A Woman's Heart
"You need to speak up when you think you may have a heart
problem such as an arrhythmia. Tell your doctor, 'I am worried because I am not used to
having these symptoms.' If your doctor is not taking your complaints seriously, see
another doctor" - Barbara Alving, M.D., acting director of the NHLBI
How Women Are Different
There are several NHLBI-sponsored clinical trials currently underway
looking at the role that hormones may play in determining cardiovascular events in women.
Here's what we know now:
AF can be more serious in women than in men. The
most common arrhythmia in women (and men) is atrial fibrillation (AF), which affects an
estimated 2.2 million people in the United States, the majority of them over 50. With AF,
a person's heart beats abnormally fast and irregularly, which increases the risk that
blood may form clots that can break away and cause strokes. Uncontrolled AF is responsible
for about 8,700 deaths each year, according to the AHA.
Even though men are more likely to develop AF than women, results
from the landmark Framingham heart study released last August reveal that, compared with
men, women have about twice the risk of stroke after the development of AF, according to
Daniel Levy, M.D., director of the study. A female AF patient's chance of having a
subsequent life-threatening heart problem is two and a half times greater than a
middle-aged man's, according to the NHLBI.
Hormonal changes have an impact. There are peak
periods in a woman's life for certain types of arrhythmias, according to Dr. Bairey Merz.
For instance, around the time of puberty girls can begin to have arrhythmias that cause a
higher heart rate and lower blood pressure and that may lead to fainting.
"Fortunately, young women sometimes grow out of the problem," she says.
"Women who have arrhythmias may notice more symptoms right
before their periods, and palpitations can be pronounced during this time in the menstrual
cycle," says Andrea M. Russo, M.D., clinical associate professor of medicine and
director of the electrophysiology laboratory at the University of Pennsylvania Medical
Center-Presbyterian in Philadelphia. Women with arrhythmias may also experience a surge in
symptoms around the time of menopause, she adds.
The constant wax and wane of a woman's hormones can often make it
difficult for electrophysiologists to get to the root of a woman's complaints, according
to Dr. Russo. For example, a procedure known as an electrophysiology study (in which
pacemaker catheters are threaded through veins in the groin up to the heart in order to
evaluate the heart's
Could You Be at Risk?
The same factors that can put you at risk for heart disease—
high blood pressure, smoking, diabetes, high cholesterol and obesity—can also put you
at risk for an arrhythmia, so it's crucial to address these issues, say doctors.
High blood pressure is an important risk factor for arrhythmias,
according to the NHLBI's Patrice Desvigne- Nickens, M.D., so you need to make sure your
pressure is under control. Quitting smoking is also key, because smoking increases the
risk of arrhythmias three- to fourfold, says Noel Bairey Merz, M.D., of Cedars-Sinai
Medical Center in Los Angeles.
Intermittent palpitations or racing heartbeat are two common signs
of arrhythmia. If your doctor suspects you may have one, she will do an electrocardiogram
(ECG), which records the electrical activity of the heart. A normal ECG, however, doesn't
eliminate the possibility of certain arrhythmias, such as atrial fibrillation, because
this rhythm may be intermittent, says George Mensah, M.D., chief of the cardiovascular
health branch at the Centers for Disease Control and Prevention in Atlanta, and "an
ECG is extremely short, maybe ten seconds at the most. If you have persistent symptoms,
you may need to be monitored for longer periods of time using a portable device called an
event recorder or Holter monitor.
If your palpitations occur with chest pain, shortness of breath,
dizziness, lightheadedness, tightening of the throat, or neck tension, you should call 911
as soon as possible, says Dr. Mensah, since these are all possible signs of heart attack.
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electrical circuitry) may be more
successful at detecting an abnormal heart rhythm if it is performed at the times of the
menstrual cycle when a woman's symptoms are most disturbing, she says. Arrhythmias can also become bothersome during pregnancy, and may even occur
in a woman with an otherwise normal heart, says Dr. Russo. And the postpartum period can
be especially dangerous if a woman has an inherited form of arrhythmia known as Long QT
syndrome, which affects an estimated one in 5,000 Americans. One out of 10 women with the
disorder will experience serious symptoms during the postpartum period, including sudden
cardiac arrest, according to Augustus Grant, M.D., professor of medicine at Duke
University School of Medicine, and president of the AHA.
That's what happened to Sandra Kawamoto, of Oregon City, Oregon, who
didn't even know she had the disorder until she almost died from it. The then- 29-year-old
had just finished nursing her newborn daughter and crawled into bed when she heard a thud
(which turned out to be a burst pipe). She scrambled out again to see what had happened.
Minutes later she was lying on her 4-year-old son's bedroom floor in sudden cardiac
arrest. Paramedics had to shock her heart twice to get it started, and she remained in a
coma for 17 hours.
Long QT syndrome, which is caused by a genetic mutation in the
heart's electrical system, can cause a very fast, irregular heartbeat. In the most severe
cases, such as Sandra's, the beat of the heart becomes so disorganized that blood stops
pumping and a person goes into sudden cardiac arrest. Arrhythmias are usually diagnosed
with an electrocardiogram (ECG), a recording of the electrical activity of the heart. But
Sandra, now 42 and a teacher's aide, had been so healthy that she had never had a reason
to have the test.
