An arrhythmia (ah-RITH-me-ah) is a problem with the
speed or rhythm of the heartbeat. During an arrhythmia, the heart can beat too
fast, too slow, or with an irregular rhythm. A heartbeat that is too fast is
called tachycardia. A heartbeat that is too slow is called bradycardia.
Most arrhythmias are harmless, but some can be
serious or even life threatening. When the heart rate is too slow, too fast, or
irregular, the heart may not be able to pump enough blood to the body. Lack of
blood flow can damage the brain, heart, and other organs.
Understanding the Hearts Electrical
System
The heart has an internal electrical system that
controls the speed and rhythm of the heartbeat. With each heartbeat, an
electrical signal spreads from the top of the heart to the bottom. As it
travels, the electrical signal causes the heart to contract and pump blood. The
process repeats with each new heartbeat.
Each electrical signal begins in a group of cells
called the sinus node, or sinoatrial (SA) node. The SA node is located in the
right atrium (AY-tree-um), which is the upper right chamber of the heart. In a
healthy adult heart at rest, the SA node fires off an electrical signal to
begin a new heartbeat 60 to 100 times a minute.
From the SA node, the electrical signal travels
through special pathways to the right and left atria. This causes the atria to
contract and pump blood into the hearts two lower chambers, the
ventricles (VEN-trih-kuls). The electrical signal then moves down to a group of
cells called the atrioventricular (AV) node, located between the atria and the
ventricles. Here, the signal slows down just a little, allowing the ventricles
time to finish filling with blood. The electrical signal then leaves the AV
node and travels along a pathway called the bundle of His. This pathway divides
into a right bundle branch and a left bundle branch. The signal goes down these
branches to the ventricles, causing them to contract and pump blood out to the
lungs and the rest of the body. The ventricles then relax, and the heartbeat
process starts all over again in the SA node.
A problem with any part of this process can cause an
arrhythmia. For example, in atrial fibrillation, a common type of arrhythmia,
electrical signals travel through the atria in a fast and disorganized way.
This causes the atria to quiver instead of contract.
For more information on the hearts electrical
system and a detailed animation, go to the Diseases and Conditions Index
article on
How
the Heart Works.
Overview
There are many different types of arrhythmia. Most
arrhythmias are harmless but some are not. The outlook for a person with an
arrhythmia depends on the type and severity of the arrhythmia. Even serious
arrhythmias can often be successfully treated. Most people with arrhythmias are
able to live normal, healthy lives.
How the Heart Works
The heart is a muscle about the size of your fist.
The heart works like a pump and beats about 100,000 times a day.
A healthy adult heart generally beats 60 to 100
times a minute, but it can beat faster or slower at times. For example,
physical activity, strong emotion, certain medicines, fever, or infection can
make the heart beat faster. A persons heart rate generally slows down
during sleep. Some very fit athletes always have heart rates below 60 beats a
minute because their hearts work so well.
The heart has two sides, separated by an inner wall
called the septum. The right side of the heart pumps blood to the lungs to pick
up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of
the heart, and the left side pumps it to the body.
The heart has four chambers and four valves and is
connected to various blood vessels. Veins are the blood vessels that carry
blood from the body to the heart. Arteries are the vessels that carry blood
away from the heart to the body.
Illustration of a
Healthy Heart Cross-Section
Heart Chambers
The heart has four chambers or
roomstwo on the left side of the heart and two on the
right.
The atria are the two upper chambers that collect
blood as it comes into the heart.
The ventricles are the two lower chambers that
pump blood out of the heart to the lungs or other parts of the body.
Heart Valves
Four valves control the flow of blood from the atria
to the ventricles and from the ventricles into the two large arteries connected
to the heart.
The tricuspid (tri-CUSS-pid) valve is in the
right side of the heart, between the right atrium and the right ventricle.
The pulmonary (PULL-mun-ary) valve is in the
right side of the heart, between the right ventricle and the entrance to the
pulmonary artery that carries blood to the lungs.
