of the TOK. Ablation site selection was based on properties during sinus rhythm with late activation, at or above the propagation wave collision, over low voltage, and with appropriate electrogram appearance. Five patients underwent mapping of the slow pathway using the HD Grid. Their median age was 14 years, their median weight was 54.1 kg, and their median height was 161.5 cm. The TOK was mapped with the HD Grid for a median of 3 min. The procedure was successful in all patients using this technique. The median lesion number to the site of success was 3, with a median total number of cryotherapy lesions of 11. No radiation was used. There were no recurrences. Using activation, propagation wave, low voltage, and electrogram appearance when mapping for slow-pathway localization and ablation with the HD Grid can be successful, results in high-density maps, and is relatively faster.