What physiological effect accompanies preoperative anxiety in patients?

Preoperative anxiety commonly triggers a physiological response known as the "fight or flight" reaction, which is mediated by the autonomic nervous system. This response leads to an increase in heart rate as the body prepares to cope with perceived threats, such as the stress of surgery. The heart accelerates to pump more blood to vital organs and muscles, ensuring they have the necessary oxygen and nutrients for heightened activity.

While anxiety can have various effects on the body, in this context, the increase in heart rate is a direct and prominent response to anxiety. Other physiological reactions can occur concurrently, such as changes in respiratory rate, but the increase in heart rate is the primary and most immediate response that is consistently observed in anxious patients prior to surgery.