Afib Treatment Ablation
Left Atrial Radiofrequency Catheter Ablation
Left atrial radiofrequency catheter ablation is a catheter technique intended to cure atrial fibrillation without major surgery.
Your Cardiologist or Electrophysiologist will help you with the decision to have an afib treatment ablation. In this procedure a specially designed catheter is inserted and positioned in the left atrium, radiofrequency energy(microwave energy that heats) is applied to the heart muscle to cauterize lesion lines(scars) that "short circuit" the rogue impulses that are generating the atrial fibrillation.
This type of procedure the afib treatment ablation, may be effective for either paroxysmal or chronic atrial fibrillation. However, it is unlikely to
be as effective if the left atrium is very enlarged.
A special type of X-ray examination (CT scan) may be performed before the ablation procedure, because it provides a 3-dimensional view of the left atrium and the veins that attach to it.
In some patients, a transesophageal echocardiogram(TEE) is performed immediately before the ablation procedure, to make sure that there are no blood clots in the left atrium. After a sedative is administered, a small tube is passed down the esophagus (the connection between the mouth and the stomach) to visualize the left atrium with ultrasound. If a blood clot is seen or detected, the ablation procedure would be postponed until the clot has dissolved.
in the afib treatment ablation procedure, the right groin is numbed with a local anesthetic, and a sedative is administered to induce sleep. Catheters are inserted with a needle into a vein at the groin and the catheter is run up to the heart.
The left atrial ablation procedure requires the insertion of a catheter into the left atrium, because the vein leads only to the right atrium a "transeptal catheterization," must be performed in which a small hole is purposely made with a needle that is pushed through the thin membrane that separates the two top chambers of the heart.
The correct position of the needle usually is confirmed visually with a tiny echo (ultrasound) probe that is on the end of a catheter positioned within the heart, and this makes transeptal catheterization a safe procedure. The catheter is visualized with an Xray camera (fluoroscopy) that emits a low level of radiation.
A computerized, 3-dimensional mapping system is used to guide the procedure. The catheter and the left atrium are visualized on the computer screen, and this makes it possible to guide the catheter very precisely. The 3-dimensional mapping system also cuts down on the amount of X-ray needed during the procedure.
By recording the electrical activity inside the heart, the short circuits that are generating the atrial fibrillation can be identified, and these spots are cauterized with the radiofrequency energy.
In a typical patient, between 150 and 250 different spots need to be cauterized to eliminate the atrial fibrillation. Certain portions of the left atrium are very sensitive to the radiofrequency energy, and the applications of radiofrequency energy may cause chest pain. Your comfort level will be closely monitored during the procedure by a nurse, and medications are used to keep you comfortable if your doctor decides to leave you awake. Most doctors now op to use a general anesthesia during the procedure. This medication usually causes amnesia for all or most of the procedure, so that there is little or no memory of any discomfort.
The entire left afib treatment ablation procedure takes about 4 hours to perform, including the time needed to prepare for the procedure and to remove the catheters from the body. After the procedure, the patient usually spends one night in the hospital before being discharged.
Heparin (an intravenous blood thinner) is infused overnight to prevent blood clots from forming in the left atrium after the procedure. In addition, warfarin (Coumadin) is used to keep the blood thin for at least 3 months before and after the procedure, until the inner lining of the heart has healed from the effects of the radiofrequency energy.(burns)
In most patients, the ablation procedure can be performed safely without interrupting treatment with warfarin (Coumadin). However, in some patients it is safer to stop taking warfarin (Coumadin) a few days before the ablation procedure. In these patients, an injectable form of heparin (Lovonox) is self-administered for a few days before and after the ablation procedure, as a precaution against blood clots. Patients are instructed on how to inject themselves with the tiny needle that is used to deliver the heparin under the skin.
Because the ablation procedure itself may temporarily irritate the
heart and cause atrial fibrillation, patients often are treated with a medication to suppress atrial fibrillation for 2-3 months afterwards. When atrial fibrillation has been chronic, the heart develops a "memory" for the atrial fibrillation, and there is a strong tendency for the atrial fibrillation to recur in the first 3 months after a normal rhythm is restored.
To stabilize the heart rhythm during the first 3 months after left atrial ablation, patients often are treated temporarily with medications to help maintain a normal rhythm.
Despite being treated with medications, many patients experience episodes of atrial fibrillation during the first 3 months after left atrial catheter ablation. This is because it may take 3 months for the full effect of the procedure to occur. The scars that are created by the radiofrequency energy may take up to 3 months to fully develop, and some patients may have atrial fibrillation during this healing phase that eventually goes away.
The success rate of left atrial ablation in patients with atrial fibrillation usually depends on whether the atrial fibrillation is paroxysmal or persistent. In the case of paroxysmal atrial fibrillation (the kind that comes and goes on its own), the atrial fibrillation can be eliminated in 70-75% of patients with a single procedure.
When the procedure is repeated in patients who still have atrial fibrillation after the 1st procedure, the overall success rate increases to approximately 85-90%.
In the case of persistent atrial fibrillation (the kind that has been present consistently for several months to years), the atrial fibrillation can be eliminated in approximately 50% of patients with a single procedure.
In about 30% of patients who undergo ablation of chronic atrial fibrillation, the atrial fibrillation is replaced by a different kind of short circuit referred to as "left atrial flutter." If this occurs, the patient is treated temporarily with medications.
The left atrial flutter sometimes goes away on its own within 3-4 months. If the left atrial flutter does not go away on its own, another catheter ablation procedure will be needed to eliminate the flutter. After a 2nd procedure in patients with persistent atrial fibrillation who still have atrial fibrillation or atrial flutter after the 1st procedure, the overall success rate increases to approximately 75-85%.
If the atrial fibrillation has been persistent for more than 1-2 years, almost all patients will require more than 1 ablation procedure before a normal heart rhythm is restored.
The risks of left atrial ablation include:
1.) 0.5% risk of a catheter puncturing a wall of the heart. If the catheter punctures the heart, blood leaks out through the hole and fills the membrane sac that surrounds the heart. This interferes with the pumping action of the heart and requires that the blood be drained out. This is accomplished by placing a drain through the front of the chest into the sac that surrounds the heart. A patient usually must stay in the hospital for 4-5 days if this complication occurs.
2) 0.5% risk of a blood clot traveling from the heart to the brain or to some other part of the body. Blood tends to clot whenever it comes into contact with a foreign body. This can happen with the catheters that are used for left atrial ablation. To prevent blood clots from forming, a strong blood thinner (heparin) is used during the procedure. However, a blood clot sometimes forms even though the blood has been thinned.
3) Less than a 1% risk of pulmonary vein stenosis. If the radiofrequency energy is delivered inside of a pulmonary vein, it can cause the vein to scar down, obstructing blood flow from the lungs into the heart. This can cause shortness of breath. The risk of this complication is very small, because radiofrequency energy is not delivered inside the pulmonary veins during left atrial ablation.
4) A very small risk of death. There has been one patient out of 3,000 who died as a result of the procedure. In this patient, the radiofrequency energy burned through the back of the heart into the esophagus (the food tube that runs from the throat to the stomach, behind the heart). One other patient also experienced damage to the esophagus, but this patient was operated upon and survived.
To avoid damage to the esophagus from the radiofrequency energy, some doctors have the patient swallow a small amount of barium paste at the beginning of the procedure. The barium allows them to see with X-rays where the esophagus is. They can then avoid using the radiofrequency energy to burn any spots in the heart that are near the esophagus.