The mitral (MI-tral) valve is in the left side of
the heart, between the left atrium and the left ventricle.
The aortic (ay-OR-tik) valve is in the left side
of the heart, between the left ventricle and the entrance to the aorta, the
artery that carries blood to the body.
Valves are like doors that open and close. They open
to allow blood to flow through to the next chamber or to one of the arteries,
and then they shut to keep blood from flowing backward.
When the hearts valves open and close, they
make a lub-DUB sound that a doctor can hear using a
stethoscope.
The first soundthe lubis
made by the mitral and tricuspid valves closing at the beginning of systole
(SIS-toe-lee). Systole is when the ventricles contract, or squeeze, and pump
blood out of the heart.
The second soundthe DUBis
made by the aortic and pulmonary valves closing at beginning of diastole
(di-AS-toe-lee). Diastole is when the ventricles relax and fill with blood
pumped into them by the atria.
Arteries
The arteries are major blood vessels connected to
your heart.
The pulmonary artery carries blood pumped from
the right side of the heart to the lungs to pick up a fresh supply of
oxygen.
The aorta is the main artery that carries
oxygen-rich blood pumped from the left side of the heart out to the body.
The coronary arteries are the other important
arteries attached to the heart. They carry oxygen-rich blood from the aorta to
the heart muscle, which must have its own blood supply to function.
Veins
The veins are also major blood vessels connected to
your heart.
The pulmonary veins carry oxygen-rich blood from
the lungs to the left side of the heart so it can be pumped out to the
body.
The vena cava is a large vein that carries
oxygen-poor blood from the body back to the heart.
For more information on how a healthy heart works,
see the Diseases and Conditions Index article on
How
the Heart Works. This article contains animations that show how your heart
pumps blood and how your hearts electrical system works.
Types of Arrhythmia
There are four main types of arrhythmia: premature
(extra) beats, supraventricular arrhythmias, ventricular arrhythmias, and
bradyarrhythmias.
Premature (Extra) Beats
Premature beats are the most common type of
arrhythmia. They are harmless most of the time and often dont cause any
symptoms. When symptoms do occur, they usually feel like a fluttering in the
chest or a sensation of a skipped beat. Most of the time, premature beats need
no treatment, especially in healthy people.
Premature beats that occur in the atria are called
premature atrial contractions, or PACs. Premature beats that occur in the
ventricles are called premature ventricular contractions, or PVCs.
In most cases, premature beats occur naturally, not
due to any heart disease. But certain heart diseases can cause premature beats.
They also can happen because of stress, too much exercise, or too much caffeine
or nicotine.
Supraventricular Arrhythmias
Supraventricular arrhythmias are tachycardias (fast
heart rates) that start in the atria or the atrioventricular node (cells
located between the atria and the ventricles). Types of supraventricular
arrhythmias include atrial fibrillation (AF), atrial flutter, paroxysmal
supraventricular tachycardia (PSVT), and Wolff-Parkinson-White (WPW)
syndrome.
Atrial Fibrillation
AF is the most common type of serious arrhythmia.
Its a very fast and irregular contraction of the atria. AF occurs when
the hearts electrical signal begins in a different part of the atrium
than the sinoatrial (SA) node or when the signal is conducted abnormally. When
this happens, the electrical signal doesnt travel through the normal
pathways in the atria, but instead may spread throughout the atria in a fast
and disorganized manner. This causes the walls of the atria to quiver very fast
(fibrillate) instead of beating normally. As a result, the atria arent
able to pump blood into the ventricles the way they should.
The animation below shows atrial fibrillation. Click
the "start" button to play the animation. Written and spoken explanations are
provided with each frame. Use the buttons in the lower right corner to pause,
restart, or replay the animation, or use the scroll bar below the buttons to
move through the frames.
The animation shows how the
hearts electrical signal begins in a different place in the heart,
causing the atria to beat very fast and irregularly.
