An arrhythmia is an irregular heartbeat. The heart may beat too quickly, too slowly, too early, or with an irregular rhythm. It is not always serious but can sometimes indicate a potentially fatal heart problem.
Arrhythmias — sometimes called dysrhythmias —
Many heart arrhythmias are harmless. However, if they are highly irregular or result from a weak or damaged heart, arrhythmias can cause severe and potentially fatal symptoms and complications.
In this article, we define arrhythmia, as well as its causes and symptoms. We also explain the possible treatments and different types.
Cardiac arrhythmia refers to conditions in which the heart beats irregularly, too slowly, or too quickly.
- bradycardia, or a slow heartbeat
- tachycardia, or a fast heartbeat
- irregular heartbeat, also known as a flutter or fibrillation, such as atrial fibrillation (A-fib)
Arrhythmias are not always serious, but some can increase the risk of stroke or cardiac arrest.
What is a normal heartbeat?
Doctors identify a healthy heartbeat by counting the number of times the heart beats every minute (bpm) during rest. This is known as the resting heart rate.
The range for a healthy resting heart rate varies between people, but the American Heart Association suggests it is usually between
This rate can change. It is often lower at night. Athletes may also have a resting heart rate of less than 60 bpm because their hearts are highly efficient.
The heart should beat with a regular rhythm, consisting of double “ba-bum” beats with even spaces in between each.
One of these beats is the heart contracting to provide oxygen to blood that has already circulated, and the other involves the heart pushing oxygenated blood around the body.
A person can measure their heart rate using their pulse. This is a point at which they can feel the heartbeat through the skin. The best locations on the body for this are:
- the wrists
- the insides of the elbows
- the side of the neck
- the top of the foot
There are several types of arrhythmia.
A-fib is the irregular beating of the atrial chambers and nearly always involves tachycardia. A-fib is common and mainly develops in adults
Instead of producing a single, strong contraction, the chamber fibrillates or quivers, often producing a rapid heartbeat.
What are the types of atrial fibrillation?
While fibrillation causes many random and different quivers in the atrium, atrial flutter usually
Atrial flutter can be a serious condition and usually leads to fibrillation without treatment.
Some people may experience both flutter and fibrillation.
What is the difference between A-fib and atrial flutter?
Supraventricular tachycardia (SVT)
Doctors classify atrial fibrillation and flutter under SVT.
Ventricular tachycardia (VT) refers to
Ventricular fibrillation (VFib) is an irregular heart rhythm consisting of rapid, uncoordinated, and fluttering contractions of the ventricles. The ventricles of the lower chamber
VFib can be life threatening and has links to heart disease. A heart attack often triggers it.
Find out more about ventricular fibrillation here.
Bradycardia is when the heart rhythm is slower than usual, below
Causes include various types of heart disease, chest trauma, genetic factors, the use of certain drugs and medications, hypothermia, and a range of other health conditions.
Long QT syndrome
Long QT syndrome refers to a heart rhythm disorder that a person is born with. It sometimes causes rapid, uncoordinated heartbeats. It can be life threatening and causes a rhythm known as QT prolongation.
It can also occur due to genetic susceptibility or taking certain medications.
Arrhythmia does not always cause noticeable symptoms. However, a doctor may detect an arrhythmia during a routine examination.
Having symptoms does not necessarily mean the arrhythmia is severe. Some people have life threatening arrhythmias with no symptoms, while others with symptoms may not have a severe arrhythmia.
Symptoms depend on the type of arrhythmia.
Symptoms of tachycardia
The symptoms of a rapid heartbeat include:
- fainting or nearly fainting
- fluttering in the chest, known as heart palpitations
- chest pain
- sudden weakness
Symptoms of bradycardia
Bradycardia can cause the following symptoms:
- angina, or chest pain
- trouble concentrating
- difficulty exercising
- shortness of breath
- fainting or nearly fainting
- profuse sweating
Symptoms of A-fib
When A-fib symptoms occur, they often have a rapid onset and may involve:
- fainting or nearly fainting
Any interruption to the electrical impulses that stimulate heart contractions may cause arrhythmia.
- a problem with the electrical signals that control the heartbeat
- damage to heart tissue
- a high level of strain or stress
- an imbalance of fluids or electrolytes in the blood
- changes in hormone levels
- some medications
To diagnose arrhythmia, a doctor will need to identify the unusual heartbeat and try to find the source of the change.
They will ask the individual about:
- any symptoms
- personal and family medical history
- lifestyle factors, such as tobacco and alcohol use
They will also
- measure the heart rate, pulse, and blood pressure
- listen for a heart murmur
- check for symptoms such as swelling due to fluid retention
A doctor may also recommend:
- blood and urine tests
- an electrocardiogram (EKG or ECG)
- a Holter monitor — a wearable device to record the heart rhythms
- an electrophysiology study to measure electrical activity in the heart
- a tilt-table test to help identify if sudden decreases in blood pressure or heart rate are the cause
- genetic testing, in some cases
- heart imaging tests, for instance, a CT or MRI scan
Some people with arrhythmia do not experience active symptoms. However, treatment is still essential because life threatening complications
A-fib means that the heart is not pumping effectively. This can cause blood to collect in pools and form clots.
If a clot dislodges, it may travel to a brain artery, causing a potentially fatal blockage, or stroke. Stroke can cause brain damage and require emergency treatment.
