Technique for producing heart block in closed-chest dogs without electrical recording.

An instrument and technique have been devised for the production of complete atrioventricular heart block in anesthetized, closed-chest animals. The instrument is inserted into the right atrium via the right external jugular vein. Localization of the atrioventricular node region by the visualization of intracardiac landmarks with fluoroscopy makes electrical recording unnecessary. Discrete injections of a radiopaque necrosing solution produces the heart block. Procedure time is under 30 min a success rate of 90%.