AV Node Ablation and Pacemaker for Atrial Fibrillation
The heart has conduction system through which electrical signals are sent. These signals are sent all over the upper chambers (atria) and the lower chambers (ventricles). This helps the heart beat in a regular, coordinated way called heart rhythm.
The electrical signals are transmitted through two nodes that contain conduction cells. The electrical impulse begins at the sinus node called the sino-atrial or SA node. It is located in the right atrium and helps set the rate and rhythm of the heart. Thus, it is the natural pacemaker of the heart.
The electrical impulse from the SA node cause the atria to contract and push blood into the ventricles. The electrical signals reach the atrioventricular node (AV node). This node regulates and slows down the impulses between the atria and the ventricles. The signals then travel into the ventricles, causing them to contract and push blood around the body.
The regular heart beat pattern is about 60 to 100 beats a minute. This is called as the sinus rhythm.
What is Atrial Fibrillation?
When the conduction pathway of the heart gets blocked, damaged or there is an extra pathway, it will cause the heart to beat abnormally. If the heart beats too quickly, it is called as tachycardia. When the heartbeat is too slow, it is called as bradycardia. These abnormal heartbeats are called as arrhythmias, that can occur either in the atria or ventricles.
One of the most common types of arrhythmia is atrial fibrillation. It occurs in the atria, where the electrical impulses do not just start in the SA node, but begins all over. These impulses spread through the atria chaotically leading to a fast and irregular heartbeat. The quickly and irregularly beating atria is said to be fibrillating. This decreases its ability to empty all blood into the ventricles, causing the blood to pool and increase the risk of developing blood clots. The doctor may have to prescribe anticoagulants to prevent a stroke from occurring.
What is AV Node Ablation?
When medications do not help in preventing episodes,rapid heart rate or controlling the fast heart rate, AB node ablation is suggested. This causes the person to suffer from palpitations, shortness of breath during exertion, dizziness, intolerance to exercise, etc. If this continues, it could lead to weak heart muscles.
AV node ablation helps in completely eliminating the rapid heartbeat due to atrial fibrillation. The procedure is suggested only to patients who do not respond to medications or suffer from drug side effects.
How is AV Node Ablation Performed?
A special ablation catheter is used to deliver radiofrequency energy to block the AV node. The radiofrequency is a type of heat energy that creates a scar on the AV node. This scar prevents the impulses from the atria to reach the ventricles and putting a stop to the fast heart rate. However, after ablation, the heart rate becomes too slow, thus, the doctor will place a permanent pacemaker to keep the heart beating in a normal rhythm.
A pacemaker is a battery-operated device that sends electrical signals in the heart. This helps start a heartbeat when the heart beats too slow. However, the AV node ablation will not convert atrial fibrillation to a sinus rhythm. The process only helps in controlling the number of impulses that reach the ventricles.
AV node ablation for atrial fibrillation is carried out under local anesthetic in a special room called the EP lab with the help of X-ray screening. The catheter is introduced into the femoral vein after being anesthetized. The procedure is totally painless and has very low risk.
What are the Risks of AV Node Ablation?
The risk of AV node ablation is very low, but with every invasive procedure, there are some risks attached. These risks include:
- Bleeding from the puncture site
- Bruising or infection at the puncture site
- Very small risk of stroke
- Puncture of a lung
- Bleeding around the heart, in case an artery burst when guiding the artery to the site of ablation
After the procedure, one may feel drowsy and have problems remembering some parts of the procedure. Once the patient wakes up fully, the effects will fade away. The leg through which the catheter was inserted will be kept straight with the head on the pillow or about 4 hours.
Make sure you do not lift any heavy weights of more than 4 kg for the next 2 to 3 days. If any bleeding that does not stop at the site of puncture is seen, it should be reported to the doctor. Any lump at the site should also be reported to the doctor.
One will have to take anticoagulant medications like warfarin or aspirin for life to prevent blood clots. The ablation helps prevent the heart from racing during atrial fibrillation and the pacemaker helps maintain a normal pace of the heart beats. Speak to your doctor regarding all the risks involved with AV node ablation and pacemaker for atrial fibrillation.
Written by: healthplus24.com team
Date last updated: January 20, 2015