A 25-year-old man arrives at the emergency department complaining of chest pain and palpitations for the past three hours. He'd had similar episodes in the past year that were resolved with deep breathing, but none had lasted as long as this one. The patient does not have any chronic medical conditions and does not take any medications. He does not smoke, drink alcohol, consume caffeine, or use illegal drugs. The blood pressure is 100/70 mm Hg, and the pulse rate is 160 beats per minute. The neck is flexible, the thyroid is functioning normally, and there is no lymphadenopathy. Auscultation reveals that the lungs are clear. ECG is shown in the exhibit. Which of the following is the most likely cause of this patient's symptoms?

Question

A 25-year-old man arrives at the emergency department complaining of chest pain and palpitations for the past three hours. He'd had similar episodes in the past year that were resolved with deep breathing, but none had lasted as long as this one. The patient does not have any chronic medical conditions and does not take any medications. He does not smoke, drink alcohol, consume caffeine, or use illegal drugs. The blood pressure is 100/70 mm Hg, and the pulse rate is 160 beats per minute. The neck is flexible, the thyroid is functioning normally, and there is no lymphadenopathy. Auscultation reveals that the lungs are clear. ECG is shown in the exhibit.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Eductional Objective: The most common type of paroxysmal supraventricular tachycardia is atrioventricular nodal reentrant tachycardia, which results from abnormal conduction through two distinct atrioventricular nodal pathways. A narrow QRS complex tachycardia with a regular rhythm and buried (not visible) P waves is typical on an ECG.

A 25-Year-Old Man Arrives at the Emergency Department Complaining of Chest