Spatial Resolution of Pace-Mapping using Automated Template Matching for Site of Origin Identification of Idiopathic Outflow Tract Premature Ventricular Contractions

Radiofrequency catheter ablation (RFCA) for the treatment of idiopathic
premature ventricular complexes (PVC) arising from the right ventricular
outflow tract (RVOT) or left ventricular outflow tract (LVOT) is a highly
effective alternative to anti-arrhythmic drugs.1 Endocardial activation mapping
is typically the preferred approach to identify the PVC site of origin (SoO)
and guide RFCA.3*5 However, activation mapping is limited when PVCs are
infrequent or absent during the procedure. Particularly in these cases,
pacemapping can provide a useful alternative to activation mapping.3,4,6 Former
studies evaluating the accuracy of pacemapping for identifying the SoO of
idiopathic PVCs are limited by the expected high intra and inter-observer
variability associated with the solely visual assessment of pacematches
(*eyeballing*) and the insufficient applicability to daily clinical practice of
in-house developed pacematching softwares.3,7,8 Moreover, there is very limited
data regarding the accuracy and clinical usefulness of pacematching in patients
with LVOT PVCs, as most of the studies included pacemapping data from patients
with RVOT PVCs only.

The automated digital pace matching module PaSoTM, integrated in the CARTO 3
System (Biosense Webster, Diamond Bar, CA) aims to improve accuracy and
efficacy of pacemapping in PVC ablation by automatically and therefore
objectively comparing pacemapping induced signals with arrhythmia signals. To
date, the clinical significance of the PaSoTM software that is easily
applicable to every electroanatomical mapping (EAM) procedure using the CARTO 3
system has not been demonstrated.

1. Assess the spatial resolution of pace-mapping using the PaSoTM software to
identify the site of origin of outflow tract idiopathic PVCs
2. Compare the spatial resolution of pace-mapping using the PaSoTM software for
PVCs originating from the RVOT vs. PVCs arising from the LVOT
3. Define the optimal template matching cut-off value for the percentage of
correlation that predicts the site of ablation success
4. Define the efficacy and clinical usefulness of solely pacemapping with the
PaSoTM software as primary ablation approach in patients with infrequent PVCs.

This will be a single-center prospective observational study.

In all patients, the electrophysiological study and mapping procedure will be
clinically indicated and scheduled before inclusion in the study. The technique
will be performed according to current standards. The only change introduced by
this protocol will be a slightly longer procedure time. During procedures *down
time* regularly exists: time in which mapping data is reviewed, before ablation
is performed. As much as possible the data collection for this protocol will be
conducted in this *down time* and as such will not add additional procedural
time. If it is not possible to collect data during *down time* the procedure
will be lengthened by a maximum of 30 minutes.