Definition
Atrial fibrillation (AFib) is one of the most common cardiac rhythm disorders. A heart rhythm disorder occurs when the heart beats too quickly, slowly, or irregularly. Atrial fibrillation occurs when both the left and right atriums of the heart beat irregularly, disrupting blood flow. Atrial fibrillation can occur in short episodes/occurrences or occur as a permanent condition.
Causes
The heart has four chambers: two atriums and two ventricles. The right atrium contains a group of cells known as the sinus node. The sinus node is a natural pacemaker. The sinus node generates the signal that starts each heartbeat. In a normal heart rhythm, the signal from the sinus node travels to both atriums. The signal then passes from the atriums to the ventricles via the atrioventricular (AV) node. This movement of signals causes the heart to contract, allowing it to pump blood to the lungs, heart muscles, and the rest of the body.
Atrial fibrillation occurs when signals in both atriums are disrupted. As a result, both atriums are unable to contract properly and instead vibrate. Not only that, the AV node is overwhelmed by signals from the atriums that are about to travel to the ventricles. These signals cause the heart rhythm to become fast and irregular. The heart rate in atrial fibrillation can range from 100-175 beats/minute, while the normal heart rate ranges from 60-100 beats/minute.
Risk factor
Several factors can increase the risk of atrial fibrillation. These include:
- Old age. The older a person is, the higher the risk of atrial fibrillation
- Heart disease, such as valve disorders, congenital heart disease, heart failure, coronary heart disease, or a history of heart attack or heart surgery
- High blood pressure. Uncontrolled high blood pressure with medication and lifestyle changes can increase the risk of atrial fibrillation
- Thyroid disease. In some people, thyroid problems can trigger heart rhythm disturbances, including atrial fibrillation
- Other chronic health conditions. Diabetes, metabolic syndrome, chronic kidney failure, pulmonary disease, or snoring all increase the risk of developing atrial fibrillation
- Alcohol consumption. In some people, alcohol consumption can trigger episodes of atrial fibrillation
- Obesity. People who are overweight have a higher risk of atrial fibrillation
- Family history. Some families are more prone to atrial fibrillation than others
Symptoms
Some people with atrial fibrillation do not experience any symptoms. Symptoms that may occur with atrial fibrillation include:
- Palpitations (sensation of a fast and racing heartbeat)
- Chest pain
- Dizziness
- Tiredness
- Lightheadedness or floating
- Unable to perform strenuous activities
- Shortness of breath
- Weakness
The types of occurrence of atrial fibrillation are as follows:
- Paroxysmal. This type of atrial fibrillation causes irregular symptoms that range in duration from a few minutes to several hours. Symptoms may last for up to a week, and episodes may recur. Symptoms may also go away on their own. Some people with this type of atrial fibrillation require therapy
- Persistent. In this type, the heart rhythm does not return to normal on its own. If people with this type experience symptoms of atrial fibrillation, they need cardioversion (correction of heart rhythm by electric shock) or medication to restore normal heart rhythm
- Long-term persistent. This type of atrial fibrillation is persistent and lasts for more than 12 months
- Permanent. This type of irregular heart rhythm cannot be restored to normal. Therefore, this type requires medication to keep the heart rate stable and prevent blood clots from forming
Diagnosis
Atrial fibrillation can be detected by hearing heart sounds. Subsequently, several tests may be performed. These include electrocardiography (ECG), a test that detects the flow of electricity in the heart. In addition to the ECG, biomarker and imaging tests may be performed. Biomarkers are substances that change levels when an organ, such as the heart, is damaged. Imaging tests can be done in the form of chest X-rays. Biomarker and imaging tests are used to identify possible causes of atrial fibrillation, such as heart failure.
Management
Atrial fibrillation is often not a life-threatening situation, but it can cause discomfort and requires therapy as it has potentially life-threatening complications. Treatment for atrial fibrillation may involve:
- Medications to prevent strokes. People with atrial fibrillation are much more prone to having a stroke. Medications are also administered to regulate heart rhythm and rate
- In certain conditions, cardioversion may be performed. Cardioversion is an electric shock that is used to correct the heart rhythm
- In the most severe cases, catheter ablation may be recommended. Catheter ablation is a procedure that uses radiofrequency waves to destroy the part of the heart that is causing the irregular heartbeat. After the procedure, you may be advised to wear a pacemaker to help your heart beat normally
Complications
Atrial fibrillation increases the risk of death from blood vessel blockage events caused by blood clots, such as a stroke. This is because atrial fibrillation restricts blood flow, causing blood to accumulate in the heart chambers and form blood clots. At some point, this blood clot can break free from the heart and block other blood vessels. One of the blood vessels that is frequently targeted is the blood vessels of the brain, so the symptoms that appear may be a stroke.
Prevention
Prevention of atrial fibrillation can include lifestyle changes. These lifestyle changes include:
- Eating a healthy diet high in vegetables and fruits and low in fat and cholesterol. If you have high blood pressure, reducing your salt intake can help you maintain normal blood pressure. You can also consult a doctor or nutritionist to manage your daily diet
- Maintain an ideal body weight by exercising regularly. The recommended exercise is moderate-intensity exercise, such as aerobic exercise, jogging, cycling, or swimming. Exercise is recommended to be done at least 30 minutes/day, 3-5 times/week
- No smoking. If you smoke, you can ask your health professional about smoking cessation programs
- Avoid or limit alcohol and caffeine consumption
- Dealing with stress, as stress and anger can cause heart rhythm problems
When to see a doctor?
If you notice any symptoms of atrial fibrillation, consult a doctor. However, if you experience chest pain, you should go to the nearest emergency room because it could be caused by a heart attack, which is life-threatening. You can also consult with a doctor if you have a consistent heart rate below 60 beats/min or above 100 beats/min, especially if it is accompanied by dizziness and shortness of breath. These signs and symptoms may indicate a heart rhythm disorder.
Looking for more information about the results of laboratory examinations, radiology, and others? Click here!
- dr Anita Larasati Priyono
Atrial fibrillation. (2021). Retrieved 11 April 2022, from https://www.nhs.uk/conditions/atrial-fibrillation/
Atrial fibrillation - Symptoms and causes. (2021). Retrieved 11 April 2022, from https://www.mayoclinic.org/diseases-conditions/atrial-fibrillation/symptoms-causes/syc-20350624
Rosenthal, L. (2019). Atrial Fibrillation: Practice Essentials, Background, Pathophysiology. Retrieved 11 April 2022, from https://emedicine.medscape.com/article/151066-overview