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Electrophysiology (EP) Study

An electrophysiology study involves studying the heart's electrical activity to look for irregularities that cause arrhythmias. Electrophysiology (EP) studies are typically performed in patients with known abnormally fast heart rates, called tachyarrhythmias. Patients with structural congenital heart disease can have any of these arrhythmias but are also more likely than other people to develop atrial flutter and, sometimes, atrial fibrillation. Some patients with specific kinds of ventricular tachycardia may benefit from EP study as well. The key point to remember is that whatever the arrhythmia is called, it is caused by something abnormal in the heart's electrical system.

On the Inside

An EP study is done by placing long, soft, flexible tubes called catheters into the big blood vessels in the body. Usually, catheters are put in the large veins on both sides of the groin and, sometimes, also on the right side of the neck. Patients who have congenital heart disease and have had surgeries that change how the veins and arteries connect – or don’t connect - to the heart may have catheters placed into different blood vessels at different locations. These catheters are maneuvered through the blood vessels and put in specific locations in the heart to map out the heart’s electrical activity.

Getting a Diagnosis

Once a patient is sedated or asleep, the catheters are placed, similar to a large IV. There are no incisions, or sutures. These catheters are small and flexible – like very long spaghetti noodles – and are advanced into different parts of the heart.

Once they're in place inside the heart, the catheters can do two things:

  1. They can sense the electrical activity of the heart and
  2. They can give a small electrical stimulus to the heart to speed up the heart rate. This is called pacing the heart.

Different pacing maneuvers will be delivered to study the electrical activity in the heart – including trying to trigger the arrhythmia. This is important because it identifies the properties of the abnormal electricity, and the location.

An EP Study can be a standalone procedure or can lead to an ablation. Your doctor will discuss this with you.