In order for the heart to do its work (pumping blood throughout the body), it needs a sort of spark plug or electrical impulse to generate a heartbeat. Normally this electrical impulse begins in the upper right chamber of the heart (in the right atrium) in a place called the sino-atrial (SA) node. The SA node is the natural pacemaker of the heart. The SA node gives off electrical impulses to generate a heartbeat in the range of 60 to 100 times per minute.
In some hearts, an abnormal heart rhythm develops when an electrical impulse either starts from a different location, other than the SA node, or follows a route (or pathway) that is not normally present. This is what happens in atrial flutter. A short-circuit develops in the right atrium as show in the diagram below.
Atrial Flutter is due to a short circuit in one of the upper chambers of your heart termed the right atrium. This rapid short circuit has several consequences:
Radiofrequency is a low power, high frequency energy that causes a tiny region of the heart near the tip of the catheter to increase in temperature, thus ablating (or cauterising) a small area of abnormal tissue. Radiofrequency energy has been used for decades by surgeons to cut tissue or to stop bleeding. For the treatment of palpitations, a much lower power of radio-frequency energy is used.
You will be transferred to the Electrophysiology Laboratory (EP lab) from your ward. Usually before leaving your ward you will be given a light sedative and your groin will be shaved.
The EP lab has a patient table, X-Ray tube, ECG monitors and various equipment. The staff in the lab will all be dressed in hospital theater clothes and during the procedure will be wearing hats and masks.
Many ECG monitoring electrodes will be attached to your chest area and patches to your chest and back. These patches may momentarily feel cool on your skin.
A nurse or doctor will insert an intravenous line usually into the back of your hand. This is needed as a reliable way to give you medications during the study without further injections. You will also be given further sedation if and as required. You will also have a blood-pressure cuff attached to your arm that will automatically inflate at various times throughout the procedure.
The oxygen level of your blood will also be measured during the EP study and a small plastic device will be fitted on your finger for this purpose. Your groin area and possibly your neck will be washed with an antiseptic cleansing liquid and you will be covered with sterile sheets leaving these areas exposed.
An anaesthetist will be present for many procedures. The procedure may be performed under local anaesthetic with sedative medication or under full general anaesthetic. This will be discussed with you before the procedure.
If the procedure is performed under local anaesthetic, the doctor will inject the anaesthetic to the area in the groin where the catheters are to be placed. After that, you may feel pressure as the doctor inserts the catheters but you should not feel pain. If there is any discomfort you should tell the nursing staff so that more local anaesthetic and sedative medication can be given. Occasionally it is also necessary to place a catheter in a vein in the side of the neck.
The catheters are positioned in your heart using X-Ray guidance. Once the catheters are in place you may feel your heart being stimulated and usually your abnormal heart rhythm will be induced. When the type of abnormal rhythm has been identified and the abnormal tissue localised, the radiofrequency ablation will be applied to this spot. This may cause a transient warm discomfort in the chest.
Radiofrequency ablation procedures are lengthy and the average duration is approximately 2 to 3 hours.
You will receive an admission letter outlining the date of your procedure.
You may be asked to discontinue some of the anti arrhythmic and Blood thinner medications prior to the procedure.
You will be required to fast for at least six hours before the study. If your procedure is in the afternoon you may have a light early breakfast. If your procedure is in the morning, DO NOT EAT OR DRINK AFTER MIDNIGHT, except for a sip of water to help you swallow your pills.
After your procedure you will be transferred back to your ward where you will have to lie flat for 4-6 hours. During this time, it is important to keep your legs straight and your head relaxed on the pillow.
Most patients stay in hospital overnight and their heart rhythm may be monitored during this time. The majority of patients have approximately 1 week away from work.
The Radiofrequency ablation procedure is a very low-risk procedure and should a complication arise, it will be dealt with at once.
The world wide complication rate for Electrophysiology studies and radiofrequency ablation procedures is less than 0.5%.
Although most people undergoing radiofrequency ablation procedures do not experience any complications, you should be aware of the following risks.
Local bleeding, blood clot or haematoma (blood collection) – this may occur at the catheter insertion site.
Major complications – stroke, heart attack, death are very rare.
As discussed above, atrial flutter carries a very small risk of stroke due to the risk of blood clot formation in the left atrium. This is one of the reasons to cure the rhythm disturbance. This risk increases slightly at the time that the heart reverts from the atrial flutter to the normal rhythm. This increased risk is present whether the rhythm is reverted with medication, with a DC shock on the chest or with a radiofrequency ablation procedure. In order to prevent this occurring the following precautions will be taken:
Radio-frequency ablation is an effective and safe way to cure patients suffering from atrial flutter.