Long-Term Outcome of Patients Initially Diagnosed With Idiopathic Ventricular Fibrillation

Background Idiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac arrest. IVF is currently defined as a resuscitated cardiac arrest victim, preferably with documentation of ventricular fibrillation (VF), in whom known cardiac, respiratory, metabolic, and toxicological causes have been excluded through clinical evaluation. In other words, IVF is diagnosed after exclusion of specific underlying diseases by comprehensive clinical investigation. However, 7% to 35% of patients initially diagnosed with IVF reveal a specific disease during follow-up. Approximately 5% of sudden cardiac deaths are attributed to IVF. The exact incidence of IVF is unknown but has decreased with the detection of new primary arrhythmia syndromes, and the introduction of high-resolution imaging modalities, such as the cardiac magnetic resonance imaging (MRI). Genetic testing has increasingly contributed in diagnosing concealed primary inherited arrhythmia syndromes, thereby excluding IVF. In addition, genetic testing is increasingly important for family screening and counseling. Limited data are available on the natural history of IVF, the diagnostic findings during long-term follow-up, including distribution of putative pathogenic mutations, and the management of patients with IVF and their family members. Our study analyzed a large cohort of patients initially diagnosed with IVF. The objective of our study was to report the natural history, the long-term follow-up including the detection of specific diseases, the yield of genetic testing, the occurrence of implantable cardioverter–defibrillator (ICD) therapy, and the yield of family screening in patients with an initial diagnosis of IVF.