Accelerated junctional rhythms usually have a regular narrow QRS. They are caused by an accelerated automatic pacemaker (i.e., non-paroxysmal), with rates ranging from 60-130 beats per minute, hence our inclusion of this arrhythmia in the tachycardia section. Retrograde P’s are common and will be negative in the inferior leads. If the junctional origin is low atrial-proximal AV node, they will precede the QRS, and if distal AV node-His bundle, they may be either hidden in or after the QRS. Retrograde VA block with dissociation is common when the origin is the distal AV node-His bundle. Digoxin toxicity and postoperative mitral valve replacement or repair are typical causes. The following animation illustrates what we have just described.