What is an Electrophysiology Study?
An electrophysiology (EP) study is a diagnostic procedure to look more closely at the electrical function of your heart.
The heart has a natural pacemaker that produces electrical impulses that travel over the heart muscle and stimulates the heart to contract or beat. The electrical signal that tells your heart to beat comes from a small area at the right upper chamber of the heart, called the sinoatrial node or SA node. When a signal is given by the SA node, a small electrical impulse runs through your heart and stimulates the heart muscle to contract. The contraction of the heart muscle produces a heartbeat and forces blood out of your heart to the rest of your body. Certain conditions can cause the electrical system to make the heart beat too slowly, too fast, or in an uncoordinated manner. These irregular patterns are called arrhythmias and they can occur in any of the four chambers of the heart.
An Electrophysiology study is the most accurate and reliable method of evaluating your heart rhythm and will help your physician determine the treatment option that is most appropriate for you. The procedure is typically carried out by electrophysiologists. Electrophysiologists are cardiologists who have additional education and training in the diagnosis and treatment of abnormal heart rhythms (arrhythmia).
Indications for an Electrophysiology Study
An electrophysiology study provides a very detailed picture of how electrical signals go through the heart and conditions associated with irregularities in electrical signals. In general, your physician may recommend an EP study if:
- You have irregular/abnormal heart rhythms.
- You have symptoms of heart problems such as fainting spells, palpitation, dizziness, and weakness; and to determine if they might be caused by a heart rhythm problem.
- You are at risk of sudden cardiac death.
- You have been advised to undergo a cardiac ablation procedure to correct arrhythmias.
- Your doctor wants to evaluate how well medications prescribed to treat heart rhythm problems are working.
How Do I Prepare for My Electrophysiology Study?
Pre-procedure preparation for an electrophysiology study may involve the following:
- A review of your medical history and a thorough physical examination
- Routine blood work, ECG, chest X-ray, and other tests specific to your condition
- Informing your physician of all the medicines (over-the-counter and prescription), herbs, vitamins, and supplements that you are taking
- Informing your doctor of any allergies to medications, iodine, anaesthesia, tape or latex
- Informing your physician of any conditions you have such as bleeding disorders or if you are taking any medications such as anticoagulant (blood-thinning) medicines, aspirin, or other medicines that affect blood clotting. You may be asked to stop taking some of these prior to the procedure.
- Refraining from solids or liquids at least 8 hours prior to the procedure
- Informing your doctor If you are pregnant or think you may be
- Signing an informed consent form after the pros and cons of the procedure have been explained
How is an Electrophysiology Study Performed?
An electrophysiology study is performed in an electrophysiology lab that has special equipment for the tests in a hospital or clinic setting. During the test:
- Your nurse will place an intravenous (IV) line in your arm to administer a sedative medicine to help you keep calm and relaxed throughout the procedure. But you will stay awake and alert to follow instructions during the study.
- The nurse will then clean and shave the region of your body where your physician will be working, which is typically the groin area but may also be the neck or arm.
- You will be administered a shot of local anaesthetic to numb the area. Your physician will make a needle puncture through the skin and into the blood vessel. A small straw-sized tube called a sheath will be inserted into your vein or artery. Your physician will gently direct several specialised EP catheters into your blood vessel through the sheath and advance them to your heart, often using fluoroscopy (real-time or moving X-ray images) as a guide. A video screen will display the position of the catheters. You may feel some discomfort or pressure in the area where the sheath was inserted, but you should not feel any pain.
- Your physician will convey small electric pulses through the catheters to make your heart beat at different speeds. You may feel your heart beat faster or stronger.
- Electrical signals produced by your heart will be captured by the special catheters and recorded. This is referred to as cardiac mapping and enables your physician to detect where arrhythmias are coming from.
- Your physician will remove the catheters and the IV line, and your nurse will put pressure on the puncture site to stop any bleeding.
- The EP study usually takes about 1 to 4 hours.
If the location and type of the arrhythmia are detected and a suitable therapy decided, insertion of a pacemaker or implantable cardioverter defibrillator (ICD) or cardiac ablation may be carried out during or immediately after the EP study.
Post-Procedure Recovery and Care
In general, post-procedure recovery and care after an electrophysiology study may involve the following:
- You will be transferred to the recovery room. You will be required to stay flat in bed for several hours following your study. Your nurse will monitor your vital signs, the insertion site, and circulation or sensation in the affected arm or leg.
- You may notice swelling, bruising, bleeding, or soreness for a few days at the puncture site. Medications are provided as needed to address these.
- Instructions on incision site care and bathing will be provided to keep the site clean and dry.
- Most patients can start eating food and taking their medications within 4 to 6 hours after the EP study.
- You may resume your daily routine the day after the procedure with certain activity restrictions such as refraining from strenuous activities for a few days.
- You are advised not to drive within 24 hours after the procedure. Hence, arrange for a friend or family member to drive you back home after the procedure.
- You will be discharged home after 3 to 4 hours of observation. Depending on your condition, your physician may give other instructions after the study.
- A follow-up appointment will be scheduled to monitor your progress.
Risk and Complications
An electrophysiology study is a safe procedure; however, as with any procedure some risks and complications may occur such as:
- Infection
- Bleeding
- Damage to the heart's electrical system
- Damage to blood vessels or heart valves
- Blood clots in the lungs or legs
- Stroke
- Heart attack
- Death (rarely)
