A 61-year-old man with a past history of episodes of paroxysmal palpitation is in the recovery room after trans-uretral prostate resection:

• Supraventricular tachycardia
• AV nodal Re-entrant Tachycardia (AVNRT) (Rate 152/min)

There was no response to vagal stimulation maneuvers. The patient was given a bolus IV injection of Adenosine and sinus rhythm was restored. The follow-up ECG 2 is normal.