In AF, electrical signals can travel through the
atria at a rate of more than 300 per minute. Some of these abnormal electrical
signals can travel to the ventricles, causing them to beat too fast and with an
irregular rhythm. AF is not usually life threatening, although it can be
dangerous when it causes the ventricles to beat very fast.
The two most serious complications of chronic
(long-term) AF are
stroke and
heart
failure. Stroke can happen when a blood clot travels to an artery in the
brain, blocking off blood flow. In AF, blood clots can form in the atria
because some of the blood pools in the fibrillating atria instead
of flowing into the ventricles. If a piece of a blood clot in the left atrium
breaks off, it can travel to the brain, causing a stroke. People with AF are
often treated with blood-thinning medicines to reduce the chances of developing
blood clots.
Heart failure is when the heart cant pump
enough blood to meet the needs of the body. AF can cause heart failure when the
ventricles beat too fast and dont have enough time to fill with blood to
pump out to the body. Heart failure causes tiredness, leg swelling, and
shortness of breath.
AF and other supraventricular arrhythmias can occur
for no apparent reason. Most of the time, however, they are caused by an
underlying condition that damages the heart muscle and its ability to conduct
electrical impulses. These conditions include
high
blood pressure (hypertension),
coronary
artery disease, heart failure, or rheumatic heart disease.
Other conditions also can lead to AF, including
overactive thyroid gland (too much thyroid hormone produced) and heavy alcohol
use. AF also becomes more common as people get older.
Atrial Flutter
Atrial flutter is similar to atrial fibrillation,
but instead of the electrical signals spreading through the atria in a fast and
irregular rhythm, they travel in a fast and regular rhythm. Atrial flutter is
much less common than atrial fibrillation, but has similar symptoms and
complications.
Paroxysmal Supraventricular Tachycardia
PSVT is a very fast heart rate that begins and ends
suddenly. PSVT occurs due to problems with the electrical connection between
the atria and the ventricles. In PSVT, electrical signals that begin in the
atria and travel to the ventricles can reenter the atria, causing extra
heartbeats. This type of arrhythmia is not usually dangerous and tends to occur
in young people. It can happen during vigorous exercise.
A special type of PSVT is called
Wolff-Parkinson-White syndrome. WPW syndrome is a condition in which the
hearts electrical signals travel along an extra pathway from the atria to
the ventricles. This extra pathway disrupts the timing of the hearts
electrical signals and can cause the ventricles to beat very fast. This type of
arrhythmia can be life threatening.
The animation below shows Wolff-Parkinson-White
syndrome. Click the "start" button to play the animation. Written and spoken
explanations are provided with each frame. Use the buttons in the lower right
corner to pause, restart, or replay the animation, or use the scroll bar below
the buttons to move through the frames.
The animation shows how an extra,
abnormal electrical pathway in the heart disrupts the normal timing of the
hearts electrical signal, causing the atria and ventricles to beat too
fast.
Ventricular Arrhythmias
These are arrhythmias that start in the ventricles.
They can be very dangerous and usually need immediate medical attention.
Ventricular arrhythmias include ventricular tachycardia and ventricular
fibrillation (v-fib). Coronary artery disease,
heart
attack, weakened heart muscle, and other problems can cause ventricular
arrhythmias.
Ventricular Tachycardia
Ventricular tachycardia is a fast, regular beating
of the ventricles that may last for only a few seconds or for much longer. A
few beats of ventricular tachycardia often dont cause problems, but
ventricular tachycardia episodes that last for more than just a few seconds can
be dangerous. Ventricular tachycardia can turn into other, more dangerous
arrhythmias, such as v-fib.
