Ablation of premature ventricular contractions utilizing QMODE+
Although vHPSD concepts have been evaluated for atrial procedures, data
for ablation within the ventricles is very limited. Only one case report
and one study for catheter ablation of PVC utilizing the QDOT
MICROTM Catheter have been published in humans up to
date.
In the initial case report a patient with frequent monomorphic PVC
originating from the right ventricular (RV) outflow tract (OT) (RVOT)
received three-dimensional electroanatomic reconstruction of the right
ventricle. The earliest activation was detected within the
antero-lateral RVOT. At this area the microelectrodes detected early
fragmented potentials which were not detectable on the standard bipolar
electrode of the ablation catheter. A single vHPSD application of 4 s
was performed resulting in an immediate loss of PVC. No periprocedural
complications occurred and no recurrent PVC was reported during
long-term follow-up.
After successful performing the above-mentioned case a pilot study for
PVC treatment via QDOT MICROTM Catheter was conducted.
In the prospective single-center FAST and FURIOUS PVC study, we sought
to investigate the efficacy, safety and clinical outcome of vHPSD
ablation for the treatment of idiopathic PVCs originating from the right
and left ventricular OTs. The data was compared to standard
power-controlled ablation strategy using conventional contact-force
sensing ablation catheters. In this study, twenty-four consecutive
patients underwent PVC ablation utilizing vHPSD ablation (study group)
and were compared with 24 consecutive patients previously treated with
power-controlled ablation (control group). Each group included 12
patients with PVCs originating from the RVOT and 12 patients with PVCs
originating from the left ventricular OT (LVOT). The acute endpoint of
PVC elimination was achieved in all patients. In this study, vHPSD was
used as the first approach and was switch to conventional QMODE after
ineffectiveness. In 16/24 (67%) patients (study group) the acute
endpoint was achieved by using vHPSD only (RVOT: 92%, LVOT 42%). The
earliest activation found on the microelectrodes of the QDOT
MICROTM Catheter was significantly earlier than on the
standard bipolar electrodes. The median RF delivery time was massively
reduced utilizing vHPSD (p<0.0001). No difference was observed
regarding procedure duration (p=0.489), follow-up (p=0.712) and severe
adverse events (4%, study group, 8%, control group, p=0.551).
Although the FAST and FURIOUS PVC study was a single center
non-randomized study it demonstrated the feasibility and safety of the
QDOT MICROTM Catheter for treatment of OVC originated
from the RVOT and LVOT. In the thin walled RVOT the success rate of
vHPSD was 92% while it was 42% for LVOT case. Therefore, it seems to
be reasonable to consider vHPSD (QMODE+) for PVC originating from the
RVOT (Figure 5 ) and conventional QMODE for PVC originating from
the LVOT.