Catheter ablation is a procedure in which a thin, flexible tube or catheter is inserted into a blood vessel in your arm, neck or groin. These catheters are then threaded through the blood vessel to the heart. The doctor can then apply radiofrequency energy, laser energy or freezing temperature (cryoablation) to destroy the abnormal heart tissue which causes the arrythmia or irregular heart beat.
Catheter ablation is considered a minimally invasive procedure since there are no incisions made to the chest wall to access the heart. Therefore, it is a relatively simple and routine procedure that carries a low risk to patients.
How does catheter ablation work?
The movement of the catheter is controlled externally by the physician. With the help of computer software, the areas which are affected are identified. Depending on which procedure is to be performed, the catheter will be fitted with electrodes or a cryoballoon system.
Radiofrequency Catheter Ablation
Radiofrequency catheter ablation directs radiofrequency energy through a catheter to the areas of heart tissue that cause erratic electrical signals. Scarring the tissue will correct the arrhythmia. In other cases, catheters that freeze the heart tissue, known as cryotherapy, can be used to get the same result. In radio frequency catheter ablation, the physician will use short bursts of intense energy to scar dysfunctional tissue which will stop it from sending disruptive electrical signals
Cryoblation (Cryoballoon Ablation)
Cryoballoon ablation is a balloon-based technology that blocks the conduction of the arrhythmia in cardiac tissue through the use of a coolant rather than heat, by way of a catheter. This freezing technology allows the catheter to adhere to the tissue during ablation, allowing for greater catheter stability. Cryoablation is a new and alternative method that uses freezing temperatures on targeted areas around the pulmonary veins. This method is favored by many physicians because it can be performed temporarily and tested for effectiveness before the arrhythmia site is scarred permanently.
When is the heart ablation surgery done?
- When medicine doesn’t control the irregular heartbeat or you can’t tolerate the medicine needed to control the arrythmia
- When you are diagnosed with atrial fibrillation or Wolff–Parkinson–White syndrome
- When you have abnormal electrical activity that put you at risk for life threatening arrythmias such as ventricular fibrillation and sudden cardiac death
What can I expect before the procedure?
Catheter ablations are performed in the hospital under the direction of the electrophysiology doctor and his staff. In some instances, when an ablation is done during open heart surgery, then the cardiothoracic surgeon will perform the procedure.
When you arrive at The Heart Institute you will be greeted by our nursing staff who will get you prepared for the procedure, and provide you with a hospital gown. You will then meet with your doctor to discuss last minute questions you may have.
Catheter abaltion is generally performed under sedation with local anesthetic, without putting you to sleep. The anesthesiologist will be on-site throughout the procedure to ensure you are comfortable. General anesthetic will be used in certain circumstances, particularly if the patient is a child. You can expect the procedure to take anywhere from 3-6 hours.
You will notice a fluroscopy machine above you that X-rays your chest so that your physician can monitor the position of the catheter. Your physician will also see detailed ultra-sound images transmitted from sensors in the catheter. He will then use one of the energy forms to destroy the area where the abnormal beats are starting.
What happens after the Catheter Ablation?
Afterwards, you will be expected to lie still for 4-6 hours in a recovery room. Some people go home that same day where others may be required to stay overnight or a few days. During this time you may feel tired or dazed as you recover from the sedative. You may have some pressure bandages covering the catheter incision site.
You may need to make arrangements for transportation the day of the procedure since your doctor may advise against driving.
Recovery from catheter ablation is quick, although you may feel some soreness at the site of the catheter. Your doctor will give you instructions, if needed. Most people will return to their normal activity within a few days.
What are the risks?
Some of the risks, though they are few, include:
- Bleeding at the catheter insertion site
- Damages to blood vessels or perforations
- Damage to the heart’s electrical signals from over-ablation
- Pain at catheter insertion site
- Post-operative blood clotting
- Allergy to contrast dye used
This procedure carries varying degrees of success. Ablation alone doesn’t always restore normal rate and rhythm. Other treatments may need to be used in addition and sometimes the ablation may even need to be repeated.
Rotablation is a process of scrapping or removing plaque and fatty deposits from the walls of the coronary arteries. A small drill with a burr on the end, coated in diamond dust, rotates and spins at high speeds to slowly break up the blockage.
The rotablator drills through the calcified plaque, breaking it up into small particles, which are safely picked up by the bloodstream and eventually eliminated.
A similar procedure called an atherectomy also removes plaque deposits (dense calcium). However, the rotablation technique leaves smaller shavings that can be expelled naturally and can be used on more extensive areas. The rotablation technique is less invasive and can be used multiple times along the stretch of a single artery.
Rotablation is also known as percutaneous transluminal rotational atherectomy or PCTRA.
This treatment can be conducted two ways, by sending an electric current to the heart or by using anti-arrhythmia medication. Some patients may need to take blood-thinning medication before and after cardioversion.
The maze procedure utilizes a scalpel to make several precise incisions that create a pattern of scar tissue, blocking the abnormal electrical impulses that cause atrial fibrillation. Radiofrequency and cryotherapy can also be used to create the scars, as these are variations of the surgical maze technique. Generally, this procedure is reserved for those who don’t respond to other therapies or when it can be done during other heart surgery. Some people may require a pacemaker insertion.
AV node ablation
AV node ablation applies radiofrequency energy to the pathway connecting the upper and lower chambers. When applied, the atria are prevented from sending electrical impulses to the ventricles. The atria will continue fibrillating and will require anticoagulation medication. A pacemaker will also be inserted to establish normal rhythm and to regulate the heart rate. This type of ablation is typically reserved for people with serious symptoms or when other treatments have failed.
PVAI (pulmonary vein antrum isolation)
Pulmonary vein ablation, also called pulmonary vein antrum isolation, is another procedure in which energy is delivered through the tip of the catheter to tissue that is targeted for ablation. The energy is applied around the connection of the pulmonary veins to the left atrium. Small circular scars are formed within two to three months blocking any impulses firing from within the pulmonary veins and isolating them from the heart. If successful, PVAI eliminates the need for medications.
In some cases, when heart rate cannot be converted, a combination of medications may be prescribed to slow the heart rate down.
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