More than six million Americans suffer from atrial fibrillation (AFib), a type of heart arrhythmia where the upper chambers (atria) of the heart beat irregularly and rapidly. This irregular atrial beat causes the impulses to pass irregularly to the ventricle (lower chambers), which results in inefficient pumping, reduced blood output, and often low blood pressure with symptoms of dizziness or shortness of breath.
Patients with AFib have worse outcomes compared to patients in sinus rhythm. AFib causes increased rates of stroke, heart failure and mortality. In some cases of AFib, blood clots can form in the atria, break off from the heart and enter the bloodstream. These can become lodged in an artery, block it and prevent blood flow. This blockage (embolism) kills any tissue after the blockage by preventing oxygenated blood from feeding it. When an embolus occurs in the brain, it’s called a stroke. AFib is the second leading cause of stroke in the U.S. and is responsible for 75,000 to 88,000 strokes every year.
AFib can range from paroxysmal– lasting from seconds to days – to persistent (always present). Fortunately, in many cases of paroxysmal and persistent AFib, medical treatment can reverse the arrhythmia. However, when that fails, surgical intervention holds the greatest promise for patients who continue to suffer from episodes of AFib, especially those that are associated with symptoms which affect a patient’s lifestyle.
The Benefits of Non-Medical AF Therapies
Techniques have been developed to treat AFib by “channeling” the electrical activity of the heart in a way that prevents the rhythm from developing. These include catheter-based pulmonary vein ablation, surgical pulmonary vein ablation, the surgical MAZE, and a combination of these (depending on the patient) known as a “hybrid” ablation procedure. These can be performed as sole therapy or in combination with cardiac surgery that treats other problems, like valve and coronary artery disease. The benefits of these AFib therapies include reducing the risk of stroke, eliminating the need for blood thinner and/or heart rhythm medication, increasing survival rates and improving quality of life for patients. Recently, it has been shown thatsuccessful treatment of AFib in patients undergoing cardiac surgery restores survival to that of patients without atrial fibrillation.
Pulmonary Vein Ablation
Research shows that episodes of paroxysmal AFib usually come from tissue surrounding the pulmonary veins (the blood vessels that bring oxygenated blood from the lungs to the left upper chamber), making them a target for treatment. One of the most popular procedures for treating AFib is pulmonary vein ablation, where an electrophysiologist inserts catheters into the blood vessels of the leg or neck and guides them into the atrium. Energy is delivered to the tissue that is targeted for ablation, creating circular “scars” to prevent the abnormal signals that cause AFib from reaching the rest of the atrium. These “scars” block any impulses firing from within the pulmonary veins, thereby electrically disconnecting them from the heart, allowing a return of the a normal sinus rhythm.
Minimally Invasive Surgical Ablation
Sometimes the scars cannot be created through the blood vessels or is unsuccessful. In those cases, a minimally invasive surgical option is available. Through small incisions in the chest, a camera can be inserted to guide the positioning of specialized clamps that encircle the pulmonary veins from the outside of the heart. Using radiofrequency energy, a surgeon can create scars similar to the catheter-based procedure described above. These walls of scar prevent the irregular impulses from entering the normal pathway. In addition, with this surgical procedure, the left atrial appendage is removed. The left atrial appendage is a small pouch of atrial tissue that is the site of clot formation in nearly 90 percent of stroke patients. By removing this tissue, the potential for stroke is reduced.
The Maze Procedure
One particular surgical intervention – the Maze procedure – is regarded as the “gold standard” for curing AFib. Just like the other AFib procedures, the Maze involves creating scars in the heart to block the electrical arrhythmia. When this was first described, the only way to create the scars was by cutting the atrial tissue and sewing it back together. New ablation technologies, such as cryothermia and bipolar radiofrequency ablation, have improved the procedure, which is now safer, faster and more widely applied to AFib patients who are undergoing cardiac surgery to treat another heart condition.
Hybrid Procedures
Since all patients are unique, oftentimes the best treatment for AFib involves a combination of the procedures listed above. Some patients require more extensive patterns of scars and need all the lesions of the Maze to restore sinus rhythm. By combining surgical and catheter techniques, the AFib experts at SLU Hospital can create all the scars of the Maze using only minimally invasive techniques. No single therapy fits all patients. The patients at SLU Hospital are prescribed the most appropriate therapy based upon their individual circumstances.
Led by Dr. Richard Lee and Dr. Ali Mehdirad, the Heart Team at SLU Hospital offers AFib patients the full spectrum of therapy, from pulmonary vein ablation through minimally invasive surgery and hybrid Mazes to classic cut-and-sew Mazes, depending on the needs and preferences of the patient. Dr. Ali Mehdirad has performed more than 500 catheter pulmonary vein ablations on AFib patients, and Dr. Lee has performed more than 100 stand-alone Maze procedures and more than 50 hybrid Maze procedures on AFib patients with excellent results. The mission of our AFib specialists is to eliminate AFib in every patient with the least invasive approach. It’s our goal to give these patients a better and longer quality of life, free of stroke.
Picture of catheter pulmonary vein isolation. Each red dot indicates a spot where the catheter delivered energy. The catheter is then moved to the next spot, until all of the red dots completely encircle the pulmonary veins.