Atrioventricular Reentrant Tachycardia

Atrioventricular reentrant tachycardia (AVRT) occurs in people with an accessory pathway that connects the atrium to the ventricle across the atrioventricular groove, a structure that separates the atria from the ventricles (Figure 1). In patients who are middle-aged or older, atrioventricular nodal reentrant tachycardia (AVNRT) is more prevalent than AVRT. However, in the adolescent population, AVRT may be more prevalent.¹  The mean age for the first presentation of AVRT is younger than that for presentation of AVNRT.²  Accessory pathways can be classified by their location and by their ability to conduct anterograde, retrograde, or in both directions.

Manifest accessory pathways are those that allow anterograde conduction, and in some cases both anterograde and retrograde conduction. Conversely, pathways that only conduct retrograde are called concealed pathways. Manifest pathways are present in between 0.1% and 0.3% of the population in Western countries.³  Most accessory pathways have properties...