Bradyarrhythmia

What is bradyarrhythmia?

A bradyarrhythmia is a heart rate that’s slower than typical because of an irregular heart rhythm. People with bradyarrhythmia have resting heart rates below 60 beats per minute. For most adults, a resting heart rate of 60 to 100 beats per minute is considered normal.

Sometimes, healthy people have naturally slow heart rates. But people with bradyarrhythmia have a heart rate that’s slow because of a medical condition, heart disease or defect that affects the heart’s rhythm.

What’s the difference between bradyarrhythmia and bradycardia?

Both terms mean having a slower than average heart rate. Bradycardia describes a resting heart rate below 60 beats per minute. Bradyarrhythmia describes a slow heart rate caused by an irregular heartbeat (arrhythmia).

Healthy young people and athletes often have resting heart rates below 60 beats per minute. For them, bradycardia doesn’t indicate disease. In fact, the slow heart rate is a sign of their fitness and well-exercised heart. It is also normal for your heart rate to drop below 60 beats per minute when you’re sleeping.

What are the types of bradyarrhythmias?

There are several different types of bradyarrhythmias. Each type has its own causes, but they all result in a slower-than-typical heart rate. Types of bradyarrhythmia include:

• Sinus node dysfunction: Sinus node dysfunction is also known as sick sinus syndrome. The sinus (or sinoatrial) node is often called the heart’s natural pacemaker. It’s an important part of the heart’s electrical system. The sinus node sends out the electrical impulse that triggers your heart to beat. An underactive thyroid gland (hypothyroidism) can result in sinus node dysfunction. Or a disease or defect that affects the sinus node can lead to sick sinus syndrome. The condition is more common as people age, but in many cases, there’s no known cause.
• Heart block: A heart block is something that gets in the way of your heart’s electrical signals. The block stops the electrical impulses in your heart from traveling as they should. A slow heart rate or skipped heartbeats can result.
• Bradycardia/tachycardia syndrome: In some cases, sinus node dysfunction leads to alternating periods of slow and fast heart rates. Atrial fibrillation (Afib) is one of these syndromes.

What causes bradyarrhythmia?

Most arrhythmias, including bradyarrhythmia, result from heart disease or damage to the heart. Some causes of bradyarrhythmia include:

• Age-related changes in the heart’s electrical system.
• Coronary artery disease.
• Heart defects.
• Heart medications, such as beta-blockers.
• Metabolic imbalances (like an underactive thyroid).
• Trauma or injury to the heart (such as from a heart attack).

What are the signs and symptoms of bradyarrhythmia?

When the heart pumps too slowly, you may not get enough blood and oxygen to your brain. Symptoms of bradyarrhythmia may include:

• Dizziness.
• Fainting (syncope).
• Fatigue.
• Shortness of breath.
• Weakness.

How is bradyarrhythmia diagnosed?

Your healthcare provider will perform a thorough physical exam, and ask about any symptoms you are experiencing.

To diagnose a heart arrhythmia accurately, your provider will measure and track your heart rate. Diagnostic tests may include:

• Electrocardiography (EKG): An EKG (also called an ECG) records the heart’s electrical impulses.
• Portable ECG device: Your heart may not produce an abnormal rhythm while in the doctor’s office. To help diagnose an arrhythmia, you may need to wear a portable (ambulatory) monitor, such as a Holter monitor, for 24 to 48 hours.
• Exercise stress test: Raising your heart rate while walking on the treadmill during an exercise stress test helps identify abnormal heart rhythms.
• Echocardiography: An echocardiogram provides pictures of your heart’s valves and chambers as they pump blood.
• Electrophysiologic testing: An electrophysiology study provides detailed information about how your heart’s electrical system is working.

How is bradyarrhythmia managed or treated?

In some cases, an underlying medical condition leads to bradyarrhythmia. Treating an underactive thyroid, for example, can help improve your slow heart rate.

When bradyarrhythmia results from changes in the heart’s electrical system, your provider may recommend inserting a pacemaker. This electronic device generates electrical impulses to help you maintain a steady, healthy heart rate.

How can I prevent bradyarrhythmia?

One preventive step is treating underlying health conditions, like hypothyroidism. You can also lower your risk of bradyarrhythmia by taking good care of your heart.

To keep your heart healthy, you should:

• Eat a heart-healthy diet.
• Limit alcohol intake.
• Maintain a healthy weight.
• Stay physically active.
• Quit smoking and using tobacco products.

What is the prognosis (outlook) for people with bradyarrhythmia?

Left untreated, bradyarrhythmia can lead to serious health problems and can lead to dizziness and syncope. Getting the right treatment can restore your heart’s normal rhythm and reduce your risk of complications.

When should I call the doctor?

You should call your healthcare provider if you experience:

• Chest pain.
• Difficulty breathing.
• Dizziness or lightheadedness.
• Fainting.
• Severe fatigue.

What should I ask my doctor about bradyarrhythmia?

You may want to ask your healthcare provider:

• How do I know if my heart rate is too slow?
• Is my heart rate low enough to cause health problems?
• Do I need medication to control my arrhythmia?
• Will I need a pacemaker to restore a normal heart rhythm?

A note from Cleveland Clinic

Bradyarrhythmia is an abnormally slow resting heart rate, typically below 60 beats per minute. A too-slow heart rhythm can result from changes in the heart’s electrical system, a heart defect or other medical conditions. Your healthcare provider can treat bradyarrhythmia with medications or a pacemaker. Restoring a normal heart rhythm helps your heart function properly and reduces your risk of complications.