Bradycardia - Symptoms and causes (2023)


Bradycardia (brad-e-KAHR-dee-uh) is a slow heart rate. The hearts of adults at rest usually beat between 60 and 100 times a minute. If you have bradycardia, your heart beats fewer than 60 times a minute.

Bradycardia can be a serious problem if the heart rate is very slow and the heart can't pump enough oxygen-rich blood to the body. If this happens, you may feel dizzy, very tired or weak, and short of breath. Sometimes bradycardia doesn't cause symptoms or complications.

A slow heart rate isn't always a concern. For example, a resting heart rate between 40 and 60 beats a minute is quite common during sleep and in some people, particularly healthy young adults and trained athletes.

If bradycardia is severe, an implanted pacemaker may be needed to help the heart maintain an appropriate rate.


A slower than typical heartbeat (bradycardia) can prevent the brain and other organs from getting enough oxygen, possibly causing these signs and symptoms:

  • Chest pain
  • Confusion or memory problems
  • Dizziness or lightheadedness
  • Easily tiring during physical activity
  • Fatigue
  • Fainting (syncope) or near-fainting
  • Shortness of breath

When to see a doctor

Many things can cause signs and symptoms of bradycardia. It's important to get a prompt, accurate diagnosis and appropriate care. See your health care provider if you are concerned about a slow heart rate.

If you faint, have difficulty breathing or have chest pain lasting more than a few minutes, call 911 or emergency medical services.

Request an appointment

(Video) Bradycardia: Slow Heart Rate Causes and Treatment with Dr. Poulina Uddin | San Diego Health

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(Video) Sinus Bradycardia ECG/EKG Interpretation, Causes, Treatment, Nursing NCLEX Review Cardiac

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Typical heartbeat

Bradycardia - Symptoms and causes (1)

Typical heartbeat

In a typical heart rhythm, a tiny cluster of cells at the sinus node sends 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.

Bradycardia can be caused by:

  • Heart tissue damage related to aging
  • Damage to heart tissues from heart disease or heart attack
  • A heart condition present at birth (congenital heart defect)
  • Inflammation of heart tissue (myocarditis)
  • A complication of heart surgery
  • An underactive thyroid gland (hypothyroidism)
  • Imbalance of chemicals in the blood, such as potassium or calcium
  • Repeated pauses in breathing during sleep (obstructive sleep apnea)
  • Inflammatory disease, such as rheumatic fever or lupus
  • Certain medications, including sedatives, opioids, and drugs used to treat heart rhythm disorders, high blood pressure and certain mental health disorders

To better understand the causes of bradycardia, it may be helpful to know how the heart typically beats.

(Video) What's bradycardia, how is it treated & why is it important to treat this type of heart arrhythmia?

The typical heart has four chambers — two upper chambers (atria) and two lower chambers (ventricles). Within the upper right chamber of the heart (right atrium) is a group of cells called the sinus node. The sinus node is the heart's natural pacemaker. It produces the signal that starts each heartbeat.

Bradycardia occurs when these signals slow down or are blocked.

Sinus node problems


Bradycardia - Symptoms and causes (2)


Bradycardia, shown on the right, is a slower than typical heart rhythm that often starts in the area of the heart called the sinus node. A typical heart rhythm is shown in the image on the left.

Bradycardia often starts in the area of the heart called the sinus node. In some people, sinus node problems cause alternating slow and fast heart rates (bradycardia-tachycardia syndrome).

(Video) 7f: Symptomatic Bradycardia (2021) OLD

Heart block (atrioventricular block)

Bradycardia can also occur if the heart's electrical signals don't move correctly from the upper chambers (atria) to the lower chambers (ventricles). If this occurs, the condition is called heart block, or atrioventricular block.

Heart blocks fall into three main groups.

  • First-degree heart block. In the mildest form, all electrical signals from the atria reach the ventricles, but the signal is slowed. First-degree heart block rarely causes symptoms and usually needs no treatment if there's no other problem in electrical signaling.
  • Second-degree heart block. Not all electrical signals reach the ventricles. Some beats are dropped, resulting in a slower and sometimes irregular heart rhythm.
  • Third-degree (complete) heart block. None of the electrical signals from the atria reaches the ventricles. When this happens, the ventricles will usually beat on their own but at a very slow rate.

Risk factors

Bradycardia is often associated with damage to heart tissue from some type of heart disease. Anything that increases the risk of heart problems can increase the risk of bradycardia. Risk factors for heart disease include:

  • Older age
  • High blood pressure
  • Smoking
  • Heavy alcohol use
  • Illegal drug use
  • Stress and anxiety

Healthy-lifestyle changes or medical treatment may help lower the risk of heart disease.


