What is Cardiac Electrophysiology (EP)?

Cardiac electrophysiology (EP) is the science of diagnosing and treating the electrical activities of the heart. EP studies involve invasive (intracardiac) catheter recording of spontaneous activity as well as of cardiac responses to programmed electrical stimulation (PES). These studies are performed to assess complex arrhythmias, evaluate abnormal electrocardiograms, assess risk of developing arrhythmias in the future, and design treatment. Often the studies involve sophisticated 3-D mapping to define arrhythmia pathways. These procedures increasingly include therapeutic methods (typically radiofrequency ablation or cryoablation) to treat atrial fibrillation, atrial flutter, ventricular tachycardia or other arrhythmias. Other therapeutic modalities employed in this field include antiarrhythmic drug therapy and implantation of artificial pacemakers and implantable cardioverter-defibrillators (CD).

The cardiac electrophysiology study (EPS) typically measures the response of the injured or cardiomyopathic myocardium to PES on specific pharmacological regimens in order to assess the likelihood that the regimen will successfully prevent potentially fatal sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) in the future. Sometimes a series of EPS drug trials must be conducted to enable the cardiologist to select the one regimen for long-term treatment that best prevents or slows the development of VT or VF following PES. Such studies may also be conducted in the presence of a newly implanted or newly replaced cardiac pacemaker or AICD.

A specialist in cardiac electrophysiology is known as a cardiac electrophysiologist or (more commonly) simply an electro-physiologist. Cardiac electrophysiology is considered a subspecialty of cardiology in most countries. In early 2011, the Centers for Medicare and Medicaid Services (CMS) promoted cardiac electrophysiology to its own specialty category in the United States. Cardiac electro-physiologists are trained to perform interventional cardiac electrophysiology studies (EPS) as well as surgical device implantations.

The Heart Rhythm Society, founded in 1979, promotes education and advocacy for cardiac arrhythmia professionals (including cardiac electro-physiologists) and patients. It is the largest society in the field.