Effect of drugs in the wolff-parkinson-white syndrome.

Electrical stimulation of the heart, using the single test stimulus method, gives the opportunity to study the mechanisms of tachycardias and the effect of drugs on these mechanisms directly in the heart of the patient with the WPW syndrome. Using these methods the effect of digitalis, procainamide, quinidine, ajmaline, lidocaine, propranolol and verapamil has been studied. Understanding of the mechanisms responsible for initiation and maintenance of tachycardias and the way in which they can be influenced by drugs should be of help in the treatment of the symptomatic patient with the WPW syndrome.