ATRIAL FIBRILLATION EDUCATIONAL MATERIAL
University of Pennsylvania

Atrial Fibrillation: Description of the Arrhythmia and Symptoms

Atrial fibrillation (A-Fib) is a heart rhythm disorder in which disorganized electrical activity in the atria (top
chambers of the heart) replaces the normal organized electrical activity that starts from the normal generator of the
heart, the sinus node. The organized electrical activity during the normal or "sinus" rhythm makes the atria contract
together. During A-Fib, multiple circuits of electrical activity appear to spin around the nooks and crannies of the
atria As a result of the disorganized atrial electrical activity, the atria quiver instead of contracting as in a regular
heartbeat.

The heart rate is determined by how often the ventricles, or bottom chambers of the heart, contract each minute. The
ventricles are the main pumping chambers of the heart. During sinus rhythm, the ventricles contract after the atria.
In A-Fib, the ventricular rate will change, depending on how many electrical signals travel through the single
electrical road that connects the atria to the ventricles (A V node). In some people, the heart rate in A-Fib is fast and
disorganized. In others, it is slower and more regular.

A-Fib may cause you to feel symptoms from the quivering of the atria, a fast heart rate, or an irregular heart beat.
You may feel: 1) palpitations, 2) fatigue, 3) breathlessness, 4) dizziness,S) vague chest discomfort or pain, or 6)
hoarseness. Some people do not experience any of these symptoms.

Many people with A-Fib also experience an abnormal rhythm called atrial flutter. Atrial flutter is a "short circuit"
that spins around the atria at a rate of 250-300 times per minute. It is more organized than A-Fib, but the heart rate
can be very fast, as the ventricles try to keep up with the atria. Some people can have a heart rate of 130-150 beats
per minute with atrial flutter. You may feel palpitations, breathlessness, chest discomfort, and fatigue, due to the
fast rate. Some people go back and forth between A-Fib and atrial flutter.

A. Sinus Rhythm =
Normal heart
rhythm that
originates from the
sinus node (*)

B. Atrial
Fibrillation =
Multiple small
circuits triggered
from the pulmonary veins(*)

C. Atrial Flutter =
one large circuit-
typically in the
right atrium

Figure 1

Atrial Fibrillation: Causes and Precipitating Factors

A-Fib may be caused by a number of factors, some of which are poorly understood. Even completely normal atria
can go into A-Fib. A-Fib usually may lasts from seconds to days. A-Fib may stop on its own. A-Fib that stops and
starts repeatedly is called paroxysmal A-Fib. Over time, A-Fib tends to last longer and longer, until it no longer
stops on its own.

There may be a family tendency to develop A-Fib. The development of A-Fib in many people is associated with
aging of the heart, similar to the aging that might be associated with losing your hair or developing wrinkles in your
skin. It appears that as the heart ages, the cells do not line up perfectly. When the heart muscle cells are lined up
perfectly, they keep each other under control. When they stop lining up perfectly, the atrial cells begin to fire out of
turn, earlier than the normal electrical activity of the sinus node. The frequent, irregular, early discharge of the atrial
cells can lead to multiple short circuits in the heart, which occur with A-Fib. Heart diseases, such as hypertension or
coronary artery disease, tend to make this atrial aging process more likely. Therefore, A-Fib is more likely to occur
in people who already have other heart diseases. Other factors such as extreme stress, excess caffeine, or alcohol,
may make extra beats more likely and may trigger A-Fib.

Some people have A-Fib at very predictable times, such as in the early morning, after large meals, with strenuous
exercise, or when bending suddenly. In each of these situations, it appears that the normal changes in the nervous
system that go along with these activities cause the extra beats that can trigger A-Fib.

In other cases, thyroid disease or other problems can lead to A-Fib. In these situations, treating tlle thyroid problem
or other condition will often prevent the A-Fib. In many people, A-Fib occurs unpredictably and without an obvious
cause. As part of the routine evaluation for A-Fib, we check blood work for anemia or thyroid problems. We also
do other heart tests to check for factors that can lead to A-Fib. Sometimes, if another heart problem can be fixed, the
A-Fib will be less of a problem.

Atrial Fibrillation: Clinical Importance and Size of Public Health Problem

A-Fib is the most common cardiac arrhythmia. Approximately 1-2% of adults have A-Fib. A-Fib becomes much
more common as we age. In one study, 5% of patients over age 65 had an episode of A-Fib in a 24-hour period.
Nearly 20% of people in the United States will experience at least one episode of A-Fib in their lifetime. Many
people will experience A-Fib several times, or for long episodes.

