"Idiopathic" ventricular fibrillations are rare and are estimated between 5% and 10% of survivors of hospital cardiac arrest, for at least some of them have as origin, a trigger in the Purkinje fibers. Interventional therapy could be an effective, long-lasting solution for these recurrent malignant arrhythmias and should be considered.
Loumaye, L., & Blommaert, D. (2017). Night syncope: a case report. Clinical Case Reports, 5(2), 81-84. https://doi.org/10.1002/ccr3.757 (Original work published 2017)