Electrophysiology

Diagnostic Electrophysiology studies

What are diagnostic studies?

Diagnostic electrophysiology studies (EPS) are tests conducted on the heart to determine the cause of abnormal heart rhythms (arrhythmia's). These tests are also used to determine causes of blackouts.

EPS can also give an indication as to which of several alternative treatments for these conditions is most suitable and most likely to work.

What is involved in the procedure?

EPS is a minimally invasive key-hole procedure where electrodes are guided via a catheter (a thin tube) from an entry point (normally a blood vessel in the groin) up into the heart. The doctor will then make the heart beat at different speeds by sending small electric pulses into the heart from the electrodes. The electrical signals of the heart are recorded in a process called 'cardiac mapping' which may indicate what is causing the irregular heart rhythms.

Sometimes treatments can be given at the same time (for example radiofrequency ablation) after the doctor has determined the cause of an arrhythmia. The whole procedure lasts approximately 1 hour (and longer if additional treatments are performed).

Often only a light sedation is used along with a local anaesthetic at the point of entry of the catheters. After the procedure is complete and the catheters have been removed, you will need to stay under observation in a recovery room for a further 4 hours until you are cleared to go home. If an ablation has been performed, you will be kept on a monitor in hospital until the following day. 

As you have received sedation, make sure you have someone to drive you home afterwards. The doctor will give you guidance on what you need to do and look out for when you are at home.

How should I prepare for the procedure?

You should not eat or drink anything in the 6 hours before the procedure. You must tell the doctor about any medicines, vitamins or supplements you are taking and they will be able to advise whether you should stop these or not.

Radiofrequency ablation

What is radiofrequency ablation?

The medical term 'ablation' means the surgical removal of body tissue. Radiofrequency ablation (often shortened to 'RFA') is a procedure where a radiofrequency electric current heats a medical device which is then used to cauterise a very small section of the heart muscle. It is also referred to as 'cardiac ablation' or 'cardiac catheter ablation'.

When is radiofrequency ablation used?

Typically patients with either supraventricular tachycardia or atrial fibrillation/flutter, where other treatments have not been effective, can benefit from an ablation.

What is involved in the procedure?

RFA involves the insertion of an 'ablation catheter' (a thin tube) via a blood vessel in the groin, which is then fed through into the heart. The tip of the catheter then delivers a controlled amount of heat to the target section of heart tissue.

Most patients are under anaesthetic during the procedure although it may be necessary to wake you if your surgeon cannot detect the heart arrhythmia while you are asleep. The procedure normally takes between 2 and 6 hours.

How do I prepare before the procedure?

You will be given information on what you must do before the procedure. You will need to avoid any food or drink for 6 hours prior to the procedure.

What happens after the procedure?

After the procedure is complete, you are moved to a recovery room where your heart activity and blood pressure are constantly monitored untill the following day.

You will be given guidelines in terms of what medication to take, the amount of physical activity to do and how to care for the small wound at the catheter insertion point.

Pulmonary vein isolation

What is pulmonary vein isolation?

There are four pulmonary veins in the body and their function is to bring oxygenated blood from the lungs and deliver it to the left atrium of the heart so it can be pumped around the body - each lung has two pulmonary veins.

A pulmonary vein isolation (PVI) is a key-hole procedure where a ring of tissue around the pulmonary veins is cauterised, which has the effect of preventing electrical impulses from the veins affecting the heart.

It is a common treatment for Atrial Fibrillation where medications have not been effective.

What is involved in the procedure?

In a procedure very similar to the radiofrequency ablation procedure (RFA), a catheter (thin tube) is inserted through a blood vessel in the groin, and moved up into the heart close to the pulmonary veins. The treatment may be use either RFA or a process known as cryoablation, which involves freezing the section/s of the heart that need to be treated.

Please see the section on radiofrequency ablation for more information on what is involved in the procedure, how to prepare for it and what to expect afterwards.