Use of Contact Force Mapping to identify low Voltage Bridging to guide
radiofrequency ablation of slow pathway: A single Center Study
Introduction: Ablation of slow pathway (SP) for AV nodal reentry
tachycardia (AVNRT), by visualization of low voltage bridges using
non-contact force sensing (CFS) catheters and cryo-ablation has been
described. This study aims to demonstrate the use of voltage mapping
using CFS catheters in patients with AVNRT undergoing SP modification by
Radiofrequency ablation (RFA). Methods Three-dimensional mapping was
performed using CFS catheter in adult patients undergoing AVNRT
ablation. Voltage values from intracardiac recordings were adjusted
until a low voltage bridge was observed. Both electro-anatomical data
and low voltage bridges were used to guide ablation. Distance from the
earliest His signal to the site of SP (His-SP) and the area of the
Koch’s triangle (KTArea) was measured. Results A total of 41 adult
patients (63% female, 48±15 years) underwent RFA using CFS catheters.
Median follow up was 12 months. There were no recurrences in any
patients. When indexed to body surface area (BSA), both mean His-SP
distance (p=0.038) and mean KTArea (p=0.019) was greater in patients
with atypical AVNRT (n=5) than in patients with typical AVNRT (n=32).
Conclusion RFA of AVNRT by visualization of low voltage bridges using
CFS is effective. In patients with atypical AVNRT, SPs are particularly
distant from the His region. Patients with atypical AVNRT have a larger
Koch’s triangle than patients with typical AVNRT.