Atrial fibrillation of one of the most common types of supraventricular tachyarrhythmias, actually it accounts for 80% of all paroxysmal supraventricular tachyarrhythmias. According to the American Heart Association, about 2.7 million Americans are diagnosed with atrial fibrillation. This type of arrhythmia is characterized by a rapid (up to 400 times per minute) and irregular contraction of the two upper chambers of the heart called atria. It happens because electrical signals spread through the atria in a fast and unorganized way causing chaotic contraction of the muscle fibers. In atrial fibrillation, the ventricles (two lower heart’s chambers) also beat rapidly, but not as rapidly as the atria since not all the electrical impulses reach them. The heart rate in this condition ranges from 100 to 175 beats per minute, whereas a normal heart rate is about 60-100 beats per minute. The atrial fibrillation symptoms include dizziness, nausea, fainting, chest pain, palpitations, shortness of breath and confusion, but some atrial fibrillation patients can experience no symptoms at all.

Atrial fibrillation can happen in patients of all age categories; however, its prevalence is much higher in elderly patients, which is associated with the increase in the organic pathologies of the heart. About 70% of atrial fibrillation patients are people aged 65 and older.

Convulsive and chaotic activity of the atria can take place in the setting of a variety of cardiaс disorders that cause damage to the structure and electrical system of the heart including:

  • Acute myocardial infarction;
  • High blood pressure also called hypertension;
  • Myocarditis (inflammation of the myocardium) and pericarditis (inflammation of the pericardium);
  • Congenital heart defects such as defects of the valves, the interior walls of the heart, or blood vessels supplying the heart muscle with blood;
  • Coronary artery disease;
  • Chronic heart failure (impairment of the myocardial structure, its contractile function and conduction);
  • Heart valve disorders;
  • Sick sinus syndrome which is the malfunction of the sinus node, the natural pacemaker of the heart;
  • Rheumatic heart disease.

There is also a group of non-cardiac disorders that can provoke the development of atrial fibrillation:

  • Thyroid gland disorders with the symptoms of thyrotoxicosis;
  • Lung disorder, such as pneumonia, pulmonary embolism (a clot of blood in the lung), emphysema, cystic fibrosis, lung cancer, or chronic obstructive pulmonary disease;
  • Viral infections;
  • Sleep apnea;
  • Electrolyte imbalance and particularly hypokalemia (low serum potassium levels) associated with the overuse of diuretics or food poisoning;
  • Prolonged periods of stress and psycho-emotional strain;
  • Metabolic disorders such as diabetes;
  • Intoxication resulting from the use of illegal drugs like cocaine or amphetamines;
  • Acute or chronic alcohol intoxication.

Moreover, an atrial fibrillation episode can be triggered by drinking a lot of caffeine-containing beverages, such as coffee, tea or energy drinks. Atrial fibrillation is the most common complication that occurs after a heart surgery as well.

However, sometimes even healthy and physically fit people like athletes can experience atrial fibrillation. When atrial fibrillation is not associated with any other disorder, it’s called lone or idiopathic atrial fibrillation. The cause of such atrial fibrillation is usually unclear and it’s highly unlikely to provoke any serious complications.

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Since Atrial Fibrillation is the most common type of arrhythmia, it is important to know more about this condition. To read the detailed information about Atrial Fibrillation, please visit