Encyclopedia / B / Bradycardia



Bradycardia is a slower than normal heart rate.


The adult heart (at rest) beats at about 60 to 80 beats per minute. Fifty-five to 60 beats per minute would be considered bradycardia for an adult. Infants, however, have a much higher at rest heart rate (110 to l30 beats per minute), thus; bradycardia in infants would be a rate below 100 beats per minute.

Slower than average heart rates are normal in people who are physically fit and people who are sleeping. Many athletes who train regularly have resting heart rates of 40 to 60 beats per minute.

Bradycardia can also occur secondary to certain illnesses (such as decreased thyroid function, certain gastrointestinal disorders, and jaundice), or the abuse of certain drugs. People with known heart disease (including hypertension) who are being treated with medications that slow the heart (such as beta-blockers and certain calcium channel blockers) can experience bradycardia. It may be a temporary consequence of certain types of heart attack. Bradycardia is common in elderly people (whether or not they suffer from arteriosclerosis) and infants with certain types of congenital heart disease.


When symptoms occur, they are usually fatigue, shortness of breath, light-headedness or fainting. Athletes and those with "trained" hearts generally have no symptoms.


Determination of bradycardia can be made by the nurse or physician in the office. Further testing to determine the cause may involve blood tests, an EKG or a heart monitor.


If the bradycardia does not cause symptoms, no treatment is necessary. If there are symptoms, medications can be given to increase the rate of the heartbeat. If fainting or serious symptoms persist despite medication, a permanent pacemaker may need to be implanted. In specific instances, certain medications may have to be withdrawn because of their slowing effect.

Severe bradycardia (fewer than 30 beats per minute) can be an emergency situation, leading to brain oxygen deprivation and convulsions. Death may result unless immediate medical measures are taken to increase the heart rate.


What tests determine if the bradycardia is abnormal?

What are the factors causing the depressed or slowed impulses?

If physically fit with a normal slow heart rate, could the heart rate slow even more with age or medication?

Should there be a concern when starting a new medication?

If the arrhythmias are due to a certain medication, will the medication be withdrawn?

What is your recommendation of treatment to relieve the symptoms of bradycardia?

What are the chances of needing a pacemaker?

Should a specialist be consulted for this condition?