Electrophysiologic Studies (EPS)

In electrophysiologic studies (EPS), mapping, recording, and stimulating electrodes are inserted into cardiac chambers via right- and/or left-sided cardiac catheterization. Atria are paced from the right or left atrium, ventricles are paced from the right ventricular apex or right ventricular outflow tract, and cardiac conduction is recorded and analyzed. Programmed stimulation and pharmacologic techniques may be used to trigger and terminate a reentrant arrhythmia. Arrhythmia substrate is mapped if ablation is planned.

Electrophysiology Study with Catheter Ablation

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In this electrophysiology study, the surface ECG and intracardiac electrograms (recorded by intracardiac mapping catheters) are visible on the right screens; a 3D map used to guide ablation is shown on the upper left screen.

Damian/stock.adobe.com

Electrophysiologic studies are indicated primarily for evaluation and treatment of arrhythmias that are:

• Serious

• Sustained

• Difficult to capture

• Confer an increased risk of sudden death

These studies may be used to make a primary diagnosis, to risk-stratify patients, to evaluate the efficacy of antiarrhythmic medications, or to map arrhythmia foci before catheter ablation of arrhythmogenic foci in patients with supraventricular tachycardia, atrial fibrillation, and ventricular tachycardia, particularly when refractory to pharmacologic therapy.

Mortality after diagnostic EPS is approximately 0.2%, or 0.03% for directly procedure-related deaths (1).