Electrophysiology Study (EPS)

EPS helps identify source of abnormal heartbeat

Certain conditions such as high blood pressure or heart attack, or even the natural aging process, can lead to “scarring” of the heart, which disrupts the heart’s electrical signals and causes arrhythmia (abnormal heartbeat). An electrophysiology study or EPS is a test involving measurement of the electrical activity of the heart. It is used to study arrhythmias and what’s causing them. An EPS can also help determine how well your arrhythmia medications are working. Once your doctor knows the source of your arrhythmia, he or she can better recommend a specific device, such as an implantable cardioverter defibrillator (ICD) or pacemaker, or certain type of medication.

Preparing for an EPS

An EPS takes several hours and requires some preparation. Because you’ll be having anesthesia (medication that helps you relax and not feel anything), you will be advised to not eat or drink anything for six to eight hours beforehand. Your doctor may have specific instructions about whether or not to take medications, including over-the-counter drugs and vitamins, and you’ll need to arrange to have someone drive you home afterwards.

How an EPS is performed

The test takes place in an EPS lab, sometimes called a catheterization lab or cath lab. You will first receive an intravenous (IV) line that allows the anesthesia to flow into your vein. The nurse will also shave, clean and numb the area of your body where the catheter (thin tube) will be inserted. Usually this is in the groin (area between your abdomen and leg) but it may be through the arm or neck. Once the area is prepared, your doctor (an electrophysiologist) will gently guide several catheters up to the heart area. The catheters used for an EPS are specially equipped to deliver a small electrical current to the heart and to measure the heart’s electrical activity. The doctor makes note of this activity and your heart’s response.

If scar tissue is discovered on the heart, your doctor may also perform catheter ablation, which is done with radio waves (radiofrequency ablation) or by freezing of the affected tissue (cryoablation)—all done through the catheter.

After the procedure is over, pressure and a bandage will be applied to the area of insertion. You will need to remain in bed for two to six hours after your test, depending on your condition.

EPS risks and recovery

There are certain risks associated with an EPS such as arrhythmia that occurs during the procedure and causes dizziness. There is also some risk of blood clots due to blood forming around the tip of catheter. Your doctor may require you to take an anticoagulant (blood thinner) to help prevent this from happening. There is also a slight risk of bleeding, infection and bruising at the point of entry.

Once you’re back home, you will need to take it easy for a few days and avoid any strenuous activity. Also keep an eye out for any unusual bleeding or signs of infection. Be sure to call your doctor right away if you have a fever (higher than 100.4˚) or chills. Also call you notice any pain, redness, swelling or drainage around the catheter insertion area, or if you experience excessive sweating, dizziness or fainting. Other unusual changes may include:

  • Chest pain or pressure
  • Nausea or vomiting
  • Coolness, numbness or tingling in the catheterized leg

Again, call your doctor if you experience anything unusual or of concern to you.