What is an arrhythmia?
An arrhythmia is an abnormal heart rhythm.
Some arrhythmias can cause problems with contractions of your heart chambers by:
- Not allowing the lower chambers (ventricles) to fill with enough blood,
because an abnormal electrical signal is causing your heart to pump too
fast or too slow.
- Not allowing enough blood to be pumped out to your body, because an abnormal
electrical signal is causing your heart to pump too slowly or too irregularly.
- Not allowing the top chambers (atria) to work properly.
An arrhythmia can occur in the sinus node, the atria, or the atrioventricular
node. These are supraventricular arrhythmias. A ventricular arrhythmia
is caused by an abnormal electrical focus within your ventricles. This
results in abnormal conduction of electrical signals within your ventricles.
Arrhythmias can also be classified as slow (bradyarrhythmia) or fast (tachyarrhythmia).
"Brady-" means slow, while "tachy-" means fast.
In any of these situations, your body's vital organs may not get enough
blood to meet their needs.
What causes an arrhythmia?
An arrhythmia occurs when there is a problem with the electrical system
that is supposed to regulate a steady heartbeat. With an impaired electrical
system, your heart may beat too fast, too slow, or irregularly.
What are the risk factors for an arrhythmia?
Many risk factors can affect the electrical system of your heart and, therefore,
cause an arrhythmia. Substances including caffeine, alcohol, tobacco,
illegal drugs, diet drugs, some herbs, and even prescription medicines
can trigger an arrhythmia. Health conditions including coronary heart
disease, high blood pressure, and diabetes contribute to developing arrhythmias.
Arrhythmias become more common with age.
What are the symptoms of arrhythmias?
The effects on the body are often the same, however, whether the heartbeat
is too fast, too slow, or too irregular. Some symptoms of arrhythmias include:
- Palpitations (a sensation of fluttering or irregularity of the heartbeat)
- Low blood pressure
- Heart failure
- Collapse and cardiac arrest
- Difficulty feeding (in babies)
The symptoms of arrhythmias may look like other conditions. Always see
your healthcare provider for a diagnosis.
How are arrhythmias diagnosed?
There are several tests that may be used to diagnose arrhythmias. Some
of these include:
Electrocardiogram (ECG). An electrocardiogram is a measurement of the electrical activity of your
heart. By placing electrodes at specific locations on your body (chest,
arms, and legs), a graphic representation, or tracing, of the electrical
activity can be made as the electrical activity is received and interpreted
by an ECG machine. An ECG can show the presence of arrhythmias, damage
to your heart caused by ischemia (lack of oxygen to the heart muscle),
or myocardial infarction (MI, or heart attack), a problem with one or
more of the heart valves, or other types of heart conditions.
There are several variations of the ECG test:
Resting ECG. For this procedure, the clothing on your upper body is removed and small
sticky patches called electrodes are attached to your chest, arms, and
legs. These electrodes are connected to the ECG machine by wires. The
ECG machine is then started and records your heart's electrical activity
for a minute or so. You are lying down during this ECG.
Exercise ECG, or stress test. You are attached to the ECG machine as described above. However, rather
than lying down, you exercise by walking on a treadmill or pedaling a
stationary bike while the ECG is recorded. This test is done to assess
changes in the ECG during stress, such as exercise.
Signal-averaged ECG. This procedure is done in the same manner as a resting ECG, except that
your heart's electrical activity is recorded over a longer period
of time, usually 15 to 20 minutes. Signal-averaged ECGs are done when
arrhythmia is suspected, but not seen on a resting ECG. The signal-averaged
ECG has increased sensitivity to abnormal ventricular activity called
"late potentials." Signal-averaged ECG is used in research and
seldom used in clinical practice.
Electrophysiologic studies (EPS). A nonsurgical but invasive test in which a small, thin tube (catheter)
is inserted into a large blood vessel in your leg or arm and advanced
to your heart. This lets your doctor find the site of the arrhythmia's
origin within your heart tissue. Your doctor is then able to determine
how to best treat it. Sometimes, your doctor can treat the arrhythmia
by doing an ablation at the time of the study.
Holter monitor. A continuous ECG recording done over a period of 24 or more hours. Electrodes
are attached to your chest and connected to a small portable ECG recorder
by lead wires. Holter monitoring may be done when an arrhythmia is suspected,
but not seen on a resting ECG. Arrhythmias may be transient in nature
and not seen during the shorter recording times of the resting ECG. You
go about your daily activities, except those that cause an excessive amount
of sweating. This could cause the electrodes to become loose or fall off
during the procedure. These activities include taking a shower or swimming.
Event monitor. This is similar to a Holter monitor, except that you start the ECG recording
only when you feel symptoms. Event monitors are typically worn longer
than Holter monitors. You can remove the monitor to shower or bathe.
