Cardiac electrophysiology

An electrophysiological (EP) study is a test to see how your heart's electrical system is behaving. 

The results of this will help us to treat you. Treatment might include you having a pacemaker or defibrillator, or performing a procedure to remove excess tissue (radiofrequency ablation).

What happens during the electrophysiological study?

One of our nurses will check your blood pressure, pulse, temperature and oxygen levels. They may need to also take a small sample of blood to make sure it is not too thin.

A small tube (cannula) will be inserted into a vein in your arm, so that you can be given sedation and other drugs directly into your blood stream.

You will be asked to remove any dentures just before the procedure. Please tell us if you have any capped or loose teeth.

You will be taken to the cardiac catheter lab for the study.

You will be awake so you will be given a local anaesthetic and possibly a mild sedative. You will need to lay flat during and you will be asked to lie as still and relaxed as possible.

A small tube (plastic catheter) will be inserted through a vein in your arm or leg and advanced until it reaches your heart. Using special x-rays called fluoroscopy to guide the catheter, it will be positioned in the correct area of the heart. Fine wires are then positioned within the heart.

From these wires, electrical activity from specific areas of your heart is able to be recorded. Extra beats are given via a pacemaker, which may bring on your palpitations, as a result, you may feel uncomfortable. The rhythm can be restored again quite quickly by giving extra beats.

A pacemaker is a device that monitors your heartbeat and prevents your heart from beating too slowly. 

The pacemaker looks like a box with two wires attached to it. We surgically insert this into your body underneath the skin or muscle beneath your collarbone. The wires pass inside the large veins of your chest from the box to your heart which transmits information about your heartbeat.

If your heart beats too slowly the pacemaker sends out a tiny electrical impulse to 'pace' the heart, making it beat at the right speed. If your heart speeds up again, this is detected by your pacemaker, which then stops pacing your heart.

If you have a pacemaker and have a question, you can find out more information on our Pacemaker and ICD patients page.

Normally all parts of the heart beat at the same time. However, in most heart failure cases this happens because the main pumping chamber (left ventricle) of the heart is not beating well enough, causing a delay. This makes the heart less effective as a pump.

The aim of cardiac resynchronisation therapy (CRT) is to stimulate the main pumping chamber, improving its function and restoring your heartbeat back to normal. 

If you have rapid, uncoordinated heartbeats (also known as tachy arrhythmias) we can treat this using radiofrequency ablation. 

Radiofrequency ablation is a source of energy that is delivered down a wire to target the area in the heart that has been causing your palpitations. This could be hot to burn away the tissue or cold to freeze the tissue. 

This will be performed under local anaesthetic. The complexity of your procedure will determine if you will need to stay overnight or if you can go home on the same day.

An Implantable Cardioverter Defibrillator (ICD) acts as a constant heart monitor. A box is implanted under your skin, usually near the collarbone and leads from it are attached to your heart. These leads detect the heart's rhythm, and feed this information back to the box.

The ICD monitors the speed of your heartrate. If your heart goes above or below the set rate, it's programmed to deliver pulses of energy to your heart to bring it back to normal function.

The treatment may be pacing therapy or shock therapy. It will continue to treat until either the heart rhythm goes back to normal or until all treatments have been delivered.

When your heart rhythm returns to normal on its own, then the ICD will switch back to 'monitor' mode and will cease treatment.

If you are a patient with this device and have a question, you can find out more information at Pacemaker and ICD patients.

A Trans oesophageal echocardiogram (TOE) is a detailed ultrasound image of your heart done by using a long flexible probe that is passed into your mouth and down your food pipe.

This helps our specialists to see your heart chambers and valves which allows us to examine how efficiently they are working. 

This procedure provides the most accurate information when diagnosing:

• Infection of the heart valves (endocarditis).
• The need to repair or replace the valve, or whether the valve needs stretching (valvuloplasty).
• A blood clot (thrombus) in the heart chambers.

The procedure is performed as a day case, under sedation. You will be able to go home two to three hours after the procedure.

Arrhythmia is a term used to describe a number of conditions where the muscle contraction of the heart is too slow, too fast or irregular because of a disturbance with the heart's normal electrical activity

Ectopic beats are early beats that frequently cause palpitations and are described as missed or extra beats. These are not normally dangerous and don't damage the heart.

Atrial fibrillation (AF) is the most common type of unusual heart rhythm that involves rapid and irregular activity in the top part of the heart (atria). 

Due to this, the bottom main pumping chamber of the heart (ventricles) are often fast and irregular too in order to try to keep up.

AF can start and stop on its own after seconds, minutes or even hours. This is known as paroxysmal AF.

Persistent AF is where this occurs but does not stop unless treated medically, usually by medicines or a small electric shock (cardioversion).

If this does not work and you still have an irregular heart beat, this is known as permanent AF.

Atrial flutter

Atrial flutter involves the top chambers of the heart beating very rapidly, as electricity circulates around them.

It arises from the top chamber on the right side of the heart. Electricity circulates around this chamber and drives the main pumping chambers at a fast rate, often 100 to 150 beats per minute.

Atrial tachycardia

Atrial tachycardia is condition of rapid palpitations that is often seen in patients with a heart disease. However, it may still occur in if you have a normal heart.

It comes from a small area (focus) of tissue in the top part of the heart. This starts to fire and drive the heart more rapidly than the heart's natural pacemaker. Usually, the focus fires only now and again (this is sometimes known as paroxysmal atrial tachycardia) but occasionally it can continue for days or even persist for months at a time.

Ventricular tachycardia (VT) is a fast rhythm that starts in the bottom chambers of the heart (the ventricles) and leads to the heart beating not very well. 

Symptoms including palpitations, breathlessness, chest pain and dizziness are a result of this. Rapid ventricular tachycardia may lead to loss of consciousness and turn into ventricular fibrillation, causing cardiac arrest.

Common causes of VT are coronary disease and cardiomyopathy. It is commonly seen in patients who have suffered a previous heart attack and in this case, it may be life-threatening. However, it can also occur even if you have a normal functioning heart. If this is the case, this may be because of a genetic condition. 

The majority of patients who die suddenly and unexpectedly have coronary artery disease.

In patients 35 years and under, may have one of the less common heart conditions which is often inherited unknowingly. These include hypertrophic cardiomyopathy, long QT syndrome and the recently recognised Brugada syndrome.

This is where the heart fails to be able pump blood around the body properly. It's a progressive disorder affecting many organs and systems in the body. 

People with heart failure may experience a limitation in exercise capacity with symptoms of breathlessness and fatigue.