To significantly reduce the morbidity, mortality and life long dependence on antiarrhythmic medications, radiofrequency catheter ablation has emerged as the treatment of choice for patients with preexcitation disorders occurring with the Wolff-Parkinson-White (WPW) syndrome. Radiofrequency ablation is usually highly successful (>95%), with a near zero mortality and low morbidity. This article, the last in a series of two, focuses on preventing complications for patients undergoing this procedure.