IMAGES IN ELECTROPHYSIOLOGY Spontaneous high degree atrioventricular block during AV nodal re-entrant tachycardia

High-degree atrioventricular (AV) block during AV nodal re-entrant tachycardia (AVNRT) is considered a rare phenomenon. A patient with slow–fast AVNRT and transient high-degree AV block is presented. Electrophysiological manoeuvres identified the site of block in the lower common pathway of the AV node. This arrhythmia was rendered non-inducible after slow pathway ablation