Ventricular fibrillation secondary to radiofrequency application for ventricular tachycardia ablation

Radiofrequency catheter ablation has become a first line therapy for severa l types of tachycardias because of its high efficacy and low complication r ate. The development of proarrhythmic complications due to a direct effect of radiofrequency is very unusual. We describe a patient with previous myoc ardial infarction and well tolerated sustained monomorphic ventricular tach ycardia who underwent catheter ablation of the tachycardia substrate. Durin g two of the radiofrequency applications, ventricular fibrillation develope d and external defibrillation was required.