Print | Search | Send-to-Friend | Health Library Home

Bradycardia

(Bradyarrhythmia)

How to Say It: Bray-dee-car-dee-uh

by Amy Scholten, MPH

• Definition • Causes • Risk Factors • Symptoms • Diagnosis • Treatment • Prevention
En Español (Spanish Version)
 

Definition

Bradycardia is an abnormally slow heart rate. In adults, it is a heart rate of less than 50 to 60 beats per minute.

The condition can range from mild to life-threatening.

Anatomy of the Heart

Copyright © Nucleus Medical Media, Inc.

 

Causes    TOP

Bradycardia may be caused by:

  • Normal responses to:
    • Deep relaxation
    • Being in excellent physical shape
  • Changes in the heart’s natural pacemaker or electrical activity
 

Risk Factors    TOP

Bradycardia is more common in older people. Other things that raise the risk are:

  • Heart disease
  • Vasovagal syncope
  • Endocrine problems, such as hypothyroidism
  • Certain medicines
  • Exposure to certain toxins
  • Low:
    • Blood sugar
    • Potassium or calcium levels
    • Body temperature
    • Blood oxygen
  • Other conditions such as:
    • Sleep apnea
    • Systemic lupus erythematosus or sarcoidosis
    • Certain infectious diseases, such as Lyme disease and viral myocarditis
  • Head injuries
 

Symptoms    TOP

Bradycardia may have no symptoms. Those who have symptoms may have:

  • Fainting or loss of consciousness
  • Lightheadedness
  • Weakness
  • Mild tiredness
  • Abnormal heart beats
  • Problems breathing
  • Chest pain

Some types of bradycardia need emergency care. They can lead to loss of consciousness or sudden cardiac arrest.

 

Diagnosis    TOP

The doctor will ask about symptoms and past health. A physical exam will be done. It will include listening to the heart.

Blood tests may be done to look for underlying problems.

Your doctor may need to test heart function. This can be done with:

  • ECG
  • Echocardiogram
  • A heart rhythm monitor—worn during normal daily activities
  • Exercise stress test
Sometimes, imaging tests are done, such as nuclear scanning and coronary angiography. Other tests may also be needed.

 

Treatment    TOP

Treatment may not be needed if there are no heart symptoms or problems. The doctor may monitor the heart rate and rhythm instead.

Those with heart symptoms and problems need care right away. The goal is to reach and maintain a normal heart rhythm.

Treatment may include:

  • Stopping any medicines that slow the heart rate
  • Diagnosing and treating underlying conditions
  • Short-term medicine to increase the heart rate
  • An artificial pacemaker to reach and keep a normal heart rhythm—may be short term or lasting (implanted)
 

Prevention    TOP

Bradycardia cannot always be prevented. Some things may help reduce the risk. They are:

  • Treating health conditions that might lead to bradycardia
  • Carefully following the doctor's instructions for using medicines
  • A heart healthy diet, daily exercise, and not smoking
RESOURCES:

American Heart Association
http://www.heart.org

Heart Rhythm Society
http://www.hrsonline.org

CANADIAN RESOURCES:

Canadian Heart Rhythm Society
http://www.chrsonline.ca

Heart and Stroke Foundation of Canada
http://www.heartandstroke.ca

REFERENCES:

Arrhythmia. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health-topics/arrhythmia. Accessed August 30, 2021.

Barstow C, McDivitt JD. Cardiovascular disease update: bradyarrhythmias. FP Essent. 2017;454:18-23.

Bradycardia—approach to the patient. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/bradycardia-approach-to-the-patient. Accessed August 30, 2021.

Bradycardia: slow heart rate. American Heart Association website. Available at: https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia#.Wh2r8FWnFxA. Accessed August 30, 2021.

Overview of arrhythmias. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/overview-of-arrhythmias. Accessed August 30, 2021.



Last reviewed July 2021 by EBSCO Medical Review Board Nicole Meregian, PA
Last Updated: 8/30/2021

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com. Our Health Library Support team will respond to your email request within 2 business days.

Copyright ©  EBSCO Information Services
All rights reserved.
Privacy Policy | Editorial Policy