If you have problems with your heart such as an irregular heartbeat (arrhythmia), your doctor might ask you to have an electrophysiology study. This test will help your doctor find out whether your medication is working, or whether you need another kind of intervention to restore a healthy heartbeat. 

It’s sometimes referred to as an EP study of the heart, or EPS. Find out more about why you might need to have an electrophysiology study and what to expect when having this procedure. 

Key points

What is an electrophysiology study?

An electrophysiology study will show your doctor how the electrical system of your heart is working. The study analyses any abnormal heart rhythms and evaluates the effect of drug therapy.

The electrical system of the heart is stimulated with electrode catheters, which are insulated wires with an electrode at the tip. 

“An electrophysiology study lets doctors record your heart’s electrical system, so that information can be analysed,” says Dr Sean Gomes, Procedural Cardiologist. 

“This helps your doctor diagnose any abnormality of your heart, and decide on the best treatment.”

Why do I need an electrophysiology study?

Your doctor might suggest an EPS if you have problems with your heart rhythm such as irregular heartbeats, or a heart that beats too quickly or slowly. You might also need one if you have a heart condition that can cause sudden cardiac death, or you have fainting episodes where you lose consciousness.

Your heart pumps blood to the lungs and body thanks to precise electrical signals that come from specific areas of the heart. The heart’s ‘pacemaker’ is the sinoatrial node, which is made up of cells that stimulate the left and right atrium (the upper chambers) to contract and push blood into the ventricles (the lower chambers). The electrical impulses then travel to the ventricles and make them contract, pumping blood to the lungs and body. 

“If there’s a problem with your heart’s ability to transmit electrical impulses, or if these impulses are blocked, your heart might beat too slowly, too quickly or irregularly,” Dr Gomes says.

“Signs of these kinds of heart rhythm disturbances include dizziness, fainting spells or palpitations.”

diagram of heart arrhythmia

The heart’s ‘pacemaker’ is the sinoatrial (or sinus) node which creates electrical signals that keep the heart pumping. If there’s a problem with your heart’s ability to transmit electrical impulses, or if these impulses are blocked, it can lead to arrhythmias.

What are the risks?

Like with all procedures, there are some risks associated with having an EPS, including: 

  • Abnormal heart rhythms during the test, which can make you feel dizzy. If necessary, your doctor will give your heart an electric shock to restore a regular heartbeat.
  • Bleeding, bruising or infection at the site where the catheters were inserted in the groin or arm. 
  • Blood clots in the legs or lungs. You may be given medication to prevent blood clots.
  • Bleeding around the heart, or damage to the blood vessels or heart valves.
  • Heart attack or stroke. 

Everything will be done to minimise these risks during the procedure. Talk to your doctor if you’re concerned.

What happens:


You’ll need to stop eating food six hours before the test, and stop drinking any clear fluids two hours before. If you’re taking any medication such as blood thinners or diabetes medication, your doctor will let you know whether to stop or change your dosage before the test. 


Your doctor will inject local anaesthetic into the skin in the groin area (and occasionally in the arm). Once the skin has been anaesthetised, a small tube is placed in the vein. Guided by an x-ray image, electrode catheters will be inserted – you should only feel minimal discomfort – and positioned at specific locations in the heart.

Your doctor will send electric signals through the catheters to speed up or slow down your heartbeat. Electric signals produced by your heart will be recorded, indicating whether there is an arrhythmia and where it’s coming from. 

nurse looking after a patient at Sutherland Heart Clinic

Our expert team will look after you at every stage of the procedure.


After the study is finished, the catheters will be removed and the doctor will apply pressure and a dressing to the wound. You’ll need to stay in recovery and rest afterwards for about four hours. 

The study will take about one hour, but you’ll need to be at the clinic for six to eight hours from the time of admission to time of discharge. 

You might be able to go home the same day, but you’ll need someone to drive you home or go with you if you are travelling by taxi or uber. You might feel sore for a few days where the catheters were inserted. 

How long does it take to recover? 

You should be able to start doing your normal activities a few days after the test. “You’ll need to have a follow-up appointment so your doctor can discuss your results and which treatment is best for you,” Dr Gomes says.

About Sutherland Heart Clinic

Sutherland Heart Clinic is a major interventional cardiology centre that’s co–located

within Sutherland Hospital at Caringbah in Sydney’s southern suburbs. The clinic offers a wide range of procedures including diagnostic studies, angioplasty procedures (with stents) and pacemaker procedures.

Learn more about our clinic, cardiology procedures, and what to expect if you’ll be visiting us for a procedure.

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