Introduction to Clinical Electrophysiology

Electrophysiology studies (EPS) began in the late 1960s in the dog laboratory where recording of the His bundle electrogram was accomplished.1 The first recordings in the human heart occurred in a patient with atrial septal defect2; whereas in 1969, Scherlag et al3 were the first investigators to percutaneously, by right heart cardiac catheterization, record a His bundle in humans by safely placing an electrode catheter across the tricuspid valve.