Ventricular Fibrillation
V-fib occurs when disorganized electrical signals
make the ventricles quiver instead of pump normally. Without the ventricles
pumping blood out to the body, a person will lose consciousness within seconds
and will die within minutes if not treated. To prevent death, the condition
must be treated immediately with defibrillation, an electric shock to the
heart. V-fib may happen during or after a heart attack, or in a heart that is
already weak because of another condition. Health experts think that most of
the
sudden
cardiac deaths that occur every year (about 335,000) are due to v-fib.
The animation below shows ventricular fibrillation.
Click the "start" button to play the animation. Written and spoken explanations
are provided with each frame. Use the buttons in the lower right corner to
pause, restart, or replay the animation, or use the scroll bar below the
buttons to move through the frames.
The animation shows how disorganized
electrical signals in the hearts ventricles can cause them to pump
abnormally and quiver.
Torsades de pointes (torsades) is a specific form of
v-fib with a unique pattern on an
EKG
(electrocardiogram). Certain medicines and imbalanced amounts of potassium,
calcium, or magnesium in the bloodstream can cause this condition. People with
a particular finding on an EKG test, called prolonged QT interval, are at
increased risk of developing torsades. People with prolonged QT interval need
to be careful about taking certain antibiotics, heart medicines, and
over-the-counter medicines.
Bradyarrhythmias
Bradyarrhythmias are arrhythmias in which the heart
rate is slower than normal. If the heart rate is too slow, not enough blood
reaches the brain, and the person can lose consciousness. In adults, a heart
rate slower than 60 beats per minute is considered a bradyarrhythmia. Some
people normally have slow heart rates, especially people who are very
physically fit. For them, a heartbeat slower than 60 beats per minute is not
dangerous and doesnt cause symptoms. But in other people, bradyarrhythmia
can be due to a serious disease or other condition.
Bradyarrhythmias can be caused by heart attack,
conditions that harm or change the hearts electrical system (such as
underactive thyroid gland or aging), an imbalance of chemicals or other
substances (such as potassium) in the blood, or even some medicines (such as
beta blockers).
Bradyarrhythmias also can happen as a result of
severe bundle branch block. Bundle branch block is a condition in which the
electrical signal traveling down either or both of the bundle branches is
delayed or blocked. When this happens, the ventricles dont contract at
exactly the same time, as they should, and the heart has to work harder to pump
blood to the body. The cause of bundle branch block is often an existing heart
condition.
Arrhythmias in Children
Normally, a childs heart beats between 70 and
100 times a minute. A newborns heart beats about 140 times a minute. A
baby or childs heart can beat faster or slower than normal for many
reasons. As is true for adults, when children are active, their hearts will
beat faster. When they are sleeping, their heart will beats slower. Their heart
rates can speed up and slow down as they breathe in and out. All of these
changes are normal.
Some children are born with heart defects that cause
arrhythmias. In other children, arrhythmias can develop later in childhood.
Doctors do the same kinds of tests in children and adults to diagnose
arrhythmias.
Treatments for children with arrhythmias include
medicines, electric shock (defibrillation), surgically implanted devices that
control the heartbeat, and other procedures that fix distorted electrical
signals in the heart.
Other Names for Arrhythmia
Dysrhythmia
What Causes an Arrhythmia?
An arrhythmia can occur when the electrical signals
that control the heartbeat are delayed or blocked. This can happen when the
special nerve cells that produce the electrical signal dont work properly
or when the electrical signal doesnt travel normally through the heart.
An arrhythmia also can occur when another part of the heart starts to produce
electrical signals, adding to the signals from the special nerve cells and
disrupting the normal heartbeat.
Stress, smoking, heavy alcohol use, heavy exercise,
use of certain drugs (such as cocaine or amphetamines), use of certain
prescription or over-the-counter medicines, and too much caffeine or nicotine
can lead to arrhythmia in some people.
A
heart
attack or an underlying condition that damages the hearts electrical
system also can cause an arrhythmia. These conditions include
high
blood pressure (hypertension),
coronary
artery disease,
heart
failure, overactive or underactive thyroid gland (too much or too little
thyroid hormone produced), and rheumatic heart disease.
