Management of recurrent idiopathic ventricular fibrillation: a case report from diagnosis to successful ablation.

Background: Idiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac death and is a diagnosis of exclusion. With the availability of genetic testing, this condition is becoming increasingly rare. Nevertheless, in some cases, no identifiable cause is found. Management of recurrent IVF episodes poses a significant clinical challenge, often requiring advanced interventional approaches. Case summary: We present a 43-year-old male with a history of out-of-hospital cardiac arrest due to VF in 2015. Despite extensive examinations, including normal coronary angiography, cardiac MRI, and genetic testing, no underlying aetiology was identified. The patient received an implantable cardioverter-defibrillator (ICD) for secondary prevention. After an 8-year arrhythmia-free period, he experienced recurrent ICD shocks in 2023. Repeated diagnostics, including MRI and genetic testing, yielded inconclusive results. An electrophysiological study revealed abnormalities in the Purkinje fibre network, including a focal source within the conduction system and a localized scar in the lower mid-left ventricular septum. Radiofrequency ablation targeting these areas successfully terminated the electrical storm. Discussion: This case highlights the complexities in diagnosing and managing IVF, demonstrating a strong association between the Purkinje fibre network abnormalities in arrhythmogenesis. It underscores the importance of electrophysiological studies and catheter ablation in refractory cases, even when advanced imaging and genetic testing fail to reveal a clear aetiology. Conclusion: In patients with recurrent IVF refractory to conventional management, targeted ablation of Purkinje-related triggers not only terminates the storm, but provides durable rhythm control, as illustrated by our 8-month follow-up.