A simple catheter technique for production of AV block

Atrioventricular (AV) block was produced in animals for experimental purposes by use of a newly devised cannula. It has bipolar electrodes; one electrode on the needle tip and the other 5.0 mm proximally from the tip. Otherwise, the cannula was electrically completely insulated. The cannula was inserted from the right external jugular vein and advanced close to the AV ring. While His bundle electrogram was obtained with the electrodes, the AV node was accessed. The injection site was determined as the point where His bundle electrogram can be well recorded and the atrial electrogram is close to or larger than the ventricular electrogram in amplitude. Xylocain solution, 0.2 to 0.4 ml, was injected with the syringe attached on the other end of the cannula. Transient AV block occurred when the needle tip was properly positioned. Then, 0.2 ml to 0.4 ml of anhydrous alcohol was added to make permanent a AV block. A possible application of this technique was implicated.