Figure 3: Sustained Polymorphic Ventricular Tachycardia Degenerating to VF Induced with Ajmaline and Triple Extrastimulation in a Patient with Brugada Syndrome and No Inducible Ventricular Arrhythmia at Baseline.

VT/VF inducibility after ajmaline was associated with the appearance of a type 1 BrS-ECG pattern and a concomitant substrate increase from 3.4 cm² at baseline to 7.2 cm² after ajmaline infusion. The duration of prolonged fragmented potentials also increased from 145–226 ms.