- Sinus bradycardia—an unusually slow heartbeat due to heart disease, a reaction to medication, or harmless causes, such as excellent fitness or deep relaxation
- Sick sinus syndrome—an unusually slow heartbeat due to a malfunction of the sinoatrial node, which is the heart's natural pacemaker
- Heart block (atrioventricular block or AV block)—an unusually slow heartbeat due to a slowing or blocking of electrical impulses in the heart’s conduction system
|Heartbeat: Anatomy of the Heart|
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Normal responses to:
- Deep relaxation
- Being in excellent physical shape
- The heart’s natural pacemaker developing an abnormal rate or rhythm
- The normal electrical conduction pathway being interrupted
- Another part of the heart taking over as pacemaker
- Increased age
- Taking certain medications used to treat:
- Exposure to certain toxins
- Cardiac disease, such as:
- Electrolyte imbalances
- Sleep apnea
- Systemic lupus erythematosus or other collagen vascular diseases (rare)
- Head injuries
- Infectious diseases, such as:
- Fainting or loss of consciousness
- Mild fatigue
- Irregular heart beat
- Shortness of breath
- Chest pain
- Your doctor may need you to have blood tests. These tests will look for problems that may explain the bradycardia.
- Your doctor may need to test your heart function. This can be done with:
- Stopping any medications that slow the heart rate
- Diagnosing and treating any underlying conditions
- Medication to temporarily increase your heart rate
- An artificial pacemaker to establish and maintain a normal heart rhythm
- Treat any health conditions that might lead to bradycardia.
- Carefully follow your doctor’s directions when using medications, especially those that can cause bradycardia.
- Check with your physician or pharmacist before using any over-the-counter medication or natural supplement. Make sure it does not interact with your other medications.
- Follow general advice for preventing heart disease, including:
American Heart Association http://www.heart.org
Heart Rhythm Society http://www.hrsonline.org
Canadian Cardiovascular Society http://www.ccs.ca
Heart and Stroke Foundation http://www.heartandstroke.com
Bradycardia. American Heart Association website. Available at: http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Bradycardia%5FUCM%5F302016%5FArticle.jsp. Updated October 25, 2012. Accessed January 18, 2013.
Fleg J. Arrhythmias and conduction disturbances. In: Beers MH, Berkow R, eds. The Merck Manual of Geriatrics (online). Merck & Co.;2000:486.
Hurst's The Heart. 11th ed; 2004.
Explore arrhythmia. National Heart, Lung and Blood Institute, National Institutes of Health website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/arr. Updated July 1, 2011. Accessed January 18, 2013.
- Reviewer: Michael J. Fucci, DO
- Review Date: 12/2014 -
- Update Date: 01/14/2014 -