This 64-year-old man presents to the Emergency Department with palpitations. He reports a five-year history of paroxysmal tachycardia starting and ending suddenly, occurring approximately once a month, lasting usually 20-30 minutes, and associated with weakness, dizziness, and neck pulsations:

• Supraventricular tachycardia: AV Nodal Re-entrant Tachycardia (AVNRT), rate 170/min
• Anteroseptal infarct, age undetermined – the patient had a myocardial infarction 7 years ago, from which he made a good recovery and had been free of chest pain since

The arrhythmia subsided shortly after arrival to the Emergency Department, before therapy could be provided.

• Sinus rhythm has replaced AV nodal reentrant tachycardia
• Anteroseptal infarct, age undetermined