Arrhythmias differ from normal heartbeats in speed or rhythm. Arrhythmias are also grouped by where they occur—in the upper chambers of the heart, in its lower chambers, or between the chambers. The main types of arrhythmia are bradyarrhythmias; premature, or extra, beats; supraventricular arrhythmias; and ventricular arrhythmias.
Bradyarrhythmia is a slow heart rate—also called bradycardia. For adults, bradycardia is often defined as a heart rate that is slower than 60 beats per minute, although some studies use a heart rate of less than 50 beats per minute. Some people, especially people who are young or physically fit, may normally have slow heart rates. A doctor can determine whether a slow heart rate is appropriate for you.
A premature heartbeat happens when the signal to beat comes early. It can feel like your heart skipped a beat. The premature, or extra, heartbeat creates a short pause, which is followed by a stronger beat when your heart returns to its regular rhythm. These extra heartbeats are the most common type of arrhythmia. They are called ectopic heartbeats and can trigger other arrhythmias.
Arrhythmias that start in the heart’s upper chambers, called the atrium, or at the gateway to the lower chambers are called supraventricular arrhythmias. Supraventricular arrhythmias are known by their fast heart rates, or tachycardia. Tachycardia occurs when the heart, at rest, goes above 100 beats per minute. The fast pace is sometimes paired with an uneven heart rhythm. Sometimes the upper and lower chambers beat at different rates.
Types of supraventricular arrhythmias include:
These arrhythmias start in the heart’s lower chambers. They can be very dangerous and usually require medical care right away.
Arrhythmia is caused by changes to heart tissue. It can also occur suddenly as a result of exertion or stress, imbalances in the blood, medicines, or problems with electrical signals in the heart. Typically, an arrhythmia is set off by a trigger, and the irregular heartbeat can continue if there is a problem in the heart. Sometimes the cause of an arrhythmia is unknown.
The following conditions may cause arrhythmia:
Strong emotional stress, anxiety, anger, pain, or a sudden surprise can make the heart work harder, raise blood pressure, and release stress hormones. Sometimes these reactions can lead to arrhythmias. If you have heart disease, physical activity can trigger arrhythmia due to an excess of hormones such as adrenaline. Sometimes vomiting or coughing can trigger arrhythmia.
An excess or deficiency of electrolytes, hormones, or fluids can alter your heartbeat.
Certain medicines can cause arrhythmia. These include medicines to treat high blood pressure and other conditions, including arrhythmia, depression, and psychosis. Some people also need to be careful about taking certain antibiotics and over-the-counter medicines, such as allergy and cold medicines.
An arrhythmia can occur if the electrical signals that control the heartbeat are delayed or blocked. This can happen when the nerve cells that produce electrical signals do not work properly or when the electrical signals do not travel normally through the heart. Another part of the heart could start to produce electrical signals, disrupting a normal heartbeat.
Disorders of electrical signaling in the heart are called conduction disorders.
Want to learn more about why arrhythmias occur?
As part of daily living, our hearts change pace to accommodate a wide range of activities, from sleeping to working out. These changes are controlled by the autonomic nervous system, which has two parts: the parasympathetic system and the sympathetic system. Overstimulation of either system can cause arrhythmia.
The chances of having arrhythmia grow as we age, in part because of changes in heart tissue and in how the heart works over time. Older people are also more likely to have health conditions, including heart disease, that raise the risk of arrhythmia.
Some research suggests that exposure to air pollutants, especially particulates and gases, is linked to a short-term risk of arrhythmia.
You may have an increased risk of some types of arrhythmia if your parent or other close relative has had arrhythmia, too. Also, some inherited types of heart disease can raise your risk of arrhythmia. With some conduction disorders, genes mutations cause the ion channels that transmit signals through heart cells to work incorrectly or stop working.
Your risk for arrhythmia may be higher because of certain lifestyle habits, including:
Arrhythmias are more common in people who have diseases or conditions that weaken the heart, but many conditions can raise the risk for arrhythmia. These include:
Studies suggest that white Americans may be more likely than African Americans to have some arrhythmias, such as atrial fibrillation, although African Americans have higher rates of high blood pressure and other arrhythmia risk factors.
Some studies suggest that men are more likely to have atrial fibrillation than women. However, women taking certain medicines appear to be at a higher risk of a certain type of arrhythmia. Certain times of the menstrual cycle also appear to increase women’s risk of some arrhythmia events. If you are a pregnant woman, you may notice that an existing arrhythmia occurs more often. Benign extra beats are also more common during pregnancy. In some cases, the complications that can develop with arrhythmia also differ by sex.
You may be at a higher risk of developing atrial flutter in the early days and weeks after surgery involving the heart, lungs, or esophagus.
