Ablation (Invasive)

Cathy Olig, RN, BS
Lead – Electrophysiology and Pacing

Why is the doctor performing this procedure?

Your cardiologist has recommended that you have an ablation in an attempt to cure symptoms related to your heart rhythm. These symptoms may be: sensations that your heart is racing, palpitations, shortness of breath, an inability to exercise, dizziness, an irregular heart rhythm or a pounding sensation in your chest. This may be caused by a non-lethal, fast heart rhythm called a tachycardia.

The procedure is done by a cardiologist who has received special training in the study of the electrical rhythm of the heart and is called an electrophysiologist.

Ablation procedures are done to eliminate fast heart rhythms called tachycardias. There are several different kinds of tachycardias. These include; AV Node Reentrant Tachycardia (AVNRT), Wolff-Parkinson White Syndrome (WPW), Concealed Accessory Pathway, A-V Reciprocating Tachycardia, Atrial Tachycardia, Atrial Flutter and Atrial Fibrillation.

What is the procedure?

Catheter ablation is a procedure in which the electrical system of the heart is mapped and areas of abnormal conduction are identified and eliminated. To disrupt the electrical circuit that is causing your symptoms, lesions are made in the heart to create a small scar. The scar breaks the abnormal electrical circuit, disrupting the pathway.

The scar can be created using either radio-frequency ablation which causes a localized burn to the area, or cryo-technology in which the area is frozen. The scar formed is about the size of a pencil eraser and does not harm the ability of the heart muscle to pump effectively.

In ablations, several catheters are placed in the heart through one or more veins. The catheters have multiple electrodes that are able to detect the tiny electrical signals that are generated by specialized tissues inside the heart. The electrical signals cause the heart muscle to contract, which causes a heart beat. The small electric signals detected by the catheters, are displayed on a specialized computer so that they can be analyzed by the electrophysiologist.

During the procedure, your heart rate and rhythm, your blood pressure and the oxygen saturation of your blood will be continually monitored. You will be given medication to relax you, through your IV, to keep you comfortable. Most patients sleep through the procedure and do not remember the ablation. If you have any pain or discomfort during the procedure, please let the staff know. It is our goal to keep you comfortable while you are in our care.

During the procedure, the electrophysiologist will look at the normal conduction of the heart and will try to induce the heart rhythm (tachycardia) that has caused your symptoms. The physician does this by pacing the heart at different rates. Medicine may be given in your IV to stimulate your heart. This may help in bringing out the tachycardia.

By interpreting the electrical signals, the electrophysiologist can determine the type of electrical pathway, the properties of the pathway and a general location of where the ablation catheter should be placed.

To ablate the pathway, the physician may use several techniques to insure the catheter is in the correct position to disrupt the electrical pathway. This may include using 3-dimensional mapping technology similar to global positioning systems, identification of local electrograms inside the heart, as well as X-ray images to show placement of the catheter.

After the pathway has been ablated, the electrophysiologist will repeat the first part of the test to confirm the absence of the abnormal pathway and the health of the normal conduction system.

The catheters will then be removed and you will be allowed to wake up. Once you are awake, you will be returned to your room and will be allowed to eat and drink. You will be asked to stay in bed until you are awake and the catheter access sites have a chance to heal. Most of our ablation patients are discharged from the hospital the same day.

Where is the procedure performed?

The procedure is performed in the Meriter Hospital's Electrophysiology Lab. The lab contains an X-ray camera to help with catheter placement, a specialized computer system to acquire and interpret the electrical signals generated by the heart and another computer system that can create a three-dimensional map of the inside of the heart.

How long does the procedure take?

It is difficult to predict the length of time it takes to complete an ablation. This is due to the type of tachycardia diagnosed, the location of the pathway and the patient's anatomy. In general, you can assume the procedure will last 4-6 hours.

6/23/2008