Bradycardia, or a slow heart rate, can occur due to heart issues and other health conditions. It may cause symptoms like shortness of breath and fatigue. Treatment can depend on the cause.
Your heart rate is the number of times your heart beats in 1 minute and is a measure of cardiac activity. Most healthy adults have a heart rate between 60 and 100 beats per minute when they’re at rest.
Bradycardia happens when your heart rate is slower than normal. While it’s possible for some healthy individuals to have a slow heart rate, a heart that’s beating slower than normal may also be an indication of a medical problem.
Keep reading to learn more about bradycardia, what causes it, and how it’s treated.
You have bradycardia when your heart rate is
In some cases, a slow heart rate is an indication of an extremely healthy heart. Athletes, for instance, often have lower than normal resting heart rates because their heart is strong and doesn’t have to work as hard to pump blood throughout the body.
Your heart rate can also slow down when you’re in a deep sleep. During this time, it’s not unusual for your heart rate to drop below 60 beats per minute.
Having a slower heart rate, however, can also be a sign of something more serious.
A heart rate that’s too slow can mean that not enough oxygen-rich blood is reaching the organs and tissues in your body. This can affect your body’s ability to effectively carry out its normal processes and functions.
Many people with bradycardia don’t have any noticeable symptoms. When symptoms are present, they may include:
- shortness of breath
- spells of dizziness or lightheadedness
- near-fainting or fainting
- exercise intolerance, which is when you tire quickly during physical activity
If you’re having symptoms consistent with bradycardia, see a doctor. They can help determine what may be causing your symptoms.
Recognizing a potential emergency situation
In certain situations, a slow heart rate could indicate a medical emergency. The following bradycardia symptoms may be a sign of a more serious condition:
- chest pain
- trouble breathing
- pallor (pale skin)
- cyanosis (bluish skin color)
- blurred or hazy vision
- trouble focusing or concentrating
- near fainting or loss of consciousness
If you have any of these symptoms and a change in your heart rate, call 911 or seek emergency medical attention immediately.
It’s possible for bradycardia to happen due to damage to the heart muscle. When this occurs, it can interfere with the electrical signaling that coordinates your heartbeat.
Some examples of heart-related conditions that may lead to the development of bradycardia include:
- coronary artery disease, a condition where blood flow to the arteries of the heart is impaired
- heart attack, in which blood flow to the heart is cut off, causing heart muscle to die
- previous surgery to the heart
- congenital heart conditions, which are abnormalities in the heart that are present from birth
- myocarditis, a swelling of the heart muscle that may be caused by infections or autoimmune disease
- pericarditis, a condition that involves inflammation of the sac surrounding your heart
- rheumatic fever, a potential complication of strep throat, that can lead to heart issues
- damage to the heart’s electrical system from prior infection or inflammation
There are also several additional underlying conditions that may lead to bradycardia. These include:
- an electrolyte imbalance, most specifically an imbalance of calcium or potassium
- hypothyroidism, which happens when your thyroid produces too little thyroid hormone
- sleep apnea, a condition where your breathing pauses when you’re asleep
Additionally, some medications may cause bradycardia as a side effect. A few examples include:
- blood pressure medications like beta-blockers and certain calcium channel blockers
- some types of anti-arrythmic drugs
The sinoatrial (SA) node is your heart’s natural pacemaker. It initiates the electrical impulses that travel through your heart muscle, resulting in your heartbeat.
When your SA node sends out electrical impulses at a slower rate, it’s called sinus bradycardia.
