In electrophysiologic studies, recording and stimulating electrodes are inserted via right- or left-sided cardiac catheterization into all 4 cardiac chambers. Atria are paced from the right or left atrium, ventricles are paced from the right ventricular apex or right ventricular out-flow tract, and cardiac conduction is recorded. Programmed stimulation techniques may be used to trigger and terminate a reentrant arrhythmia.

Electrophysiologic studies are indicated primarily for evaluation and treatment of arrhythmias that are difficult to capture, serious, or sustained. These studies may be used to make a primary diagnosis, to evaluate the efficacy of antiarrhythmic drugs, or to map arrhythmia foci before radiofrequency catheter ablation (see Arrhythmias and Conduction Disorders: Radiofrequency (RF) ablation). Various mapping techniques are available.

Last full review/revision December 2012 by Michael J. Shea, MD