Electrophysiology Study

An EP study is an accurate method for studying the heart’s electrical system. It allows doctors to find abnormal sites inside the heart that may be causing serious arrhythmias (abnormal heart rhythms).

During an EP study, doctors insert special electrode catheters (long, flexible wires) into the heart. These catheters can sense electrical activity in different parts of the heart. They can also be used to deliver tiny electrical impulses to pace the heart (cause it to beat).

Why is the EP Study Important?

The EP study helps doctors diagnose your problem accurately and lets them choose the best treatment for you. EP studies are most often used for people who have symptoms of a rhythm problem, such as palpitations, lightheadedness, or fainting spells.  They are also used for people who have had dangerous arrhythmias or are at risk for cardiac arrest.  (During cardiac arrest, the heart stops pumping blood.)

The reasons for the EP study test:

  • To diagnose the cause of your symptoms, such as palpitations, lightheadedness, or fainting spells.
  • To see how severe an arrhythmia is and predict the risk of a future cardiac event, such as dying from a heart-related problem.
  • To decide whether you need an implantable device (such as a pacemaker or defibrillator) or a treatment procedure (such as catheter ablation).
  • To pinpoint the location of a known arrhythmia and decide the best treatment
  • To see how well certain medications are working to control an arrhythmia

 Before the Procedure:

  • Do not eat or drink anything for 6 to 8 hours before the procedure. You may have small sips or water to take your medications.
  • You may be asked to stop some medications (such as antiarrhythmic drugs) for 2 or 3 days before the test. Check with your doctor several days before the procedure.
  • Bring a list of the names and dosages of all the medications you are taking.
  • Ask someone to drive you to and from hospital. You will not be permitted to drive home after the procedure, since you may be sedated.
  • Pack a small bag in case you will have to stay in the hospital overnight. Take a robe, slippers, pajamas or nightgown, and toiletries.
  • Tell the doctor or nurse if you have had any allergic reactions to medications or x-ray dye (contrast), iodine or seafood, or if you have a history of bleeding problems.
  • Empty your bladder as much as possible before the procedure begins.

 What To Expect

An EP study usually takes from 1 to 4 hours, but it can sometimes last longer.

You will be given medication to help you relax and make you drowsy. You may be awake, or you may sleep through part or all of the test. The staff will be monitoring you at all times.

The EP study generally is not painful, although you may feel some pressure as the catheters are put in. you may also feel some discomfort from lying still for a long time.

During the study, doctors may stimulate your heart with tiny electrical impulses. You will not feel these impulses, but they may bring on the arrhythmia that has caused your symptoms in the past. Let the staff know if you feel palpitations, lightheadedness, chest pain, shortness of breath, or other symptoms.

An arrhythmia brought on in the EP lab will often stop on its own. If it does not, doctors will pace the heart or give medications through the IV line to try to restore a normal heart rhythm.

If a very fast rhythm still does not stop, an electric shock may be delivered to the heart to restore a normal rhythm. You will not feel the shock because you will be sedated first.

 Is the EP Study Safe?

The EP Study  test is generally safe, however, because one or more catheters are put into the body, an the test does have some risk. The risk is small, however.

Some people may have bleeding at the insertion site. Blood collects under the skin and causes swelling and/or bruising in the groin or arm.

More serious complications, such as infection, blood clots, damage to the heart or blood vessels, collapsed lung, stroke, or heart attack are rare.  Death is very rare.

Most patients who have an EP Study do not have serious complications. However, you should be aware of the risk involved. If you have any questions about your own risk, ask your doctor.

 After You Go Home

  • Limit your activity during the first couple of days at home. You can move about, but do not strain or lift heavy objects.
  • A bruise or a small lump under the skin at the catheter insertion is quite common. It should disappear within a few weeks.
  • Ask your doctor when you can return to your normal activities and whether there are things you should not do.
  • If you had catheter ablation, you may have occasional skipped heartbeats for a few weeks. You may also feel palpitations that last for 2 to 3 beats. These symptoms are common and will happen less often over the time.
  • Ask your doctor or nurse which medications you can keep taking and which ones you need to stop.
  • Call you doctor or nurse if the insertion site becomes painful or warm to the touch, or you develop a temperature over 100°F.
  • Call your doctor if your rapid heart rhythm returns, or if you have dizzy spells, chest pain, or shortness of breath.
  • Call your doctor if the insertion site begins to bleed, the bruising or swelling increases, or the leg ( or arm) where the catheters were inserted feels cold or numb.