Experimental creation of complete A-H block.

A new technique to block conduction from both atria to the atrio-ventricular node (A-V node) was devised through anatomical considerations of the junctional area. To assess the validity of the technique, a series of experiments were performed in mongrel dogs. Under cardiopulmonary bypass, the interatrial septum was incised along the tendon of Todaro, followed by cryosurgical ablation of the approach to the A-V node. Postoperative electrophysiological studies revealed complete conduction block between both atria and the A-V node. A spontaneous A-V nodal rhythm was produced. Initial activation was proved to be within the junctional area. This technique may lead to improved surgical management for atrial fibrillation and other supra-ventricular tachyarrhythmias.