Slow heart rate (Bradycardia)

2021-07-30 03:12 PM

Bradycardia is caused by something disrupting the normal electrical impulses that control the heart's rate of pumping action. Many problems can cause or contribute to abnormalities of the heart's electrical system.


Bradycardia is a heart rate that is too slow for a normal heart rate. The heart rate is usually between 60 and 100 beats a minute in adults. If the heart rate is slow, the heart rate is less than 60 times a minute.

Bradycardia can be a serious problem if the heart is not pumping enough oxygen-rich blood to the body. However, for some people, bradycardia causes no symptoms or complications.

Implantable pacemakers and other treatments can help slow the heart rate and maintain an appropriate rate.


If there is a slow heart rate, the brain, and other organs may not get the oxygen it needs. As a result, you may experience symptoms of bradycardia:

Almost fainting or fainting.




Shortness of breath.

Chest pain.

Difficulty sleeping.

Confusion or impaired memory.

Fatigue easily during physical activity.

When bradycardia is normal. A heart rate slower than 60 beats per minute, which can be normal for some people, especially young adults and athletes. In these cases, bradycardia is not considered a health problem.

Several causes can cause the signs and symptoms of bradycardia. It is important to obtain a prompt, accurate diagnosis and appropriate care. See your doctor if you experience any symptoms of bradycardia.

If fatigue, shortness of breath, or chest pain persists for more than a few minutes, get emergency care or call emergency medical care. Seek urgent care for anyone experiencing these symptoms.


Bradycardia is caused by something disrupting the normal electrical impulses that control the heart's rate of pumping action. Many problems can cause or contribute to abnormalities of the heart's electrical system, including:

Cardiac tissue degeneration is associated with aging.

Damage to heart tissue from heart disease or a heart attack.


Congenital heart.


Complications of heart surgery.


Imbalance of electrolytes, essential minerals.

Obstructive sleep apnea, the repetitive interruption of breathing during sleep.

Inflammatory diseases, such as rheumatic fever or lupus.

Tissue iron pigmentation, the accumulation of iron in the organ.

Medications, including some for heart rhythm disorders, high blood pressure, and mental disorders.

Electrophysiology of the heart

The heart is made up of four chambers, two uppers, and two lower. The normal rhythm of the heart is controlled by the natural pacemaker system - the sinus node - located in the right atrium. The sinus node generates an electrical impulse at the start of each heartbeat.

From the sinus node, electrical impulses pass through the atria, causing contraction of the atria and pumping blood into the ventricles. The electrical impulses then reach the cluster of cells called the atrioventricular (AV) node.
The AV node transmits signals to cells called his bundles. These cells transmit signals down to the left branch serving the left ventricle and the right branch serving the right ventricle. As the electrical impulses travel down the branches, the ventricles contract and pump blood, the right ventricle carries oxygen-poor blood to the lungs, and the left ventricle carries oxygen-rich blood to the body's organs.

Bradycardia occurs when electrical signals slow down or are blocked.

Sinus node dysfunction

Bradycardia usually begins at the sinus node. Bradycardia can occur because of the sinus nodes:

Discharge electrical impulses at a slower rate than normal.

Pause, or not pulse at a regular rate.

The electrical impulse is blocked before causing atrial contraction.

In some people, sinus node dysfunction can lead to bradycardia alternating with tachycardia (bradycardia syndrome, tachycardia).

Atrioventricular (AV) block

Rhythmic delays can also occur because signals are transmitted through the atria. The disordered signal may occur in the AV nodal, the bundle of His, or elsewhere along the left and right branches. The atrioventricular block is classified based on level signals from the atria.

AV highest level. In certain software formats of AV blocks, all the electrical signals from the signal reach the ventricles, but the signal slows down a bit. Acute blocking is a rarity when symptomatic and usually does not require treatment if nothing else is in the signal communication.

Block AV level two. To two degrees, not all signals reach the ventricles. Some rhythms are dropped, resulting in slower and sometimes irregular times.

Third level AV blocking. There is no electrical impulse from the atria to the ventricles. When this happens, the bundle of His or other functions of the ventricles takes the place of the regulating ventricle. Alternating electrical impulses give slow and sometimes unreliable results for checking the ventricular beat.

Branch block

The end of the signal in the branch must or left, near the end of the chip conflict, is called the block branch. Block-level depends on both affected branches, the presence of block type, and the damage level of the pattern.


The uncorrected variable pacing varies depending on the cause of the chronograph, where electrical problems and other types of damage may be present in the timing. If the time slow value, enough to give the summon, the certificate of the time slow time may include:

Frequent fainting.

The heart does not have enough energy (heart failure).

Cardiac arrest or death.

Risk factors

Age. One major risk factor that slows downtime is age. is associated with more common causes of bradycardia in the elderly.

Related to heart disease. Bradycardia is commonly associated with heart damage from certain types of heart disease. So factors that increase your risk of heart disease can also slow your heart rate to increase your risk. Lifestyle changes or medical values ​​can reduce the risk of heart disease-related to the following factors:


High blood cholesterol.


Drink a lot of alcohol.

Use recreational drugs.

Mental stress or anxiety.

Preparations for medical examination

Regardless of first urgent care, it is likely to be referred to a cardiologist for one or more visits for a full diagnostic evaluation.

If possible, bring along a family member who can provide some emotional support and help keep track of new information. Because there can be a lot of presentation issues, it is helpful to be as prepared as possible.