For some arrhythmias, such as Wolff-Parkinson-White
syndrome, the underlying heart defect that causes the arrhythmia is present at
birth (congenital). Sometimes, the cause of an arrhythmia cant be
found.
Who Is At Risk for an Arrhythmia?
Populations Affected
Millions of Americans have arrhythmias. They are
very common in older adults. About 2.2 million Americans have atrial
fibrillation (a common type of arrhythmia that can cause problems).
Most serious arrhythmias happen in adults older than
60. This is because older adults are more likely to have heart disease and
other health problems that can lead to arrhythmias. Older adults also tend to
be more sensitive to the side effects of medicines, some of which can cause
arrhythmias. Some medicines used to treat arrhythmias can cause arrhythmias as
a side effect.
Some types of arrhythmia happen more often in
children and young adults. Paroxysmal supraventricular tachycardias (a fast
heart rate that begins and ends suddenly), including Wolff-Parkinson-White
syndrome, are more common in young people.
Major Risk Factors
Arrhythmias are more common in people who have a
disease or condition that weakens the heart, such as:
Sleep
apnea (when breathing becomes shallow or stops during sleep), which can
stress the heart because it doesnt get enough oxygen
Overactive or underactive thyroid gland (too much
or too little thyroid hormone in the body)
In addition to certain diseases and conditions,
several other risk factors increase a persons chance of having an
arrhythmia. Heart surgery, certain drugs (such as cocaine or amphetamines), or
an imbalance of chemicals or other substances (such as potassium) in the
bloodstream can increase a persons chance of having an arrhythmia.
What Are the Signs and Symptoms of
Arrhythmias?
Many arrhythmias cause no signs or symptoms. When
signs or symptoms are present, the most common ones are:
Palpitations (a feeling that your heart has
skipped a beat or is beating too hard)
A slow heartbeat
An irregular heartbeat
Feeling of pauses between heartbeats
More serious signs and symptoms include:
Anxiety
Weakness
Dizziness and light-headedness
Fainting or nearly fainting
Sweating
Shortness of breath
Chest pain
How Are Arrhythmias Diagnosed?
Arrhythmias can be hard to diagnose, especially
types that only cause symptoms every once in a while. Doctors use several
methods to help diagnose arrhythmias, including family and medical history,
physical exam, and diagnostic tests and procedures.
Specialists Involved
Doctors who specialize in the diagnosis and
treatment of heart diseases include:
Cardiologists (doctors who take care of adults
with heart problems)
Pediatric cardiologists (doctors who take care of
babies and children with heart problems)
Electrophysiologists (e-LEK-tro-fiz-e-OL-o-jists)
(cardiologists or pediatric cardiologists who specialize in arrhythmias)
Family and Medical History
To diagnose an arrhythmia, your doctor will ask
questions about:
Symptoms. What symptoms are you having? Is there
a feeling of fluttering in your chest? Do you feel dizzy or lightheaded?
Medical history, including other health problems,
such as a history of heart disease,
high
blood pressure, diabetes, or thyroid problems.
Family medical history. Does anyone in your
family have a history of arrhythmias? Has anyone in your family ever had heart
disease or high blood pressure? Has anyone died suddenly? Are there other
illnesses or health problems in your family?
Medicines youre taking, including
over-the-counter medicines and vitamin or mineral or nutritional
supplements.
Health habits, such as physical activity,
smoking, or using alcohol or drugs (for example, cocaine).
Physical Exam
Your doctor will listen to the rate and rhythm of
your heart and for a
heart
murmur (an extra or unusual sound heard during your heartbeat). The doctor
also will:
Check your pulse to find out how fast your heart
is beating
Check for swelling in your legs or feet, which
could be a sign of an enlarged heart or
heart
failure
Look for signs of other diseases (such as thyroid
disease) that could be causing the problem
Diagnostic Tests and Procedures
An
EKG
(electrocardiogram) is the most common test used to diagnose arrhythmias. An
EKG is a simple test that detects and records the electrical activity of your
heart. It shows how fast the heart is beating and its rhythm (steady or
irregular). It also records the strength and timing of the electrical signals
as they pass through each part of the heart.
