In some patients with atrial fibrillation, medications are not effective in preventing episodes or in controlling the heart rate or rhythm. Patients who have a rapid heart rate during atrial fibrillation are often troubled by uncomfortable palpitations, shortness of breath during exertion, dizziness, exercise intolerance and a weakened heart muscle.
For patients whose atrial fibrillation is not well-controlled with medications, our first line of treatment is catheter ablation, a minimally invasive technique intended to control atrial fibrillation without major surgery.
AV node ablation is also effective in eliminating the rapid and irregular heartbeat that may accompany atrial fibrillation. This procedure is performed only in patients who do not respond to medications or cannot take them because of side effects, or who are not good candidates for a curative procedure.
Node Ablation Procedure
A catheter is inserted into a vein in the area of the groin and positioned near the AV node, a nerve that conducts electrical impulses from the top chambers to the bottom chambers of the heart. Radiofrequency energy is passed through the catheter to destroy the AV node. This eliminates the rapid and irregular heartbeats caused by atrial fibrillation.
The pulse rate usually drops to 30 beats per minute, and a pacemaker must be implanted to maintain a normal heart rate. The pacemaker will increase the heart rate during exertion or exercise, simulating a normal heart rhythm.
The pacemaker is an electronic device that is implanted on the upper chest, under the skin. It is connected to one or two wires that are inserted through a vein and sit in the heart. It delivers painless electric pulses that stimulate the heart to beat.
The procedure (including implantation of the pacemaker) takes about three hours to perform and the patient spends two nights in the hospital before going home.
Advantages of AV Node Ablation
Advantages of AV node ablation with pacemaker implantation are that it has a very high success rate and very low risk of serious complications while being very effective in alleviating symptoms caused by a rapid and irregular heart rate, which can eventually weaken the heart muscle. The procedure also eliminates the need for medications aimed at preventing atrial fibrillation and controlling the heart rate.
The disadvantages are that the patient becomes dependent on a pacemaker for the rest of his or her life as the AV node ablation does not cure the atrial fibrillation. Hence, there may still be a need to take a blood thinner to prevent strokes. And while the heart functions much more efficiently after the procedure than it did with a rapid and irregular rate, it does not function as efficiently as when atrial fibrillation is not present, so a patient’s energy level improves after AV node ablation but may not become totally normal.
Complications of AV Node Ablation
There is a 1-2 percent risk of a complication during the pacemaker implantation procedure, with the most common complications being:
- Puncture of a lung
- Displacement of one of the pacemaker wires, which requires another procedure to reposition the wire in the heart
Make an Appointment
The Arrhythmia Program at the University of Michigan has been a national and international leader in the treatment of arrhythmias for more than 30 years. To schedule an appointment to discuss your heart arrhythmia or other cardiovascular condition, call us at 888-287-1082 or email us at CVCCallCtr@med.umich.edu. Visit our Make an Appointment page for more information about what to expect when you call us.