What can be done? Make a list in advance that you can share with your doctor. The list should include:

Symptoms already present, including any that seem unrelated to the heart?

Personal information, including any or recent life changes?

Medicines, including vitamin supplements?

List of questions from most important to least important in case time is limited.

Questions to ask your doctor include

What can cause bradycardia?

What kind of tests do you need?

What kind of risks?

How to monitor the heart?

How often will I need to be re-examined?

Is it necessary to restrict activity?

In addition to prepared questions to ask your doctor, don't hesitate to ask questions anytime you don't understand something.

Your doctor will likely ask some questions. Ready to answer them.

The doctor may ask

When did you start experiencing the first symptoms?

Have you experienced fainting in the past?

Does anything, such as exercise, seem to worsen symptoms?

Is there smoking?

Are you being treated for heart disease, high blood pressure, high cholesterol, or other problems that may affect your circulatory system?

What medicine did you take?

Tests and diagnostics

Your doctor will order a series of tests to measure your heart rate, establish a link between your bradycardia and symptoms, and identify possible causes of your bradycardia.

Electrocardiogram (ECG). Electrocardiogram - also called ECG or EKG, is a key tool to evaluate bradycardia. ECG uses small sensors (electrodes) attached to the chest and arms to record electrical signals as they pass through the heart. Your doctor can look for patterns in these signals to identify types of bradycardia.

ECG strip showing a normal heartbeat


ECG strip showing bradycardia

Your doctor may also be able to use a portable ECG device at home to provide more information about your heart rate and help establish a correlation between bradycardia and the onset of symptoms. These devices include:

Holter followed. The portable ECG device is carried in a pocket or worn or worn on a shoulder strap. It can record heart activity over a whole 24-hour period, providing doctors with a 24-hour heart rate. Your doctor may ask you to keep a diary for 24 hours. Describe any symptoms you have had and record when they occurred.

Record events. Hand-held electrocardiogram devices are designed to monitor heart activity for a few weeks to months. Activate it only when experiencing symptoms possibly related to bradycardia. When symptoms are felt, press the button and an ECG strip of the previous few minutes and the following minutes is recorded. This allows the doctor to determine the heart rate at the time of the symptoms.

Your doctor may also perform an electrocardiogram while performing other tests to understand the effects on bradycardia. These tests include:

Tilting table test. This test helps your doctor better understand the slow heart rate that contributes to fainting. Lie flat on the table, and then tilt the table as if standing up. Changing position can cause fainting and allows your doctor to establish a correlation between your heart rate and fainting.

Stress test. Your doctor may monitor your heart rate while walking on a treadmill or riding a bicycle to check how your heart rate responds to physical activity.

Other tests. Your doctor will test your blood to look for an underlying cause that may be contributing to your bradycardia, such as an infection, hypothyroidism, or an electrolyte imbalance. If sleep apnea is suspected to be contributing to bradycardia, other tests may be performed to monitor sleep.

Treatments and drugs

Treatment for bradycardia depends on the type of electrical conduction problem, the severity of the symptoms, and the cause of the slow heart rate.

Treat underlying disorders. If an underlying disorder, such as hypothyroidism or obstructive sleep apnea, is causing bradycardia, treating these disorders may eliminate the bradycardia.

Change medication. Some medications, including other heart medications, can cause a slow heart rate. Your doctor will check what medications you are taking and may recommend alternative therapies. Changing the medicine or reducing the dose can correct the bradycardia problem. When alternative treatments are not possible and symptomatic treatment is needed, a pacemaker is needed.

Pacemaker. A pacemaker is a battery-operated device implanted under the collarbone. Wires from the device through a vein and into the heart. The electrodes at the end of the wire are attached to the heart tissue. This pacemaker monitors the heart rate and generates the electrical impulses needed to maintain an appropriate rate.

Most pacemakers also record information that a cardiologist can use to monitor the heart. Regular follow-up visits will be required to check the heart and ensure the proper functioning of the pacemaker.


The most effective way to prevent bradycardia is to reduce your risk of developing heart disease. If you already have heart disease, monitor it and follow a treatment plan to reduce your risk of bradycardia.

Prevent heart disease. Treat or eliminate risk factors that can lead to heart disease. Perform the following steps:

Exercise and eat healthy. Live a heart-healthy lifestyle with regular exercise and eating a low-fat diet rich in fruits, vegetables, and whole grains.

Maintain a healthy weight. When you gain weight, your risk of developing heart disease increases.

Control blood pressure and cholesterol. Make lifestyle changes and take medications as prescribed to treat high blood pressure or high cholesterol.

No smoking. If you smoke and can't quit on your own, talk to your doctor about strategies or programs to help break the habit.

If you drink alcohol, do so in moderation. In some cases, it is recommended to avoid alcohol altogether. Ask your doctor for advice specific to each condition. If alcohol can't be controlled, talk to your doctor about a program to quit drinking and manage other behaviors related to alcohol abuse.

Do not use recreational drugs. Talk to your doctor about an appropriate program if you need help ending recreational drug use.

Stress management. Avoid unnecessary stress and learn techniques to deal with stress in a healthy way.

Scheduled test. Get regular checkups and report any signs or symptoms to your doctor.

Monitor and treat existing heart disease. If you already have heart disease, there are steps you can take to reduce your risk of developing bradycardia or another arrhythmia.

Follow the plan. Be sure to understand your treatment plan and take all prescribed medications.

Report changes immediately. If symptoms change or get worse or develop new symptoms, tell your doctor right away.