A case of VT catheter ablation in the setting of electrical storm and ischaemic heart disease with severely impaired left ventricular ejection fraction (23%). The first line ablation strategy was substrate modification due to haemodynamic instability during VT and small caliber femoral vessels (ECMO was at high risk of peripheral ischaemia). Following catheter insertion in the left ventricle, incessant ventricular tachycardia was mechanically induced, determining electrical instability and consequently a low-output state, precluding a substrate modification approach (A and B). Rescue ECMO (a reperfusion cannula prevented peripheral ischaemia) allowed eventual rhythm stabilization and substrate mapping. A wide area of low voltage was recorded, involving the entire inferior wall (C), in absence of late potentials at the LAT map (D) and abnormal electrograms recorded during sinus rhythm at the site of ablation (E). During ECMO support, VT induction was possible, achieving a mean arterial pressure of ≥90 mmHg during VT (F). VT activation mapping was performed (G) and the diastolic pathway of the re-entrant circuit was located at the mid-basal inferior wall (H). RF ablation at this site determined interruption of the tachycardia and non-inducibility of any VT at the end of the procedure (I). At 18 months of follow-up, no VT recurrences were recorded. ECMO, extracorporeal membrane oxygenation; LAT, local activation time; RF, radiofrequency; VT, ventricular tachycardia.