A standard EKG test only records the heartbeat for a
few seconds. It wont detect arrhythmias that dont happen during the
test. To diagnose arrhythmias that come and go, your doctor may have you wear a
portable EKG monitor that can record the heartbeat for longer periods of time.
The two most common types of portable EKGs are:
Holter monitor. This device records the hearts
electrical activity continuously over a 24-hour period.
Event monitor. Event monitors are useful to
diagnose arrhythmias that only occur once in a while. The device is worn
continuously, but only records the hearts electrical activity when you
push a button on the device. You push the button on the device when you feel
symptoms. Event monitors can be worn for 1 to 2 months, or as long as it takes
to get a recording of the heart during symptoms.
Other tests used in the diagnosis of arrhythmias
include:
Blood tests. These tests check the level of
substances in the blood, such as potassium or thyroid hormone, that can
increase your chances of having an arrhythmia.
Chest x ray. A chest x ray takes a picture of your heart and
lungs. It can show whether the heart is enlarged.
Echocardiogram. This test uses sound waves to create a moving
picture of your heart. Echocardiogram provides information about the size and
shape of your heart and how well your heart chambers and valves are
functioning. The test also can identify areas of poor blood flow to the heart,
areas of heart muscle that are not contracting normally, and previous injury to
the heart muscle caused by poor blood flow.
There are several different
types of echocardiograms, including a stress echocardiogram. During this test,
an echocardiogram is done both before and after your heart is stressed either
by having you exercise or by injecting a medicine into your bloodstream that
makes your heart beat faster and work harder. A stress echocardiogram is
usually done to find out if you have decreased blood flow to your heart (coronary
artery disease).
Transesophageal (trans-e-SOF-ah-ge-al)
echocardiography, or TEE. This is a special type of echocardiogram that takes
pictures of the back of the heart through the esophagus (the tube leading from
your mouth to your stomach).
Stress test. Some heart problems are easier to
diagnose when your heart is working harder and beating faster than when
its at rest. During stress testing, you exercise (or are given medicine
if you are unable to exercise) to make your heart work harder and beat faster
while heart tests are performed.
During exercise stress testing,
your blood pressure and EKG readings are monitored while you walk or run on a
treadmill or pedal a bicycle. Other heart tests, such as nuclear heart scanning
or echocardiography, also can be done at the same time. These would be ordered
if your doctor needs more information than the exercise stress test can provide
about how well your heart is working.
If you are unable to exercise, a
medicine can be injected through an intravenous line (IV) into your bloodstream
to make your heart work harder and beat faster, as if you are exercising on a
treadmill or bicycle. Nuclear heart scanning or echocardiography is then
usually done.
During nuclear heart scanning,
radioactive tracer is injected into your bloodstream, and a special camera
shows the flow of blood through your heart and arteries. Echocardiography uses
sound waves to show blood flow through the chambers and valves of your heart
and to show the strength of your heart muscle.
Electrophysiologic study (EPS). This test is used to assess
serious arrhythmias. During an EPS, a thin, flexible wire is passed through a
vein in your groin (upper thigh) or arm up to the heart. The wire records the
hearts electrical signals. Your doctor uses the wire to electrically
stimulate your heart and trigger an arrhythmia. This allows the doctor to see
whether an antiarrhythmia medicine can stop the problem. Radiofrequency
ablation, a procedure used to fix some types of arrhythmia, may be done during
an EPS.
Tilt table testing. This test is sometimes used
to help determine the cause of fainting spells. You lie on a table that moves
from a lying down to an upright position. The change in position can bring on
loss of consciousness. The doctor monitors your symptoms, heart rate, EKG, and
blood pressure throughout the test. The doctor also may give you a medicine and
then monitor your response to the medicine.
