Definition and Overview
Atrial ablation is a catheter-based procedure used to treat arrhythmias caused by atrial fibrillation. It does so by destroying abnormal heart tissue without affecting other parts of the heart.
The procedure, which is also called radiofrequency ablation, aims to restore the heart’s regular rhythm. It was developed in the early 1990s as a permanent treatment for atrial fibrillation. During that time, it was believed that the condition could not be effectively treated. Thus, the development of the procedure, which further improved in the late 1990s, was considered a significant medical breakthrough.
Cardiac ablation for atrial fibrillation underwent several changes and improvements over the years, resulting in several different ablation strategies. These strategies were eventually merged, which paved the way for the procedure that is in use today.
Who Should Undergo and Expected Results
Atrial fibrillation ablation is beneficial for patients who suffer from arrhythmias or abnormal heart rhythms due to persistent atrial fibrillation. Doctors prescribe it if the patient’s condition does not respond to medical therapy.
Arrhythmia refers to an abnormal heart rhythm. In atrial fibrillation, electrical short circuits develop inside the upper chambers of the heart. When this occurs, the said chambers are not able to pump blood properly and effectively, causing blood flow to the left and right atrium to slow down. Patients who suffer from this condition may experience symptoms, such as:
Shortness of breath
Patients also face an increased risk of stroke and blood clots. When left untreated, the condition may lead to heart failure.
While most patients respond positively to medications used to control the abnormal heart tissue that is causing arrhythmia, some patients either do not respond to them or experience negative side effects. It is in such cases that an atrial flutter ablation is most promising.
Following the procedure, the patient is placed under close monitoring to check their heartbeat, pulse, and blood pressure. Since the abnormal tissues are destroyed, they can no longer affect the heart’s rhythm. Thus, atrial flutter ablation procedure is considered a long-term and highly effective treatment.
How is the Procedure Performed?
Prior to an ablation for atrial flutter, patients are given pre-operative instructions and are generally not allowed to eat around 6 to 8 hours before the procedure.
The procedure is performed either in an electrophysiology (EP) lab or a catheterisation (cath) lab. It takes anywhere between 2 and 4 hours if abnormal tissues are found on just one site, or longer if more sites are affected.
The nurse will put an intravenous line into a vein in the arm to facilitate the administration of anaesthesia. Some patients are also given a sedative to help them relax, as well as a local anaesthesia injection in the part of the body where the needle is inserted.
After the administration of anaesthesia, the doctor will pierce through the skin with a needle to access a blood vessel, usually a vein or an artery. This is often performed in the groin area. A sheath (a small tube) is then inserted into the blood vessel to facilitate the passage of the catheter. The position of the catheter is monitored real-time via a computer screen.
The doctor then sends mild electrical pulses through the catheter to identify the location of the abnormal heart tissue that is causing the problem. Once located, mild radiofrequency energy is delivered through the catheter, causing the abnormal tissues to heat up. The process is performed around the entire pulmonary vein to make sure that electrical connections between the heart and the vein are halted. This prevents abnormal electrical impulses from initiating atrial fibrillation. This technique, which focuses on the pulmonary vein, was developed in the late 1990s based on the belief that pulmonary veins are the main source of electrical activity that causes atrial fibrillation. The technique is also being used as a way to reduce the risks of the procedure.
However, in some cases, other coronary veins, such as the coronary sinus, superior vena cava, and inferior vena cava, are also involved. If so, these veins are also isolated in the same way.
Catheter ablation for atrial fibrillation can destroy about 1/5 of an inch of the heart muscle, thus allowing doctors to target just the abnormal tissues. It is not considered a painful procedure, although patients may experience some pressure where the catheter is inserted. Depending on its extent and outcome, patients can either go home on the same day or stay overnight at the hospital. Either way, patients should arrange for a ride home, as they are not allowed to drive for the first 24 hours after the procedure.
Possible Risks and Complications
Patients who undergo cardiac ablation for atrial fibrillation face certain risks, such as:
Blood clots forming in the heart. To prevent this, doctors prescribe blood-thinning medications, such as aspirin or warfarin.
The risks of catheterisation, or the insertion of a long thin tube into the veins and arteries, such as:
Damage to the blood vessels
While recovering from ablation of atrial fibrillation, patients are advised to watch out for some signs of complications or side effects. These include:
Swelling at the puncture site
Continuous bleeding at the puncture site
Feet that feel cold/turn blue
Abnormal fluid drainage from the puncture site
Pain and discomfort in the chest area that radiates to the neck, arm, and jaw
Shortness of breath
Kirchhof P, Calkins H. “Catheter ablation in patients with persistent atrial fibrillation.” Eur Heart J. 2017. 38(1):20-26. https://academic.oup.com/eurheartj/article/38/1/20/2936207/Catheter-ablation-in-patients-with-persistent
Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer. “Approaches to Catheter Ablation for Persistent Atrial Fibrillation.” N Engl J Med. 2015. 372:1812-1822. http://www.nejm.org/doi/full/10.1056/NEJMoa1408288#t=article
Gillinov AM, Gelijns AC, Parides MK, et al. “Surgical ablation of atrial fibrillation during mitral-valve surgery.” N Engl J Med. 2015. 372:1399-1409. http://www.nejm.org/doi/full/10.1056/NEJMoa1500528#t=article