Cardiac Electrophysiological Study (EPS)
What is a cardiac electrophysiological study (EPS)?
A cardiac electrophysiological study (EPS) is a test designed to detect abnormal heart rhythms (arrhythmias) – both slow heart rhythms and fast heart rhythms. The EPS is also used to locate short circuits which cause arrhythmias so that the short circuits can be destroyed to cure the arrhythmia (this is called catheter ablation). The EPS can also be used to help decide whether a pacemaker or defibrillator is needed.
How is an EPS performed?
EPS’s are always performed at a hospital. The procedure is performed on an x-ray table and the patient is usually sedated or has a general anaesthetic. Once the patient is asleep, a small puncture is made in the femoral vein which is a large vein situated in the groin. A tube is then placed in the vein and through this tube a number of plastic coated wires are advanced using x-ray control from the groin into the heart. Each of these wires, known as electrode catheters, contains small metal electrodes and these are used to record electrical signals from the heart to help diagnose abnormal heart rhythms. Since abnormal heart rhythms are caused by alteration on the flow of electrical currents in the heart, the doctor can use the signals recorded from these catheters to determine if an abnormal heart rhythm is present. If the abnormal heart rhythm occurs only now and again, it can usually be started using small pulses of electricity (this is known as pacing). At the end of the procedure the catheters are removed leaving one to four small incisions in the groin around 3-4 mm long each. Usually no stitches are inserted. It is necessary for the patient to remain in bed and not to move the legs for 4 hours after the procedure.
Will there be discomfort after the procedure?
Discomfort after an EPS is usually minimal. Usually, no medication for pain is required.
What are the risks of EPS?
The risks of EPS are small. The chance of dying or having a heart attack or stroke is in the order of 1 in 5000. The risk of other complications such as bleeding, a blood clot (deep venous thrombosis) or damage to the blood vessels requiring a small surgical repair is usually less than 1 or 2 in 100.
When can I return to work?
When you can return to work depends on your occupation. It is important not to lift anything heavy or exercise vigorously for a week after the procedure to decrease the risk of bleeding or bruising from the puncture site. If your work does not involve physical exertion, it should be possible to return to work a day or two after the procedure.
Can I have an EPS if I am pregnant?
Because x-rays are used during this procedure it is essential that you are not pregnant at the time of the EPS. However, in an emergency or for example in the case of a life threatening abnormal heart rhythm, electrophysiological studies are sometimes performed during pregnancy.
What preparation is required for an EPS?
You should have no food or liquids (including water) for 6 hours before an EPS. Certain medications should be stopped before an EPS – you must discuss this with the doctor before the procedure. If your doctor asks you to take some medications you may do so with a small amount of water.
Sometimes you will say in hospital overnight following an EPS but more commonly you will be able to go home. However, you will not be able to drive so you will need a friend or relative to drive you home.
© Dr Mark McGuire 5/1/2016