Procedural details
Peri-procedural details are shown in Table 2 . In all procedures, a 3D mapping system and an irrigated ablation catheter were utilized during VT ablation. A force-sensing ablation catheter, a multipolar mapping catheter, and an intracardiac echocardiography incorporated with the 3D mapping system were used in 44.8%, 69.0%, and 64.0% of the procedures, respectively.
The rationale of avoiding PES after RF delivery is shown inTable 3 . The most frequent cause was non-inducibility of VT before RF delivery (46.6%). Following this, procedure time of >6 hours (average 392±59 min), complications (2 cardiac tamponade, 2 transient atrioventricular block, 1 cardiac arrest, 1 air emboli in right coronary artery), intolerant hemodynamic state, and an inaccessible/unsafe target (1 His area, 1 right bundle area, and 1 epicardial origin) were observed. With regard to the prevalence of procedure suspension before sufficient RF delivery, required RF delivery was applied in all procedures with non-inducibility of VT before RF delivery whilst more than 80% of procedures were suspended before sufficient RF delivery in procedures with complications or inaccessible/unsafe target (Table 3 ).