Bradycardia (Slow Heart Rate)
What is bradycardia?
Having bradycardia (say "bray-dee-KAR-dee-uh") means that your heart beats slower than normal. For most adults, a heart rate of about 60 to 100 beats a minute while at rest is considered normal.
For some people, bradycardia is healthy and normal. It does not cause any symptoms or problems.
In other people, bradycardia is a sign of a problem with the heart's electrical system. It means that the heart's natural pacemaker isn't working right or that the electrical pathways of the heart are disrupted. Sometimes, the heart beats so slowly that it doesn't pump enough blood to meet the body's needs. This can cause symptoms, such as feeling dizzy or weak. In some cases, it can be life-threatening.
What causes it?
Bradycardia can be caused by many things. Examples include:
- Changes in the heart that are the result of aging.
- Physical activity. For example, endurance athletes often have a slow heart rate.
- Diseases that damage the heart's electrical system. These include a heart attack and infections.
- 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.
- Many types of medicines. Examples include chemotherapy medicines, heart medicines, and opioids.
What are the symptoms?
A very slow heart rate may cause you to:
- Feel dizzy or lightheaded.
- Feel short of breath and find it harder to exercise.
- Feel tired.
- Have chest pain or a feeling that your heart is pounding or fluttering (palpitations).
- Feel confused or have trouble concentrating.
- Faint, if a slow heart rate causes a drop in blood pressure.
Some people don't have symptoms.
You can find out how fast your heart is beating by taking your pulse.
How is it diagnosed?
To diagnose bradycardia, your doctor may take your pulse, do a physical exam, ask questions about your health, and do an electrocardiogram (EKG or ECG). An EKG measures the electrical signals that control heart rhythm.
Bradycardia often comes and goes, so a standard EKG done in the doctor's office may not find it. An EKG can identify bradycardia only if you have it during the test.
You may need to wear or carry a device called a portable, or ambulatory, electrocardiogram. Examples include a Holter monitor and a cardiac event monitor. You might use it for a day or more. It records your heart rhythm while you go about your daily routine.
You may have other tests to find out if another problem is causing your slow heart rate.
How is bradycardia treated?
How bradycardia is treated depends on what is causing it. Treatment also depends on the symptoms. If bradycardia doesn't cause symptoms, it may not be treated. You and your doctor can decide what treatment is right for you.
- If damage to the heart's electrical system causes your heart to beat too slowly, you may get a pacemaker. A pacemaker is an implanted device that helps correct the slow heart rate.
- If another medical problem, such as hypothyroidism or an electrolyte imbalance, is causing a slow heart rate, treating that problem may cure the bradycardia.
- If a medicine is causing your heart to beat too slowly, your doctor may adjust the dose or prescribe a different medicine.
The goal of treatment is to raise your heart rate and relieve symptoms. For certain types of bradycardia, treatment may help prevent serious problems. These problems include fainting, injuries from fainting, and even death.
How can you care for yourself?
Bradycardia is often the result of another heart condition, so a heart-healthy lifestyle can help improve your overall health. This lifestyle includes:
- Having a heart-healthy eating plan that includes vegetables, fruits, nuts, beans, lean meat, fish, and whole grains. Limit alcohol, sodium, and sugar.
- Being active on most, if not all, days of the week. Your doctor can tell you what level of exercise is safe for you.
- Staying at a weight that's healthy for you. Talk to your doctor if you need help losing weight.
- Trying to get 7 to 9 hours of sleep each night.
- Trying to quit or cut back on using tobacco and other nicotine products. This includes smoking and vaping. Try to avoid secondhand smoke too.
- Managing other health problems, such as high blood pressure, high cholesterol, and diabetes. If you think you may have a problem with alcohol or drug use, talk to your doctor.
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Current as of: June 25, 2023
Author: Healthwise Staff
Clinical Review Board: All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.