Bradycardia happens when your heart beats slower than normal. Your heart normally beats between 60 and 100 times per minute. Bradycardia is defined as a heart rate slower than 60 beats per minute.

Sinus bradycardia is a type of slow heartbeat that originates from the sinus node of your heart. Your sinus node is often referred to as your heart’s pacemaker. It generates the organized electrical impulses that cause your heart to beat.

But what causes sinus bradycardia? And is it serious? Continue reading as we explore more about bradycardia as well as how it’s diagnosed and treated.

Sinus bradycardia doesn’t always indicate a health problem. In some people, the heart can still pump blood efficiently with fewer beats per minute. For example, healthy young adults or endurance athletes can often have sinus bradycardia.

It can also occur during sleep, particularly when you’re in a deep sleep. This can happen to anyone, but is more common in older adults.

Sinus bradycardia can also occur along with sinus arrhythmia. Sinus arrhythmia is when the timing between heartbeats is irregular. For example, someone with sinus arrhythmia can have variation of the heartbeats when they inhale and exhale.

Sinus bradycardia and sinus arrhythmia can commonly occur during sleep. Sinus bradycardia can be a sign of a healthy heart. But it can also be a sign of a failing electrical system. For example, older adults may develop a sinus node that doesn’t work to generate electrical impulses reliably or fast enough.

Sinus bradycardia can begin to cause problems if the heart isn’t efficiently pumping blood to the rest of the body. Some possible complications from this include fainting, heart failure, or even sudden cardiac arrest.

Sinus bradycardia happens when your sinus node generates a heartbeat less than 60 times in a minute. There are many possible factors that can cause this to occur. They can include:

Many people who have sinus bradycardia don’t have any symptoms. However, if not enough blood is being pumped to the organs of your body, you may begin to experience symptoms, such as:

To diagnose sinus bradycardia, your doctor will first do a physical exam. This can include things like listening to your heart and measuring your heart rate and blood pressure.

Next, they’ll take your medical history. They’ll ask you about your symptoms, what medications you’re currently taking, and if you have any underlying health conditions.

An electrocardiogram (ECG) will be used to detect and characterize the bradycardia. This test measures the electrical signals that pass through your heart using several small sensors attached to your chest. Results are recorded as a wave pattern.

Bradycardia may not occur while you’re in the doctor’s office. Because of this, your doctor may ask you to wear a portable ECG device or “arrhythmia monitor” to record your heart’s activity. You may need to wear the device for a few days or sometimes longer.

A few other tests may be performed as part of the diagnostic process. These can include:

  • Stress testing, which monitors your heart rate while you exercise. This can help your doctor understand how your heart rate responds to physical activity.
  • Blood tests, which can help detect if things like an electrolyte imbalance, an infection, or a condition like hypothyroidism is causing your condition.
  • Sleep monitoring to detect sleep apnea that may be causing bradycardia, especially at night.

If your sinus bradycardia isn’t causing symptoms, you may not require treatment. For those who need it, the treatment of sinus bradycardia depends on what’s causing it. Some treatment options include:

  • Treating underlying conditions: If something like thyroid disease, sleep apnea, or an infection is causing your bradycardia, your doctor will work to treat that.
  • Adjusting medications: If a medication you’re taking is causing your heartbeat to slow, your doctor may either adjust the dosage of the medication or withdraw it completely, if possible.
  • Pacemaker: People with frequent or severe sinus bradycardia may need a pacemaker. This is a small device that’s implanted in your chest. It uses electrical impulses to help maintain a normal heart rate.

Your doctor may also suggest making lifestyle changes. These can include things like:

If you’re experiencing symptoms consistent with sinus bradycardia, make an appointment with your doctor. While sometimes sinus bradycardia may not need treatment, it can also be a sign of serious health conditions that need attention.

Always seek emergency medical care if you experience chest pain that lasts longer than a few minutes, trouble breathing, or fainting. The Healthline FindCare tool can provide options in your area if you don’t already have a doctor.

Sinus bradycardia is a slow, regular heartbeat. It happens when your heart’s pacemaker, the sinus node, generates heartbeats less than 60 times in a minute.

For some people, such as healthy young adults and athletes, sinus bradycardia can be normal and a sign of cardiovascular health. It can also occur during deep sleep. Many people with the condition don’t even know they have it.

Sometimes, sinus bradycardia can cause symptoms, including dizziness, fatigue, and fainting. If you experience these symptoms, see your doctor. They can work with you to diagnose sinus bradycardia and develop a treatment plan, if needed.