Intracardiac electric stimulation in conscious rabbits. A new model for screening membrane-stabilizing antiarrhythmics.

Cardiac arrhythmics were induced in conscious rabbits by intracardiac electric stimulation. The arrhythmic threshold remained constant for a period of more than 6 months. The antiarrhythmic drugs ajmaline, prajmalium, disopyramide, quinidine, lidocaine, propranolol and verapamil, given i.v. or orally, were screened for their threshold-raising potency. Particularly the membrane-stabilizing antiarrhythmics showed significant effects. The model may constitute a useful screen for such drugs in the conscious animal.