The heart is a hollow, muscular organ with four chambers.
- The top two chambers of the heart are the left and right atrium. The right atrium receives blood from the body. The left atrium receives blood from the lungs.
- The bottom two chambers of the heart are the ventricles. The right ventricle receives blood from the right atrium and pumps it out to the lungs. The left ventricle receives blood from the left atrium and pumps it out to the rest of the body.
- The heart's normal pacemaker initiates contractions of its four chambers in a regular, coordinated rhythm. A normal resting heart rate is sixty to one hundred beats per minute. The beats happen at regular intervals.
- An arrhythmia can cause the heart to beat irregularly (i.e., at varying intervals from beat to beat) and/or at abnormally fast or slow rates.
Your healthcare provider may recommend an electrophysiology study so they can better understand what is causing an abnormal heart rhythm. This test is also called an EP Study, EPS, Cardiac Mapping, or Heart Rhythm Evaluation.
- During the procedure, a cardiologist will insert a small tube, called a catheter, into a vein in your leg. The cardiologist will then thread the catheter into your heart.
- Using the catheter, measurements of electric activity are made to locate where the electrical impulse for an abnormal heartbeat comes from. It then maps the pathway the impulse travels before causing a contraction of the heart muscle.
- This test differs from standard monitoring of the heart, such as a holter monitor. Unlike standard heart monitoring, an EPS is invasive and involves placement of a catheter directly into the heart.
Once an EP study has mapped the origin and pathway of an abnormal electrical impulse, the cardiologist can often destroy the pathway by a procedure called an ablation.
- An ablation is the use radiofrequency or microwave energy, delivered through the catheter to a specific area of the heart.
- The energy destroys the pathway and stops the abnormal impulse from causing a contraction of the heart muscle.
An abnormal heartbeat is a heartbeat that is too fast, too slow or has an irregular rhythm. Your cardiologist may recommend an EPS if you have episodes of an abnormal heartbeat. It can help your healthcare provider determine:
- Where an abnormal heartbeat starts and the best way to treat it.
- The risk related to the abnormal heartbeat, including the possibility of sudden cardiac death.
- If an abnormal heart rhythm is well controlled by medication.
- If an ablation procedure is needed.
- If a permanent pacemaker or defibrillator (ICD) is needed. (An ICD is a device that detects life-threatening arrhythmias and delivers an electrical shock to the heart to convert the rhythm back to normal.)
Prior to the procedure, tell your healthcare provider about any medications you are taking (including over-the-counter medications and supplements). Ask about specific instructions you should follow before the procedure. These may include:
- Medications you should not take before the procedure, such as blood thinners or aspirin
- Regular medications you should continue to take on the day of your procedure
- How many hours you should stop eating and drinking before procedure
If you are a smoker, you should quit smoking, as it can interfere with your recovery.
EP studies are typically done by a cardiologist in a hospital. Most people are able to go home the same day of the procedure.
- You may be given some medicine to help you relax. However, you will be awake for the test and may feel some mild pressure or discomfort where the catheter is inserted.
- When the catheter is removed, pressure will be applied to the puncture site. You will have to lay flat on your back and keep your leg straight for a short period - up to several hours - to avoid bleeding at the insertion site.
- Your vital signs will be monitored and the puncture site will be checked often for bleeding.
It is important to understand procedures your healthcare provider recommends. You should ask questions, such as those outlined below, before having an electrophysiology study.
- What is my diagnosis and reason for the procedure?
- Why is an electrophysiology study needed instead of a less invasive test or procedure, such as standard cardiac event (holter) monitoring?
- Are there any alternatives to this test in diagnosing my symptoms?
- What are the possible complications to this procedure?
- How will I feel after the procedure? Will I have to modify my activity?
- Are the facilities where you perform the procedure designated as UHC Premium Facilities for cardiac tests and procedures?
- Do I need to fast (avoid eating and drinking) before the procedure and, if so, for how long? Is there any other special preparation for the procedure? (If so, get clear instructions on what you need to do.)
- Will I have any type of sedation? What are the possible side effects?