Electrophysiology Studies - Thumbay University Hospital

Electrophysiology Studies

Quick Facts

Electrophysiology studies test the electrical activity of your heart to find the source of the irregular heartbeat (arrhythmia).

These results can help you and your doctor decide if you need medication, a pacemaker, an implantable cardioverter-defibrillator (ICD), cardiac ablation or surgery.

These studies are done in a special room called an electrophysiology (EP) lab or catheter lab while you’re lightly sedated.


Why do people have electrophysiology studies?

When a person’s heart is not beating normally, doctors use EPS to find the cause. Electrical signals normally travel through the heart in a regular pattern. The heart attacks, aging, and high blood pressure may cause scarring of the heart. This may cause the heart to beat in an irregular (irregular) pattern. Excess abnormal electrical pathways found in some congenital heart defects can cause an arrhythmia.

During an EPS procedure, doctors insert a thin tube called a catheter into a blood vessel that leads to your heart. Specialized electrical catheters designed for EP studies allow electrical signals to be sent to your heart and record its electrical activity.

Doctors use EPS to learn:

  • Where does arrhythmia come from?
  • How effective some medications are in treating your irregular heartbeat.
  • If they must they treat a problem by destroying the place inside your heart that is causing the abnormal electrical signal. This procedure is called catheter ablation.
  • If a pacemaker or an implantable defibrillator (ICD) can help.
  • If you are at risk of developing heart conditions such as fainting or sudden cardiac death from cardiac arrest (when your heart stops beating).
  • During the EPS procedure, about 3 to 5 electrically sensitive catheters are placed inside the heart to record the electrical activity.

What are the risks of EPS?

Risks may include:


During EPS, you may have abnormal heart rhythms that make you feel dizzy. If this happens, your doctor may give an electric shock to restore a regular heartbeat.

Sometimes blood clots can form at the tip of the catheter, breaking off and blocking a blood vessel. Your doctor may give you the medicine to prevent blood clots.

Infection, bleeding and bruising where the catheter was inserted (groin, arm or neck). Your doctor or the nurse will help you to avoid these problems.

How do I prepare for EPS?

  • Do not eat or drink anything for 6 to 8 hours before test.
  • Tell your doctor about any medications you are taking, including over-the-counter medicines, herbs, and vitamins. You may be asked not to take it before the EPS.
  • Have someone drive you to your appointment and take you to home.
  • If you normally wear a hearing aid, wear it during the procedure. If you wear the glasses, bring them with you to your appointment.

What happens during EPS?

In a hospital or clinic, doctors and nurses make EPS in a room with special equipment for tests. You may hear this room called an electrophysiology lab, or EP lab. Some call it a catheter lab (catheter lab). During the test:

The nurse will place an IV in your arm. You will be given a medicine (sedative) to help you relax. But you will be awake and able to follow the instructions during the test.

Your nurse will clean and shave the part of your body where the doctor will operate. Usually this is in the groin but may be in the arm or neck.

You will be given an injection – you will be given a local anesthetic – to make the area numb. Your doctor will put a needle through your skin and into your blood vessels. A small tube the size of a tube called a sheath will be inserted into the artery or vein. Your doctor will gently guide several specialized EP catheters into your blood vessels through the sheath and advance them into your heart. The video screen will show the catheter placement. You may feel some of the pressure in the area where the sheath was inserted, but you shouldn’t feel any pain.

Your doctor will send small electrical impulses through the catheter to make your heart beat at different speeds. You may feel like your heart is beating stronger or faster.

The electrical signals from your heart will be picked up by the special catheter and recorded. This is called cardiac mapping and allows the doctor to determine the source of the arrhythmia,

Your doctor will remove the catheter and the intravenous line. Your nurse will apply pressure to the puncture site to stop any bleeding.

EPS usually lasts from 1 to 4 hours.

If the type and location of the arrhythmia has been identified and appropriate treatment decided, a cardiac ablation or insertion of a pacemaker or ICD can be performed during or immediately after the EPS procedure.

What happens after EPS?

You will be taken to a recovery room where you must rest quietly for 1 to 3 hours. During this time:

  • Remain consistent as long as your nurse tells you to. Make sure to keep the arm or leg used for the test straight.
  • Your nurse will check 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 the test results.
  • Before you leave, you will be told what to do at home.

What happens after I get home?

Follow the instructions given to you by your nurse or doctor, including taking any new medicines prescribed to you. Most people can start eating and taking their medication within 4 to 6 hours after the test. Most can go about their usual daily activities the day after the test. Do not drive for at least the 24 hours.