Abstract
Introduction : Stand-alone substrate ablation without baseline
ventricular tachycardia (VT) induction and activation mapping has become
a standard VT ablation strategy. We sought to evaluate the influence of
baseline VT inducibility and activation mapping on ablation outcomes in
patients with structural heart disease (SHD) undergoing VT ablation.
Methods : This is a single center, observational and
retrospective study including consecutive patients with SHD and
documented VT undergoing ablation. Baseline VT induction was attempted
before ablation in all patients and VT activation mapping performed when
possible. Ablation was guided by activation mapping for mappable VTs
plus substrate ablation for all patients. Ablation outcomes and
complications were evaluated.
Results : 160 patients were included (203 VT ablation
procedures) and were classified in 3 groups according to baseline VT
inducibility: group 1 (non inducible, n=18), group 2 (1 VT morphology
induced, n=53), and group 3 (>1VT morphology induced,
n=89). VT activation mapping was possible in 35%. After a median
follow-up of 38.5 months, baseline inducibility of >1VT
morphology was associated with a significant incidence of VT recurrence
(42% for group 3 vs. 15.1% for group 2 and 5.6% for group 1, Log-rank
p<0.0001) and activation mapping with a lower rate of VT
recurrence (24% vs. 36.3%, Log-rank p=0.035). Independent predictors
of VT recurrences and mortality were baseline inducibility of
>1VT morphology (HR 12.05 IC 95% 1.60-90.79, p=0.016) and
LVEF<30% (HR 2.43 IC 95% 1.45-4.07, p=0.001), respectively.
Complications occurred in 11.2% (5.6% hemodynamic decompensation).
Conclusions : Baseline VT inducibility and activation mapping
may add significant prognostic information during VT ablation
procedures.
Key words: ventricular tachycardia; ablation; activation
mapping; substrate mapping