Possible complications of bradycardia can include:

  • Frequent fainting
  • Inability of the heart to pump enough blood (heart failure)
  • Sudden cardiac arrest or sudden death


Bradycardia can be caused by certain medications, particularly if they are taken at high doses, so it's important to take all medications as directed. Although bradycardia is not typically preventable, health care providers recommend strategies to reduce the risk of developing heart disease. Take the following heart-healthy steps:

  • Get regular exercise. Your health care provider may give you recommendations about how much and what type of exercise is best for you.
  • Eat a healthy diet. Choose a healthy, low-fat, low-salt, low-sugar diet that's rich in fruits, vegetables and whole grains.
  • Maintain a healthy weight. Being overweight increases the risk of developing heart disease.
  • Keep blood pressure and cholesterol under control. Make lifestyle changes and take medications as prescribed to manage high blood pressure, diabetes and high cholesterol.
  • Don't smoke. If you need help quitting, talk to your health care provider about strategies or programs to help.
  • If you drink, do so in moderation. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men. If you can't control your alcohol use, talk to a health care provider about a program to quit drinking and manage other behaviors related to alcohol abuse.
  • Manage stress. Intense emotions may affect heart rate. Some ways to relieve stress are getting regular exercise, joining a support group and trying relaxation techniques, such as yoga.
  • Go to scheduled checkups. Have regular physical exams and report signs or symptoms to your health care provider.

Monitor and treat existing heart disease

If you already have heart disease, there are steps you can take to lower your risk of developing bradycardia or another heart rhythm disorder:

  • Follow the plan. Be sure you understand your treatment plan. Take all medications as prescribed.
  • Report changes immediately. If your symptoms change or worsen or you develop new symptoms, tell your health care provider immediately.

By Mayo Clinic Staff

(Video) Causes of bradycardia - Dr. Durgaprasad Reddy B


What is the most common cause of bradycardia? ›

Causes of bradycardia

Metabolic problems such as hypothyroidism (low thyroid hormone) Damage to the heart from aging, heart disease or heart attack. Certain heart medications that can cause bradycardia as a side effect. Congenital heart defects (present at birth)

What are the first symptoms of bradycardia? ›

A slower than typical heartbeat (bradycardia) can prevent the brain and other organs from getting enough oxygen, possibly causing these signs and symptoms:
  • Chest pain.
  • Confusion or memory problems.
  • Dizziness or lightheadedness.
  • Easily tiring during physical activity.
  • Fatigue.
  • Fainting (syncope) or near-fainting.
May 7, 2022

When should you worry about bradycardia? ›

But it's a good idea to know the signs of trouble because bradycardia in some cases does require treatment. For example, if your heart rate drops into the 30s, you might not get enough oxygen to your brain, making fainting, lightheadedness and shortness of breath possible.

How does bradycardia make you feel? ›

The main symptom of bradycardia is a heart rate below 60 beats per minute. This abnormally low heart rate can cause the brain and other organs to become oxygen-deprived, which can lead to symptoms such as: Fainting. Dizziness.

How do you fix bradycardia? ›

Bradycardia treatment may include lifestyle changes, medication changes or an implanted device called a pacemaker. If an underlying health problem, such as thyroid disease or sleep apnea, is causing the slow heart rate, treatment of that condition might correct bradycardia.

At what low heart rate should you go to the hospital? ›

When should I see my doctor? If you have a pulse rate less than 60 bpm, and you're experiencing any symptoms mentioned above, especially if you aren't very fit, it's important to see your doctor. It might help to note the times you notice your heart is beating slowly, and how you're feeling at the time.

Do I need to see a cardiologist for bradycardia? ›

But with bradycardia, it goes down to less than 60 beats a minute. This might not cause a problem for some people. But it could be a clue that you have an issue with the electrical system in your heart. You need to see a doctor who can figure out why it's beating slowly and if you should get treatment.

What makes bradycardia worse? ›

Bradycardia Symptoms

These symptoms worsen with exercise because the body's needs increase when it's placed under stress. However, symptoms may also be present when the body is at rest if bradycardia is severe.

Is it OK to live with bradycardia? ›

Bradycardia can be harmless, but in some cases it can be life-threatening. For certain people — mostly young adults and trained athletes—a slow heart rate is normal and doesn't cause any symptoms or health problems.