Mobile cardiac monitoring. This is similar to both a Holter and event monitor. The ECG is monitored
constantly to allow for detection of arrhythmias, which are recorded and
sent to your doctor regardless of whether you have symptoms. You can also
start recordings yourself when you have symptoms. These monitors can be
worn up to 30 days.
Implantable loop recorder. This is a miniature heart recording device that is implanted underneath
the skin overlying your heart. It can record the heart rhythm for up to
2 years and it useful in diagnosing intermittent or rarely occurring arrhythmias.
How is an arrhythmia treated?
Some arrhythmias may cause few, if any, problems. In this case, you may
not need treatment. When the arrhythmia causes symptoms, you have several
different choices for treatment. Your healthcare provider will choose
a treatment based on the type of arrhythmia you have, how severe your
symptoms are, and whether you have other conditions such as diabetes,
kidney failure, or heart failure. These can affect the course of the treatment.
Some treatments for arrhythmias include:
Lifestyle changes. Stress, caffeine, and alcohol can cause arrhythmias. Your healthcare provider
may recommend that you avoid caffeine, alcohol, or any other things that
may be causing the problem. If your provider thinks that stress is a cause,
he or she may recommend meditation, stress-management classes, an exercise
program, or psychotherapy to ease stress.
Medicine. Medicine is available to treat arrhythmias. Your healthcare provider will
recommend a medicine based on to the type of arrhythmia you have, whether
you have other health conditions, or whether you take other medicines.
Cardioversion. In this procedure, the healthcare provider sends an electrical shock to
your heart through the chest. This will stop certain very fast arrhythmias
such as atrial fibrillation, supraventricular tachycardia, or atrial flutter.
You are connected to an ECG monitor, which is also connected to the defibrillator.
The electrical shock is delivered at the point during the ECG cycle to
change the rhythm to a normal one.
Ablation. This is an invasive but nonsurgical procedure done in the electrophysiology
lab. The healthcare provider puts a thin, flexible tube (catheter) into
your heart through a vessel in your groin or arm. The provider uses a
method such as radio frequency ablation to destroy the site of the arrhythmia.
The procedure uses very high frequency radio waves to heat the tissue
until the site is destroyed. Cryoablation is another procedure that is
used. For this an ultra-cold substance is put on the site. This freezes
the tissue and destroys the site.
Pacemaker. A permanent pacemaker is a small device that is put under the skin, often
in the chest region just under the collarbone. It sends electrical signals
to start or regulate a slow heartbeat. A permanent pacemaker may be used
to make the heart beat if the heart's natural pacemaker (the SA node)
is not working as it should, or if the electrical pathways are blocked.
Pacemakers are often used for slow arrhythmias such as sinus bradycardia,
sick sinus syndrome, or heart block.
Implantable cardioverter defibrillator (ICD). An ICD is a small device similar to a pacemaker. It is put under the skin,
often just under the collarbone. An ICD senses the rate of the heartbeat.
When your heart rate goes higher than the level entered into the device,
it sends an electrical shock to the heart. This corrects the rhythm to
a slower, more normal heart rhythm. ICDs are used with a pacemaker to
send an electrical signal to regulate a slow heart rate. ICDs are used
for life-threatening fast arrhythmias such as ventricular tachycardia
or ventricular fibrillation.
Surgery. Surgery is usually done only when all other treatments have failed. Surgical
ablation is a major surgery that needs general anesthesia. The surgeon
opens your chest to reach your heart. The surgeon destroys or removes
the tissue causing the arrhythmia.
What are the complications of an arrhythmia?
Some arrhythmias have no complications. However, arrhythmias that are more
serious can result in heart failure, stroke, or even cardiac arrest.
Living with an arrhythmia
Living with an arrhythmia includes making lifestyle changes (avoiding caffeine,
alcohol, or other triggers) and taking medicines as directed. It may also
include having a pacemaker or implantable cardioverter defibrillator inserted.
If you have a pacemaker or implantable cardioverter defibrillator, make
sure that you ask your healthcare providers about any restrictions or
lifestyle changes you may need to make. Working with your provider can
promote your health and well-being.
When should I call my healthcare provider?
Tell your healthcare provider if:
- Your symptoms get worse or you start to have new symptoms
- You have side effects from your medicine
- Need help with managing stress or emotions
Key points about arrhythmias
An arrhythmia is an abnormal heart rhythm.
- An arrhythmia can occur in the sinus node, the atria, or the atrioventricular
node, or the ventricle.
- Some arrhythmias cause few, if any, problems.
- Other arrhythmias can cause serious complications such as heart failure,
stroke, or even cardiac arrest.
- Many treatment options are available to treat arrhythmia, including medicines,
devices, cardiac ablation, and surgery. Many arrhythmias can be cured
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your
provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines,
treatments, or tests. Also write down any new instructions your provider
- Know why a new medicine or treatment is prescribed, and how it will help
you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or
- If you have a follow-up appointment, write down the date, time, and purpose
for that visit.
- Know how you can contact your provider if you have questions.