Symptoms of atrial fibrillation or flutter depend on how fast the ventricles are beating. If the heart rate is less than 120 beats a minute, there may be no symptoms. If the rate is higher, heart palpitations or discomfort in the chest may be present.
Other symptoms may include:
- Irregular, fast pulse if experiencing atrial fibrillation
- Regular, fast pulse if experiencing atrial flutter
- Feeling of weakness
- Dizziness or faintness
- Shortness of breath
- Chest pain, especially in older adults
- Rarely, blood pressure may fall causing shock. This typically only occurs in people having atrial fibrillation or flutter who also have very severe heart disease.
Causes and Risk Factors
Although atrial fibrillation or flutter may occur even without other signs of heart disease, most often it is caused by conditions such as rheumatic fever, high blood pressure, coronary artery disease, alcohol abuse, an overactive thyroid gland (hyperthyroidism) or a birth defect of the heart.
Rheumatic fever (which leads to heart valve disorders) and high blood pressure cause the atria to enlarge, making atrial fibrillation or flutter more likely.
Atrial fibrillation and atrial flutter are more common among older people.