Modification of a left-sided accessory atrioventricular pathway by radiofrequency current using a bipolar epicardial-endocardial electrode configuration

Transcatheter ablation of a left posterolateral free wall accessory atrioventricular pathway using radiofrequency current and a bipolar epicardial–endocardial electrode configuration was attempted in a 19-year-old woman. The patient had suffered from recurrent syncope due to atrial fibrillation with rapid conduction to the ventricles. Following applications of radiofrequency current between one electrode in the coronary sinus and another in the left ventricle placed high against the mitral annulus, the anterograde effective refractory period was increased from less than 205 ms to a lasting value of 460 ms. Radiofrequency application could be performed without general anaesthesia and caused no side-effects.