If you or your child is at increased risk of arrhythmia, the doctor may want to do a screening to assess the risk of a life-threatening event. Sometimes screening is required to participate in competitive sports. If your child carries a genetic risk of arrhythmia, your child’s doctor may recommend regular screening to monitor your child’s heart or other family members’ health. The doctor may also ask about risk factors and may suggest genetic testing if your child, parent, or other family member has a known or suspected arrhythmia or other heart condition. Heart-healthy lifestyle changes and other precautions can help decrease the risk of triggering arrhythmia.
Your doctor may recommend screening tests based on your risk factors, such as age or family history.
Learn about prevention strategies that your doctor may recommend, including:
If you are the parents of a child with an inherited condition that increases the risk of arrhythmia, discuss prevention strategies with your pediatrician as part of your child’s care.
An arrhythmia may not cause any obvious Signs or symptoms. You may notice something that occurs only occasionally, or your symptoms may become more frequent over time. Keep track of when and how often arrhythmia occurs, what you feel, and whether these things change over time. They are all important clues your doctor can use. If left untreated, arrhythmia can lead to life-threatening complications such as stroke, heart failure, or sudden cardiac arrest.
You may be able to feel a slow or irregular heartbeat or notice pauses between heartbeats. If you have palpitations, you may feel like your heart skipped a beat or may notice it pounding or racing. These are all symptoms of arrhythmia.
More serious signs and symptoms include:
What else will your doctor want to know about your symptoms?
Some arrhythmias tend to happen at certain times or under certain circumstances. If you notice signs or symptoms of arrhythmia, note when they happened and what you were doing. This information can help your doctor diagnose what is going on and find the right treatment. Here are questions to ask yourself.
Arrhythmias that are unrecognized or left untreated can cause sometimes life-threatening complications affecting the heart and brain.
To diagnose arrhythmia, your doctor will ask you about your symptoms, your medical history, and any signs of arrhythmia in your family. Your doctor may also do an EKG and a physical exam as part of your diagnosis. Additional tests may be necessary to rule out another cause or to help your doctor decide on treatment.
To diagnose an arrhythmia, your doctor will ask about your eating and physical activity habits, family history, and other risk factors for arrhythmia. Your doctor may ask whether you have any other signs or symptoms. This information can help your doctor determine whether you have complications or other conditions that may be causing you to have arrhythmia.
During a physical exam, your doctor may take these steps:
Common arrhythmia treatments include heart-healthy lifestyle changes, medicines, surgically implanted devices that control the heartbeat, and other procedures that treat abnormal electrical signals in the heart.
Your doctor may recommend that you adopt the following lifelong heart-healthy lifestyle changes to help lower your risk for conditions such as high blood pressure and heart disease, which can lead to arrhythmia.
Your doctor may give you medicine for your arrhythmia. Some medicines are used in combination with each other or together with a procedure or a pacemaker. If the dose is too high, medicines to treat arrhythmia can cause an irregular rhythm. This happens more often in women.
Treatment may also include managing any underlying condition, such as an electrolyte imbalance, high blood pressure, heart disease, sleep apnea, or thyroid disease.
Your doctor may use supplements to treat magnesium or electrolyte deficiencies. Electrolytes can also be an alternative to medicines that treat arrhythmia if your doctor is concerned that those medicines might trigger an arrhythmia.
Your doctor may also perform certain techniques to slow your heart rate. The exercises stimulate your body’s natural relaxation processes. They do this by affecting the vagus nerve, which helps control the heart rate. Techniques can include:
If you have been diagnosed and treated for arrhythmia, make sure to follow your treatment plan. Your ongoing care may focus on reducing the chance that you will have another episode or a complication. Keep your regular appointments with your doctor. Ask about heart-healthy lifestyle changes that you can make to keep your arrhythmia from happening again or getting worse.
How often you need to see your doctor for follow-up care will depend on your symptoms and treatment.
Return to Treatment to review possible treatment options for arrhythmia.
To monitor your condition, your doctor may recommend the following tests.
Arrhythmia can lead to serious complications, such as sudden cardiac arrest and severe bleeding in the brain. If you suspect any of the following in yourself or someone else, call 9-1-1 immediately:
F—Face: Ask the person to smile. Does one side of the face droop?
A—Arms: Ask the person to raise both arms. Does one arm drift downward?
S—Speech: Ask the person to repeat a simple phrase. Is their speech slurred or strange?
T—Time: If you observe any of these signs, call 9-1-1 immediately. Every minute matters.
If you have arrhythmia, you will need to learn ways to care for your condition at home. You will also need to avoid activities that may trigger your arrhythmia.
Learn about the following ways the NHLBI continues to translate current research into improved health for people with arrhythmia. Research on this topic is part of the NHLBI’s broader commitment to advancing heart and vascular disease scientific discovery.
Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.
In support of our mission, we are committed to advancing arrhythmia research in part through the following ways.
Learn about exciting research areas the NHLBI is exploring about arrhythmia.
We lead or sponsor many studies on arrhythmia. See whether you or someone you know is eligible to participate in our clinical trials.
After reading our Arrhythmia Health Topic, you may be interested in additional information found in the following resources.