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Flutter in the heart: A look at atrial fibrillation
Seattle Times medical reporter
The sensation deep in Cari Widmer's chest came without warning. It was like a little storm in her heart.
"I was having no normal heart beats, just a continuous fluttering sensation ... a vibrating quiver up to my esophagus," said Widmer. "Then I got short of breath."
Widmer, 35, an emergency-room nurse, was in the middle of evaluating a patient. She kept her cool through the approximately 15-second episode last fall, and the patient, who really wasn't very ill, never knew anything was wrong.
"Afterwards, I felt like my whole body had been through a major workout," said Widmer, who works at the University of Washington Medical Center.
Widmer was undergoing her first detectable occurrence of atrial fibrillation, in which the heart's upper two chambers (atria) quiver instead of contract and cause the lower pumping chambers (ventricles) to race up to 120 to 175 beats a minute. When the blood pools in the upper heart, it sometimes forms clots that can lead to a stroke.
For a huge variety of people, atrial fibrillation, or AF, is on the increase.
Already, more than 5 million people in the U.S. have the condition, and it may affect nearly 16 million by 2050, according to a recent study by the Mayo Clinic.
"You can call it an epidemic. And it's on the horizon for occurring more and more," said Dr. Richard Page, director of cardiology at the UW medical school and a nationally known expert on AF.
Being part of the epidemic affected Widmer in big way. She worried that treating patients who were especially emotional would trigger an episode. Her medications made her tired. She withdrew socially.
"It was a very frightening sensation when I did have it," said Widmer, who received treatment and now rarely has even a trace of a flutter.
What causes AF?
Everyone's heart skips a beat occasionally, just because the pattern of electrical impulses that cause the heart muscles to contract aren't perfect. Many people also have very brief periods — several seconds or so — in which their hearts race or flutter. These may be caused by emotional stress, caffeine, rigorous exercise or occur for unknown reasons.
True atrial fibrillation is usually more pronounced with flutters that last longer — usually a minute or more. Other symptoms include lightheadedness, shortness of breath, fatigue and, occasionally, chest pain and fainting. And some people have no symptoms.
Page and other authorities believe the increase in AF is partly a result of the aging of the population: Fewer than 1 percent under age 60 have AF, but as many as 10 percent of those in their 80s have it.
Experts also blame the increasing incidence of obesity, which can lead to major risks for AF: heart disease, high blood pressure and diabetes. Other risk factors include thyroid problems, abnormal heart valves, emphysema or other lung diseases, viral infections and having had a previous stroke or heart surgery or a family history of the disorder. Overexposure to stimulants such as coffee and tobacco and alcohol abuse also can weaken the heart and bring on AF.
Doctors don't know the cause of Widmer's bout with the disease. She has a form called "lone" atrial fibrillation, which has no clear risk factor. As many as one-third of all patients have this type.
Widmer seems an unlikely candidate for AF: She is young. She was a competitive gymnast for 10 years. She has never smoked, rarely drinks alcohol or coffee and has always had a healthy diet.
Her physicians have speculated about possible contributing factors. She may have had an infection at some time that slightly inflamed her heart; recent research has linked inflammation with AF. And she was stressed out — working full-time in the emergency room, plus studying to become a family nurse practitioner.
"It's really hard to know. ... It does happen in young people, but in most cases there is no known cause," said Dr. Robert Rho, the UW expert in AF who treated Widmer.
Treatments for AF have three approaches, which are used alone or in combination:
One uses a blood thinner such as aspirin or warfarin to thin the blood and reduce the risk of stroke.
Another uses drugs such as digoxin, calcium channel blockers or beta blockers to slow the heart rate.
A third treatment attempts to restore normal rhythm through drugs such as amiodarone or briefly shocking the heart while the patient is sedated.
But even with drugs, patients usually have occasional episodes. If the medications don't substantially reduce the incidents, more invasive treatments may be offered.
For about eight months, Widmer took a drug to slow her heart rate. Her AF episodes decreased from three or four a month to about one. But the fatigue caused by her medication was a real problem. And she still worried about having another episode.
"I just didn't want to go out and socialize," said Widmer, who was so tired she also stopped her regular walks around Alki and working out at a gym.
Widmer didn't want to take the medications and have the side effects for the rest of her life. She elected to have a procedure to quell the episodes permanently.
The procedure, called "ablation," involves threading a catheter through a leg vein up to the heart and applying electrical current near the openings to the pulmonary veins.
It is in those veins, which carry blood from the lungs to the heart, where fibrillation episodes often are triggered. Doctors map the veins electronically, then apply electric current to tissue surrounding the trigger points. That creates scar tissue, which blocks the electrical impulses. About 1 percent of the time, things go wrong; the heart may be punctured or the patient my have a stroke.
The procedure has been used for about eight years, and studies so far indicate it eliminates AF about 70 to 80 percent of the time.
Surgeons also may perform the "maze procedure" if they've opened the chest of a patient with AF to treat a separate heart condition. In the maze surgery, scars to block the disruptive electrical impulses are created by injuring the atrial tissue with an electrical probe or one that is very cold.
Widmer's five-hour ablation procedure last June went well. She had no lingering pain from the operation, but, like all patients, her risk for a recurrence of AF increased the first three months because the operation irritated the tissue. She took medications to prevent any new fibrillation episodes and a blood thinner to prevent clots.
Widmer had "a few little flutters" right after she went off the drugs a few weeks ago, but no real AF since the surgery. Now she's looking forward to a new job with more responsibility. And she's returned to walking and regular workouts.
"I want to become very athletic again," she said. "I'm still a little apprehensive. ... But I'm definitely on that road."
Warren King: 206-464-2247 or firstname.lastname@example.org
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