In a typical heart rhythm, a small group of cells in the sinus node send out an electrical signal. The signal then travels through the atria to the atrioventricular (AV) node and into the ventricles, causing them to contract and pump blood.
An arrhythmia is an irregular heartbeat. Arrhythmias (arrhythmias) occur when the electrical signals that coordinate your heart's beat aren't working properly. Improper signal transmission causes the heart to beat too fast (tachycardia), too slow (bradycardia), or irregularly.
Arrhythmias can feel like a fluttering or racing heart and be harmless. However, some cardiac arrhythmias can cause annoying, sometimes even life-threatening, signs and symptoms.
However, sometimes it is normal for a person to have a fast or slow heart rate. For example, heart rate may increase during exercise or decrease during sleep.
Treatment for abnormal heart rhythms may include medications, catheter procedures, implanted devices, or surgery to control or eliminate fast, slow, or irregular heartbeats. A heart-healthy lifestyle can help prevent heart damage that can trigger certain cardiac arrhythmias.
In general, cardiac arrhythmias are classified according to the speed of the heart rhythm. For example:
- Tachycardia is a fast heart. The resting heart rate is over 100 beats per minute.
- Bradycardia is a slow heartbeat. The resting heart rate is less than 60 beats per minute.
Rapid heartbeat (tachycardia)
Types of tachycardia include:
- Atrial Fibrillation (AF).Chaotic heart signals result in a rapid and uncoordinated heart rate. The condition may be temporary, but someFAThe episodes may not stop if left untreated.FAit is associated with serious complications such as stroke.
- atrial flutter.resembles atrial flutterFA, but the heartbeat is more organized. Atrial flutter is also linked to stroke.
- supraventricular Tachycardia.Supraventricular tachycardia is a broad term that includes arrhythmias that begin above the lower chambers (ventricles) of the heart. Supraventricular tachycardia causes episodes of heart palpitations (palpitations) that begin and end abruptly.
- ventricular fibrillation.This type of arrhythmia occurs when fast, chaotic electrical signals cause the heart's lower chambers (ventricles) to quiver instead of touching in a coordinated manner and pumping blood to the rest of the body. This serious problem can be fatal if normal heart rhythm is not restored within minutes. Most people with ventricular fibrillation have heart disease or have suffered major trauma.
- Ventricular tachycardia.This fast, regular heartbeat begins with faulty electrical signals in the lower chambers (ventricles) of the heart. The heart's chambers cannot fill properly with blood due to the fast heart rate. As a result, the heart cannot pump enough blood through the body. In people with otherwise healthy hearts, ventricular tachycardia may not cause serious problems. In people with heart disease, ventricular tachycardia can present a medical emergency that requires immediate medical attention.
Slow heartbeat (bradycardia)
Although a resting heart rate of less than 60 beats per minute is considered bradycardia, a low resting heart rate does not always indicate a problem. If you are physically fit, your heart may still be able to pump enough blood to your body at less than 60 beats per minute when you are resting.
If your heartbeat is slow and your heart isn't pumping enough blood, you may have a type of bradycardia. Types of bradycardia include:
- Sick-Sinus-Syndrom.The sinus node is responsible for setting the heart's rhythm. When it's not working properly, your heart rate can alternate between being too slow (bradycardia) and too fast (tachycardia). Sick sinus syndrome can be caused by a scar near the sinus node that slows, interrupts, or blocks the transmission of impulses. Sick sinus syndrome is more common in older adults.
- driving block.A blockage in the heart's electrical wiring can cause the signals that trigger the heartbeat to slow down or stop. Some blockages may not cause any signs or symptoms, others may cause cardiac arrest or bradycardia.
Premature heartbeats are extra beats that occur individually, sometimes in patterns that alternate with the normal heartbeat. The extra beats can come from the upper chamber of the heart (atrial premature contractions) or from the lower chamber (ventricular premature contractions).
A premature heartbeat can appear as if your heart has missed a beat. Those extra hits aren't usually anything to worry about, and rarely mean you have a more serious condition. However, a premature heartbeat can trigger a prolonged cardiac arrhythmia, especially in people with heart disease. Sometimes, very frequent premature heartbeats that last for several years can lead to heart failure.
Premature resting heartbeats may occur. Sometimes premature heartbeats are caused by stress, strenuous exercise, or stimulants such as caffeine or nicotine.
Heart arrhythmias may not cause any signs or symptoms. A doctor may notice an irregular heartbeat during an exam for another health reason.
Signs and symptoms of abnormal heart rhythms in general may include:
- A fluttering in the chest
- Rapid heartbeat (tachycardia)
- Slow heartbeat (bradycardia)
- chest pain
- difficulty breathing
Other symptoms can be:
- lightheadedness or dizziness
- Fainting (syncope) or near fainting
When should you see a doctor?
