Evolving patterns of ventricular tachycardia modifying our mapping techniques

The introduction of the implantable cardioverter defibrillator (ICD) and the demonstration of its leading role in the prevention of sudden death over the last 20 years, aside from the indisputable benefits, have caused a negligent attitude of the electrophysiologists towards the use of catheter ablation in patients suffering from recurring ventricular tachycardias (VTs). In the recent years, however, the increasing number of patients surviving potentially lethal ventricular arrhythmia, and the awareness of the negative impact of VT recurrences and shock treatment on survival, is triggering an increasing interest by the Electrophysiological Community towards catheter ablation, as a truly effective treatment strategy. 1‐6 Initial studies were focused on mapping of post-myocardial infarction (MI) VTs. 7‐12 Extensive knowledge on mechanism of re-entry in this setting was accumulated and proper criteria on activation mapping and pacing manoeuvres were established to identify the effective ablation site aimed to the termination of the index VT and the prevention of its re-inducibility. 7‐9 Subsequently, for many years, the prevention of any inducible VT was considered an even more effective endpoint. 10‐13 At this point, however, catheter ablation of VT was conceptually a ‘focal’ intervention with an endpoint far different from the complete removal of the arrhythmogenic substrate that was the purpose of anti-arrhythmic surgery. 14