Electrophysiology Key Facts

• Electrophysiology is the fastest growing of all the cardiovascular disciplines.
• Electrophysiologists are cardiologists who have additional education and training in the diagnosis and treatment of abnormal heart rhythms. Close collaboration between electrophysiologists and other doctors who treat patients with heart disease is important.
• Based on the Heart Rhythm Society Workforce Survey, 999 electrophysiologists¹ (experts in heart rhythm disorders) were identified for the 1995 U.S. population of 263,434,000, a ratio of 1:263,690. Of these 999, 795 are certified as having added special competency in electrophysiology by the American Board of Internal Medicine. Many have also passed the International Board of Heart Rhythm Examiners (IBHRE®), formerly NASPExAM®, examination of special competence in cardiac pacing and implantable defibrillation.
• With about 16,000 cardiologists in the United States, these numbers result in 1 electrophysiologist:16 cardiologists.
• When the number of electrophysiologists/1,000,000 population was calculated, the U.S. average was 3.79/1,000,000.
• Twenty-one states had less than eight electrophysiologists and 12 states had less than 2.2 electrophysiologists/1,000,000 population.
• Major cities, such as Philadelphia and Washington, D.C., had high electrophysiologist/population densities. For example, there are some 50 electrophysiologists in the metropolitan Philadelphia area. In contrast, some rural areas have a minimal number of electrophysiologists (e.g., at the time of the survey, there was only one electrophysiologist in Idaho).
• Even in states that have electrophysiologist densities higher than the national average, patients may have to travel over 250 miles to the nearest electrophysiologist. For example, New Mexico has 3.93 electrophysiologists/1,000,000 population, however, all are located in Albuquerque.

When to See an Electrophysiologist

Electrophysiologists determine whether an individual is in a group that is at high risk for sudden cardiac arrest (SCA) or other cardiovascular diseases. A number of tests may be performed including:

• Echocardiogram is a painless, noninvasive test, in which a device called a transducer is placed on the chest and sound waves are bounced off the heart. This provides a moving picture of the heart.
• Holter monitors are external devices that are worn by an individual who may be at risk for heart disease. The monitor automatically records a continuous electrocardiogram (ECG) of the heart's electrical activity; it is usually worn for 24 to 48 hours.
• An event recorder is a small, pager-sized device that also records the electrical activity of the heart. Unlike a Holter monitor, it does not operate continuously, but instead is activated by the individual whenever he or she feels the heart begin to beat too fast or chaotically. After the device is activated to record the heart rhythm, the patient can report the event and transmit the recording by phone to his doctor or other health care provider.
• An electrophysiology study (EPS) is a test that can help predict if an individual is at high risk forSCA. Signals are administered to the heart muscle in patterns to see if they will stimulate ventricular tachycardia (VT). The test is performed in a safe and controlled electrophysiology laboratory at a hospital or clinic and the patient is in no danger. In an EPS, local anesthetics are used to numb areas in the groin or near the neck, and small catheters are passed into the heart to record its electrical signals. During the study, the physician studies the speed and flow of electrical signals through the heart, identifies rhythm problems, and pinpoints areas in the heart's muscle that give rise to abnormal electrical signals.
• An electrophysiology study can:
• • Identify which patients who have had a prior heart attack are at risk for serious ventricular arrhythmias and, perhaps, SCA.
  • Help determine which patients may require aggressive treatment to prevent SCA.
  • Identify individuals whose hearts cannot be induced into dangerous arrhythmias. They appear at lower risk for developing spontaneous, sustained VT that can lead to ventricular fibrillation and SCA.

¹The criteria used in the survey for defining a physician as an electrophysiologist included either having the ABIM Clinical Electrophysiology Added Special Competency "boards" or having met essentially the same requirements and practicing invasive electrophysiology. Performance of invasive electrophysiology studies but not ablative procedures or device implantation/follow-up was required for designation as an electrophysiologist in the latter category.