Medications may put you at risk. Certain
over-thecounter and prescription medications—including some antihistamines and even
some drugs used to treat arrhythmias—can actually cause a heart rhythm abnormality
called Torsades de Pointes. The problem occurs twice as often in women as it does in men,
according to Raymond Woosley, M.D., Ph.D., vice president for health sciences at the
University of Arizona, who was one of the first to detect this adverse reaction with
Seldane in the mid-1980s. The medications can cause a very rapid heart rate that, if
sustained long enough, can result in sudden cardiac death. Dr. Desvigne-Nickens says that
there are about 200,000 cases of Torsades each year.
"If you're on any medication and get dizzy, call your
doctor," says Dr. Woosley. "Torsades is usually a self-limiting problem if it is
recognized early and the drug is stopped. Awareness can make a big difference," he
says. Dr. Woosley maintains a web site (www.azcert.org)
that lists all of the medications that can cause Torsades de Pointes.
The FDA is developing new guidelines to help women avoid potentially
lethal drug-induced arrhythmias such as Torsades de Pointes. "We ask drug companies
to submit their drug analysis data by age and sex so it is easier to sort for potential
problems, and we're trying to develop ways to detect a potential problem with a drug
before it goes to market," says Susan F. Wood, Ph.D., assistant commissioner for
Women's Health at the FDA. |
How They're Treated
DRUGS
In many cases, abnormally fast rhythms can be safely treated with high blood pressure
medicines such as beta-blockers or calcium channel¨Cblockers, which help to slow the
heart rate. If you take any of these medications, it's important to always check with your
physician or pharmacist before taking another medication or even an over-the-counter
dietary supplement or vitamin, since these may interact with the heart medication.
Another effective medicine, especially for atrial fibrillation (AF),
is the anticoagulant drug warfarin (Coumadin). According to the Framingham heart study
released last August, treating AF patients with anticoagulant drugs like warfarin can cut
the incidence of stroke by as much as 83 percent, yet "only one-third to a little
more than half of patients with atrial fibrillation who would be good candidates for
warfarin therapy actually receive it, with elderly patients the least likely to be treated
with warfarin."
Many patients aren't good candidates for warfarin because of the
risk of bleeding and the need for frequent blood tests to regulate the dose, so doctors
are hopeful that a new drug now in clinical trials called Exanta (ximelagatran) may be a
good alternative. Researchers say it appears to be easier to use than warfarin, is
relatively safe and equally effective.
PACEMAKERS
If your arrhythmia is due to an abnormally slow heart rate, doctors can surgically implant
a palm-size pacemaker under your collarbone to help you maintain a normal heart rhythm.
The newest kinds of pacemakers, called automatic internal cardiodefibrillators (AICDs),
are also used to shock at-risk patients out of lethal arrhythmias.
ABLATION
For many patients with abnormally fast rhythms, the treatment of choice is a medical
procedure called ablation, which has an overall cure rate of roughly 90 percent, according
to Melvin Scheinman, M.D., professor of medicine at the University of California, San
Francisco, who performed the first ablation in 1981. Both Julia Swift and Mary Corle had
ablation after their arrhythmias were diagnosed. An electrophysiologist inserts a thin
tube or catheter through a blood vessel in the upper thigh and then threads it up to the
heart. A small wire at the end of the catheter uses radio frequency energy to burn away
the abnormal areas of the heart that cause an arrhythmia. "I just feel so different
now," says Mary. "I didn't know this was how your chest was supposed to
feel."
Young patients with arrhythmias are "ideal candidates" for
ablation because they may not want to take medicine the rest of their lives, and shouldn't
take medicine while they're pregnant, says Dr. Wolbrette. But as successful as ablation
is, a recent study in the Journal of the American College of Cardiology revealed
that compared with males, females "were referred for ablation on an average of 28
months later after onset of symptoms and after having been given more antiarrhythmic
drugs."
"Women are referred for less of practically everything, with
the exception of sex-specific things like mammography," says Dr. Bairey Merz.
"The reasons behind this are in part medical, because we have done less research in
women and so sometimes feel less certain about the effectiveness of a therapy."
In the rare cases where medication or the ablation procedure doesn't
solve the problem, surgery may be necessary. That's what happened to Christine Shapter, a
nurse from West Hartford, Connecticut, who was diagnosed with multiple arrhythmias at age
23. Even after she was treated with ablation twice, she still had unrelenting symptoms.
"It was really affecting my life a lot," says Christine. "I was in and out
of the hospital, changing medications." In October of 1997 she had open heart surgery
to cure her arrhythmia. Now 35, she's doing fine and recently got married.
"Christine's problems are the far end of the spectrum,"
says her doctor, Robert Chamberlain, M.D., of St. Francis Hospital and Medical Center in
Hartford. "Nevertheless, an ordinary woman probably would have been clueless as to
what was going on. But because Christine was so intimately involved in the medical field,
she understood more about what her symptoms meant and was closer to getting help than the
average person. That made all the difference in her getting the appropriate
treatment."
"Twenty years ago, we were in the dark about gender
differences," says Barbara Alving, M.D., acting director of the NHLBI. "Back
then, my mother—an overweight diabetic who clearly had risk factors for heart
disease—felt terrible pain in her chest and called her doctor's office. The nurse
told her to take Pepto Bismol for her upset stomach, but she had really had a major heart
attack. We've come a long way."
WANT TO KNOW MORE?
Last updated: February 2004
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