Download atrial fibrillation - Downriver Cardiology

ATRIAL FIBRILLATION
Congratulations! You have just been diagnosed with atrial fibrillation, and you have joined the largest Cardiac
Club for patients with heart rhythm disorders. Even though it is not such a select group, let’s summarize some
information for you, and then review some general instructions.
Atrial fibrillation is the most common sustained heart rhythm disorder in America. The likelihood of atrial
fibrillation increases with age. Most people with atrial fibrillation are older than 65 years of age and more than
10% of people aged 80 have atrial fibrillation. When patients have atrial fibrillation, they lose their body’s
natural mechanism to maintain a regular, controlled heartbeat. Instead of the body’s normal pacemaker
providing a signal for the heartbeat at a rate that is appropriate for the person’s activity level, patients with atrial
fibrillation have an irregular, chaotic signal to the pumping chamber of the heart. Most of the time when atrial
fibrillation occurs, the heart rate is not only irregular but it is very fast. Patients become most aware of the
symptoms of the atrial fibrillation when it first occurs. After atrial fibrillation has been present for a long time,
patients adjust to it and are no longer aware of the irregular heart rhythm. Some patients never notice the
irregular rhythm even when it first happens.
We have four general management goals with atrial fibrillation. Usually the first one is to slow down the heart
rate when patients come to us when it is too fast. The second goal is to determine if there is an underlying heart
condition that caused the atrial fibrillation. For more than 90% of people at least some identifiable cardiac
condition is found, even if it is usually pretty minor. Our third goal is to protect patients against the most
important complication of atrial fibrillation, and that is a stroke. Because of atrial fibrillation, blood clots can
form in the heart which might break loose. If they travel to the brain, they would cause a stroke. Therefore,
almost all patients with atrial fibrillation need to take some type of a medicine to reduce their risk of blood clots
forming. For the majority of patients, this is therapy with warfarin (Coumadin). Sometimes patients are treated
with aspirin and/or Plavix. Finally, patients need a decision about controlling their heart rhythm to try to restore
their normal pacemaker function of the heart. Sometimes electrocardioversion is used to straighten out the heart
rhythm, and sometimes medications are effective. For many patients it is more appropriate just to allow them to
remain in atrial fibrillation, and to control the heart rate.
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WHAT TO LOOK FOR:
We will want you to help us monitor your heart rhythm. If you now have a regular heart rhythm, you will want
to watch for episodes of atrial fibrillation. We use the medical term paroxysmal because these events happen
suddenly and without warning. Now that you have been diagnosed with atrial fibrillation, you don’t need to run
to the hospital emergency room when one of these episodes occurs but you should take note of it and depending
on how uncomfortable you feel with the episode, call your doctor and report this symptom.
The second thing to look for is how fast your heart rate is both at rest and with activity. While you were in the
hospital, you were almost always at rest, and other people brought you meals, assisted you with daily activities,
etc. At home you might find that your heart rate increases considerably when you resume your regular
activities. You will want to check your pulse at least once a day when you first get home in order to monitor
this. If your heart rate is faster than 100 when you are at rest, or if it seems to increase excessively with modest
activity, you should call and let your doctor know that.
Many people who have atrial fibrillation never notice an irregular heart rate. Instead, atrial fibrillation affects
them by causing them to feel short of breath with activity or to tire out excessively. When you see your doctor
in follow up, you will be asked about those symptoms. Health care providers can evaluate patients more
effectively if you can give us an idea about what kind of regular activities cause your symptoms. For example,
does shortness of breath or easy fatigue occur with dressing and bathing? Climbing a flight of stairs? Or, only
with walking more than a mile on level ground?
MEDICATIONS
The medications used to treat atrial fibrillation match the treatment goals that are described above. They are
used to control the heart rate, to maintain a regular heart rhythm and to prevent blood clots. Sometimes people
take medications because they solve more than one problem. For example, many patients who have high blood
pressure also have atrial fibrillation. Both beta-blocking agents and some of the calcium channel blocking
agents are good for both conditions. Therefore, if you discuss atrial fibrillation with your friends, you may
discover that you are not on exactly the same medications.