Sinus bradycardia can happen naturally due to the aging process. It can also occur due to several of the factors discussed above, including:
- damage to your heart muscle due to conditions such as a heart attack, a pervious heart surgery, or myocarditis
- congenital heart conditions
- health conditions like hypothyroidism or sleep apnea
- side effects from certain medications
A thorough medical evaluation by a healthcare professional is necessary to determine the cause of a slow heart rate. This will typically include the following:
- a thorough medical history
- a physical examination, which will include measurement of your vital signs, including your heart rate, blood pressure, and respiratory rate
- an electrocardiogram (EKG or ECG), which measures the electrical activity in your heart
Based on the findings from the evaluation above, it’s possible that your doctor may recommend additional testing, such as:
- laboratory tests, which may include tests of blood glucose, electrolyte levels, or thyroid function
- an echocardiogram, which uses ultrasound technology to create pictures of your heart
- Holter monitoring, which measures the electrical activity of your heart while you go about your daily activities
- a sleep study to determine if you have sleep apnea that may be contributing to your bradycardia
The treatment of bradycardia depends on what’s causing it. Bradycardia that’s mild or occasional may not require treatment.
If a slow heart rate is due to the effect of a medication, it’s possible that your doctor may adjust your medication dosage. If possible, they could also switch you to a different medication that doesn’t have bradycardia as a side effect.
Similarly, if an underlying condition is contributing to your bradycardia, your doctor will work to address that condition. For example, the medication levothyroxine can be used to manage hypothyroidism.
It’s also possible that your doctor may recommend a pacemaker. This is an implanted medical device that stimulates heartbeats so that they occur at a regular rate and rhythm. Bradycardia is one of the main conditions for which a pacemaker may be recommended.
There are also a few medications that may be used to treat bradycardia. These may be utilized when bradycardia is causing acute symptoms and isn’t due to a reversible cause, such as a medication side effect.
Medications for bradycardia work to increase your heart rate and can include:
All of these medications are given via intravenous (IV) infusion. If they’re not effective at managing acute symptoms of bradycardia, temporary pacing (either transcutaneous or transvenous) may be used to ease bradycardia.
COVID-19 is the illness that’s caused by the novel coronavirus, SARS-CoV-2. There are several potential cardiovascular symptoms associated with COVID-19, one of which is bradycardia.
It’s still unclear what exactly causes this symptom in individuals with COVID-19, but it may be due to one or a combination of the following factors:
- direct damage to the heart muscle
- the body’s inflammatory response
- low oxygen levels in the body (hypoxia)
- a drop in blood pressure (hypotension)
Currently, most of the
The reports on how bradycardia during COVID-19 is treated can vary. While some individuals had bradycardia that resolved on its own, others required a temporary or permanent pacemaker.
If you’re curious about your heart rate, you can measure it yourself. First, find your pulse by holding a finger (not your thumb) to the radial artery on the inside of your wrist. Then, count the number of beats per minute while you’re resting.
Other places your heart rate can be measured include:
- on your neck, alongside your windpipe (carotid artery)
- inside your elbow (brachial artery)
- on the inside of your groin/upper thigh (femoral artery)
- on the top of your foot (pedal pulse)
When you’re determining your heart rate, here are some numbers to keep in mind:
- A resting adult heart rate is normally between
60 to 100 beats per minute.
- Athletes or people on certain medications may have a lower-than-normal resting heart rate.
- The normal heart rates for children can be different from those of adults, depending on a child’s age:
- up to 3 months old: 85 to 205 beats per minute
- 3 months to 2 years: 100 to 190 beats per minute
- 2 to 10 years: 60 to 140 beats per minute
- older than 10 years: 60 to 100 beats per minute
Bradycardia is when your heart rate is too slow. It can be caused by a variety of conditions, particularly those that can impact the heart’s normal electrical signaling. If you have bradycardia, your body may not be receiving enough oxygen to carry out its normal functions.
Some people with bradycardia may not have any noticeable symptoms. However, others may experience fatigue, weakness, or shortness of breath. In serious cases, chest pain, confusion, and loss of consciousness can occur.
Bradycardia can be effectively managed through treatments that address what’s causing it. Make an appointment with your doctor if you notice any changes in your heart rate, especially if the changes are accompanied by other symptoms.