Table of contents:
- How to identify bradycardia
- How to confirm the diagnosis
- Possible causes
- When bradycardia is severe
- How the treatment is done
Bradycardia is a medical term used when the heart slows down, starting to beat at a rate lower than 60 beats per minute at rest.
Normally, bradycardia has no symptoms, however, due to the decrease in blood flow, caused by the decrease in heart rate, fatigue, weakness or dizziness may appear. When this happens, it is recommended to go to the cardiologist to have tests done, identify any possible cause and start the most appropriate treatment, which may include the placement of a pacemaker.
Bradycardia is very common in high competition athletes, since their heart has already adapted to the physical effort that is done regularly, which ends up decreasing the heart rate during rest.In the elderly, there may also be a decrease in heart rate due to the natural aging of the heart, without indicating the presence of he alth problems.
How to identify bradycardia
To measure the heart rate, you can place the index and middle fingers on the side of the neck, above the collarbone, and count for 1 minute the number of beats felt. For the result to be closer to reality, a device called a frequencymeter can be used, which is placed on the finger. Enter your data into the calculator below to see if your heart rate is adequate:
Bradycardia usually has no symptoms, but some people may have:
- Shortness of breath.
Generally, bradycardia is found after using a digital blood pressure device, which also shows the heart rate, or an oximeter, which measures the percentage of oxygen in the blood and also shows what the heart rate is.
If a decrease in heart rate is identified, it is recommended to look for a cardiologist to evaluate the person's complaints and define the most appropriate treatment for bradycardia. Learn more about normal, high, or low heart rate.
How to confirm the diagnosis
After identifying a possible decrease in heart rate, it is recommended to consult a cardiologist to perform more specific tests such as electrocardiogram, echocardiogram or stress test, also known as exercise test. It can also be performed with a 24-hour Holter, which is a test that assesses whether the bradycardia is controlled or if at any time during the 24 hours there is some type of heart block.
In some cases, a doctor may also prescribe some blood tests to see if the cause of bradycardia could be due to infections, hypothyroidism, or a change in the amount of electrolytes, such as calcium or potassium, in the blood.
The decrease in heart rate can be considered normal when it happens during sleep or in people who exercise regularly, such as runners and cycling athletes. It is also normal for it to happen after a big meal or during blood donation, disappearing after a few hours.
However, bradycardia can be caused by some cardiac or physiological conditions that need to be identified and treated:
- Sinus node disease, which is characterized by an inability of the heart to maintain an adequate heart rate;
- Infarction, which happens when the blood flow is interrupted and the heart does not receive the blood and oxygen it needs to do its activity;
- Hypothermia, when body temperature drops below 35ºC and body functions slow down, such as heart rate, to preserve temperature;
- Hypothyroidism, characterized by a decrease in the amount of thyroid hormones, which can affect the cardiac system and decrease the heart rate;
- Hypoglycemia, which is a decrease in the amount of sugar in the blood that can slow the heart rate;
- Decreased concentration of potassium or calcium in the blood, can influence heart rate, decreasing it;
- Use of medication for hypertension or arrhythmia, which usually have bradycardia as a side effect;
- Exposure to toxic substances, such as nicotine, for example;
- Meningitis, which consists of inflammation of the membranes surrounding the brain and spinal cord and which can result in bradycardia;
- Central nervous system tumor, can cause bradycardia due to increased pressure inside the skull;
- Intracranial hypertension, can lead to a decrease in heart rate due to changes in the brain;
- Sleep apnea, which corresponds to a momentary stop in breathing or shallow breathing during sleep, which can compromise blood flow.
In most cases these causes are accompanied by symptoms other than bradycardia, such as heart pain in the case of a heart attack, chills in the case of hypothermia, dizziness or blurred vision in the case of hypoglycemia, and fever or neck stiffness in the case of meningitis.
In less common situations, bradycardia can happen due to infections with viruses or bacteria, such as diphtheria, rheumatic fever and myocarditis, which is an inflammation of the heart muscle caused by infection with viruses or bacteria. See what the main symptoms are and how to treat myocarditis.
When bradycardia is severe
Bradycardia can be serious when it causes the appearance of other symptoms such as:
- Easy fatigue;
- Shortness of breath;
- Cold skin;
- Chest pain in the form of burning or tightness;
- Pressure decrease;
In case of any of these symptoms, it is important to go to the cardiologist for a more detailed evaluation and to carry out tests that can diagnose the problem.
How the treatment is done
The treatment of bradycardia must be guided by the cardiologist and varies according to the cause, symptoms and severity. If bradycardia is associated with another cause, such as hypothyroidism, changing medications or better treatment for hypothyroidism may resolve the bradycardia.
In more severe cases, it may be necessary to use a pacemaker, which is a surgically placed device that aims to regulate the heartbeat in case of bradycardia, for example. Learn more about the cardiac pacemaker.