Limitations of the case
The inability to visualize the MB as a distinct band across the RV cavity made it difficult to localize the arrhythmia focus to the MB. In addition, no P potential was clearly recorded at the site of the original ablation. Nevertheless, the behavior of the arrhythmia pre and post initial ablation with VF provoked by PVCs of the same morphology makes it likely that the Purkinje fibers were the focus of the PVCs. Ablation of ventricular myocardium has not been shown to create VF as a pro-arrhythmic mechanism.