ABSTRACT
Atrial fibrillation (AFib) is characterized by rapid and irregular activation in the atria without discrete P waves on the surface electrocardiogram (ECG). It may be further categorized into paroxysmal (PAF: termination spontaneously or via intervention within 7 days), persistent (PersAF: AFib sustained beyond 7 days), or permanent (persistent AFib with no further attempts to restore sinus rhythm). In the context of studies of AFib, the definition of the young patient also varies widely: many (older adult) studies of AFib define the group as those under 40-45 years of age (or even under 60 years).
For the purposes of this chapter young will be defined as those under 25 years of age, an age group in which the epidemiological and pathophysiological factors are very different from those in the older adult population. A detailed discussion of the pathophysiological mechanisms of AFib is beyond the scope of this chapter. In brief, AFib initiation and subsequent perpetuation of AFib represents a synergy between the focal or triggered activity that initiates AFib, and the presence of a “vulnerable substrate” necessary for AFib persistence.