MEDICATIONS TO SLOW THE HEART RATE: There are three types of medications to control the heart
rate with atrial fibrillation. The most commonly used medications are beta-blockers and calcium channel
blockers. Examples of beta-blockers include metoprolol (Lopressor, Toprol XL), atenolol (Tenormin), and
propranolol (Inderal). Beta-blocking agents are among the most common medications used in cardiology.
They are also used to protect patients against having heart attacks, control symptoms of angina, and for the
treatment of high blood pressure. Their most common side effect is a sensation of fatigue and sometimes they
can cause people to have cold hands and feet in the winter.
Calcium channel blockers are also effective in controlling the heart rate. Examples of these include diltiazem
(Cardizem, Tiazac, Cartia) and verapamil (Calan, Isoptin). Some of the calcium channel blockers that are used
for the treatment of high blood pressure such as Norvasc, Procardia and Dynacirc do not slow the heart rate and
are not used with atrial fibrillation. Calcium channel blockers are commonly used medications and they are also
effective in the treatment of high blood pressure and angina pectoris (chest pain). Their most common side
effect is constipation, but they can also cause a rash in some patients, and they may cause swelling of the
ankles.
Digitalis (Lanoxin, Digitek) has been used for centuries in patients with heart disease. It is not used for the
treatment of atrial fibrillation quite as much as it was a few years ago. It is going to be the first choice if the
patient with atrial fibrillation also has heart failure because Digitalis strengthens the heart beat. On the other
hand, digitalis has its greatest effect on slowing down the heart rate when the person is just resting and it is not
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as effective when the patient is physically active. Therefore, for most people it is not the first choice with
atrial fibrillation. Digitalis has virtually no side effects in the proper therapeutic dose. However, an overdose of
digitalis can cause symptoms of nausea, intestinal upset, vision disturbances and may even be life-threatening.
For these reasons, patient should never just take an extra dose of digitalis if they think they need better control
of their heart rate.
MEDICATIONS TO CONTROL THE HEART RHYTHM: There is no medication that will maintain a nice
regular rhythm in 100% of the people, all of the time. Instead, doctors try to choose the medication that has the
greatest likelihood of success in your particular situation. Sometimes the doctors get it right with the first
medication they try and sometimes it is a process of trial and error (doctors like to call this empirical testing).
The type of medicine that is chosen usually depends on how great the likelihood is that atrial fibrillation will
return, how hard it is going to be to maintain a regular rhythm and how serious the consequences are of a return
to atrial fibrillation. Many times, if the patient has just had a single episode of atrial fibrillation and they don’t
have significant underlying heart disease, the doctors may choose not to use any medication at all and just
follow the patient to see how they do. This is especially true of younger people and people for whom an
obvious cause of the atrial fibrillation is found (such as excessive alcohol consumption).
BETA-BLOCKERS: Beta-blockers were listed in the previous section as medications that are used to control the
heart rate. They also have beneficial effects maintaining a regular heart rhythm. As a very general statement, if
a person has had an episode of sustained atrial fibrillation that returns to a regular heart rhythm, there is a 25%
chance that their heart rhythm will be regular when they are seen one year later. Beta-blocking agents double
that success rate, to about 50%.
CALCIUM CHANNEL BLOCKERS: Calcium channel blockers diltiazem and verapamil also have beneficial
effects in maintaining a regular heart rhythm in addition to their use to control the heart rate. Most people think
they are just about as effective as the beta-blockers just mentioned.
NORPACE, QUINIDINE, RYTHMOL AND PROCAINAMIDE: In this modern era, it is rare to use
procainamide or quinidine for the management of atrial fibrillation. Norpace (disopyramide) and Rythmol
(propafenone) increase the likelihood of a regular heart rhythm at one year to about 60%. These medications
have the disadvantage that they need to be taken 2-3 times a day. The doctor needs to follow the use of these
medications by performing an EKG and doing blood tests at intervals to be sure that the dosage is just right.
BETAPACE-AF (SOTALOL): Betapace is a special type of a beta-blocking agent. At low doses, the effect of
this medicine is that it is just a beta-blocker. At higher doses, it takes on antiarrhythmic effects. That is, it
increases the likelihood that the heart rhythm will remain normal. In patients who take this medication, the
chance of a regular heart rhythm one year later is about 70%. A disadvantage of sotalol is that patients must be
hospitalized in order to receive the medication, just to be sure the drug does not cause different types of heart
rhythm problems.
