What is Bradycardia?

What is Bradycardia?

Bradycardia is classified as abnormal heart rhythm, causing a slow heart rate —less than 60 beats per minute instead of a typical 60 to 100 beats per minute. A person with bradycardia may experience shortness of breath, dizziness, high blood pressure, or weakness due to a lack of blood pumped from the heart to the rest of the body. 

A slower heart rate is common in senior citizens , athletes, and healthy younger adults. But for others, it can indicate a problem with your heart’s electrical system and how its signals travel through the four heart chambers. It’s important to familiarize yourself with the symptoms of bradycardia to determine if you need treatment

Types of Bradycardia


Bradycardia is an abnormal heart rhythm or arrhythmia that affects your heart’s electrical system. There are several types of bradycardias, each having its own complications and treatment options:

  • Sinus bradycardia - Often seen in athletes, no symptoms or complications. Heart rate is less than 60 beats per minute.
  • Sinus arrest (or sinus pause) - A pause or stop in the heart's rhythm, lasting for 2 seconds or more
  • Tachy-brady syndrome - Occurs when the heart's natural pacemaker is damaged, resulting in abnormal rhythm and is too fast and then too slow. This condition is common in people diagnosed with atrial fibrillation.
  • Sick sinus syndrome - A type of heart rhythm disorder that affects the sinus node
  • Heart block (or AV block) - The heart's electrical signal becomes partially or entirely blocked. As a result, the heart doesn't pump blood effectively, leading to a slower heart rate and skipped beats. Symptoms include fainting, dizziness, and shortness of breath. This is due to disease in the atrioventricular node (AV node), which is the junction box between the upper and lower chambers, or disease in the Bundle branches, which are conducting tissue in the heart's lower chamber.

Signs & Symptoms of Bradycardia


Bradycardia can prevent the brain and other vital organs from getting the necessary blood to function properly. Bradycardia symptoms can vary; some individuals may not exhibit any signs or complications.

The most common symptoms of bradycardia can include:

  • Chest pain
  • Dizziness
  • Heart palpitations
  • Fainting (syncope)
  • Shortness of breath
  • Memory problems
  • Confusion
  • Lack of energy/tiring easily during physical activity
  • Syncope

Left untreated, bradycardia can cause:

  • Frequent fainting
  • Severe chest pain
  • Heart failure
  • Cardiac arrest
  • Sudden death

What Causes Bradycardia?​


The heart has four chambers, two on the top (atria) and two on the bottom (ventricles). Bradycardia occurs when the heart’s electrical impulses between the chambers don’t flow properly, causing the heart to beat in an irregular rhythm.

Common causes of bradycardia in adults include:

  • Aging - Heart tissue can become damaged as we grow older
  • Heart attack - Injury from a heart attack can make it susceptible to bradycardia
  • Heart muscle inflammation (myocarditis)
  • Heart disease
  • Complications from heart surgery
  • Hypothyroidism (underactive thyroid gland)
  • Congenital heart defect
  • COVID and bradycardia - Some hospitalized COVID-19 patients developed sinus bradycardia and heart/atrioventricular block
  • Lyme disease
  • Sleep apnea
  • Certain medications - Such as opioids, sedatives, and drugs for heart rhythm disorders
  • Sinus node problems - Malfunctions in the sinus node can cause alternating fast and slow heart rates
  • Atrioventricular block (heart block)
  • Partial or complete interruption of the electrical signals between the ventricles in the heart

Risk Factors

Risk Factors

While anyone can develop bradycardia, including healthy young adults, certain genetic, environmental, and behavioral factors can lead to heart disease, which can elevate your risk of developing the condition, including:

  • Advanced age
  • High blood pressure
  • High cholesterol



Your lifestyle choices can affect the heart. Your doctor may recommend a heart-healthy routine to strengthen the heart muscle, which naturally lowers heart disease risk, a risk factor for bradycardia.

Tips for preventing heart disease include:

  • Maintaining a healthy diet and weight
  • Adopting a regular exercise routine
  • Minimize alcohol intake
  • Quitting smoking

Consulting your doctor about right medications for blood pressure and cholesterol management.

Get Care

Trust NewYork-Presbyterian for Bradycardia Care

NewYork-Presbyterian is home to world-renowned cardiologists and care treatments for patients with heart conditions and arrhythmias , including valvular, coronary artery, aortic, and congenital heart disease. Our knowledgeable cardiac specialists are familiar with the signs and symptoms and can deliver an expert diagnosis and treatment for bradycardia.

If left unchecked, bradycardia can lead to severe health consequences. Make an appointment today if you or a loved one are experiencing symptoms of bradycardia or have questions about how specific risk factors can affect your heart health.