Manifest Fast and Slow AV Nodal Conduction Patterns and Reentry.A 52‐year‐old woman with paroxysmal supraventricular tachycardias (PST) showed short and long PR intervals during sinus rhythm. Repetitive episodes of PST due to simultaneous anterograde conduction through fast and slow conduction pathways (one P‐two QRS) were recorded. A self‐limited episode of non‐paroxysmal AV nodal reentry with anterograde slow and retrograde fast pathway conduction was initiated by a single atrial premature beat. Each pathway depicted distinct refractory periods, conduction velocities, unidirectional block, and Wenckebach‐type block suggesting the possibility of a well‐defined anatomic