The results of your electrophysiology study (EPS) may show that you have an area within the heart capable of generating/conducting abnormal electrical beats. In such cases it is possible to permanently interrupt this abnormal rhythm and to provide a potentially permanent cure for your arrhythmia. This procedure is known as a Catheter Ablation. It is achieved by delivering energy through a catheter positioned in the area of the abnormal signal to cauterise the cardiac tissue there. Depending on your specific arrhythmia, your consultant might need to enter the left side of your heart either by puncturing your artery or the septum of the upper chambers of the heart. Your consultant will use the ablation catheter to deliver a small amount of energy (hot or cold) onto the area of extra electrical activity to create a scar.

In many cases it is possible to proceed to the ablation procedure immediately following the EPS. The doctor will discuss the results of the EPS with you and the possibility of proceeding if appropriate. Patients undergoing ablation stay in hospital overnight after the procedure during which time your heart rhythm will be monitored.

You will be required to fast for six hours prior to your procedure, unless you are told otherwise.

If you are female you must inform the staff if there is any chance that you may be pregnant.

You must arrange to be collected on discharge, as you are not allowed to drive or travel home unaccompanied.

If a catheter ablation needs to be performed you will require an overnight stay. Your doctor will discuss this at the time with you.

When arranging your appointment, please tell us about any medication you are taking and discuss any instructions with your doctor.

If you are on heart rhythm medications you may be told to stop taking them for three to four days before your procedure. Your doctor will discuss this with you.

Unless your doctor tells you differently, medications should be taken as usual.

If you are taking a blood thinner, you should skip taking this on the morning of the procedure.  If you are taking Warfarin you should ask your doctor about stopping it.

Please inform the staff if you are aware of any allergies, as you might receive medication during the procedure.

In general you do not need to be put asleep for this procedure.  You will receive some sedation, which will be given through a drip in your arm to help you relax.

A local anaesthetic is applied to the top of the leg/groin area – both sides may be used.  Once the area is numb, a puncture is made through which a needle is inserted into a blood vessel.

A catheter is passed through a sheath and gently advanced through the blood vessel to the heart. These special wires will record the electrical signals from inside your heart

Once the catheters are in place, your consultant will attempt to start your arrhythmia by giving your heart small electrical impulses to make it beat at different speeds.

During the test you may be aware of your heart rate speeding up, slowing down and missing a beat.  This allows the doctor to collect detailed information about the cause of your arrhythmia and pinpoint where the area of extra electrical activity responsible for your arrhythmia is within your heart.

If the test initiates the abnormal heart rhythm, you may feel the symptoms that you have been complaining of.

During the procedure you may be given a special drug through a drip which also helps to stimulate your abnormal fast heart rhythm. The doctor can terminate the tachycardia by using pacing.

In the very unlikely event of a dangerous, life-threatening heart rhythm occurring, it may be necessary to give you an external defibrillation shock. If you need this treatment your consultant will give you more sedation.

If you do have any uncomfortable symptoms during the procedure, for example chest pain, dizziness or shortness of breath, please inform the nurse. It is important for your consultant to know how you feel when you have your arrhythmia.

Strict bed rest is required for four to six hours after the completion of the electrophysiology study.

You will be asked to limit leg movement on the puncture site(s) to reduce the risk of bleeding.

The nurse will inspect the puncture site to ensure there is no bleeding.

You may go home after 4 to 6 hours, or as directed by the Consultant.

The catheter ablation will add an additional time to your procedure and you will be advised to stay in the Hospital for the night

If you had a catheter ablation, you are restricted from driving for two days following your procedure as per the "medical fitness to drive" guidelines by the Road Safety Authority.

Risks may vary according to the need of ablation therapy and to the actual type of arrhythmia. A diagnostic electrophysiology study (EPS) itself carries a very low risk.

The procedure is simple and safe, and usually is relatively painless, though minor discomfort such as the following may occur:

• Possible discomfort when injecting local anaesthetic
• Bruising, mild soreness or mild oozing from the puncture site(s)
• Some bruising around the puncture site following the procedure is usual
• If bleeding, a pressure dressing may be placed on the wound to stop it. On very rare occasions the wound may need to be reopened to remove collected blood and treat the source of bleeding
• Possible reaction to medications administered

Very rare complications occur in less than 1-in-500 cases:

• Infection of blood, heart valve or puncture site
• Pseudo aneurysm or arterio-venous fistula
• Phrenic nerve injury
• Damage to the blood vessels that might need surgical correction
• Aortic dissection
• Deep venous thrombosis
• Bleeding around the heart (Cardiac Tamponade) requiring emergency corrective surgery
• Damage to the normal electrical pathway may occur requiring placement of a permanent pacemaker

Extremely rare complications occurring in less than 1-in-1,000 cases:

• Heart attack
• Pulmonary embolus
• Stroke
• Death