Background

3-dimensional (3D) Mapping of the left atrium (LA) using high-definition (HD) catheters is of utter importance in patients undergoing pulmonary vein isolation (PVI) or complex ablations of LA tachycardias. Basic anatomical mapping, characterization of atrial substrate (bipolar mapping), activation mapping and isochronal late activation mapping can be safely and rapidly achieved using HD catheters. However, there are no data in the literature comparing the speed of acquisition of high quality LA HD maps among the available catheters.

 

Purpose

This study aimed to compare four HD catheters in respect to the speed of complete LA HD mapping, using milliliter/minute (ml/min) as unit of measurement.

 

Methods

We retrospectively studied 182 consecutive patients undergoing LA procedures using 3D mapping from June 2022 to May 2023. All patients with paroxysmal or persistent atrial fibrillation (AF) refractory to antiarrhythmic treatment (class I and III antiarrhythmics) or complex left atrial tachycardia were considered eligible if they were older than 18 years of age, and provided informed consent before inclusion.

Four HD catheters were used, depending on the corresponding 3D mapping system employed: Orion (Boston Scientific), HD Grid (Abbott), PentaRay and OctaRay (Biosense Webster) and the exact number of minutes was noted for the acquisition of a full 3D map in each case. After calculating the LA volume (echocardiographically, using the biplane method of discs), the speed of LA HD map was derived by dividing the LA volume to the amount of time needed to obtain the map.

 

Results

The indications for the LA procedure were as follows: 51% (n=93) PVI for paroxysmal AF, 36% (n=65) PVI for persistent AF and 13% (n=24) ablation of complex atrial tachycardia. The patients were on average 68 years old, the median CHA2DS2VASc score was 3 points, and the median LA volume index (LAVI) was 34 ml/m2. 

The four HD catheter groups included the following number of patients: 86 (OctaRay), 23 (PentaRay), 44 (Orion), 29 (HD Grid). The median LA mapping time differ significantly among groups (Kruskal-Wallis test, p = 0.001): in the Octaray group 11 minutes, PentaRay group 18 minutes, Orion group 24 minutes and HD Grid group 21 minutes. The differences were significant between the OctaRay group and any of the other three groups. Otherwise, there were no significances between the groups. 

Likewise, the mapping speed differed also significantly among groups: 5.9 ml/min in the OctaRay group, 3.1 ml/min in the PentaRay group, 3 ml/min in the Orion group and 2.5 ml/min in the HD Grid group (Figure). The pairwise comparisons showed that the mapping speed in the OctaRay group was significantly higher as compared to each of the other groups, whereas there were no differences between other groups.

 

Conclusion

The mapping speed of LA using the OctaRay HD catheter was significantly higher as compared to other widely used HD catheters.