Atrial Fibrillation (AF) is the most common heart rhythm abnormality, affecting more than 2 million Americans, especially as people get older. Once thought to be a nuisance condition, atrial fibrillation is now known to be very dangerous, causing one of every seven strokes. It can prevent the heart’s ability to pump blood efficiently. Moreover, atrial fibrillation can be deadly—patients with AF have double the risk of dying from a heart condition.
Standard management of atrial fibrillation uses medications to slow down the heart rate, but this can result in decreased pumping efficiency. Using a blood thinner, Coumadin (wafarin), can prevent half but not all of the strokes caused by atrial fibrillation. Coumadin, however, interferes with normal blood clotting and can cause serious and even fatal bleeding—a serious side effect.
The other widely used strategy for atrial fibrillation management uses medications to restore normal sinus rhythm, which will prevent stroke, maintain the efficient pumping action of the heart and avoid the need for blood thinners. Unfortunately, the best available anti-arrhythmic drugs fail in 45 percent of cases and can cause some serious side effects, too, which often cancel the benefits from recovering sinus rhythm.
In the vast majority of patients, atrial fibrillation is caused by an abnormal electrical impulse, which starts in cells in one of the four pulmonary veins. These veins return oxygenated blood from the lungs to the left atrium. Insulating the heart electrically from the four veins prevents the spread of abnormal electrical signals to the atrium and is an effective cure for atrial fibrillation.
A surgical therapy to create such insulation against atrial fibrillation (called the Maze procedure) has been offered for 20 years, but it is a long, open-heart surgical procedure requiring a heart-lung machine and temporary stoppage of the heart. Fortunately, Beth Israel cardiac surgeons can offer patients a minimally invasive surgical option, called Mini-maze surgery, which provides safe and easy access to the heart through a two-inch incision between the ribs. The Mini-Maze procedure does not require separation of the breastbone nor use of a heart-lung machine.
During a Mini-maze procedure, our heart surgeons go between the ribs and apply a special clamp around the junction of the pulmonary veins and the left atrium. A brief burst of measured radiofrequency energy passing between the jaws of the clamp creates the needed insulation line between the pulmonary veins and the atrium, thus blocking the abnormal electrical impulse pathway. Also during Mini-maze, through the same small incision, specialized electrical testing locates nerve tissue collections, which lie in the fat on the surface of the heart. These are interrupted as well, with no ill effects to the heart, adding further protection against AF.
In all patients, the left atrial appendage, an unnecessary, small pouch on the atrium, is removed using a special stapler. This is the main site where blood clots can form within the heart.
The Mini-maze operation takes around three hours and is safe and highly effective. Most patients stay in the hospital three days and can return to full activity two weeks after the procedure. Most can be gradually weaned off anti-arrhythmic and blood-thinning medications in three months.
Open-Heart Surgical Alternatives for Stopping AF
For patients who are undergoing open-heart surgery procedures, such as mitral valve repair surgery or coronary artery bypass surgery, Beth Israel cardiac surgeons can treat atrial fibrillation at the same time they address those problems.
Using two advanced techniques–radiofrequency ablation or cryoablation–they can effectively eliminate abnormal heart rhythms and provide relief from atrial fibrillation.
Radiofrequency ablation or cryoablation are performed after the chest cavity is opened, and the heart is exposed. Surgeons use flexible, hand-held probes, with tips that generate thermal radiofrequency energy or are super-cooled to sub-zero temperatures to destroy abnormal heart tissue and electrical pathways contributing to a patient’s arrhythmia. As with the Mini-maze procedure, surgeons also alter some normal tissue as well, creating that insulating line or “firebreak” to prevent abnormal impulses from reoccurring.
The radiofrequency or cryoablation procedure maintains left and right atrium pumping function, so overall cardiac output is preserved.
After surgery, patients are transferred to an intensive care unit where they are closely monitored for one or two days. Once a patient’s condition is stable, he or she is transferred to a regular inpatient unit. Most patients stay in the hospital five to seven days after an open-heart/ablation operation, depending on their rate of recovery.
Full recovery takes about six to eight weeks. Some patients may experience rapid heartbeats during the first three months after surgery, due to inflammation of heart tissue. This is treated with medication. A small number of patients may require pacemakers after open-heart/ablation because of an underlying abnormal heart rhythm is unmasked by treating AF.
The atrial fibrillation cure rate for open-heart surgical ablation, whether cryoablation or radiofrequency, is 75 to 90 percent. Complications are rare. The procedure reduces the risks of blood clots and stroke, and patients don’t have to take blood thinners, such as Coumadin, and anti-arrhythmic drugs, such as Amiodarone.
Beth Israel heart surgeons have the experience and expertise to consistently achieve successful outcomes using radiofrequency or cryoablation to treat atrial fibrillation during open-heart surgery.