After trauma, tachycardia is noted. Which statement best explains the tachycardia in this patient?

• A. The patient’s heart is beating quickly due to blood loss and pain
• B. The tachycardia indicates a rhythm requiring immediate cardioversion
• C. The patient’s heart rate is elevated due to dehydration
• D. The patient’s heart rate is normal

Answer: (A)

In the aftermath of trauma, tachycardia is usually a compensatory response to decreased circulating blood volume. When bleeding occurs, venous return and preload drop, which lowers stroke volume. To maintain cardiac output and keep blood flow to vital organs, the body increases heart rate through sympathetic stimulation. The stress and pain of the injury also trigger catecholamine release, further elevating the heart rate. This combination best explains why the heart is beating faster in this patient. While dehydration can raise heart rate, the acute trauma scenario makes hypovolemia from blood loss the more likely cause. A normal heart rate would not match the observed tachycardia.