Experimental production of AV block. Comparison between electrical ablation and a new catheter technique using anhydrous alcohol.

Production of chronic complete atrioventricular block (CAVB) was attempted by two closed-chest methods in dogs. One is a modified electrical ablation method (EA), and the other is a new catheter technique to inject anhydrous alcohol into the subendocardium of the AV junction (alcohol method). EA was performed in 6 dogs and the alcohol method in 10 dogs. Chronic CAVB was produced in 5 dogs (83%) by EA and in 7 dogs (70%) by the alcohol method. Escape ventricular rhythm with narrow QRS morphology was found in 4 dogs (80%) with EA, and in 3 dogs (43%) with the alcohol method. Except for transient supraventricular tachyarrhythmias which occurred immediately after EA, both methods were performed without complication. EA had a higher success rate in producing CAVB on the narrow QRS of the escape ventricular rhythm occurred more frequently than reported in the literature and than in the case of the alcohol method. The alcohol method, though, may be superior to EA for human applications because it does not require general anesthesia.