A-Fib increases the risk for stroke and slightly increases the overall risk of death. In the case of stroke, the
connection to A-Fib is clear. For example, in one study, patients with A-Fib had a greater than 5% risk of stroke.
The risk of stroke from A-Fib increases with age and is closely linked to the presence of other risk factors such as
heart disease, high blood pressure, and diabetes and an enlarged heart. Very short lived episodes of atrial fibrillation
do not appear to associate with a risk of stroke. A longer lived episode results in a quivering atrium that does not
contract vigorously. The loss of contraction of the sac that extends from the left atrium, predisposes to clot
formation and stroke. Of note, the risk of stroke is greatly reduced by thinning the blood with a medication
like Coumadin.

A-Fib may also cause severe symptoms from loss of uncoordinated contractions of the atrium, a fast heart rate
response to the atrial activity, or symptoms due the irregularity of the heart rate. You may feel palpitations, fatigue,
shortness of breath, or chest pain. Preexisting cardiac conditions, such as congestive heart failure, may become
more severe. On the other hand, many people with atrial fibrillation may not feel any symptoms, even when
the heart rate is fast or irregular. It is also important to know that a sustained fast heart rate (over 90-100 beats
per minute) may actually weaken the pumping power of the heart.

Finally, it appears that A-Fib tends to beget A-Fib. In other words, the more A-Fib that you have, the more A-Fib
you will tend to get. The fast, abnormal rhythm in the atria tends to cause electrical changes and increase the size of
the atria over time. These changes promote the further development of more and longer lasting A-Fib. Some of
these changes appear to be reversible over time, if the A-Fib is prevented.

There are two main treatment strategies for people with A-Fib: 1) Maintain sinus rhythm, or 2) Control the heart
rate, but leave the heart in A-Fib. There are benefits of maintaining sinus rhythm, as opposed to simply controlling
the heart rate. Some of these benefits include minimizing symptoms by coordinating the atria and ventricles,
minimizing the risk of stroke, and not needing blood thinners like Coumadin. All people who have A-Fib managed
with rate control only, and some people who tend to go in and out of sinus rhythm, need to take blood thinners in
order to prevent a stroke.

Of note, it is often difficult to maintain a normal sinus rhythm. The most commonly used therapy for maintaining
sinus rhythm is antiarrhythmic drug therapy. Unfortunately, studies have shown that such drugs only work about
50% of the time, and tend to have lots of side effects. In fact, certain antiarrhythmic drugs may actually cause life
threatening ventricular arrhythmias. Fortunately, this is very uncommon in people who do not have other heart
disease. However, many people are admitted to the hospital for monitoring when starting certain antiarrhythmic
drugs.

Because of risks, side effects, and the relatively low success rate of antiarrhythmic drugs, your doctor may suggest
that it would be better for you to just keep the heart rate controlled with safer medications, and not try to maintain
sinus rhythm. Exercise testing or other monitoring may be necessary to show that the heart rate is well controlled.

Taking blood thinners also carries some risk. For example, one study showed that people taking Coumadin have a
higher risk of minor bleeding than other people. Therefore, the blood needs to be monitored on a regular basis to
ensure it has been adequately thinned to reduce the risk of stroke, but not too thin, which would increase the risk of
bleeding.

Overall, the current medication treatments available for A-Fib are not always the perfect solution for everyone.
Still, many people can be successfully treated so that their A-Fib is prevented with antiarrhythmic drugs. Other
people can stay in A-Fib with their heart rate controlled in a normal range, using other types of medications. These
people may lead an active, normal life with the risk of stroke dramatically reduced by taking blood thinners like
Coumadin. Your doctor will discuss drug treatment options with you, with special considerations for any other heart
disease or bleeding problems that you may have. In addition, your doctor will tell you about any side effects of
medications that you are taking. Most side effects go away when you stop taking the medication.

