What Is Bradycardia?

Bradycardia is a slower-than-normal heart rate or pulse rate. One of its most common types is sinus bradycardia, where the heart rate is lower than 60 beats per minute. Your heart usually beats between 60 and 100 times a minute. If you have bradycardia, your heart rate will be less than 60 beats per minute (BPM). If your heart doesn't pump enough oxygen-rich blood to the body with each contraction, bradycardia can be a serious problem. But for some people, a slow heart rate won’t cause symptoms or complications.

Bradycardia is considered relatively common for some groups of people. Bradycardia occurs in many physically active adults, who have a resting heart rate below 60 BPM with no negative effects. Your heart rate may also fall below 60 BPM during deep sleep. Seniors are also more prone to bradycardia. Being physically inactive or unfit with a low resting heart rate can indicate a potential heart condition.

Baptist Health is known for advanced, superior care for patients with heart disease and the diagnosis, management, and treatment of bradycardia. You will appreciate timely appointments and respectful attention to your concerns, all in a positive and friendly atmosphere. At Baptist Health, you have access to the region’s most comprehensive, multidisciplinary team of specialists and innovative therapies, including many available only through specialized clinical trials. In every way, we work to demonstrate the utmost in excellent care to those who trust us with their health.

Types of Bradycardia

There are several versions of bradycardia, each with a different risk profile and associated treatment options. The major types of bradycardia include:

• Sinus bradycardia: Sinus bradycardia means having a resting heart rate of fewer than 60 beats per minute. In some people, especially those that are physically active, this is normal and no cause for alarm. If, however, your resting heart rate falls below 40 beats per minute, medical attention is required.
• Sinus pause: Sinus pause is the skipped-beat form of bradycardia. Your heart acts as a natural pacemaker but, in this case, occasionally fails to send the electrical charge required to initiate muscle contractions. If this happens with any regularity, complications may arise. Another name for this type of bradycardia is sinus arrest.
• Sick sinus syndrome: The heart’s natural pacemaker is called the sinus node. If the node is working incorrectly, it can lead to heartbeat irregularities, also known as arrhythmias. Arrhythmias can be fast, slow, or a back-and-forth combination of the two.
• Tachycardia-bradycardia (“tachy-brady”) syndrome: This is a specific type of arrhythmia, combining fast (tachycardia) and slow (bradycardia) resting heart rates. It is often associated with a heart condition called atrial fibrillation.
• Heart block: A heart block is an abnormality in the heart’s electrical pathways that disrupts the signals being sent from the sinus node to the cardiac muscles, leading to a reduction in heart rate.

Signs and Symptoms

Bradycardia symptoms occur if the slow heart rhythm is causing insufficient blood flow to the brain and may include:

• Fatigue
• Dizziness
• Lightheadedness
• Shortness of breath
• Chest pain or palpitations
• Confusion or trouble concentrating
• Fainting or near-fainting spells

How Serious Is Bradycardia?

The seriousness of bradycardia depends on your personal circumstances. A heart rate below 60 BPM is common for young people, older people in good shape, and people who are sleeping. But if a slow heart rate leads to the symptoms described above, then you need to see your physician.

Causes

Bradycardia causes in adults vary from lifestyle choices to other types of heart disease. If bradycardia results from heart disease, it is caused by damage to heart tissue from heart disease. Factors that increase the risk of developing heart disease also increase the risk of bradycardia.

Bradycardia can be caused by:

• Coronary artery disease
• Heavy alcohol use
• High blood pressure
• Psychological stress or anxiety
• Recreational drug use
• Sleep apnea
• Smoking

Many medications – including those prescribed for other heart conditions – can also cause bradycardia. Your physician will check what medications you’re already taking and lower doses or offer alternative treatments that may correct problems with a slow heart rate.

Risk Factors

Bradycardia frequently results from heart disease. The damage to heart tissue from a wide range of cardiac conditions increases the likelihood of a slow heart rate.

Risk factors for bradycardia include:

• Age: Men and women aged 65 and older are most likely to develop a slow heart rate that needs treatment.
• Congenital heart defect: Problems with the structure or function of the heart present at birth can cause a slow heart rate.
• Electrolyte imbalance: Any abnormality in the body’s mineral balance – including calcium, chloride, magnesium, phosphate, potassium, and sodium – can lead to a slow or irregular heart rate.
• Infection of the heart: Certain bacteria, viruses and parasites can infect the heart muscle, causing inflammation and damage leading to an irregular heart rate.
• Previous heart attacks: Heart attacks can weaken the heart muscle or cause problems with its electrical system.
• Low thyroid: An abnormally low level of thyroid hormones can cause a slow heart rate.
• Medications for other heart problems: Some medications for treating high blood pressure or other heart conditions like beta blockers, antiarrhythmics and digoxin (for heart failure) can cause bradycardia.

