Tachycardia and the AV nodal region: guilt by association?

Tachycardias that are successfully ablated in the vicinity of the atrioventricular (AV) node are common, and although frequently successfully treated, are among the most difficult arrhythmias to understand in cardiac electrophysiology. Even AV node reentrant tachycardia (AVNRT), despite near universal cure, is complex with the anatomic constructs for typical, atypical forms, left-sided AVNRT, upper common pathway block, and lower common pathway block, not readily apparent.1 Even less understood arrhythmias in this group are junctional tachycardias and peri–AV nodal “atrial” tachycardias that may or may not be reentrant and may or may not involve AV node–like tissue.2,3