Heart arrhythmias like atrial fibrillation are common and can be dangerous. They can cause a multitude of symptoms such as palpitations, skipped beats, tiredness, and more serious conditions such as strokes. Treatments for atrial fibrillation have advanced greatly over the past several years, to include catheter ablation with radiofrequency energy.
Elad Anter, a Professor of Medicine at the Cleveland Clinic, Ohio explains how the catheter ablation using radiofrequency energy is used for the treatment of atrial fibrillation and details some of the advances in medical science in this area.
What is Atrial Fibrillation?
Atrial Fibrillation is a relatively common heart rhythm abnormality that may occur in up to 10 percent of people over 65. The risk factors of Atrial Fibrillation are not fully understood and include genetic predisposition, increased age, high blood pressure, diabetes, sleep apnea, existing heart disease, excessive alcohol intake, and vigorous exercise, says Dr. Elad Anter.
During atrial fibrillation, the heart’s upper chambers, called atria, beat very fast and chaotically. This leads to metabolic demand on the atria and development of scar that can perpetuate the disease. The most fearful result of atrial fibrillation is stroke. This is because the upper chambers of the heart do not squeeze in a regular fashion, which leads to slow blood flow in certain pockets within the atria. This slow blood flow promotes clot formation. When the clot leaves the heart, it may travel to the brain and cause a stroke. This is called an ischemic stroke – a clot that blocks blood flow into the brain. Blood thinners like Warfarin are usually prescribed to reduce the risk for stroke, however, in these patients’ stroke can result from excessive bleeding into the brain.
Treatment for atrial fibrillation include changes in lifestyle, medications to reset the heart rhythm, and catheter ablation.
There are several treatment options for patients with atrial fibrillation, says Elad Anter, MD. These depend on the specific symptoms and risk factors in each patient. The first line of defense is often prescription medicine like metoprolol, propranolol, and diltiazem to slow a rapid heart rate. Patients may also be given blood thinners to reduce the risk of stroke.
Patients are encouraged to change their lifestyles and pay more attention to their general health, cutting back on alcohol consumption and quitting smoking, and controlling their other comorbid disorders like hypertension, diabetes, sleep apnea and obesity. Catheter ablation is the most effective and safest method to control atrial fibrillation in symptomatic patients, says Dr. Elad Anter.
Breaking Down the Radiofrequency Ablation Process
Catheter ablation is a percutaneous procedure that includes heart catheterization in which the electrophysiologist (a heart rhythm specialist) inserts a catheter into the heart through one of the leg veins. The catheter tip can deliver energy that heats the ill tissue causing atrial fibrillation. This tissue often resides in the left atrium at locations where the pulmonary veins drain into the atria. The procedure is often called pulmonary vein isolation of PVI.
The technology of catheter ablation has evolved significantly over the past two decades and it is now considered a first line therapy for most patients with symptomatic atrial fibrillation as it is effective and safe compared to medications. Dr. Elad Anter’s laboratory has been involved in development of many new technologies for catheter ablation. Radiofrequency energy is the most common energy source used in catheter ablation of atrial fibrillation. Energy transferred from the tip of the catheter to the tissue results in heating of the tissue, and once this heating reaches a threshold, the cells die. Recent innovation in radiofrequency ablation include use of very high energy for significantly shorter duration. This resulted in more rapid and effective ablation as was shown by Dr. Anter’s laboratory.
Clinical Outcomes of Radiofrequency Ablation for Atrial Fibrillation
Most people see improvements in their quality of life after catheter ablation. However, there’s a chance that atrial fibrillation may return. If this happens, the procedure may be repeated, and more specific triggers are targeted. Dr. Elad Anter says that a significant proportion of patients have triggers other than the pulmonary veins. In these patients, there is an increasing effort to identify the specific triggers for each patient.
Radiofrequency Ablation for Atrial Fibrillation Versus Other Types of Ablation Therapy
In addition to radiofrequency ablation, other energies such as cryothermy (cooling) are often used. However, radiofrequency ablation is the most studied, and it allows to perform a more complete ablation when needed in addition to pulmonary vein isolation, says Dr. Anter. A newer ablation technology using pulsed-field energy had been recently introduced. Dr. Anter reports that this energy is likely to improve the safety and efficacy of the procedure, and results from his own laboratory are encouraging. However, this technology is only available in the United States as part of several clinical trials.
Deciding to Have Radiofrequency Ablation
Before having radiofrequency ablation to treat atrial fibrillation, Elad Anter, MD states that patients should research and have honest discussions with their cardiologists about atrial fibrillation, lifestyle modifications, and gain a full understanding of the procedure details, expectations, and limitations.
Catheter ablation for atrial fibrillation can have a huge positive impact on patients’ life. Elad Anter is an expert in this procedure, and he believes in its effectiveness in treating atrial fibrillation.