Referral to specialized genetic testing centers is important if local exper- tise is unavailable. 2. VF in the absence of identifiable structural heart disease or known genetic arrhythmia syndromes such as catecholaminergic polymorphic ventricu- lar tachycardia, long QT syndrome, short QT syn- drome, Brugada syndrome, or J wave syndromes is usually the result of short coupled PVCs arising from the Purkinje system in either the right or left ventricles or, less commonly, from the ventricular The recurrence risk after resuscitation of idiopathic VF is very high.S8.4-12 Among 38 consecutive patients from 6 different centers who underwent ablation of primary idio- pathic VF initiated by short coupled PVC, 87% had experienced 2 VF episodes in the preceding Because idiopathic VF is associated with Recommendations for Idiopathic Polymorphic VT/VF (Continued) COR LOE Recommendations CLINICAL STATEMENTS AND GUIDELINES a very high risk of recurrent VF, an ICD is indi- cated to prevent SCD. Catheter ablation of the triggering focus has proved to be highly effective in eliminating the repetitive PVCs which induce VF in these patients.S8.4-11 During a median post- procedural follow-up of 63 months, 7 (18%) of 38 patients undergoing catheter ablation of idio- pathic VF induced by short coupled PVCs experi- enced VF recurrence at a median follow-up of 4 months. Five of these 7 patients underwent repeat ablation without VF recurrence. Thus, although catheter ablation is very effective in idiopathic VF, the recurrence risk remains substantial after an apparently successful procedure and the patient should be protected with an ICD. The subcuta- neous ICD may not be a good therapy for these patients due to the higher risk of T-wave over- sensing seenin this population; however, data are 3. 