Uses and Fallacies of Intracardiac Electrograms at the Pulmonary Valve

Intracardiac electrograms by cardiac catheterization were first recorded by Lenegre and Maurice (1945). The electrographic patterns in various chambers of the heart were studied by Hecht (1946), Battro and Bidoggia (1947), and Kossmann et al. (1950), and were mainly of value in studying the activation of the heart. Their importance during cardiac catheterization was first shown by Emslie-Smith (1955), who also suggested their usefulness in the exact localization of pulmonary stenosis (Emslie-Smith et al., 1956). Although various authors have studied the pat- terns of the intracardiac electrogram in the great vessels and in the different chambers of the heart, no systematic study of the changes occurring at the pulmonary valve has been presented except by Emslie-Smith et al. (