Importance of a successful ablation of all clinical VT
isthmuses
Previous randomized multicenter trials have shown that substate ablation
reduces any VT recurrences during the follow-up as compared to targeting
only a clinical and stable VT, making substate ablation a basic strategy
for VT ablation.14-16 In the present study, the
identification and RF ablation of the clinical VT isthmus in addition to
a substate ablation was shown to be associated with fewer VT
recurrences. Hadjis et al. reported that the identification of the VT
isthmus in addition to a substate ablation significantly reduced the
recurrence rate (HR 0.21, 95% CI: 0.07-0.63, P <
0.01).17 Cano et al. also reported that a baseline
inducibility of greater than 1 VT morphology was an independent
predictor of VT recurrence (HR 12.05, 95% CI: 1.60-90.79, P = 0.02) and
complete activation mapping was associated with a reduction in the VT
recurrence.18
In this study, patients in whom VT non-inducibility could not be
achieved at the end of the RF ablation were included, so in many cases,
VT was induced with or without hemodynamic stability at the end of the
RF ablation. Nevertheless, a successful ablation of all clinical VT
isthmuses was correlated with non-recurrence, suggesting that the
identification of the VT isthmus is important in addition to the basic
strategy of substate ablation.