If you feel your heart is beating too fast, too slow, or if you miss a heartbeat, make an appointment to see your doctor. Seek medical attention right away if you experience shortness of breath, weakness, dizziness, lightheadedness, fainting or near fainting, or chest pain or discomfort.
A type of arrhythmia called ventricular fibrillation can cause a dramatic drop in blood pressure. Collapse can occur in a matter of seconds, and soon the person's breathing and heart rate will stop. In this case, follow the steps below:
- Call 911 or the emergency number for your area.
- If no CPR-trained person is nearby, provide purely manual care.RCP. Press firmly and quickly in the center of the chest at a rate of 100-120 compressions per minute until paramedics arrive. Mouth-to-mouth resuscitation is not required.
- If you or someone close to you knowsRCP, to startRCP.RCPIt can help maintain blood flow to the organs until an electric shock (defibrillation) can be delivered.
- If an automated external defibrillator (AED) is available nearby, have someone pick it up and follow the instructions. ADeais a wearable defibrillation device that can deliver a shock that can restart the heartbeat. No training is required for operationDea. IsDeaIt will tell you what to do. It is programmed to download only when needed.
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To understand the cause of abnormal heart rhythms, it can be helpful to know how the heart normally works.
How does the heart beat?
The heart consists of four chambers: two upper chambers (atria) and two lower chambers (ventricles).
Heart rhythm is normally controlled by a natural pacemaker (the sinus node) in the right upper chamber (atrium). The sinus node sends out electrical signals that normally trigger each heartbeat. These electrical signals travel through the atria, causing the heart muscles to contract and pump blood into the ventricles.
The signals then reach a group of cells calledVONnodes where they slow down. This slight delay allows the ventricles to fill with blood. When electrical signals reach the ventricles, the chambers contract, pumping blood to the lungs or the rest of the body.
In a healthy heart, this cardiac signaling process is normally smooth, resulting in a normal resting heart rate of 60 to 100 beats per minute.
Things that can cause an irregular heartbeat (arrhythmia) include:
- Recent heart attack or scarring from a previous heart attack
- Blocked arteries in the heart (coronary artery disease)
- Changes in the structure of the heart, such as those caused by cardiomyopathy.
- Infection with COVID-19
- Overactive thyroid (hyperthyroidism)
- sleep apnea
- Underactive thyroid (hypothyroidism)
- Certain medications, including cold and allergy medications, are bought without a prescription.
- Drinking too much alcohol or caffeine
- substance abuse
- from smoking
- stress or anxiety
Things that can increase the risk of heart arrhythmias include:
- Coronary heart disease, other heart problems, and previous heart surgery.Narrowed heart arteries, a heart attack, abnormal heart valves, previous heart surgery, congestive heart failure, cardiomyopathy, and other heart damage are risk factors for almost any type of abnormal heart rhythm.
- Hypertension.This condition increases the risk of coronary artery disease. It can also cause the walls of the heart's lower left chamber (left ventricle) to become stiff and thick, which can change the way electrical signals travel through the heart.
- Congenital heart defects.If you're born with a heart condition, it can affect your heart's rhythm.
- thyroid disease.An overactive or underactive thyroid can increase the risk of an irregular heartbeat.
- Obstructive sleep apnea.This condition causes breathing pauses during sleep. Slow heartbeat (bradycardia) and irregular heartbeat, including atrial fibrillation, can occur.
- The electrolyte disorder.Substances in the blood called electrolytes, such as potassium, sodium, calcium, and magnesium, help trigger and send electrical impulses to the heart. An imbalance in electrolytes (such as being too low or too high) can interfere with heart signals and cause an irregular heartbeat.
- Certain medications and dietary supplements.Some prescription drugs and certain over-the-counter cough and cold medicines can cause abnormal heart rhythms.
- Excessive alcohol.Too much alcohol can impair the heart's electrical impulses and increase your risk of developing atrial fibrillation.
- Use of caffeine, nicotine or illegal drugs.Caffeine, nicotine, and other stimulants can cause the heart to beat faster and develop more serious abnormal heart rhythms. Illicit drugs such as amphetamines and cocaine can severely affect the heart, causing many types of abnormal heart rhythms or sudden death from ventricular fibrillation.
Complications depend on the type of arrhythmia. In general, complications of cardiac arrhythmia can include stroke, sudden death, and heart failure.
Heart rhythm disorders are associated with an increased risk of blood clots. When a blood clot dissolves, it can travel from the heart to the brain and cause a stroke. Blood thinners can reduce the risk of stroke associated with atrial fibrillation and other heart rhythm disorders. Your doctor will determine if an anticoagulant medication is right for you.
If an abnormal heart rhythm is causing symptoms of heart failure, heart rate control methods can improve heart function.
Lifestyle changes to reduce the risk of heart disease can help prevent abnormal heart rhythms. A heart-healthy lifestyle includes:
- A heart-healthy diet
- Stay physically active
- Maintain a healthy weight
- smoking prohibited
- Limit or avoid caffeine and alcohol.
