BY JULIA EVANGELOU STRAIT
AS HE SAWED A BACKYARD TREE, Steve Gaal felt his heart start to race, and somehow it didn’t feel right. Over the next month he experienced more of these worrisome episodes. Sometimes the frantic beats stopped after a few minutes; other times they lasted more than an hour.
“If I was walking up stairs when it started, I could finish the staircase,” he says. “I could force myself through it, but I felt like I shouldn’t do anything while it was happening. Most of the time, I would just sit and wait for it to run its course.”
An active retiree, the former president and CEO of Delta Dental of Missouri sought the advice of his doctor, who referred him to a cardiologist. A heart monitor revealed the problem — atrial fibrillation, the heart’s most common irregular beat.
Pioneers in combining surgical techniques for treating atrial fibrillation, from left: Hersh S. Maniar, MD, Ralph J. Damiano Jr., MD, Mitch N. Faddis, MD, PhD, and Phillip S. Cuculich, MD.
Photo by Mark Gilliland
After standard treatments failed, Gaal’s doctors at the School of Medicine suggested a new “hybrid” procedure. The approach combines minimally invasive surgical techniques with the latest advances in catheter ablation, a technique that applies scars to the heart’s inner surface to block the signals that cause the heart to misfire. The two-pronged approach gives doctors access to both the inside and outside of the heart at the same time, helping to more completely block the erratic electrical signals that cause atrial fibrillation.
Atrial fibrillation affects more than 2 million Americans. While not fatal in itself, patients who suffer from atrial fibrillation are at increased risk of stroke and congestive heart failure. And many, especially those like Gaal who feel the fibrillations, have shortness of breath, chest pain, fatigue and feelings of anxiety, among other problems.
“For some patients, it’s a difficult way to live,” says Phillip S. Cuculich, MD, assistant professor of medicine and a cardiac electrophysiologist who treats patients with atrial fibrillation at Barnes-Jewish Hospital.
Atrial fibrillation occurs when the upper chambers of the heart, called atria, get irregular electrical signals that disrupt the coordinated pumping of blood through the heart to the rest of the body. Instead of a normal beat, these signals cause the heart to quiver, preventing adequate blood flow to the ventricles, the heart’s main pumps.
Despite its prevalence, atrial fibrillation remains tricky to treat. Medications that maintain a normal heart rhythm often stop working after a period of time.
“I tried medication,” Gaal says. “They thought it was working. But within a day or two after they released me from the hospital, I felt the fibrillations starting up again.”
When medication fails, doctors typically recommend catheter ablation, which involves threading long, thin tubes through a vein in the groin into the heart. The tips of these catheters can be heated, allowing doctors to perform a series of ablations, or burns, on the heart’s inner surface. The goal of ablation therapy is to create scar tissue that isolates the irregular electrical signals and blocks them from spreading over the heart and causing fibrillation. After a catheter ablation procedure, about 70 percent of patients remain free of symptoms after one year.
Enters through small incisions on both sides of the chest; operates an electrical clamp on the heart
Inserts electrical catheters through veins in the groin; operates the catheters inside the heart
Washington University physicians at Barnes-Jewish Hospital pioneered the surgical treatment of atrial fibrillation. The original procedure involved opening the chest, stopping the heart and applying a “maze” of incisions. Although this proved highly effective, researchers continued to seek less disruptive approaches. Incisions can be replaced by controlled scars, called ablations, created with electrical currents applied in or on the beating heart. However, the limited depth of such scarring permits tissue to regrow, and fibrillation can recur. Now, a team of specialists has joined forces to perform inner and outer ablations during one minimally invasive surgery, offering effective treatment and quicker recovery.
A surgeon performs a series of ablations on the heart’s outer surface. These burns surround the pulmonary veins, where the erratic signals that cause atrial fibrillation often originate.
An electrophysiologist uses catheters to perform ablations on the inner surface to further contain the signals.
The electrophysiologist tests the heart to see if fibrillation is impeded; more work may be needed. Lastly, the surgeon removes the left atrial appendage, a point of origin for blood clots that can cause strokes.
Although success rates for catheter ablation are higher than medication, it doesn’t always work; some patients may require a second or third procedure to achieve a successful result. And it does not work well for patients with an enlarged left atrium, like Gaal.
For these hard-to-treat patients, doctors may recommend the Cox-Maze surgical procedure, developed in 1987 by James L. Cox, MD, at Washington University.
The left atrium connects to the pulmonary veins. During the procedure the surgical team can test the heart to see if fibrillation has been impeded (red areas, right). A gap in the red (white box) means more ablation is needed.
With a high success rate, the Cox-Maze procedure is considered the gold standard of atrial fibrillation treatment. The original Cox-Maze procedure has been refined by Ralph J. Damiano Jr., MD, the John M. Shoenberg Professor of Surgery, and is effective in 90 percent of patients. Damiano has made the procedure easier to perform and more widely available. But many patients consider it too invasive.
“If you have other open-heart cardiac surgery that you need, like bypass surgery or valve surgery, and you have atrial fibrillation, the Cox-Maze procedure is an excellent choice to do at the same time,” Cuculich says. “But most of my patients just have atrial fibrillation.”
After medication failed and since he had no other heart problems, Gaal’s doctors determined he would be a good candidate for the hybrid procedure. Available at only a handful of U.S. medical centers, the hybrid approach attempts to recreate the success rates of the Cox-Maze procedure with the minimally invasive nature and shorter recovery times associated with catheter ablation.
Because catheters enter through a vein, electrophysiologists only have access to the inside of the heart. A surgeon, in contrast, can provide access to the outside.
“By applying the energy to make scars from both the inside and outside of the heart, we’re better able to achieve a full-thickness ablation,” says Hersh S. Maniar, MD, assistant professor of surgery, who performs the new hybrid procedure and the Cox-Maze. “A complete scar that crosses through the full thickness of the heart wall will more permanently block atrial fibrillation signals.”
To avoid open surgery, the hybrid procedure is performed through three small incisions under both of the patient’s armpits. The surgeons view their work by inserting a small camera into one of the incisions.
After the surgeon has performed the ablations on the outside of the heart, the electrophysiologist uses the catheters inside the heart to attempt to induce a fibrillation, testing the integrity of the ablation lines. If the atrial fibrillation persists, the electrophysiologist can touch up the ablation lines inside the heart until fibrillation can no longer be induced. Finally, the surgeon closes off the left atrial appendage, the area of the heart where most stroke-causing blood clots originate.
A clinical trial is planned to compare the new hybrid procedure to catheter ablation in patients whose atrial fibrillation is persistent, meaning it does not start and stop on its own, and whose left atrium is enlarged. This group of patients has not done well historically with catheter ablation.
But outside the clinical trial, the procedure is now available to any patient with atrial fibrillation after consultation with his or her doctor.
“Right now we’re doing this for people who have persistent atrial fibrillation and for people who have had a failed catheter ablation procedure,” Cuculich says. “I think this is an important step forward in improving patient quality of life in a less invasive way than traditional surgery.”
Gaal is pleased with the results.
“I’ve had no recurrences of the fibrillations since the procedure,” he says. “I feel good and I know in the next few months I’m going to be that much better. I’m looking forward to it.”