A Child with a History of Asthma Is Brought to the Clinic

A child with a history of asthma is brought to the clinic with a rapid heart rate. A cardiac monitor shows a heart rate of 225 beats per minute. The provider notifies transport to take the child to the emergency department. What initial intervention may be attempted in the clinic?

A) Intravenous adenosine
B) Administration of a beta blocker
C) A loading dose of digoxin
D) A carotid massage