Electrophysiology (EP) studies are performed in patients with rhythm disturbances of their hearts.
The purpose of this procedure is to study the electrical function of your heart to determine its susceptibility to very fast or very slow rhythms which may need specific treatment. Cardiac ablation may then be performed to prevent recurrence of the rhythm abnormality.
What to Expect
Electrophysiology studies and cardiac ablation procedures are performed in the Electrophysiology (EP) lab in the hospital. Specially trained EP nurses and cardiac technicians work with your electrophysiologist as a team to provide your care.
An intravenous line will be started and you will be given a mild sedative to help you relax. You will be sleepy, but you will probably be awake during the procedure. This is called conscious sedation, which means you will be aware of your surroundings, and able to communicate with the staff, but not able to feel pain.
A portion of both groin areas, and possibly the right side of your neck, will be cleaned and shaved in preparation for insertion of the catheters. Your doctor will numb the sites where catheters are to be placed in your body with a local anaesthetic. You will feel a "prick" or "sting" as the local anaesthetic is administered. Then you will be covered from your neck to your toes with large sterile sheet.
Small, flexible tubes, called sheaths, will be inserted into the blood vessels at the insertion sites. The doctor then inserts one or more catheters into the sheath. An X-Ray machine (fluoroscopy) provides images of your heart during the procedure to help your doctor accurately position the catheters. You should not feel the catheters being inserted into your heart.
Before your doctor can perform the actual ablation, he/she must identify the specific area of your heart where your arrhythmia is coming from. To do this, an electrical "map" of your heart is created. This is done by recording the electrical activity of your heart while your arrhythmia is active. Thus, you may experience some of the same symptoms that occur as a result of your arrhythmia. These could include palpitations, light-headedness, or chest pain.
While this is understandably a cause for concern, it is important for you to know that in the controlled setting of this test, the heart rhythm can be restored to normal immediately. Usually, this is accomplished by pacing your heart for a period of time, but occasionally, a small electrical shock may be required. It is very important to know if your heart is susceptible to these fast heart rhythms so that your doctors may prescribe treatment to prevent their occurrence after you leave the hospital.
Most patients experience minimal discomfort during the EP study.
Depending on the complexity of your arrhythmia, the procedure may take about one hour, or several hours. If you experience any chest discomfort or pressure during the procedure, be sure to inform the staff. Do not hesitate to ask any questions you may have, at any time. The lab staff will do everything possible to keep you comfortable.
Once your doctor has located the precise origin of your arrhythmia, a special ablation catheter will be inserted. The tip of the ablation catheter is placed next to the heart tissue in the targeted area. Energy is delivered through the tip of the catheter to neutralise (or ablate) the specific problem cells in your heart that cause the arrhythmia. This restores the normal electrical pathways of your heart, allowing it to beat normally again.
Cardiac ablation is an important advancement in the treatment of arrhythmias. For many arrhythmias, it is a widely used procedure that is proven to be safe, effective, and long-lasting. Radiofrequency (RF) electrical energy is most commonly used, and consists of high frequency radio waves and has been used safely in surgical procedures for many years.
Risks and Complications
Electrophysiology studies and cardiac ablation is a safe and widely used procedure, but as with all medical procedures this test carries some risk about which you should be informed. Your doctors are aware of these risks and have determined that the benefits to be gained from the test in diagnosing and treating your heart condition outweigh the potential risks.
Any medical procedure that involves the heart and blood vessels has some potential risk. Less than 1% of procedures result in serious complications. The most common risks are infection and bleeding. Other potential serious complications include injury to the blood vessels or heart chambers (which may require surgical correction), stroke, and heart attack. In rare cases, the catheter ablation can damage a small part of the normal electrical system, requiring the implantation of a permanent pacemaker. Very rarely (1 in 5000 patients), death may occur as a result of the procedure.