Prolonged tachycardia or bradycardia can result in heart failure. When the heart fails, it cannot pump enough blood to the body and its organs. Treatment can usually help improve this.
A heart attack happens when blood
A cardiac arrest is when the heart
What is the difference between a heart attack and a cardiac arrest?
Is it a heart attack?
Heart attacks occur when there is a lack of blood supply to the heart. Symptoms include:
- chest pain, pressure, or tightness
- pain that may spread to arms, neck, jaw, or back
- nausea and vomiting
- sweaty or clammy skin
- heartburn or indigestion
- shortness of breath
- coughing or wheezing
- lightheadedness or dizziness
- anxiety that can feel similar to a panic attack
If someone has these symptoms:
- Dial 911 or the number of the nearest emergency department.
- Stay with them until the emergency services arrive.
If a person stops breathing before emergency services arrive, perform manual chest compressions:
- Lock fingers together and place the base of hands in the center of the chest.
- Position shoulders over hands and lock elbows.
- Press hard and fast, at a rate of 100–120 compressions per minute, to a depth of 2 inches.
- Continue these movements until the person starts to breathe or move.
- If needed, swap over with someone else without pausing compressions.
Use an automatic external defibrillator (AED) available in many public places:
- An AED provides a shock that may restart the heart.
- Follow the instructions on the defibrillator or listen to the guided instructions.
There are many risk factors for arrhythmias, and different types may have different risk factors.
Here are a few of them:
- being aged
65 yearsor older
- emotional stress
- panic disorders
- inherited genetic factors
- underlying heart problems
- hypothyroidism or hyperthyroidism
- some prescription medications and over-the-counter drugs
- high blood pressure
- obstructive sleep apnea
- lung diseases, such as chronic obstructive pulmonary disease (COPD)
- electrolyte imbalances
- high alcohol consumption
- using recreational drugs, such as cocaine
In the United States, white people are
Some monitoring studies have
In some cases, a doctor may monitor the heart rhythm but not offer treatment.
A person may need treatment if they have:
- an underlying condition
- a risk of complications
- severe symptoms
The various arrhythmias require different treatments.
Treatments for tachycardia
There are several treatments for tachycardia. The precise options will depend on the type and cause:
- Vagal or Valsalva maneuver are movements and exercises that might stop some types of arrhythmia.
- Medications to reduce the frequency of episodes or promote electrical conduction through the heart.
- Cardioversion is an electric shock treatment or medication that resets the heart to its regular rhythm.
- An implantable cardioverter-defibrillator (ICD) near the left collarbone enables monitoring of the heart rhythm. If the rate speeds up, it stimulates the heart to return to its normal speed.
- In the Maze procedure and other types of cardiac ablation surgery, a surgeon makes incisions in the heart that heal into scars and form blocks that guide the electrical impulses. This helps the heart beat efficiently.
- Surgery can resolve an aneurysm that may be causing arrhythmia.
- Heart bypass surgery involves grafting blood vessels from elsewhere in the body onto the coronary arteries. The circulation can bypass narrowed parts, and blood supply to the heart muscle improves.
What is a coronary artery bypass graft?
Treatments for bradycardia
Treatment for bradycardia
- intravenously medicating with atropine if tests show that blood pressure is unstable
- warming up the person before deciding on treatment if bradycardia is due to hypothermia
- providing appropriate treatment for a heart problem or other underlying condition
- implanting a pacemaker
A pacemaker is a small device that a doctor places under the skin of the chest or abdomen to help control abnormal heart rhythms. Pacemakers use electrical pulses to prompt the heart to beat at a regular minimum rate.
Treatment for atrial fibrillation
Treatment options for A-fib
- lifestyle measures, such as physical activity, following a heart-healthy diet, quitting smoking, and avoiding alcohol
- maintaining a moderate weight
- managing stress
- using medication, such as beta-blockers, blood thinners, or calcium channel blockers, as a doctor prescribes
- procedures such as electrical cardioversion or installing a pacemaker
- heart surgery, for example, catheter ablation or closing off part of the heart
It is not always possible to prevent heart problems, including arrhythmia.
Steps a person can take to reduce their risk include:
- seeking help for any underlying condition and following the treatment plan
- doing regular exercise
- avoiding the use of tobacco and recreational drugs
- limiting alcohol consumption
- checking with a doctor before using any medications or supplements
- following a varied and nutritious diet
Here are some questions people often ask about arrhythmia.
What is the main cause of arrhythmia?
Overall risk factors for arrhythmia include having an existing heart condition, being born with unusual structural features in the heart, and being aged
Is arrhythmia serious?
It is not always serious, but it can indicate an underlying heart problem or a higher risk of a stroke or heart attack. Anyone with signs of arrhythmia should seek medical advice and follow the recommended treatment plan.
What are the warning signs of arrhythmia?
This will depend on the type of arrhythmia, but common warning signs
Arrhythmia is when the heart does not beat as it should. In most cases, the heart should beat at a rate of 60–100 beats per minute. If the heartbeat is faster, slower, or irregular, a doctor will diagnose arrhythmia.
There are many causes of arrhythmia, but underlying heart disease is often a factor. Other causes include the use of certain medications. Often, arrhythmias are not serious, but they can be a sign of a more serious condition. For this reason, it is essential to seek medical advice if a person notices symptoms of arrhythmia.
It is not always possible to prevent arrhythmias, but getting regular exercise, maintaining a moderate weight, and seeking treatment for underlying conditions can help.