Coronary angiography. This test is an x-ray exam of the heart
and blood vessels. The doctor passes a catheter (thin, flexible tube) through
an artery in your leg or arm up to the heart. The catheter measures the
pressure inside the heart and blood vessels. A dye that can be seen on x ray is
injected into the blood through the tip of the catheter. The dye lets the
doctor study the flow of blood through the heart and blood vessels, which helps
to diagnose blockages that can cause a heart attack.
How Are Arrhythmias Treated?
Common arrhythmia treatments include medicines,
medical procedures, and surgery. Treatment is needed when an arrhythmia causes
serious symptoms, such as dizziness, chest pain, or fainting, or when it
increases your chances of developing complications, such as
heart
failure,
stroke, or
sudden
cardiac death.
Medicines
Medicines can be used to speed up a heart
thats beating too slow, or slow down a heart thats beating too
fast. They also can be used to convert an abnormal heart rhythm to a normal
steady rhythm. Medicines can be used to control an underlying medical
condition, such as heart disease or a thyroid condition, that might be causing
an arrhythmia. Medicines used to convert an abnormal rhythm are called
antiarrhythmics.
Some of the medicines used to slow a fast heart rate
are beta blockers (such as metoprolol and atenolol), calcium channel blockers
(such as diltiazem and verapamil), and digoxin (digitalis). These medicines are
often used to slow the heart rate in people with atrial fibrillation.
Some of the medicines used to restore an abnormal
heartbeat to a normal rhythm are amiodarone, sotalol, flecainide, propafenone,
dofetilide, ibutilide, quinidine, procainamide, and disopyramide. These
medicines often have side effects. Some of the side effects can make an
arrhythmia worse or even cause a different kind of arrhythmia.
People with atrial fibrillation and some other
arrhythmias are often treated with blood-thinning medicines (anticoagulants) to
reduce the chances of developing blood clots. Aspirin, warfarin
(Coumadin®), and heparin are commonly used blood thinners.
Medical Procedures
Some arrhythmias are treated with a device called a
pacemaker. The pacemaker is a small device thats surgically placed under
the skin at the collarbone; wires lead from it to the atrium and ventricle(s).
The pacemaker sends small electric signals through the wires to control the
speed of the heartbeat. Most pacemakers contain a sensor that activates the
device only when the heartbeat is abnormal.
Some arrhythmias are treated with a jolt of
electricity delivered to the heart. This type of treatment is called
cardioversion or defibrillation, depending on which type of arrhythmia is being
treated.
Some people who are at risk for ventricular
fibrillation are treated with a device called an implantable cardioverter
defibrillator (ICD). This device is surgically implanted in the chest and
connected to the heart with wires. It continuously monitors the heartbeat. If
it senses a dangerous ventricular arrhythmia, it sends an electric shock to the
heart to restore a normal heartbeat.
A procedure called radiofrequency ablation is
sometimes used to treat certain types of arrhythmias when medicines dont
work. In this treatment, a special wire is inserted through a vein in the arm
or leg and threaded up to the heart. Radiowave energy is sent through the wire
to destroy abnormal tissue in the heart thats interrupting the normal
flow of electric signals. Radiofrequency ablation is usually done in the
hospital as part of an
electrophysiologic study.
Surgery
Sometimes, surgery is used to treat arrhythmia.
Often this is done when surgery is already being performed for another reason,
such as repair of a heart valve. One type of surgery for atrial fibrillation is
called maze surgery. In this operation, the surgeon makes small
cuts or burns in the atria, which prevent the spread of disorganized electrical
signals.
Coronary artery bypass surgery may be needed for
arrhythmias caused by
coronary
artery disease. The operation improves blood supply to the heart
muscle.
Other Treatments
Vagal maneuvers are another arrhythmia treatment.
