Electrophysiology study

The heart needs electrical impulses to make it beat. The normal heartbeat is initiated by an electrical impulse from the sinoatrial node (the heart’s natural pacemaker), which send signals for the heart muscle to contract and produce a normal heartbeat.

The signal starts from a node called the sinoatrial node (SA node) and sends an impulse to the atrioventricular node (AV node). After crossing this node the signal travels down special fibres to make the heart contract. However, the paths the impulses take can become altered so the heart beats too quickly (tachycardia) or too slowly (bradycardia).

The electrophysiology study is used to diagnose heart rhythm disorders. The study involves passing several electrodes (wires) through the veins to the heart to record the electrical impulses. The electrodes are first inserted into a blood vessel in the groin. The recordings from different places in the heart, and the responses to electrical stimulation from the electrodes, allow detailed information about the cause of the disorders to be identified. The study provides much more detail than an electrocardiogram.

During the electrophysiology study, we try to stimulate the heart into an abnormal rhythm. This is vital for the test, and in the controlled setting of an electrophysiology study it is not a danger to you. This test is performed while you are being X-rayed, so if you think you may be pregnant you should let us know before the study.

It is common to get bruising in the groin after the electrophysiology study. However, this usually disappears within a week and does not cause a problem. More serious complications are extremely rare. Sometimes your heart may go into a different rhythm that stops us from continuing with the study. In this situation we will shock the heart, after first giving you a brief anaesthetic. Once your heart rhythm is regular again, we will continue with the procedure.

If you are already taking medication for your heart rhythm disorder, we may ask you to stop taking the medication three days before the study. This can allow a better assessment of the heart rhythm. And if you take warfarin, it is usually best to stop taking it two days before the study. You may also be told to take an extra aspirin before or after the procedure.

You should have a bath or shower on the morning of the test. And you should have nothing to eat for six hours before the study, and no fluids for two hours before the study. Before coming into hospital, please shave the hair on both sides of your groin (the hollow at the top of the thigh where the leg meets the lower abdomen), as this is where the tube is passed into the blood vessel at the top of your leg. If you are concerned about shaving, you can be supervised doing it on the ward.

When you get on the ward you will be introduced to the nurse who will be looking after you. He or she will sit and talk to you and your family about your visit to hospital and answer any questions you have.

The doctor will also see you and discuss the procedure with you. He or she will ask you to sign a consent form. This is to make sure you understand the procedure and its side effects. If you have any worries or questions at this stage, do not be afraid to ask. If you have any allergies or have had bad reactions to any drugs or other tests, tell the nurse or doctor.

The nurse will give you a hospital gown to put on. The doctor or nurse will need to insert a small needle in the back of your hand to allow any drugs to be given to you during the procedure.

You will be wheeled to the investigation department on your hospital bed.