TIKOSYN (DOFETILIDE): Dofetilide is a brand-new medication used for the treatment of atrial fibrillation. It
was released in 2000 with a whole new set of restrictions imposed by the FDA. Patients must be hospitalized to
receive the medication. The medication is not available in all hospitals and is not available in pharmacies. It
can only be administered by a health care provider who has fulfilled certain FDA requirements. The medication
is shipped to the patient’s home by UPS. Apart from these inconvenient aspects, it is an effective medication
for treatment of atrial fibrillation. Although there is not nearly as much experience with this medication as with
others, its success rate at one year is in the range of 70%.
AMIODARONE (CORDARONE, PACERONE): Amiodarone has been used for nearly 20 years in the
management of rhythm problems. It is quite an unusual medication. First of all, think about a simple aspirin or
Tylenol pill. You swallow the medication and it is in your bloodstream 30 minutes later producing beneficial
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effects, and four hours later it is gone. In contrast, amiodarone may take a month to build up in your
bloodstream and it takes 2-3 months to wash out once you discontinue the medicine. For this reason, sometimes
patients are placed in the hospital to receive amiodarone where they can get it in high dose in pill form or
through an I.V. Or, patients take it in a loading dose of two or three pills daily for one month before they settle
into their long term dosage. Amiodarone is the strongest medication for the treatment of atrial fibrillation, and
about 80% of patients have a regular rhythm one year later. It also has the highest likelihood of side effects.
Patients on amiodarone need blood tests every six months to make sure the medication has not affected the
function of their thyroid or liver. They need a chest x-ray once a year. Amiodarone interacts with a lot of other
medications. For patients with atrial fibrillation, the most important interactions are with Coumadin (warfarin)
and digitalis.
MEDICATIONS TO PREVENT BLOOD CLOTS:
COUMADIN (WARFARIN): Coumadin is the mainstay of medications used to prevent blood clots in atrial
fibrillation. To use it successfully calls for the patient to work carefully with the physician’s office. Coumadin
is only effective when the medication produces a change in the blood so that the test results fall in the
therapeutic range. If the blood is too thin, patients are at risk for excessive bleeding, including a stroke. If the
blood is not thin enough, the medication doesn’t do any good. Typically, patients are started on a dose that is
predicted to be the right dose for them and then they have their blood tested at regular intervals until the dosage
is just right. There are so many medications that can interfere with the effectiveness of Coumadin that you need
to check with your doctor or nurse anytime someone recommends that you start a new medication. The food
you eat, and the alcohol you drink may also affect your blood thinner levels.
ASPIRIN AND PLAVIX: For certain patients, Coumadin is either not necessary or it is not the best choice. For
these people, aspirin and/or Plavix may be prescribed. These medicines are called antiplatelet agents because
they prevent blood clots by a mechanism different from Coumadin. They have the advantage that patients on
aspirin or Plavix do not need to have blood tests to be sure that they are taking the right dose. They have the
disadvantage that they are not quite as effective as Coumadin in preventing blood clots. If the risk of blood
clots is very low, aspirin may be used just for “insurance.” In some patients the risk of blood clots is fairly high
but aspirin is used because the risk of bleeding from Coumadin is even higher.
ACTIVITY INSTRUCTIONS
Patients who have atrial fibrillation may be limited by the atrial fibrillation itself or they may be limited by the
heart condition that has caused the atrial fibrillation. In general, patients need to get out and increase their
activity levels in order to determine how much limitation they are going to experience. If patients are
participating in a cardiac exercise program, they can learn about their limitations very efficiently. The EKG
monitoring they receive will let them know how their heart rate is doing with activity. They can also exercise
on a treadmill or bicycle and gradually adjust the intensity of their activity in order to get a feel for their
exercise limitations. In patients who are exercising at home, they can monitor their progress by checking their
pulse with activity, and by observing how they feel with standard activity.
In general, patients should not have their activities restricted because of the atrial fibrillation itself. In fact, they
should resume their normal activities and then let their doctor know how their heart rate responds to these
activities. They can resume their usual household activities, light chores and activities, sexual intercourse,
shopping and other pursuits. As a rule patients should avoid strenuous activities and vigorous exercise
programs until they have followed up with their doctor one week after discharge.