Abstract: AIM:To investigate the clinical characteristics and the efficacy of radiofrequency catheter ablation of ventricular fibrillation/polymorphic ventricular tachycardia (VF/PVT) triggered by idiopathic premature ventricualr contraction (PVC). METHODS: Among the 313 patients without structural heart disease in whom radiofrequency catheter ablation was conducted for idiopathic PVC, the clinical characteristics and the efficacy of radiofrequency catheter ablation were analyzed in six patients with PVC-triggered VF/PVT. RESULTS: Compared with those of the other 307 PVC patients, Holter recordings of the six PVC-triggered VF/PVT patients showed no significant difference in the frequent isolated PVCs (16303±5854/day vs. 15570±4743/day), the coupling interval of PVC and the baseline QT interval ［(412±44) ms and (407±10) ms vs.(419±36) ms and (404±8) ms］. Monomorphic PVC-triggered VT was recorded in 88 patients. The incidence of syncope in VF/PVT group was higher than that in monomorphic VT group (3/6, 50.0% vs. 4/88, 4.5%; P<0.01). The cycle length of PVT was shorter than that of monomorphic VT ［(235±22) ms vs.(324±29) ms; P<0.05］. By targeting the triggering PVCs, radiofrequency catheter ablation eliminated the episodes of syncope, VF and cardiac arrest in all six patients during the follow-up periods of 10-36 months. CONCLUSION: Malignant VF/PVT is occasionally present in patients with idiopathic PVCs and radiofrequency catheter ablation is effective as a treatment option for these patients.