Some people who have intermittent (paroxysmal) A-Fib, or who have a slow heart rate during A-Fib, may benefit
from the implantation of an .electncal device to prevent or stop an episode of A-Fib. These devices can be in the
form of a pacemaker, or an implantable atrial .defibrillator. A pacemaker seems to be most helpful for people who
have a slow heart rate as a result of medications that are effective in preventing A-Fib. In addition, pacing the atrium
may prevent recurrence of A-Fib in up to 20% of patients. However, in general, a pacemaker is not
implanted unless the heart rate IS too slow with or without drug therapy.
An implantable atrial defibrillator is now available. This device is slightly larger than a pacemaker and can
automatically give the heart a small shock to stop the A-Fib. This device may be appropriate for people who continue
to get infrequent episodes of A-Fib and can tolerate the discomfort of a small shock to stop the arrhythmi
quickly. This device is similar to the standard implantable cardiac defibrillator (ICD), except that it is specifically
designed to threat arrhythmias such as A-Fib. Standard ICDs, on the other hand, treat lethal ventricular
arrhythmias that originate from the bottom of the heart..

In the 1970's surgeons developed procedures to ablate, or cure, some common arrhythmias. They found that
A surgical scar along the electrical circuit of the arrhythmia prevented the short circuit from conducting, and
the arrhythmia was cured with a high success rate. Rapid technologic improvements allowed for the development of
catheter-based ablation procedures for many arrhythmias. This eliminated the need for an open-chest surgical
procedure. Many arrhythmias like atrial flutter can be cured with more than a 95% success rate.

Ablation of atrial flutter involves making a small burn line in the bottom of the right atrium. This ablation line
prevents the atrial flutter circuit from spinning, and reliably cures the atrial flutter. In some people, medication
causes A-Fib to change to atrial flutter. When this happens, your doctor can use the flutter ablation procedure,
combined with antiarrhythmic medication, to control the arrhythmias. 50-75% of people with A -Fib and atrial
flutter will have both arrhythmias prevented with the atrial flutter ablation procedure and antiarrhythmic medicine.
This combination therapy is most helpful for people whose arrhythmia becomes mostly atrial flutter with medical
therapy alone.

Until recently, ablation procedures for atrial fibrillation were only directed at keeping the rate under control. This
rate control was achieved by permanently blocking the electrical road from the atria to the ventricles, then placing a
pacemaker, to provide regular electrical activity to the ventricles. This procedure is still helpful for people who have
a low chance of success with curative ablation procedures, and have fast heart rates during A-Fib, which cannot be
controlled with medications.

Ablation treatment to actually cure A-Fib has been a significant challenge in the history of electrophysiology. The
"Maze" procedure is a surgical procedure that has been effective in suppressing A-Fib, albeit with small but
significant procedure-related risks. The Maze procedure is based on the thought that if the atrial muscle is
electrically divided into many separate segments, the multiple short circuits required for A-Fib cannot exist.
Therefore, the arrhythmia is prevented. The procedure involves making numerous incisions in the right and left
atria, while the patient is on heart -lung bypass in the operating room. These incisions divide the atria into multiple
electrically isolated segments that can still be activated by a regular heartbeat from the sinus node. The procedure
has been very successful at restoring normal sinus rhythm and atrial mechanical function, even in people with
significant heart disease. These people, then, have a low risk of stroke, even without blood thinners. The surgical
Maze approach to controlling or preventing A-Fib has been attempted with catheters in the electrophysiology
laboratory. The results of this catheter-based approach has been somewhat successful, but has been replaced at most
centers by a catheter-based approach that targets the triggers for A-Fib.

Atrial Fibrillation Ablation Treatment: Targeting the Triggers of Atrial Fibrillation

The newest ablation procedures for A-Fib involve using catheters to isolate or directly burn the triggers that start the
atrial fibrillation. These procedures have been performed for the last 4 years by our team of rhythm specialists, and
are proving to be successful for many people with A-Fib.

A-Fib is thought to be triggered by "hot spots" from the atria. These hot spots can occur anywhere in either atrial
chamber. In over 90% of cases, however, these triggers appear to originate from the edges of the pulmonary veins,
which return blood from the lungs into the left atrium. When these triggers fire rapidly, the atria cannot keep up
with the electrical impulses, and will develop A-Fib.

The new ablation procedures for A-Fib involve using catheters to eliminate or isolate these triggers. Although the
general technique of using catheters for ablating atrial arrhythmias is now almost 15 years old, using the technique
for triggers initiating A-Fib is a more recently important advancement.

