A 16-year-old boy was brought to the emergency department because of palpitations and lightheadedness that began 16 hours ago. He had been binge drinking the night before. After regaining consciousness, he was admitted for observation. His temperature is 37.1°C (98.8°F), pulse is 220/min, respirations are 20/min, and blood pressure is 92/54 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Physical examination shows no abnormalities. An ECG shows a regular heart rate of 240/min with narrow QRS complexes and no identifiable P waves. . Which of the following is the most likely cause of this patient's hypotension?

Question

A 16-year-old boy was brought to the emergency department because of palpitations and lightheadedness that began 16 hours ago. He had been binge drinking the night before. After regaining consciousness, he was admitted for observation. His temperature is 37.1°C (98.8°F), pulse is 220/min, respirations are 20/min, and blood pressure is 92/54 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Physical examination shows no abnormalities.   An ECG shows a regular heart rate of 240/min with narrow QRS complexes and no identifiable P waves. . Which of the following is the most likely cause of this patient's hypotension?

Quizplus · Accepted Answer

Eductional Objective: Supraventricular tachycardia is characterized by an elevated heart rate with a regular rhythm and narrow QRS complexes due to an abnormal electrical impulse originating above the ventricles.  Sustained tachycardia shortens ventricular diastole, leading to decreased stroke volume and cardiac output and subsequent hypotension.

A 16-Year-Old Boy Was Brought to the Emergency Department Because