Yoshihisa Enjoji, M.D., Kaoru Sugi, M.D., Takanori Ikeda, M.D., Masashi Kasao, M.D., Mahito Noro, M.D., Takao Sakata, M.D., So Yabuki, M.D. and Tetsu Yamaguchi, M.D.

Abstract
Radiofrequency catheter ablation of the slow pathway is commonly used to treat atrioventricular (AV) nodal reentrant tachycardia. However, there has been little study of the follow-up assessment of AV nodal physiology. We compared AV nodal electrophysiological characteristics before, immediately after, and again 3 months after successful catheter ablation in 17 patients (mean age 50±16 years). Sinus cycle length, Wenckebach cycle length, A-H interval at a paced cycle length of 600 ms, effective refractory period and functional refractory period of the fast pathway were significantly changed immediately after catheter ablation, but had recovered 3 months after the procedure. There were no significant differences between the electrophysiological parameters immediately after catheter ablation and those 3 months after the procedure under the intravenous injection of atropine sulfate. We conclude that, due to changes in autonomic nervous tone, AV nodal electrophysiological characteristics are influenced immediately after catheter ablation of the slow pathway in AV nodal reentrant tachycardia.
(Jpn Circ J 1996; 60: 853-860)

Key Words: AV nodal reentrant tachycardia, Slow pathway, Radiofrequency catheter ablation

Mailing address: Yoshihisa Enjoji, M.D., Toho University School of Medicine, Ohashi Hospital, Third Department of Internal Medicine, 2-17-6 Ohashi, Meguro-ku, 153 Tokyo, Japan