Ablation is the destruction of heart tissue that is causing an arrhythmia, a disturbance in the heart's rate or rhythm using radiofrequency or cold energy.
When other treatments, such as medication, lifestyle changes, pacemakers, or defibrillators are not effective, or if the patient is highly symptomatic or unwilling to take long-term medication, physicians use ablation.
Catheter ablation is safe and effective and is successful in more than 90 percent of cases.
Radiofrequency ablation (RFA) is a minimally invasive treatment for arrhythmias, disturbances in the heart's rate or rhythm. During RFA, one or more catheters are threaded through the blood vessels to the heart. Catheters are positioned along electrical pathways that are causing the arrhythmia. Most frequently, electrodes at the catheter tips are heated with radiofrequency energy, which destroys (ablates) a small spot of heart tissue and creates an electrical block along the pathway that is causing the arrhythmia. Physicians can use other forms of energy as well, including laser energy, cryoablation, and ultrasound.
Arrhythmias that physicians treat with RFA include:
Supraventricular tachycardia (SVT);
Wolff-Parkinson-White syndrome (WPW);
Ventricular fibrillation; and
WHEN IS IT INDICATED?
RFA is indicated for patients who:
Have arrhythmias that cannot be controlled with medication or lifestyle changes;
Do not wish to take anti-arrhythmia medications for a long period;
Have atrial fibrillation that causes bothersome symptoms despite medications; and
Have ventricular arrhythmias that cause frequent shocks from an implanted cardiac defibrillator.
Typically patients stop taking antiarrhythmic medications so the physician can reproduce the arrhythmia to pinpoint its location during the procedure. Patients who take anticlotting medications may also be asked to stop taking them to prevent bleeding during the procedure.
The patient should inform the physician if he or she is allergic to contrast dye.
Typically, the patient is required to fast after midnight the night before the procedure.
WHO IS ELIGIBLE?
Pregnant women are ineligible for RFA because the x rays used with fluoroscopy can harm the fetus.
WHAT TO EXPECT
A nurse will start an intravenous (IV) line to give the patient medication and fluids during the procedure. In addition, the patient will be connected to monitors, including an electrocardiogram (ECG). In most cases, only a mild sedative and a local anesthetic are needed. The patient will be given medication to help him or her relax, after which the insertion site will be shaved, cleaned, and numbed with a local anesthetic.
The physician makes tiny incisions (or nicks) in the groin, wrist, or neck, and inserts one or more catheters (thin, flexible tubes) into a vein or artery. Using imaging, the physician steers the catheters through the blood vessels to the heart, pinpoints the origin of the arrhythmia by triggering it (called mapping), and analyzes it. During this part of the procedure, the patient's heartbeat may increase.
Once the source of the arrhythmia has been located, the physician then positions the ablation catheter. The ablation catheter is a catheter with an electrode on its tip. It is placed in contact with the abnormal tissue and radiofrequency energy is run through the catheter. RF energy causes the tissue to heat, which ablates the abnormal tissue. Some physicians use other forms of energy to ablate the tissue, using lasers, microwaves, cold (cryoablation), or ultrasound.
After the ablation, the physician will try to trigger the arrhythmia again. If the arrhythmia is triggered, the physician will repeat the procedure of mapping and ablating until the arrhythmia cannot be triggered. The physician removes the catheters and direct pressure is applied to the insertion point or points to prevent any bleeding. The procedure typically takes 2 to 4 hours to complete.
POST-TREATMENT GUIDELINES AND CARE
After RFA, the patient will be observed for several hours for symptoms, including rhythm problems, bleeding from the insertion point and from the areas where the ablation took place.
For the first 24 hours after the procedures, patients should avoid driving a car, exercising strenuously, or climbing stairs.
During recovery, the patient's heart rate and rhythm will be monitored remotely.
Many patients experience skipped heartbeats or short episodes of atrial fibrillation during the first 3 months after surgery, a common occurrence that occurs because of inflammation of the heart, which should subside when the heart heals. It is treated with medication.
The patient may also take the following medications:
Anticoagulants (such as Coumadin [warfarin]);
Antiarrhythmic medications to control abnormal heartbeats; and
Diuretics to combat fluid retention.
Aspirin is sometimes prescribed for 2 to 4 weeks after ablation to prevent blood clots (called thrombi) from developing.
Complications of RFA include:
Damage to the heart from the energy source, which may require pacemaker implantation;
Damage and scarring of the pulmonary veins, which return blood from the lungs to the heart;
Leakage of blood vessels;
Rare complications from ablation occur in less than 1 percent of cases, but include heart attack, stroke, or sudden death from blood clots that break away during the procedure. A few patients require the placement of a pacemaker following surgery because of an underlying arrhythmia that was previously undetected.