Cardiac ablation is a specialized cardiac catheterization procedure used to treat various cardiac arrhythmias, when those arrhythmias cannot be managed adequately with drug therapy or other forms of treatment. During cardiac ablation procedures, careful computerized mapping is done of the heart’s electrical system to identify specific areas that are responsible for the arrhythmia. Once the target area is mapped out, it is ablated (that is, the tissue is damaged) by applying either radiofrequency energy (electrical energy) or cryothermal energy (freezing energy) through a catheter, in order to create a tiny scar. Because scar tissue is electrically inert, a strategically-placed scar should prevent the arrhythmia from recurring.
Purpose of Cardiac Ablation
Cardiac ablation procedures are aimed at eliminating certain kinds of cardiac arrhythmias.
Ablation procedures are worth considering any time a person has a cardiac arrhythmia that meets both of these criteria:
- The arrhythmia is disruptive to their life (because it causes recurrent bouts of symptoms such as severe weakness or lightheadedness), or because it is life-threatening.
- The arrhythmia cannot be managed adequately with drugs or other kinds of treatments,
How Do Ablation Procedures Work?
The underlying mechanism of cardiac arrhythmias often renders them amenable to ablation therapy. Many cardiac arrhythmias are produced by an “irritable focus” in the heart that can start rapidly firing off electrical signals (so-called By creating a scar at the irritable focus, the arrhythmia can be eliminated.
Other arrhythmias are caused by abnormal electrical pathways in the heart in the heart that form a potential electrical circuit An electrical impulse can become “trapped” within this circuit, spinning around and around, and causing the heart to beat with each lap. With this kind of arrhythmia, a well-placed scar can interrupt the circuit and prevent a re-entrant arrhythmia from starting up.
So, with either of these two mechanisms (automatic or re-entrant), the arrhythmia is potentially treatable if a scar can be precisely placed. The ablation procedure aims to create this precise scar.
As an aside, cardiac ablation can also be used, as a last resort, that is causing a rapid heart rate that has proven to be refractory to drug treatment. In this case, the ablation is used to create A permanent pacemaker is placed at the same time to allow a normal heart rate despite the new heart block.
Which Arrhythmias Can Be Treated With Ablation?
Ablation is at least potentially useful with a wide variety of cardiac arrhythmias. These include:
The success rate with ablation for some of these arrhythmias is high enough that ablation ought to be considered as a potential first-line therapy,1 that is, as treatment that can be reasonably prioritized even ahead of drug therapy. These arrhythmias include atrial flutter, Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and some cases of ventricular tachycardia. For such arrhythmias, ablation procedures are completely successful in well over 95% of cases.
Risks and Contraindications
The risks of cardiac ablation include:
- Blood vessel injury
- Blood clots
- Cardiac damage, possibly requiring surgical repair
- The generation of new arrhythmias
- Inadvertent heart block, requiring a pacemaker
In addition, because cardiac ablation requires fluoroscopy for the positioning of catheters within the heart, there is a variable amount of radiation exposure (depending on the specific type of ablation being performed).
The overall risk of having one of these complications is about 3%. However the risk of actually dying from this procedure is about 1 out of 1,000. 2
While the risk is statistically low, it is real. This is why ablation procedures should be done only when the arrhythmia itself (or alternative therapies for the arrhythmia) are highly disruptive to your life, or life-threatening.
Cardiac ablation procedures should not be done in people who have:
- Ongoing infections
- Major bleeding problems
- A cardiac mass or blood clot
Before the Procedure
Cardiac ablation procedures are performed by cardiac electrophysiologists, cardiologists who have specialized in the management of cardiac arrhythmias. You and your electrophysiologist together will decide whether cardiac ablation is a good option for you, based on the arrhythmia you have, the problems it is causing or may cause, and the other treatment options that may be available to you.
The electrophysiologist will perform a complete medical history and physical exam, and review all available medical records pertinent to your arrhythmia, especially any electrocardiograms that have “captured” your arrhythmia.
Before deciding whether an ablation procedure is right for you, it may be necessary to have preliminary cardiac testing, most likely including possibly (to confirm the nature of your arrhythmia) and/or In some cases, a standard cardiac catheterization may be needed as well.
During your discussion with the electrophysiologist, it is important to make sure you talk about all your other treatment options, the expected chance of success, whether you have any particular risk factors that may make ablation more risky in your case, and what you are likely to experience during and after the procedure.
Once the decision is made to proceed with the ablation procedure, your doctor’s office will give you specific instructions on how to prepare. You should make sure you specifically clarify which of your medications you should take on the day of the procedure, and whether any of your medications (even over-the-counter medications, such as aspirin), need to be stopped in the days before the procedure.
You may or may not be required to stay in the hospital overnight after an ablation procedure. Discuss this with your doctor ahead of time.
The duration of an ablation procedure is highly variable. For many arrhythmias, the procedure itself can be completed in less than an hour. For more challenging arrhythmias (most typically, for atrial fibrillation), the ablation procedure may last as long as six hours. You should ask your doctor to estimate the duration of your specific procedure during your pre-procedure discussion.
If you are being discharged the same day, you will be able to go home an hour or so after the end of the procedure.
Cardiac ablation procedures are typically performed in specialized cardiac catheterization laboratories, which are almost always located in hospitals.
