Atrial fibrillation is one of the most common arrhythmias. According to the most recent American Heart Association/American College of Cardiology/Heart Rhythm Society Atrial Fibrillation Guidelines, approximately 2.7 million people in the United States are living with atrial fibrillation. This number is expected to double in the next 25 years. The most commonly associated cardiac condition of this arrhythmia is hypertension, although it is also common to find atrial fibrillation in patients with other types of cardiac abnormalities such as myocardial infarction and ischemia, valvular disease, and hypertrophic cardiomyopathy.
Atrial fibrillation is diagnosed as an irregular rhythm in which the atrial depolarization occurs in a very fast, chaotic manner. The mechanism may be related to abnormal stretch and/or foci in the myocardium at areas such as the pulmonary veins, the coronary sinus, and the right atrial appendage.
Atrial fibrillation may be classified based on two criteria: 1) episode frequency; and 2) the ability to convert spontaneously back into normal sinus rhythm. If a patient presents with two or more episodes, this is called recurrent atrial fibrillation. Recurrent atrial fibrillation may be paroxysmal (terminates spontaneously) or persistent (does not terminate spontaneously, but only after pharmacologic or electrical cardioversion). Longstanding persistent atrial fibrillation may also be called chronic atrial fibrillation. When this tachyarrhythmia is unable to be cardioverted successfully, it is called permanent atrial fibrillation.