This 32-year-old woman is referred by her family physician because of almost constant palpitation during the past 2-3 months and recent onset of dyspnea on mild to moderate exertion:

• Nearly-incessant supraventricular rhythm – rate 100/min (upper strips – note paper speed 12.5mm/sec) – 80/min (lower strips)
• Consider atrial tachycardia (tachycardia terminates with QRS, not with P-wave) or permanent junctional reciprocating tachycardia (PJRT)

Comments: Electrophysiological studies demonstrated a slowly conducting concealed accessory pathway in the right posteroseptal region and atrioventricular re-entrant tachycardia (called PJRT when the accessory pathway is slowly conducting). The accessory pathway was successfully ablated. There was no recurrence of the arrhythmia.