What to Wear
You can wear anything you want on the day of the test, but since you will be changing to a hospital gown it is best to wear loose clothing that you can get on and off easily. It is best not to wear any jewelry for the procedure, and many hospitals have rules that prohibit jewelry (even wedding rings) during these procedures.
Food and Drink
The ablation procedure needs to be performed while your stomach is empty. Typically, you will be asked to fast for eight to 12 hours before the procedure. You should get specific instructions regarding food and drink from your doctor’s office.
Cost and Health Insurance
The cost of a cardiac ablation procedure varies tremendously, but it is always very expensive (many thousands of dollars). Medical insurance almost always covers this procedure, but you may need pre-approval by your insurance company before it can be done. Your doctor’s office can usually help you with this.
What to Bring
If you are staying overnight in the hospital, bring some comfortable slippers, pajamas, and something to read.
You will need to arrange for someone to drive you home, either the day of the procedure or at the time of your hospital discharge.
During the Procedure
When you check in on the day of the procedure, you will first have to complete some administrative processes. You will be asked to produce your insurance card and identification, and will have to read and sign several forms (such as insurance forms and consent forms) pertaining to the procedure.
You will then be directed to a prep area. There, you will change into a hospital gown and turn over your street clothes for storage. You will then be interviewed by one of the medical staff members, often a nurse, about your medical conditions and medication, especially focusing on any changes that may have occurred since your last discussion with the electrophysiologist. The ablation procedure will then be explained to you once again, and you will have the opportunity to ask any last-minute questions.
When it is time to do the ablation, you will be wheeled into the catheterization lab.
Throughout the Procedure
In the catheterization lab, you will be asked to lie down on the procedure table. An IV will be started and a blood pressure cuff will be attached, and electrodes to record your ECG will be attached. Depending on the type of computerized mapping system your doctor uses, a large electrode may be attached to your back.
You will be surrounded by an abundance of electronic equipment, including several large computer screens and monitors that your doctor will be using during the procedure.
During most ablation procedures, is administered intravenously to create a sort of “twilight sleep.” This anesthetic state will not make you unconscious, so you will be able to answer questions and inform the medical staff of any discomfort you may be having—but you will lose all sense of time, and most likely will not remember much of the procedure once it is finished.
Several areas of your skin will be cleaned, sterilized, and anesthetized, and the electrophysiologist will insert several specialized electrode catheters (usually anywhere from two to four) into your veins. Most commonly, femoral veins are used (in the groin area), but additional catheters may be inserted via the jugular vein (at the base of the neck), subclavian vein (under the collarbone), or brachial vein (in the arm). Using fluoroscopy, these catheters will be positioned in strategic areas within your heart, and, using a sophisticated computerized mapping system, your heart’s electrical system will be fully mapped out in detail.
Depending on the arrhythmia for which you are being treated, it is very likely that the doctor will intentionally induce the arrhythmia several times (using sophisticated pacing techniques). This will allow electrical mapping of your heart during the arrhythmia itself.
By analyzing the maps that are generated, your doctor will be able to identify specific areas of your heart that are critical to the generation of your arrhythmia. Once these target locations are identified, one of the catheters will be carefully guided to that location. A tiny area of tissue damage (generally, smaller than the size of a pencil eraser), will be created at that spot, using either radiofrequency energy (electricity) or cryoenergy (freezing).
After the ablation itself has been performed, the doctor will again try to induce the arrhythmia. If the ablation is successful, the arrhythmia should no longer be inducible.
When the ablation procedure is finished, all the catheters will be removed, and any bleeding will be controlled by putting pressure for several minutes over the veins at the site of catheter insertion.
When the procedure is finished, you will be taken to a recovery area and observed until the anesthesia is completely worn off. (In some facilities you will simply remain in the catheterization laboratory until you are wide awake.) Once you are back to your baseline state of consciousness, the electrophysiologist should visit you to explain exactly what she or she did during the ablation procedure, and how confident he or she is that the procedure was a complete success.
You may be discharged an hour after the procedure unless you are staying overnight in the hospital.
After the Ablation
You will be given instructions to follow when you are at home. Typically you will be asked to take it easy for the rest of the day, and possibly the next day, but after that there are usually no specific limitations. You should not experience any significant pain. You will be asked to observe the catheter insertion sites for signs of bleeding, bruising or pain, and will be given a contact person to call if you experience any difficulties. People can generally resume their normal diet and medications immediately after the procedure.
Most electrophysiologists will schedule you to make a follow-up visit a few weeks after the ablation. The main purpose of this visit is to determine whether the ablation seems to have alleviated all of the symptoms you were having before the procedure.
If any of your symptoms have not disappeared, the doctor may want you to have ambulatory cardiac monitoring for a period of time to determine whether episodes of the arrhythmia may still be occurring. If your ablation was aimed at eliminating atrial fibrillation, or if the target arrhythmia is known to have occurred prior to the ablation procedure without causing you any symptoms, it is likely that your electrophysiologist will recommend performing periodic ambulatory monitoring (every three to six months) for the first year or so, whether you are experiencing symptoms or not.
However, for the majority of people who have ablation for most kinds of cardiac arrhythmias, the arrhythmia will be gone for good once the procedure is over. After the initial follow-up visit, there’s no reason to expect to have to see an electrophysiologist ever again.
Cardiac ablation procedures have revolutionized the management of difficult cardiac arrhythmias. For a growing list of arrhythmias, modern computerized cardiac mapping systems have made it possible for ablation procedures to eliminate the arrhythmia altogether.