Does caffeine help bradycardia? ›

Heart rate

Caffeine may induce bradycardia either through physiological mechanisms or by toxicological effects. It is generally accepted that tachycardia and bradycardia are caused by activation of the sympathetic and vagal nervous systems, respectively.

Can lack of water cause bradycardia? ›

Some other conditions can cause bradycardia. These include sleep apnea, an electrolyte imbalance caused by dehydration or extreme dieting, and hypothyroidism, which is also referred to as an underactive thyroid.

What are the 4 signs your heart is quietly failing? ›

Warning signs and symptoms of heart failure include shortness of breath, chronic coughing or wheezing, swelling, fatigue, loss of appetite, and others. Heart failure means the heart has failed to pump the way it should in order to circulate oxygen-rich blood throughout the body.

What is the first treatment for bradycardia? ›

Atropine. Atropine is the first line medication for the treatment of bradycardia. The administration of atropine typically causes an increase in heart rate. This increase in the heart rate occurs when atropine blocks the effects of the vagus nerve on the heart.

What are the two types of bradycardia? ›

Types of Bradycardia
  • Sinus bradycardia. When a person has sinus bradycardia, the heart rate is less than 60 beats per minute. ...
  • Sinus pause (also called sinus arrest) ...
  • Sick sinus syndrome. ...
  • Tachy-brady syndrome. ...
  • Heart block.

What medications cause bradycardia? ›

Clinically significant bradycardia can be induced by beta-blockers and non-dihydropyridine (DHP) calcium-channel antagonists such as verapamil and diltiazem. Although drug-related bradycardia is frequently observed in clinical practice, it is a poorly defined clinical problem.

What should you avoid if you have bradycardia? ›

Limit alcohol, sodium, and sugar. Get regular exercise. Try for 2½ hours a week. If you do not have other heart problems, you likely do not have limits on the type or level of activity that you can do.

What vitamin is good for bradycardia? ›

Magnesium and potassium help keep your heart stable. If your body doesn't have enough magnesium, it can cause an irregular heartbeat, muscle weakness, and irritability. Too much magnesium can cause: bradycardia.

Can an EKG detect bradycardia? ›

Bradycardia can sometimes be diagnosed in your physician's office with an electrocardiogram (ECG or EKG). But when bradycardia is an occasional event, a regular ECG may be normal.

Should I go to the ER if my heart rate is 40? ›

Adults and children who have a low pulse and experience symptoms such as chest pain, fainting, or exercise intolerance should also go to the hospital. A person should contact a doctor about bradycardia when they: experience an unexplained change in heart rate that lasts for several days.

What is the lowest heart rate to live? ›

Records. Daniel Green holds the world record for the slowest heartbeat in a healthy human, with a heart rate measured in 2014 of 26 BPM.

Why is my resting heart rate 45? ›

In people who are not physically active, a resting heart rate below 60 is sometimes a sign of an electrical problem with the heart, a low thyroid level (hypothyroidism), or damage from a heart attack or heart disease.

Does everyone with bradycardia need a pacemaker? ›

Bradycardia is the most common medical condition needing a pacemaker. This means the heart rate is too slow or irregular to meet the needs of the body during normal daily activities.

Can bradycardia cause stroke? ›

A specific type of bradycardia called junctional bradycardia, in which the heart rate is below 40 beats per minute, may be associated with ischemic stroke, a type of stroke in which a blood vessel to the brain is obstructed or blocked.

Does exercise help bradycardia? ›

A resting heart rate of less than 60 BPM could indicate bradycardia. For some people, specifically athletes and those who are physically active, lower resting heart rates are still considered normal. Exercise improves the efficiency of the heart, which allows more blood flow in fewer beats per minute.

Does bradycardia ever go away? ›

The good news is that bradycardia can be treated and even cured. Friedman explains that certain medications can slow down a person's heart rate, and stopping that treatment can in turn stop bradycardia. Even if the condition can't be reversed, doctors can still treat it with a pacemaker.

Can anxiety cause bradycardia? ›

What many may not realize is that anxiety can cause the heartbeat to slow down as well. It's not that common, but it is possible, and in some cases the issue may not be a slow heartbeat at all but your own mind telling you that your heart rate is abnormal even when this isn't necessarily the case.

Can potassium help bradycardia? ›

Potassium plays an important role in regulating the contractions of all muscles, including the heart muscle. Very low levels of potassium in the body can lead to irregular heart rhythms, including sinus bradycardia, ventricular tachycardia, and ventricular fibrillation.

