Electrophysiology study (EP) is a test that makes doctors understand the nature of abnormal heart rhythms. This test is used to map the electrical activity within one’s heart. Doctors recommended this test to people with heart rhythm problems (arrhythmias) and other heart problems, it helps to detect the exact cause and determine which treatment will be effective. In some cases, doctors use EP studies to predict the risk of sudden cardiac death.
Electrical signals usually travel via the heart in a regular pattern. Heart attacks, aging and high pressure might cause scarring of the heart. This might cause the heart to beat in an uneven pattern. Arrhythmias can also be caused by additional irregular electrical pathways present in some congenital heart defects.
EP Study is used to see:
- Where an arrhythmia is heading from.
- How well certain medicines are working to treat one’s arrhythmia.
- If one is at risk of severe heart problems.
- If a pacemaker or implantable cardioverter defibrillator (ICD) may help the patient.
- If an issue of irregular electrical signals is to be dealt with by removing or scarring the heart tissues triggering that signal. This procedure is called cardiac ablation.
Why do doctors recommend this test?
- If one has been diagnosed with an arrhythmia, such as astral fibrillation, atrial flutter, tachycardia, ventricular tachycardia or supraventricular tachycardia. The doctors will suggest EP study to the patient, to have a better vision of the conditions and understand how electrical signals move in one’s heart and how best to treat one’s condition.
- If someone is undergoing cardiac ablation, an EP test is conducted at the beginning of the arrhythmia cardiac procedure. Heat or cold energy is used in cardiac ablation to form scar tissue in the heart to block irregular electrical signals.
- If someone has temporary loss of consciousness (syncope). Doctors might use this test for the people who experience syncope or fainting, to understand the cause.
- If anyone has a risk of sudden cardiac death. Doctors recommend this test to people who have a heart condition, which might be increasing their risk of sudden cardiac death. This test will make them understand the risks in a better way.
- If anyone is having heart surgery. The doctors will prescribe an EP analysis if the patient is planning for heart surgery in which heart ablation may be done at the same time.
During the Test
Doctors insert a thin tube known as a catheter into a blood vessel that leads to one’s heart. Around 3 to 5 electrically sensitive catheters are inserted inside the heart to record the electrical activities. Doctors can send electrical signals to one’s heart and record its electrical activity with a specialized electrode catheter designed for EP studies. This test takes place in a room known as the electrophysiology laboratory, or EP lab. Some may call it the catheterization laboratory (Cath lab).
- A nurse or other person from the team will put an IV (intravenous line) in one’s arm. This will be followed with a medicine (a sedative) which will help the patient to relax, but be awake during the procedure.
- The area, on which the doctors will be working, will be cleaned and shaved; usually the groin but can also be an arm or the neck.
- A local anaesthetic shot will be given to the patient to make the area numb. The doctors will make a needle puncture via the patient’s skin and into the patient’s blood vessel. A sheath, a small straw-sized tube, will be inserted into the patient’s artery or vein. After this, doctors will gently guide various specialized EP catheters into the patient’s blood vessel via sheath and advance that into the patient’s heart. A video screen, placed next to the doctors, will show the position of the catheters. The patient might feel some pressure in the areas, where the small tube (sheath) was inserted, but the patient should not feel any pain.
- The doctors will start sending small electric pulses via catheters to make the patient’s heart beat at different speeds. The patient will feel his or her heart beat stronger or faster.
- Electrical signals produced by the patient’s heart will be picked up by the special catheters. This is known as cardiac mapping and this helps the doctors determine where the arrhythmias are coming from.
- At the end of this test, doctors will remove the catheters and IV line. They will put a little amount of pressure on the puncture site to avoid bleeding, if any.
- This test usually lasts 1 to 6 hours.
Once the form and position of the arrhythmia is identified and a suitable treatment is chosen, like cardiac ablation or insertion of a pacemaker or ICD, can be performed during or immediately after the EPS.