Electrophysiology Study

What is it?

An electrophysiology study (EPS) evaluates your heart’s electrical system and helps your doctor diagnose any abnormal heart rhythms you may have experienced or be at risk of experiencing

Quick facts

  • Electrophysiology studies test the electrical activity of your heart to find where an arrhythmia (abnormal heartbeat) is coming from.
  • These results can help you and your doctor decide whether you need medicine, a pacemaker, an implantable cardioverter defibrillator (ICD), cardiac ablation or surgery.
  • These studies are performed in a special room called an electrophysiology (EP) or catheterization (cath) lab while you are mildly sedated

Frequently Asked Questions

Electrical signals usually travel through the heart in a regular pattern. Heart attacks, aging, and high blood pressure may cause the heart to beat in an irregular, uneven pattern called arrhythmia. Abnormal electrical pathways found in certain congenital heart defects can also cause arrhythmias.

During EPS, doctors insert a thin tube called a catheter into a blood vessel that leads to your heart. A special electrode designed for EP studies lets the doctor send mild electrical signals to your heart and record its electrical activity.

EPS allows your doctor to see:

  • Where an arrhythmia is coming from.
  • If certain medicines would work to treat your arrhythmia.
  • If the problem could be treated by a procedure called cardiac ablation. This removes the place inside your heart that is causing the abnormal electrical signal.
  • If a pacemaker or implantable cardiac defibrillator (ICD) might help you.
  • If you are at risk for heart problems such as fainting or sudden cardiac arrest (when your heart stops beating).

During an EPS, 3 to 5 electrically sensitive catheters are placed inside the heart to record electrical activity.

  • During EPS you may have abnormal heart rhythms that make you dizzy. If this happens, your doctor may give your heart an electric shock to restore a regular heartbeat.
  • Blood clots sometimes can form at the tip of the catheter, break off and block a blood vessel. Your doctor may give you medicine to prevent blood clots.
  • Infection, bleeding and bruising at the site where the catheter was inserted (groin, arm or neck). Your doctor or nurse will help you avoid these problems.

  • Don’t eat or drink anything for 6 to 8 hours before the test.
  • Tell your doctor about any medicines you take, but don’t stop taking them unless your doctor tells you to.
  • Tell your doctor about all over-the-counter medicines you take, including herbs, supplements, and vitamins. Your doctor may ask you not to take them before the EPS.
  • Have someone drive you to your appointment and take you home.
  • If you usually wear a hearing aid, wear it during your procedure. If you wear glasses, bring them to your appointment.

Our facility uses a special room called the electrophysiology (EP) or catheterization (cath) laboratory to for this procedure.

  • A nurse will put an intravenous (IV) line in your arm. You’ll get a sedative through the IV that will help you relax. But you’ll be awake and able to follow instructions during the test.
  • Your nurse will clean and shave the part of your body where the doctor will be working. This is usually in the groin, but it may be the arm or neck.
  • You’ll be given a local anesthetic injection to make the area numb.
  • Your doctor will make a needle puncture into your blood vessel. A small straw-sized tube called a sheath will be inserted into your artery or vein.
  • The doctor will gently guide several specialized EP catheters into your blood vessel through the sheath and advance them to your heart. A special video screen will show the position of the catheters. You may feel some pressure in the area where the sheath is inserted, but you shouldn’t feel any pain.
  • Your doctor will send small electric pulses through the catheters to make your heart beat at different speeds. You may feel your heart beat stronger or faster.
  • The catheters will record the electrical signals produced by your heart. This is called cardiac mapping; it allows the doctor to determine where the arrhythmias are coming from.
  • Depending on the type and location of the arrhythmia identified, the doctor may perform a cardiac ablation or insert a pacemaker/ICD during or immediately after the EPS.
  • Once the test is complete, your doctor will remove the catheters and the IV line. Your nurse will put pressure on the puncture site to stop any bleeding.

You’ll be moved to a recovery room where you should rest quietly for 1 to 3 hours. During this time:

  • Stay still as long as your nurse tells you to. Keep the arm or leg used for the test straight.
  • Your nurse will check on you often to see if there is bleeding or swelling at the puncture site.
  • After the sedative wears off, your doctor will talk to you about your test results.

Follow the instructions your nurse or doctor gave you, including taking any new medicines that were prescribed. Most people can start eating food and taking their medicines within 4 to 6 hours after the test. Most can do their usual daily activities the next day after the test. Don’t drive for at least 24 hours.

The puncture site may be sore for several days. A small bruise at the site is normal. If the site starts to bleed, lie flat and press firmly on top of it. Have someone call the doctor or EP lab.

Call 9-1-1 if you notice:

  • A sudden increase in swelling around the puncture site.
  • Bleeding doesn’t slow down when you press hard on the site.

Call your doctor right away if you notice:

  • Your arm or leg that was used for the sheath feels numb or tingles.
  • Your hand or foot feels very cold or changes color.
  • The puncture site looks more and more bruised.
  • The puncture site begins to swell or fluids begin to come from it.

The cardiologist takes care of the heart’s arteries, muscle, and valves and the electrophysiologist takes care of the heart’s electrical system.