Diagnosis

Bradycardia can often be diagnosed during a visit to your doctor's office using an electrocardiogram (ECG or EKG). However, in cases where bradycardia occurs intermittently, a standard ECG might yield normal results.

To diagnose bradycardia, we ask questions about your medical history and do a physical exam. We then use advanced diagnostic procedures and technology to effectively diagnose, inform treatment and carefully monitor the condition. Common diagnostic procedures for bradycardia can include:

• Blood test: Blood tests check the levels of certain fats, cholesterol, sugar, and protein in the blood that could indicate bradycardia and other heart conditions.
• Electrocardiogram (EKG): This test measures the electrical activity of the heart and can help determine if parts of the heart are enlarged, overworked, or damaged. The heart’s electrical currents are detected by 12 to 15 electrodes that are attached to the arms, legs, and chest via sticky tape. A patient must be under observation at the EKG location for a diagnosis of bradycardia to occur.

Longer-term monitoring diagnostic methods include:

• Event monitor: This portable EKG device records the heart rate when a button is pressed. It can be worn for weeks or until symptoms occur.
• Holter monitor: This portable EKG device continuously records the heart’s rhythms and is worn for 24 to 48 hours during normal activity.
• LINQ insertable cardiac monitor: This wireless, powerful, small insertable cardiac monitor is ideal for patients experiencing infrequent symptoms that require long-term monitoring or ongoing management.

Prevention

While some bradycardia risk factors like age and congenital heart defects cannot be controlled, the most effective way to prevent bradycardia is to reduce your risk of developing heart disease. Take these steps to help prevent bradycardia:

• Control stress: Avoid unnecessary stress and learn healthy ways to handle everyday tension.
• Don’t smoke: If you already smoke and are having trouble quitting, ask your physician about programs and strategies to help you break the habit.
• Don’t use recreational drugs: If you’re using drugs, talk to your physician about treatment programs.
• Exercise and eat healthy: Get regular physical activity and eat a low-fat diet rich in fruits, vegetables, and whole grains.
• Get regular checkups: Have regular physicals and, if you experience new or changing symptoms, see your physician.
• If you drink, do so in moderation: You may need to avoid alcohol if you have certain conditions. Ask your physician for advice. Limit your intake if you can consume alcohol.
• Keep blood pressure and cholesterol under control: Make the lifestyle changes listed above and take medications as prescribed.
• Maintain a healthy weight: Exercise and eat a healthy, balanced diet to stay in a normal range.
• Monitor and treat existing heart disease: Understand your treatment plan. Take medications as directed. And report new or worsening symptoms immediately.

Prognosis

Prognosis varies depending on what’s causing bradycardia. Some conditions can be reversed or managed through medication, lifestyle changes and regular monitoring. Others may require a pacemaker or implantable cardioverter defibrillator.

Treatment

Bradycardia treatment depends on its cause, the presence of heart disease and the severity of your symptoms. There are bradycardia treatment options with and without a pacemaker.

Medication

Some types of medication that may be given to bradycardia patients include:

• Beta blockers
• Pain medication

Implantable Cardioverter Defibrillator

This battery-powered device, placed under the skin, keeps track of the heart rate. If an abnormal heart rhythm is detected, the device will deliver an electric shock to restore a normal heartbeat. Newer-generation ICDs may have a dual function which includes the ability to serve as a pacemaker. The pacemaker feature would stimulate the heart to beat if the heart rate is detected to be too slow.

Pacemaker

This small, battery-operated device can detect an abnormal heart rate and emit electrical impulses that stimulate your heart to beat at a normal rate. A pacemaker implant is placed under the skin near your collarbone in a minor surgical procedure. A wire extends from the device to your heart.

Treatment of Underlying Conditions

If you are found to have a disorder like hypothyroidism, an electrolyte imbalance or sleep apnea, your physician will treat that condition, in addition to bradycardia, to restore your normal heart rate.

Complications

Possible complications of bradycardia can include:

• Frequent fainting (syncope): If the heart doesn’t pump enough oxygen-rich blood to the brain, fainting and fall-related injuries can occur.
• Heart failure: When the heart is unable to pump oxygen-rich blood to the rest of the body efficiently, symptoms affect various body systems.
• Sudden cardiac arrest or death: Inadequate blood flow can cause the heart to stop beating – leading to loss of consciousness. Breathing may also stop. This is a rare complication and usually seen in extreme cases.

Some cases of bradycardia don’t cause symptoms or complications.