Is alcohol good for bradycardia? ›

Small amounts of alcohol can speed up the heart rate. Although that doesn't make it a tonic for bradycardia, moderate drinking is safe for most people with bradycardia. Moderate means one or two drinks a day for men, no more than one drink a day for women.

Can bradycardia be genetic? ›

In the absence of underlying structural disease or aging, bradyarrhythmia may occur primarily due to genetic defects.

How do you fix bradycardia naturally? ›

Treating other underlying causes of bradycardia naturally can help to relieve the symptoms and may help bring your heart back into a normal rate range.
  1. Eat a heart-healthy diet. ...
  2. CoQ10. ...
  3. L-Carnitine. ...
  4. Magnesium. ...
  5. Acupuncture. ...
  6. Reduce stress. ...
  7. Relieve Anxiety. ...
  8. Sleep.
Apr 21, 2018

Does slow heart rate mean clogged arteries? ›

Summary: Bradycardia -- a slower than normal heartbeat -- does not increase the risk of developing cardiovascular disease, according to a study. The heart usually beats between 60 and 100 times a minute in an adult at rest.

Can eating less cause bradycardia? ›

What Causes Bradycardia? Bradycardia is more commonly observed in individuals with anorexia nervosa who are severely underweight. However, bradycardia is also found in individuals who have recently lost a significant amount of weight, even if they are not currently underweight.

What are 3 early warning signs your heart is failing? ›

11 signs you might have heart disease
  • Chest pain. It's the classic sign of a heart attack, yet many people don't realise this could be a medical emergency. ...
  • Feeling sick. ...
  • Stomach pain or indigestion. ...
  • Feeling sweaty. ...
  • Leg pain. ...
  • Arm pain. ...
  • Jaw or back pain. ...
  • Choking sensation.

What are 2 warning signs of heart disease? ›

Warning signs and symptoms of heart disease
  • Chest Pain. ...
  • Shortness of Breath. ...
  • Coughing or Wheezing. ...
  • Swelling in the Legs, Ankles, or Feet. ...
  • Poor Blood Supply to Extremities. ...
  • Fatigue. ...
  • Fast or Uneven Heartbeat (Palpitations) ...
  • When to Call the Doctor.

What are sneaky signs of heart failure? ›

Indicators that you may have heart problems include:
  • Dizziness.
  • Changes in skin color (blue or gray tinge)
  • Struggling to catch your breath while doing things that used to be easy or struggling to breathe while lying down.
  • Swelling in your legs, feet or ankles.
  • Fatigue.
  • Coughing and wheezing.
  • Rapid weight gain.
  • Rapid heartbeat.
Jan 23, 2023

What are 2 causes of bradycardia? ›

Other causes of bradycardia
  • A response of the vagus nerve affecting the heart (see Reflex Syncope in the Syncope article)
  • High pressure inside the skull (intracranial pressure)
  • Heart attack.
  • Obstructive sleep apnea.
  • Certain medications.
  • Hypothyroidism (underactive thyroid)

What foods should you avoid if you have bradycardia? ›

Eat a heart-healthy diet that includes vegetables, fruits, nuts, beans, lean meat, fish, and whole grains. Limit alcohol, sodium, and sugar.

What deficiency can cause bradycardia? ›

Conditions that can slow electrical impulses through the heart. Examples include having a low thyroid level (hypothyroidism) or an electrolyte imbalance, such as too much potassium in the blood.

What is the reversible cause of bradycardia? ›

Reversible causes and management of symptomatic bradycardia:

Hypoxia. Hydrogen ion (acidosis) Hyperkalemia.

Can vitamin D cause bradycardia? ›

A vitamin D deficiency can cause an irregular heartbeat, but taking too much vitamin D can have the same effect. Vitamin D levels affect the amount of calcium your body absorbs; calcium helps generate electronic impulses and muscle contractions that help regulate your heartbeat.

What organs are affected by bradycardia? ›

A slower than typical heartbeat (bradycardia) can prevent the brain and other organs from getting enough oxygen, possibly causing these signs and symptoms: Chest pain. Confusion or memory problems. Dizziness or lightheadedness.


1. 7f: Symptomatic Bradycardia (2023)
(Disque Foundation)
2. What Are the Symptoms of Bradycardia? - Dr. Usman Siddiqui
(My Heart Club)
3. Low Heart Rate - Causes, Symptoms, Dangers
(Wander Woman)
4. Slow heart rate or Bradycardia: Will my heart stop?
(York Cardiology)
5. Bradycardia
(The First Aid Show)
6. What is a normal vs. a slow heart rate? (Medical Animation)
(Gebrüder Betz Medical Animation)


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