Symptoms and causes
Bradycardia is a heart rate that is lower than normal. The heart of an adult at rest typically beats between 60 and 100 times per minute. If you have bradycardia, your heart beats less than 60 times per minute.
Bradycardia can be a serious problem if the heart rate is very slow and the heart cannot 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 causes no symptoms or complications.
If bradycardia is severe, a pacemaker may be implanted to help the heart maintain a proper heart rate.
Slower than normal heartbeat (bradycardia) prevents the brain and other organs from getting enough oxygen and may cause the following signs and symptoms:
- Chest pain
- Confusion or memory problems
- Dizziness or dizziness
- Easily fatigued during physical activity
- Fainting (fainting) or near fainting
- Shortness of breath
When to see a doctor
Many things can cause the signs and symptoms of bradycardia. It is important to get timely, accurate diagnosis and appropriate care. If you or your child have symptoms of bradycardia, talk to your healthcare provider.
If you faint, have trouble breathing or have chest pain that lasts more than a few minutes, call 999 or emergency medical services. Seek emergency care for anyone with these symptoms.
Bradycardia may be caused by:
- Ageing-related cardiac tissue damage
- Damage to heart tissue from heart disease or heart attack
- Heart disease at birth (congenital heart defect)
- Inflammation of heart tissue (myocarditis)
- Complications of cardiac surgery
- Low thyroid function (hypothyroidism)
- An imbalance of chemicals in the blood, such as potassium or calcium
- Repeated pauses in breathing during sleep (obstructive sleep apnea)
- Inflammatory diseases, such as rheumatic fever or lupus
- Medications, including sedatives, opioids, and drugs used to treat cardiac arrhythmias, high blood pressure, and certain mental health disorders
To better understand the causes of bradycardia, it may be helpful to understand how the heart normally beats.
A typical heart has four chambers—two upper chambers (atria) and two lower chambers (ventricles). In the upper right chamber of the heart (right atrium) is a group of cells called the sinoatrial node. The sinoatrial node is the heart's natural pacemaker. It generates the signal that initiates each heartbeat.
When these signals are slowed down or blocked, bradycardia occurs.
Sinus node problems
Bradycardia usually begins in an area of the heart called the sinoatrial node. In some people, sinus node problems can cause the heart rate to alternate between slow and fast (bradycardia-tachycardia syndrome).
Heart block (AV block)
Bradycardia can also occur if the heart's electrical signals do not 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 are divided into three main groups.
- First degree heart block. In its mildest form, all electrical signals from the atria reach the ventricles, but the signals are slowed down. First-degree heart block rarely causes symptoms and usually does not require treatment if there are no other problems with the electrical signals.
- Second degree heart block. Not all electrical signals reach the ventricles. Some beats drop, causing the heart rate to become slower and sometimes irregular.
- TThird degree (complete) heart block. None of the electrical signals from the atria reach the ventricles. When this happens, the ventricles usually beat on their own, but very slowly.
Bradycardia is often associated with damage to heart tissue from certain types of heart disease. Anything that increases the risk of heart problems increases the risk of bradycardia. Risk factors for heart disease include:
- Drinking a lot
- Illegal drug use
- Stress and Anxiety
Healthy lifestyle changes or medications may help reduce your risk of heart disease.
Possible complications of bradycardia include:
- Faint often
- The heart cannot pump enough blood (heart failure)
- Cardiac arrest or sudden death
Bradycardia can be caused by certain medications, especially when they are taken in high doses, so it is important to take all medications as directed. Although bradycardia usually cannot be prevented, health care providers recommend strategies to reduce the risk of heart disease. Take these heart-healthy steps:
- Exercise regularly. Your healthcare provider may be able to advise you on the amount and type of exercise that is best for you.
- Eat a healthy diet. Choose a healthy, low-fat, low-salt, low-sugar diet rich in fruits, vegetables, and whole grains.
- Maintain a healthy weight. Being overweight increases your risk of heart disease.
- Control blood pressure and cholesterol. Manage high blood pressure, diabetes, and high cholesterol by making lifestyle changes and taking medications as prescribed.
- Don’t smoke. If you need help quitting smoking, talk with your health care provider about strategies or plans to help.
- If you drink alcohol, do it in moderation. If you choose to drink alcohol, do so in moderation. For healthy adults, this means up to one drink per day for women and up to two drinks per day for men. If you are unable to control your alcohol use, talk with your health care provider about plans to stop drinking and manage other behaviors related to alcohol abuse.
- Manage stress. Strong emotions may affect heart rate. Some ways to relieve stress are to exercise regularly, join a support group and try relaxation techniques such as yoga.
