Electrophysiological Study

What are electrophysiology studies?
Electrophysiology studies (EPS) are tests that help doctors understand the nature of abnormal heart rhythms (arrhythmias).
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 take place in a special room called an electrophysiology (EP) lab or catheterization (cath) lab while you are mildly sedated.

Why do people have electrophysiology studies?

When someone’s heart doesn’t beat normally, doctors use EPS to find out why. Electrical signals usually travel through the heart in a regular pattern. Heart attacks, aging and high blood pressure may cause scarring of the heart. This may cause the heart to beat in an irregular (uneven) pattern. Extra 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 specialized electrode catheter designed for EP studies lets them send electrical signals to your heart and record its electrical activity.

Doctors use EPS to see:

Where an arrhythmia is coming from.
How well certain medicines work to treat your arrhythmia.
If they should 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 implantable cardioverter defibrillator (ICD) might help you.
If you are at risk for heart problems such as fainting or sudden cardiac death due to cardiac arrest (when your heart stops beating).

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

What are the risks of EPS?

Risks may include:

Arrhythmia. 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 bring back 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 went in (groin, arm or neck). Your doctor or nurse will help you avoid these problems.

How do I prepare for EPS?

Don’t eat or drink anything for 6 to 8 hours before the test.
Tell your doctor about any medicines you take, including over-the-counter medicines, herbs and vitamins. He or she may ask you not to take them before EPS. Don’t stop taking your medicine until your doctor tells you to.
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.

What happens after EPS?

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. Be sure 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.
Before you leave, you’ll be told what to do at home.

What happens after I get home?

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 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 puncture 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.