Catheter ablations are performed with thin catheters (soft wires) placed through veins at the top of the leg and at the neck. The catheters are positioned inside the heart’s chambers. where they are used to locate (map or record) electrical activity and delivery energy to ablate (erase or destroy) unwanted electrical currents.

The wires are placed using fluoroscopy, (live, moving x-ray pictures of the heart), and can be seen as they float to the upper heart chambers (atria). Usually 2 of these wires are placed into the left atria through a small hole made between the left atrium and the right atrium. This is called a transseptal puncture.

How long does the procedure take?

The Atrial Fibrillation Catheter Ablation Procedure may take 3 to 6 hours during which time you are sleeping (under anesthesia). Experienced anesthesiologists work with us during the procedure.

How do you know where to ablate?

A CT scan image of your heart taken previously is merged into the fluoroscopy to give us a 3-dimensional view and the electrophysiologist steers the catheters to the areas of the heart that are known to be involved with atrial fibrillation. (To see New Technologies Available, click here.)

In addition, the catheters have thin wires and electrodes that both detect the electrical activity of the heart and delivery energy to the heart. The recordings are similar to those made during a standard 12-lead ECG but are displayed on the computer as a 3D map. The electrical mapping system has a system that can track the catheter position inside the heart in 3D, a type of global positioning system (GPS). We refer to this as an electroanatomical mapping system. The recordings show the heart's electrical forces as the travel through the heart. We can watch the recordings in motion or as still images.

Using the combined images of CT and fluoroscopy, and the electroanatomical maps of the heart beats, the physician can see where to place the catherter most effectively. In addition, the catheter can be steered away from areas where ablation is not wanted.

What kind of energy is delivered to the heart?

The energy delivered to the heart has 2 purposes, to pace the heart in a way similar to what a pacemaker does and to ablate (destroy or erase) the arrhythmia.

When pacing the heart, tiny electrical impulses are delivered to create (stimulate) single heart beats. Pacing is used to help start the heart rhythm irregularity if the patient does not happen to have the arrhythmia at the time of the procedure. Pacing also helps us evaluate the heart for other abnormal rhythms.

During ablation, larger amounts of energy are delivered. When radiofrequency (RF) current is used, it heats the spots the catheter touches. The object of the procedure is to make small scars along the left atrium across which electricity cannot conduct. The scars or lesions are made to circle the pulmonary veins, and are placed in rows or lines across other areas of the atrium where AF is thought to have beginnings. Radiofrequency (RF) energy has been used in the heart this way for over 20 years. We also are involved with studies using other energy sources.

What are the risks of catheter ablation procedures for AF?

Any procedure carries some risk of complications. Please ask questions about the risks if you do not understand them.

The possible complications of EP tests and ablations, although rare, include heart attack, stroke, blood vessel injury, nerve injury, allergic reactions, arrhythmias, blood loss with need for transfusions, bleeding around the heart, need for a permanent pacemaker, worsening of heart failure or kidney function, and death. Possible additional complications of ablation in the left atrium include injury to the pulmonary veins causing narrowing, injury to the food pipe (esophagus), and injury to the diaphragm (breathing muscle). Emergency surgery may be necessary to repair one or more of these injuries.

Each of the possible risks is rare but the risks are real and cannot be underemphasized. You need to weigh these risks against the risks and discomforts of continuing in AF. There may be other risks that we cannot foresee.

Overall our complication rate has stayed low due to our careful attention to details.

Risk Reduction: Transesophageal echocardiography is performed to help with the transseptal procedure. A probe or tube is passed into the esophagus (food pipe) where images of the left atrium can be seen and the puncture between the right and left atria can be made precisely. A very thin temperature probe in placed in the esophagus during use of radiofrequency energy delivery.

With the CT scan on hand the areas of concern can be reviewed. A preliminary plan can be drawn onto the 3D image to help guide the ablation.  The integration of the atrium and the x-ray helps the physician more precisely direct the ablation catheter to the areas ablation is needed and avoid other areas.

How do I prepare for an ablation?

Early preparations: Your diagnosis will be confirmed. We will need to be certain that you have AF. If there is no documentation of your AF, you may be given a monitor to take home to record an AF episode. Your medical history will be reviewed to be sure that all treatable conditions that may influence the AF have been considered and to assess your general health issues.
 
You may be asked to discontinue some of your AF medications before the procedure. Coumadin will be discontinued for at least 3 days before the procedure and you will be asked to start one adult aspirin daily. Other medicines you may be taking will need to be individually reviewed.

You will undergo a CT scan before the procedure. This helps us see how many pulmonary veins you have and how big they are. The scan may be repeated 1 to 3 months after the procedure.

Closer to the procedure: You will be asked to not eat or drink for 8 -12 hours before the procedure so your stomach can be empty. You will be given instructions about when and where to arrive at the medical center. You may need to have additional blood tests when you arrive. It is probably a good idea to leave jewelry and other valuables at home but bring your identification, insurance, implantable device information, and medication and allergy lists. You should arrange for a ride as we would advise not driving when you go home next day.

What happens after the procedure?

Immediately after the procedure, the doctor takes out all the catheters and puts pressure on the entry area. You will rest in bed for about 6 hours to prevent any bleeding. Generally you will go home the next day or the day after. You will often have an echocardiogram before you leave to check for any complications.
 
You will continue on warfarin (CoumadinTM) and/or aspirin for at least 1-3 months after the procedure. Other heart rhythm medications might be continued or new medications may be started after the procedure. In some instances, these medications may be stopped after a few weeks or months.

A follow-up appointment with us or your local care giver should be scheduled for about 1 month after the procedure.

If you have other questions or concerns you can speak to your doctor or contact us.