- Go to your scheduled inspection. Get 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 reduce your risk of bradycardia or other arrhythmias:
- Follow the plan. Make sure you understand your treatment plan. Take all medications as prescribed.
- Report changes immediately. Tell your health care provider right away if your symptoms change or worsen, or if you develop new symptoms.
To diagnose bradycardia, a health care provider usually performs a physical exam and listens to your heart with a stethoscope. He or she may ask you questions about your symptoms and medical history.
Your healthcare provider may recommend tests to check your heart rate to see if you have a heart problem that may be causing bradycardia. Blood tests may be done to check for other conditions that may be causing a slow heartbeat, such as infection, hypothyroidism (underactive thyroid disease), or electrolyte imbalances.
An electrocardiogram (ECG or EKG) is the main test used to diagnose bradycardia. AnECG measures the electrical activity of the heart. Adhesive patches (electrodes) are placed on the chest and sometimes on the arms and legs. Wires connect the electrodes to a computer that displays the results. An EKG can show if the heart is beating too slowly, too fast or not at all.
BecauseECG cannot detect bradycardia unless a slow heartbeat occurs during the test, so you Your healthcare provider may recommend a portableECG device. PortableECGEquipment includes:
- Holter monitor. The device can be carried around or worn on a belt or shoulder strap and can continuously record heart activity for 24 hours or more.
- Event recorder. This device is similar to a Holter monitor, but it only records for a few minutes at a time at a specific time. It has a longer wear time than a Holter monitor, typically 30 days. When you feel symptoms, you usually push the button. Some devices automatically record when an irregular heart rhythm is detected.
AnAn EKG can be done along with other tests to understand how bradycardia affects you. These tests include:
- Tilt table test. This test can help your healthcare provider better understand how your bradycardia may cause fainting. When you lie flat on a special table, the table tilts as if you were standing. Perform a tilt test to see if a change in position causes fainting.
- Stress exercise testing. AECG can be done while you are riding on a stationary treadmill Bike or walk to monitor your heart activity. If you have trouble exercising, you can take an exercise-like drug to stimulate your heart.
If your healthcare provider thinks that repeated pauses in breathing during sleep (obstructive sleep apnea) are causing bradycardia, a sleep study may be recommended.
Treatment of bradycardia depends on the severity of symptoms and the cause of the slow heart rate. If you have no symptoms, you may not need treatment.
Treatment for bradycardia 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 your heart to beat slower than normal, treating the condition may correct the bradycardia.
Many drugs, including those used to treat other heart problems, can cause bradycardia. Always let your health care provider know about all the medicines you take, including medicines purchased without a prescription.
If you are taking a medication that causes bradycardia, your healthcare provider may recommend a lower dose or a different medication.
Surgery or other procedure
When other treatments are not available and symptoms of bradycardia are severe, a device called a pacemaker is needed to control the heart rhythm. The pacemaker only works when needed. When the heart beats too slowly, the pacemaker sends electrical signals to the heart to beat faster.
Pacemaker implantation requires surgery. One or more wires are inserted into a major vein under or near the collarbone and directed to the heart using an X-ray as a guide. One end of each wire is anchored to the appropriate area of the heart, while the other end is connected to a device (pulse generator) implanted under the skin just below the collarbone.
Leadless pacemakers are smaller and typically require less invasive surgery to implant the device.
Preparing for your appointment
Whether you see your primary care provider first or get urgent care, you may be referred to a doctor trained in heart disease (cardiologist) for diagnosis and treatment.
What can you do
If possible, write down the following information and bring it with you to your healthcare provider appointment:
- Your symptoms,including those that do not seem to be related to your heart, and when they started
- Important personal information,including major stressors or recent life changes and your medical history
- Medications, Including vitamins and other supplements you take, including dosage
- Askyour health care provider questions
If possible, bring a family member or friend to help you remember the information you receive.
Basic questions to ask your healthcare provider for bradycardia include:
- What could be causing my heart rate to be slow?
- What tests do I need to do?
- What is the most appropriate treatment?
- What are the possible complications?
- How do I monitor my heart?
- How often do I need follow-up appointments?
- How may other medical conditions or medications I take affect my heart problem?
- Do I need to limit my activities?
- Can I have brochures or other printed materials? What websites do you recommend?
Don’t hesitate to ask additional questions.
What you expect from your doctor
Your healthcare provider may ask you questions such as:
- Have you fainted?
- Does anything, such as exercise, make your symptoms worse?
- Do you smoke?
- Are you being treated for heart disease, high blood pressure, high cholesterol, or other conditions that may affect your heart?