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Electrophysiology study (EPS)

  • An electrophysiology study (EPS) is a detailed study of the heart's electrical system and is done to investigate an abnormal heart rhythm (arrhythmia).

    The heart's electrical system

    The heart has four chambers. Two upper chambers (atria) pump blood to the two lower chambers (ventricles). In order for the heart to pump, it requires an electrical impulse to start a heartbeat.

    Each heartbeat originates from the sinoatrial (SA) node—the heart's natural pacemaker—which is located in the upper right atrium. This impulse travels through the atria, signaling them to contract. The impulse is received by the atrioventricle (AV) node.

    The AV node acts as a relay center to delay the impulse before sending it from the atria to the ventricles. The impulse then spreads throughout the muscle of the ventricles, stimulating them to contract.

    Normally, impulses are generated from the sinus node at a rate of 60 to 100 beats per minute (bpm). That is called a normal sinus rhythm.

    Sometimes the heart will beat slower than 60 bpm (called bradycardia) or faster than 100 bpm (called tachycardia).

    Tachycardias that start in the upper chambers of the heart are called supraventricular tachycardia. Heartbeats that are too slow or too fast may cause fainting, fatigue, palpitations (fluttering in the chest), shortness of breath, chest pain or pressure.

    Before the study

    • Talk with your regular doctor about your medicine needs. Be sure to ask your doctor about your medicines if you have:
      • bleeding problems or if you take blood thinning medicines (such as warfarin)
      • diabetes [You may need to stop taking or adjust your regular dose of medicine for this test. Be sure to find out what dose(s) to take and when you can return to your usual medicine schedule.]
    • You may eat up to eight hours before your procedure.
      • Eat light meals, such as oatmeal or toast.
      • Avoid foods that are heavy or high in fat, such as meat or fried foods.
    • Do not use chewing tobacco six hours before your procedure.
    • You may have clear liquids up to two hours before your procedure.
      • Drink water, fruit juice without pulp, black coffee, tea, hard candies and gum.
      • Do not have milk, yogurt or alcohol.
    • The morning of the study, take the medicines your doctor has told you to take with a sip of water.
    • An intravenous (IV) line will be started to give fluids and medicines during your study. One or more blood tests, and EKG may be taken before the study.
    • The hair on your groin, neck, upper chest and back may be clipped. Your skin in those areas will be scrubbed.
    • After your questions have been answered, you will be asked to sign a consent form.
    • You will be taken to the Electrophysiology Lab on a transport cart.
    • Your family members will wait in the waiting area.

    During the study

    • After being positioned on the table in the Electrophysiology Lab, you will be connected to many monitors. You will also be gently secured to the table with soft restraints to help keep you safe.
    • The skin over the catheter sites will be prepped again. A sterile drape is placed over these sites.
    • You may be given a medicine to make you feel drowsy. The electrophysiologist will numb the skin over the catheter insertion sites. If you have any discomfort, tell the nurse.
    • Small hollow tubes will be placed through the skin and into veins in your groin, neck or both. The catheters are placed through the small hollow tubes and guided to your heart using X-ray. You won't feel the catheters advanced into your heart.
      A small catheter may be placed into the groin artery and will be used to monitor your blood pressure.
    • The electrophysiologist reviews the data and decides the right treatments for you. He or she will talk with you about all possible treatments. Options may include:
      • catheter ablation: This uses a special catheter to deliver high-frequency (hot) or freezing energy to destroy a portion(s) of heart tissue causing the arrhythmia.
      • a pacemaker: This permanent therapy may be required if your heart has a problem conducting impulses from the upper to lower chambers.
      • an implantable cardioverter defibrillator: This may be inserted if your heart has a life-threatening arrhythmia. It automatically monitors your heart and delivers a shock to restore the heart to a normal sinus rhythm.
    • At the end of the study the catheters and small hollow tubes will be removed. To prevent bleeding, pressure will be applied to the sites for about 10 to 30 minutes.
    • You will be brought back to your room or prepare to leave the hospital.

    After the study

    • You will need to stay in bed for two to five hours to keep the insertion sites from bleeding.
    • Keep your head flat while in bed.
    • Call your nurse if you feel warmth, pain or swelling at the catheter sites.
    • You will be able to eat and drink. At the end of the rest time you may get up and walk.
    • You may need to stay overnight at the hospital.
    • The IV line will be removed before you go home.

    When to call your doctor

    Call your doctor if you develop:

    • swelling
    • pain
    • drainage at the catheter sites
    • fever