Effect of DC-shocks of 400 Joules on the AV-node.

Ablation of the AV-node with direct current shocks and 6-French U.S.C.I. catheters was performed in 8 patients with disabling supraventricular arrhythmias. An initial shock of 400 Joules was chosen in most instances. In all patients transient or permanent complete AV-block was obtained. For one patient the procedure was considered a failure, after three sessions. Five patients remain in complete AV-block. Average escape rhythm at first ambulatory follow-up was 47 bpm. The block seems to be situated at the level of the bundle of His, or distal of this level. The other two patients are clinically improved with impaired AV-conduction. A pacemaker was implanted in all patients.