Cardiac Catheter Ablation

What is a Cardiac Catheter Ablation

A Cardiac Catheter Ablation (commonly known as an ‘ablation’) is a minimally invasive procedure performed by an Electrophysiologist Cardiologist (known as an EP). An EP is a cardiologist who has undergone additional years of training to specialise in diagnosis and treatment of rhythm problems of the heart. An ablation procedure is used to treat abnormal heart rhythms. It targets and treats areas of the heart that are contributing to abnormal heart rhythms (arrhythmias).

A Cardiac Catheter Ablation procedure is used most often to treat a condition called supraventricular tachycardia, or SVT, which is irregularly fast or erratic heartbeat. Catheter ablation is also used to help control other heart rhythm problems such as atrial flutter and atrial fibrillation (AFib or AF).


Cardiac Catheter Ablations uses small diameter catheters (like thin wires) which are passed into the heart usually from the vein in the leg. The catheter is guided to the specific site in the heart where the abnormal electrical signals have been arising. Once in location, the ablation catheter is able to deliver energy to specific sites in the heart, deliberately causing targeted damage to the muscle / nerve bundles which are contributing to arrhythmia.

The electrical energy causes a small burn in the heart muscle which is in direct contact with the electrode. This very targeted ablation does not damage the surrounding heart muscle; it just renders a small section of problem causing tissue inactive, stopping the abnormal heart rhythm.

In the weeks that follow after the ablation, the damaged heart muscle heals with fibrous scar tissue which creates a barrier to stop the abnormal electrical signals that cause arrhythmias. Sometimes a patient may need two or more cardiac ablations to manage their symptoms effectively.

There are two common types of catheter ablation procedures: Radiofrequency Ablation and Cryoablation

  1. Radiofrequency Ablations use hot energy to burn. There is a very fine tip at the end of the catheter that uses radiofrequency energy (a bit like a microwave) to create heat. The EP uses this to make a series of individual burns in a line where the ablation needs to occur – usually in a circle around the pulmonary veins within the atrium.
  2. Cryoablation uses cold energy to burn. The cryoablation catheter has a special design with an inflatable balloon at the end. The EP positions the catheter near where the pulmonary vein enters the atrium and inflates the balloon. As the balloon inflates, it makes contact with the tissue in a circle around the pulmonary vein – precisely where the ablation needs to occur. Once the balloon is positioned correctly, then it uses extreme cold to create the ablation – down below minus 40 degrees Celsius.

At QCG, we have access to both of these technologies and use them widely. Both types of ablation have a similar success rate. The choice of type of ablation depends on several factors, related to you as a patient, as well as the availability of the technology at particular hospitals or session times, and the EP’s training or preference.

How do I prepare for a Cardiac Catheter Ablation procedure

You will be required to fast for six hours prior to the Cardiac Catheter Ablation procedure. You may also be required to take a blood thinning medication for a few weeks prior to the procedure. Your cardiologist will advise you on which medication you should cease prior to the procedure, but generally you will stop taking any arrhythmic medications a few days prior. You may also be required to have a CT Coronary Angiography (CTCA) scan just before the procedure.

What happens during a Cardiac Catheter Ablation procedure

A small incision is made in the groin or neck area and thin, and flexible wires (catheters) are passed through the vein and advanced to the heart under X-ray guidance. Special equipment that creates 3D images of heart chambers is often used in these procedures.

Once the catheters reach the heart, electrodes at the tips of the catheters gather data which detects electrical signals from different parts of the heart. This data pinpoints the location of the tissue causing the arrhythmia. Once the source of the arrhythmia is confirmed, energy is used to destroy, or ablate, that tissue, putting an end to the disturbance of electrical flow through the heart and restoring a normal heart rhythm. This energy may be intense cold, which freezes, or cryoablates, the tissue, or radiofrequency energy, which burns the tissue.

The procedure is not painful, though some patients have reported feeling a slight discomfort.

What happens after a Cardiac Catheter Ablation procedure

You will be required to lie flat for 6 hours after the procedure to prevent any potential bleeding from the incision site in your groin. It is normal to have some bruising and discomfort around the incision site. You may also experience some minor chest discomfort.

You will stay in hospital overnight for monitoring, and will generally be discharged in the following day or two.

You will be advised to avoid any strenuous activities and exercise in the few days following your procedure. Most people resume their normal activities after the first week.

You will remain on blood thinning medication for three months after your procedure, and sometimes longer. You will also continue to take any arrhythmic medications as advised by your cardiologist.

Catheter Cardiac Ablations Frequently Asked Questions

While cardiac ablation is a form of surgery, it is considered a minimally invasive procedure that involves a lower risk of complications and a shorter recovery period than traditional open-heart surgery. However, it still requires specialised training and expertise (an electrophysiologist cardiologist) to perform and should be considered a serious medical intervention.

Many patients are eager to know if the ablation has been successful in treating their AFib. Unfortunately, it can take a while to know this answer.

Immediately after an ablation, the tissues in the heart will be irritated, and it will take a while for them to recover. The areas of ablation will slowly form scar tissue which is part of the benefit of the ablation and this can take weeks to months. As a result of the time it takes for the heart to settle and heal properly, it can take approximately three to six months after an ablation to reach the full benefit of the procedure. This period is commonly referred to as the ‘blanking period’.

During this time, an occurrence of atrial fibrillation doesn’t necessarily mean that the ablation has failed. The blanking period is a stabilisation period after an ablation, during which a patient’s AFib ‘quiets down’. This can particularly be the case for people who have more persistent AFib or had longer periods of AFib prior to the ablation.

Talk to your EP about any episodes of AFib you have in the 3 months after an ablation. Your EP may want to adjust your medication or they may want to do a cardioversion to bring you back to normal rhythm while you are healing.

If your ablation is performed at a well-regarded medical hospital, with highly-trained EPs, nurses, and technicians, like the team at QCG, then the risks of complications are very, very small. Extremely rare risks of ablations include bleeding, infection, and/or pain where the catheter was inserted.

There is a risk of blood clots (which is very rare), which can travel to the lungs or brain and cause a stroke. To reduce this risk, the EPs at QCG may perform a Transoesophageal Echocardiogram (or TOE) before starting an ablation. This enables them to obtain a clear picture of the inside of the heart and ensure that there are no existing blood clots that have formed inside the heart before they start the procedure. Another test that can be used to detect or rule out the presence of a blood clot is a CT scan of the left atrium. The CT scan is commonly done before an atrial fibrillation ablation to obtain a 3-dimensional image of the left atrium for use in the ablation procedure.

It is very important for your blood to be “thin” to reduce the risk of clots and strokes. You will be fully anti-coagulated during and after the procedure, with blood thinners administered via your “drip”, along with your orally-taken blood thinners.

As with any medical procedure, you should discuss the risks and benefits of cardiac ablation with your doctor to understand if this procedure is right for you.

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