These are simple exercises that sometimes can stop or slow down certain types
of supraventricular arrhythmias. They stop the arrhythmia by affecting the
vagus nerve, which is one factor that controls the heart rate. Some vagal
maneuvers include:
Gagging
Holding your breath and bearing down (Valsalva
maneuver)
Immersing your face in ice-cold water
Coughing
Putting your fingers on your eyelids and pressing
down gently
Vagal maneuvers arent an appropriate treatment
for everyone. Discuss with your doctor whether vagal maneuvers are safe and
effective for you to try.
Living With an Arrhythmia
Many arrhythmias are harmless. Its common to
have an occasional extra heartbeat and not even be aware of it, or to only have
mild palpitations. People with harmless arrhythmias can live healthy lives and
usually dont need treatment for their arrhythmias.
Even people with serious types of arrhythmia are
often treated successfully and lead normal lives.
Ongoing Health Care Needs
If you have an arrhythmia that requires treatment,
you should:
Keep all your medical appointments. Always bring
all medicines youre taking to all of your doctor visits. This helps
ensure that all of your doctors know exactly what medicines youre taking,
which can help prevent medication errors.
Follow your doctors instructions for taking
medicines. Check with your doctor before taking over-the-counter medicines,
nutritional supplements, or cold and allergy medicines.
Tell your doctor if you are having side effects
from your medicines. side effects could include depression and palpitations.
These side effects can often be treated.
Tell your doctor if arrhythmia symptoms are
getting worse or if you have new symptoms.
Allow your doctor to monitor you regularly if
youre taking blood-thinning medicines.
If you have an arrhythmia, taking care of yourself
is important. If you feel dizzy or faint, you should lie down. Dont try
to walk or drive. Tell your doctor about it.
Many arrhythmias are caused by underlying heart
disease. Keep your heart healthy by following a healthy diet, getting regular
physical activity, quitting smoking, maintaining a healthy weight, and keeping
your blood cholesterol and blood pressure at healthy levels.
Your doctor may want you to avoid certain things if
they make your heart beat too fast. These things can include alcohol and cold
and cough medicines.
Ask your doctor about learning how to do vagal
maneuvers. These are exercises that people with certain arrhythmias can do that
may help to stop an episode of rapid heartbeat.
Learn how to take your pulse. Discuss with your
doctor what pulse rate is normal for you. Keep a record of changes in your
pulse rate and share this information with your doctor.
Key Points
An arrhythmia is a change in the hearts
rhythm that causes the heart to beat too fast, too slow, or irregularly. A
heartbeat that is too fast is called tachycardia. A heartbeat that is too slow
is called bradycardia.
An arrhythmia happens when some part of the
hearts electrical system doesnt function as it should.
Most arrhythmias are harmless, but some can be
serious or even life threatening.
Millions of Americans have arrhythmias, and
arrhythmias are especially common among older adults. About 2.2 million
Americans have atrial fibrillation. Health experts think that most of the
sudden
cardiac deaths that occur every year (about 335,000) are due to ventricular
fibrillation.
Arrhythmias have many causes. Heart disease is a
common cause of serious arrhythmias. Stress, smoking, heavy alcohol use, heavy
exercise, some drugs (such as cocaine or amphetamines), and some medicines can
lead to arrhythmias in some people.
Signs and symptoms of an arrhythmia include:
Palpitations (an unpleasant feeling that your
heart is skipping beats or beating too hard)
A fast or racing heartbeat, a slow heartbeat,
or an irregular heartbeat
Weakness, dizziness, light-headedness,
sweating, and fainting
Shortness of breath
Chest pain
Anxiety
Usually the first test used to diagnose an
arrhythmia is an
EKG
(electrocardiogram).
Arrhythmias can be treated with medicines,
medical procedures (for example, electrical energy delivered to the heart), and
surgery.
Serious arrhythmias can often be successfully
treated. Most people with arrhythmias are able to live normal lives.