Abstract
The history of intracardiac electrography has been reviewed with particular reference to its practical application. The increasing versatility of electrode catheters is stressed and a new multipurpose diagnostic catheter with a platinum electrode is described. Electrograms chosen from 500 consecutive cases have been presented to demonstrate the use of an intracardiac lead during routine cardiac catheterization, and the special value of this technic in the investigation of congenital heart disease in babies and small children is emphasized.