For years, you have had a noncritical condition called atrial fibrillation (irregular heart beat). It can be caused by high blood pressure, coronary artery disease or heart failure, and you run the risk of forming blood clots that might give you a stroke. To minimize this risk, your physician keeps you on a regular course of anti-coagulant medications. Now, recent diagnostic tests show that you've developed coronary artery disease and your physician recommends bypass surgery. An additional procedure, the maze procedure performed in conjunction with the bypass, will correct your chronic irregular heart beat and reduce your risk of stroke.

"At Doylestown Hospital, we offer the maze procedure to patients with chronic atrial fibrillation who need open heart surgery for other reasons, such as valve replacements or coronary artery bypass grafting," explains John Mitchell, director of cardiovascular services. "The maze procedure adds only about 15 minutes to bypass surgery, but has a 95 percent success rate in correcting irregular heart rhythm."

Why is atrial fibrillation dangerous?

Normal heartbeats are controlled by electrical signals from the sino-atrial node, a specialized collection of muscle fibers located in the right atrium. This signal travels down a specific electrical path that causes the heart to beat. A healthy pattern of electrical impulses causes the heart to beat in a constant, even rhythm of about 60 to 100 times per minute at rest.

In patients with atrial fibrillation, electrical impulses from other parts of the heart spread throughout the atrium causing it to beat much faster. "The atrium is beating erratically," Mitchell explains. "It doesn't contract normally. As a result, the atrium chamber does not empty properly." Because the heart isn't pumping properly, some blood may pool in the atrium. Over time, this pooling can cause blood clots to form and travel to the brain, causing a stroke.

"Having a stroke is the main risk of atrial fibrillation," Mitchell says. "As a result, patients are typically placed on anti-coagulation therapy to prevent clots."

The maze procedure - recovering a steady beat

The maze procedure is a surgical intervention that interrupts the circular electrical patterns responsible for atrial fibrillation. Mitchell explains that the procedure puts controlled lesions in specific areas of the heart, creating a "maze" that redirects electronic impulses and corrects atrial fibrillation.

Using a range of technologies, surgeons create a series of strategically placed incisions. The resulting scar tissue forms a "maze" that permanently blocks the pathways of wayward electrical impulses while channeling normal electrical impulses from the top of the heart to the bottom.

Doylestown cardiovascular surgeons Brian Priest, MD, and Randy Metcalf, MD, have trained specifically to do the maze procedure. Currently they use radiofrequency ablation to create the maze. But that may change as new technologies emerge. "We are looking at cryoablation (freezing the tissue). It is becoming popular, and we are thinking of adding that to our repetoire," Mitchell says.

Long-term benefits

More than 95 percent of patients return to normal heart rhythm after having the maze procedure. In three to six months, the heart heals and medications are stopped. The procedure has multiple benefits. The symptoms of atrial fibrillation -as well as the risk for stroke and other problems caused by blood clots-are significantly reduced, enabling patients to stop taking blood-thinner medications. "If you need heart surgery, "Mitchell says, "this is a convenient way to correct your atrial fibrillation while you are there."