New Treatment for Atrial Fibrillation
Ventura County Star
by Lamar Bushnell, M.D.
Atrial fibrillation is a serious affliction affecting 2.3 million individuals in the United States with an annual incidence of 160,000. It occurs when the upper chambers of the heart quiver rather than beating fully and effectively in a rhythmic fashion. This, in turn, signals the lower pumping chambers of the heart to beat more rapidly than they should.
It is a common problem that affects approximately 1 percent of the population, and over 10 percent of patients in their 70s and 80s. This has particular implications in our area with a growing population of elderly patients. Furthermore, atrial fibrillation carries with it an increased long-term mortality rate, with much of the risk attributable to stroke rates associated with the disease. In fact, 24 percent of patients over age 80 with atrial fibrillation experience a stroke, and for ages 70-79 the stroke rate is 10 percent. And, the 10-year mortality rate of males with atrial fibrillation is 62 percent; women, 58 percent.
Adding to the problem is that medication is often ineffective at controlling atrial fibrillation. Though pharmacological agents continue to be developed, medication has only about a 50 percent success rate in symptomatic patients, and the side effects can be numerous and severe.
Advances in minimally invasive procedures continue to revolutionize medicine, and this includes a new way to treat atrial fibrillation
For more than a decade there has been one surgical option for treating atrial fibrillation called the “MAZE procedure”, but it is an open-heart operation requiring a heart-lung bypass machine. It is a major operation with significant risks and mortality rate. Now a newer procedure - utilizing the knowledge gained from the open MAZE procedure – is available. It is the thoracoscopic “mini-MAZE procedure” that has an approximately 80 percent long-term restoration of regular rhythm.
Instead of opening the chest, the mini-MAZE procedure uses a catheter that is inserted through tiny incisions (ports) on the side of the chest. Because the procedure is minimally invasive, patients generally spend only two days in the hospital. Using an endoscope – a tiny camera that can be inserted through the ports – the surgeon is able to view the heart without having to open the chest cavity. Special instruments are then inserted through the ports to perform the procedure, including the endoscope, small scissors, and graspers. These tools help move a Guidant FLEX Probe into position. Using the probe, the surgeon will then deliver targeted amounts of microwave energy to the heart. This creates lesions (helpful scars) on the heart muscle. The lesions create barriers for the irregular conduction patterns of the heartbeat, helping to eliminate the problem.
The Guidant FLEX Microwave Ablation System has been used in more than 12,000 procedures worldwide and, unlike traditional cardiac surgery, which requires a sternotomy or thoracotomy, this option is generally performed through ports involving only a few Band Aid®-sized incisions. The discomfort and recovery time associated with this new approach are thereby significantly reduced – making this treatment a more attractive option for the increasing number of patients with symptomatic atrial fibrillation.
—Lamar Bushnell, M.D., is a leading cardiac surgeon practicing at Community Memorial Hospital. He has an office in Ventura.