A 28-year-old woman presents with recurrent episodes of palpitations lasting 30 minutes to 2 hours, associated with dyspnea and chest discomfort. Physical examination during an episode reveals a regular tachycardia at 180 bpm with a normal blood pressure. A 12-lead ECG obtained during sinus rhythm is normal. Which investigation is most appropriate to establish the diagnosis of atrioventricular reentrant tachycardia (AVRT)?