The goal of A-Fib ablation is to identify the site of origin of the triggers for A-Fib. After the .triggers, or "hot spots,"
have been identified, the sites are either destroyed or isolated from the rest of the atrium. This IS done by applying a
small amount of energy through the tip of the catheter that is inserted into the heart through the large veins in the
groin. Most of the time, the triggers are located at the edges of tle pulmonary veins. The doctor places the catheter
near the edges of the pulmonary veins and delivers energy to disconnect the tnggers from the rest of the atnum, so
that the triggers can no longer cause A-Fib. Unlike the surgical Maze procedure, the catheter ablation doe~ not
involve any cutting or sewing; it only uses energy to deliver a "bum" to the heart cells ill order to electncally
disconnect them. The small amount of energy is precisely delivered to prevent any injury to the heart except at the
small area targeted. The amount of damage with the burning IS small enough so as not to effect the way the top of

the heart works as a pump. (Figure 2)

In order to determine whether you may benefit from ablation, you may need a number of tests to evaluate your heart
structure and function.

1. Echocardiogram - Ultrasound waves are directed at the heart from the surface of the body. The sound
   waves create a picture of the heart, which allows your doctor to assess each heart chamber size and
   function. This will determine whether the top and bottom heart chambers are normal in size. People with
   enlarged heart chambers may not have as much success with the ablation procedure as people with normal
   heart chamber size. People with very large heart chambers appear to have more A-Fib triggers and a higher
   rate of their A-Fib recurring. Of note, the heart chambers do stretch with persistent A-Fib. However, it
   appears that some of the stretching can be reversed when the arrhythmia is controlled.
2. Transtelephonic ECG monitoring - You will be asked to wear a small heart monitor all the time for one
   month. The monitor allows us to take snapshots of your heart rhythm and transmit this information over
   the telephone. You will be asked to record your heart rhythm twice a day, even if you are not having any
   symptoms. You should also record and transmit your heart rhythm when you have symptoms. These
   recordings help your doctor determine how many symptomatic episodes you are having over a prolonged
   period. Also, the recordings you make when you are not having symptoms helps to identify A-Fib episodes
   that you may have, even though you do not feel them.
3. Drug Infusion Study - If you do not have frequent episodes of A-Fib or skipped beats without sustained A-
   Fib, you may need to undergo a drug infusion study to determine if these triggers can be provoked using
   medications like adrenaline, such as isoproterenol or adenosine. Before the drug infusion, you will need to
   stop your rhythm medication. We typically will restart this medication at tile end of your hospitalization
   for the drug infusion. This drug infusion study will usually happen on a separate day from your ablation
   procedure. During the drug infusion, you will be monitored by a sophisticated electrocardiographic
   recording system, but there will be no catheters inserted into your body. The medications that typically
   trigger the A-Fib will be given through your IV. The information from this test helps us to determine if
   your triggers for A-Fib can be easily initiated. After the drug infusion, we often monitor you in tile hospital
   overnight to assess the amount of extra beats or A-Fib that you have without medications. During this
   time, or the night before the actual ablation procedure, we may use a special heart monitor that collects
   recordings of extra beats and A-Fib episodes.

Typically, you will come to the hospital one day prior to the procedure for additional monitoring and to start
Heparin therapy. We will do several blood tests when you arrive. If you are taking Coumadin and your INR is high,
the blood thinning can be reversed with intravenous medication, called Vitamin K, before the procedure. Even if
your blood is already thinned with Cournadin, you will receive Heparin, an intravenous blood thinning medication.
Heparin works immediately, and the effects only last for a short time after tile drug is stopped. You will be on
Heparin during the hospitalization while you are not taking Coumadin, to reduce the risk of stroke. Some patients
may not be taking Cournadin prior to the procedure. If you are not taking Coumadin, your doctor will determine
whether you should come into the hospital the day before the procedure for Heparin or any additional monitoring.

Prior to the procedure, you will meet one of the electrophysiology fellows. He or she will answer any additional
questions that you have, and will once again review the risks of tile procedure, so that you can give written informed
consent for the procedure. This electrophysiology fellow is a physician who is at a very advanced level of training.
He or she typically has already gone through 3 years of Internal Medicine training and 2-3 years of Cardiology
training before starting the Cardiac Electrophysiology fellowship. Only the brightest and most technically skilled
individuals are accepted into the Electrophysiology fellowship program. These fellows will be involved with the
ablation procedure, and will be assisting your attending doctor.

You will be brought to the electrophysiology laboratory typically between 7:00 and 8:00 A.M. In the
electrophysiology laboratory, you will meet a number of additional people who will be involved in your procedure.
These individuals include dedicated nurses and technicians, as well as tile anesthesiologist. Do not hesitate to ask
questions and voice your concerns to these people. They are all working to make sure that you are comfortable and
your procedure runs smoothly.