- Reduce stress, as high levels of stress and anger can lead to abnormal heart rhythms.
- Use the medicines as directed and tell your doctor about all medicines you are taking, including those obtained without a prescription.
By Mayo Clinic staff
If you feel like your heart is beating too fast or too slowly, or it's skipping a beat, make an appointment to see a doctor. Seek immediate medical help if you have shortness of breath, weakness, dizziness, lightheadedness, fainting or near fainting, and chest pain or discomfort.What are 4 symptoms of arrhythmia? ›
- Fatigue or weakness.
- Dizziness or lightheadedness.
- Fainting or near-fainting spells.
- Rapid heartbeat or pounding in the chest.
- Shortness of breath and anxiety.
- Chest pain or pressure.
- Alternating fast and slow heart rate.
Common triggers for an arrhythmia are viral illnesses, alcohol, tobacco, changes in posture, exercise, drinks containing caffeine, certain over-the-counter and prescribed medicines, and illegal recreational drugs.What's cardiac arrhythmia? ›
What is an arrhythmia? An arrhythmia is an abnormal heart rhythm. Your heart is controlled by a conduction system which sends out electrical impulses. This causes a heartbeat. Arrhythmias are caused by a problem in this conduction system, which can make your heart beat too slowly, too quickly, or in an irregular way.Can anxiety cause arrhythmia? ›
Both atrial fibrillation and anxiety can lead to irregular heart rhythms, known as arrhythmia. Anxiety may contribute to some heart conditions, including atrial fibrillation. Having atrial fibrillation may also contribute to anxiety. is an irregular beating of the upper chambers of the heart.What is the most common form of cardiac arrhythmia? ›
Atrial fibrillation is the most common sustained arrhythmia, increases with age, and presents with a wide spectrum of symptoms and severity. Paroxysmal, persistent, and permanent forms require very individualized approaches to management.What can be mistaken for arrhythmia? ›
- Anxiety and Panic Attacks.
- Low Blood Pressure.
- Other Heart Arrhythmias.
- Coronary Artery Disease.
- Heart Valve Disorder.
The most serious arrhythmia is ventricular fibrillation, which is an uncontrolled, irregular beat.What are 4 life threatening arrhythmias? ›
Ventricular fibrillation, ventricular tachycardia and prolonged pauses or asystole are dangerous. Arrhythmias associated with very low potassium or magnesium or those associated with inherited causes such as QT prolongation are also serious.What deficiency causes heart arrhythmia? ›
Atrial fibrillation is a common type of arrhythmia and is an important cause of stroke and heart failure. vitamin D is an emerging risk factor of AF, and is implicated in the pathophysiology of atrial fibrillation.
This can lead to abnormal heart rhythm. When you're dehydrated, your body's electrolytes (electrolytes in general, and sodium and potassium in particular) are crucial for heart health. Electrolyte levels plummet when you're dehydrated. This can lead to abnormal heart rhythm.Can caffeine cause arrhythmia? ›
“The available research suggests that caffeine in doses typically consumed, about 400 mg a day or about five cups of coffee, does not provoke arrhythmias,” says Helga Van Herle, MD, a cardiologist at Keck Medicine of USC and associate professor of clinical medicine at the Keck School of Medicine of USC.What is the best position to sleep in with heart arrhythmia? ›
AFib patients know that they need to get high-quality sleep. Therefore, many wonder if there is an atrial fibrillation sleep position. While there is no specific position, certain postures can help. Side sleeping is the favorite position of health experts.How can I check my arrhythmia at home? ›
The most basic is a simple pulse test, where you place your index and middle fingers on your left wrist and search for a pulse. It's important to remember that you are checking for a consistent rhythm, not counting the beats-per-minute.Does heart arrhythmia go away? ›
Can a Heart Arrhythmia ever just go away? Yes. People can have only one episode. This can be caused by pericarditis (membrane or sac around your heart is inflamed), alcohol or other drugs, acute illness, or electrolyte abnormalities.Can you self diagnose heart arrhythmia? ›
Heart rhythm charity Arrythmia Alliance has more information about knowing your pulse and how to check it. Checking and assessing your pulse can give you a good indication of whether you have atrial fibrillation, but a full medical investigation will be needed before a diagnosis can be made.Can you have arrhythmia and not know it? ›
Atrial fibrillation, also referred to as AF or A-fib, is the most common type of irregular heartbeat, or heart arrhythmia. The American Heart Association reports that there are 2.7 million Americans living with AF, though that number could be much higher, as people can have the condition unknowingly.Can heart arrhythmia go away on its own? ›
Can an irregular heartbeat go back to normal? Yes, heart arrhythmias sometimes go away on their own. But if you notice any of the things mentioned above that go along with your arrhythmia, you should get it checked out as soon as possible.