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About EPS

Cardiac Electrophysiology (EPS) is the study of normal and abnormal electrical behaviour of the heart. There are generally 3 reasons that an electrical study of the heart will be considered.

  1. To get to the bottom of unexplained blackouts;
  2. To assess the mechanism and potentially cure a racing rhythm (tachycardia);
  3. To assess the risk of life threatening rhythms (ventricular tachycardia / fibrillation) occurring in the future e.g. in the context of prior heart muscle damage.

An EP Study is an invasive electrical examination of the heart. The results will help you and your cardiologist determine whether you need medication, an ablation, a pacemaker, an Implantable Cardiac Device (ICD), or surgery.

Pre-operative Preparation


Most medication should be continued as usual, but some may interfere with the operation. Your cardiologist will inform you of the medication you should stop. As a guide, the following medication may require special instruction:

  • Aspirin (or any related products);
  • Blood thinners (Warfarin, Heparin);
  • Arthritis medication;
  • Pain medication;
  • Anti-inflammatory medication;
  • Insulin.

Don’t forget to mention any homeopathic or herbal remedies you are taking, as these can have interactions and side effects too.


In most cases you will be required to fast (no food or drink) for six to eight hours prior to the procedure. You can take your usual medications with a small sip of water early on the morning of the procedure.



Each individual EPS can greatly vary in length. Your doctor will discuss this with you prior to your procedure.

Cardiac Catheter Laboratory

The procedure is performed in the Cardiac Catheter Laboratory where X-ray equipment is available to guide us.


We use a sedative to make you drowsy and comfortable, but general anaesthesia is rarely required. Many patients, however, sleep through the whole thing.

Operative Procedure

1-4 catheters (electrical cables) each about 2mm diameter are passed up and into the chambers of the heart. We might position them in the right atrium, near the AV node, in the ventricle and in the heart’s own draining vein (coronary sinus) which runs around the back of the heart to help us identify any of the extra connections (bypass tracts). With the catheters in place we can both record electrical activity (shown on a video screen) and stimulate the heart at various locations.

We can then assess the conduction properties, presence of extra connections and try to bring on the patient’s tachycardia. In the case of curable arrhythmias (SVTs, VTs, atrial flutter and atrial fibrillation) a radiofrequency ablation (RFA) may be performed.

Post-operative Care


The catheter insertion site, heart rhythm and basic vital signs such as blood pressure, pulse and breathing will be carefully monitored usually for four hours following the procedure.


Before you are discharged from hospital, you will be advised on matters such as wound care, medication changes and level of activity. If you are discharged on the same day, you will need to arrange for someone to escort you home, and where possible, have someone stay with you overnight. Please advise us if this is a problem.

Your doctor will advise on any symptoms where you should seek immediate help. These may include symptoms such as chest pain, and bleeding, discharge or excessive pain from the insertion site.

Follow-Up Appointments

Your doctor will advise on when your follow up appointment is required and one of our staff members will be in contact to make the booking.