Radiofrequency Ablations for Arrhythmias
Radiofrequency ablation is a nonsurgical procedure used to treat certain types of heart arrhythmia, such as tachycardia. Most frequently, radiofrequency ablation is performed to treat supraventricular tachyarrhythmia, rapid irregular heartbeats that start in the atria (upper chambers) or middle of the heart. Heart arrhythmia can be serious because, when irregular heartbeats are severe or prolonged, the ability of the heart to pump enough blood throughout the body can be compromised.
Reasons for a Radiofrequency Ablation
Radiofrequency ablation is performed on patients who do not respond well to medications for arrhythmia, or for whom the side effects of such medications make them intolerable. The ablation procedure is helpful in treating a number of types of cardiac arrhythmia, including the following:
- Atrial fibrillation
- Atrial flutter
- Supraventricular tachycardia
- Atrioventricular reentrant (reciprocating) tachycardia (AVRT)
- Atrioventricular nodal reentrant tachycardia (AVNRT)
- Wolff-Parkinson-White syndrome (WPW)
- Premature ventricular contractions (PVC)
- Ventricular tachycardia
AV node ablation, a type of radiofrequency ablation, is very effective in treating atrial fibrillation when performed in combination with the implantation of a pacemaker.
The Radiofrequency Ablation Procedure
Radiofrequency ablation, performed with the patient under mild sedation and local anesthesia, is mild and usually painless. It has a success rate greater than 90 percent, requires only a few days of downtime, and carries a very low risk of complications. For these reasons, it is most often the preferred option for treating arrhythmic disorders.
During the procedure, the doctor guides a catheter with an electrode on its tip through a small incision in the groin to the site where the heart muscle has sustained damage. The doctor is aided by the use of fluoroscopy to find the appropriate pathway. Attempts are made to provoke an arrhythmia during the procedure to identify the parts of the heart muscle that are causing the problem. Once this is done, the defective heart muscle cells are targeted with energy, similar to that of a microwave, and destroyed. Hopefully, once these few cells stop conducting extra electrical impulses, the rapid heartbeats will stop. The patient's heart rate and rhythm, as well as oxygen level and blood pressure, are monitored throughout the procedure.
Once the ablation procedure is complete, the doctor tries once again to provoke an arrhythmia. The procedure is considered successful if this cannot be done. If an arrhythmia occurs, additional radiofrequency energy is administered. On average, the procedure lasts for approximately 2 hours.
For some patients, the implantation of a pacemaker, a small electrical device that remains in the body to stimulate heart contractions, is part of radiofrequency ablation. At times, the doctor knows that a pacemaker will be needed in advance; at other times, the necessity for a pacemaker is a complication of the original procedure.
Recovery from Radiofrequency Ablation
After undergoing radiofrequency ablation, the patient is monitored closely until the sedative wears off. Several hours of bed rest are necessary to prevent bleeding at the site of the catheter insertion; pain medication is prescribed if needed. Fatigue is to be expected after the procedure. Some patients are admitted to the hospital overnight; others return home the same day. All patients will have to restrict their activities temporarily to avoid putting stress on the catheter site. Patients may be instructed to take aspirin as a blood thinner for several weeks, or may be prescribed more powerful anticoagulants.
Risks of a Radiofrequency Ablation
Radiofrequency ablation is considered generally safe but, like all invasive surgical procedures, it carries some risks. Risks of radiofrequency ablation include the following:
- Excessive bleeding, bruising or injury to blood vessels
- Accidental damage to the muscles or valves of the heart
- Blood clots that may travel to the lungs or brain
- Development of a new arrhythmia
- Radiation exposure
One serious potential complication is the failure of an electrical impulse to travel from the atria (upper chambers of the heart) to the ventricles (lower chambers of the heart). It this complication continues, a pacemaker becomes necessary. Although the risk of radiation exposure during radiofrequency ablation is very low, it is not performed on pregnant women because the fetus is highly susceptible to radiation damage.