Indications for electrophysiologic studies.

The indications for invasive electrophysiologic evaluation of patients with arrhythmia problems have broadened considerably in the last decade. The major advantage of electrophysiologic studies over other forms of arrhythmia evaluation, particularly passive monitoring techniques, is the ability to detect the arrhythmia by provocative stimulation techniques, eliminating the need for serendipitous recording of a sporadic event. Once the arrhythmia can be reproducibly induced, its electrophysiologic characteristics may be studied and the effect of drugs and/or pacemakers in preventing or terminating the arrhythmia can be determined. Furthermore, if these therapeutic modalities are unsuccessful, electrophysiologic mapping procedures can be performed to determine the feasibility of surgical therapy of the arrhythmia and can help to guide the surgical approach and maximize success. Electrophysiologic evaluation is not without its limitations. It is applicable only to arrhythmias that can be reproducibly induced by programmed ventricular stimulation, and it has the potential for significant complications, including vascular complications of catheterization plus potential morbidity from the induction of life-threatening arrhythmias. Therefore, electrophysiologic evaluation should not be applied haphazardly to any patient with arrhythmia-related symptoms or even documented asymptomatic arrhythmias. Still, in the hands of experienced personnel and in the appropriate setting, electrophysiologic studies have become a valuable tool in the evaluation and therapy of patients with significant and often life-threatening arrhythmias.