What physiological effect is most likely during a panic attack involving the autonomic nervous system?

During a panic attack, the body activates the sympathetic nervous system, which is part of the autonomic nervous system responsible for the "fight or flight" response. This activation leads to a cascade of physiological changes aimed at preparing the body to respond to a perceived threat. One of the most prominent effects is an increase in heart rate, which helps to pump more blood to vital organs and muscles, enhancing physical readiness.

In situations of stress or panic, neurotransmitters like adrenaline (epinephrine) are released, contributing to this increase in heart rate. Consequently, during a panic attack, it is common for individuals to experience a racing heart or palpitations as a direct result of this heightened sympathetic activity. This physiological response is typically not accompanied by a stable or decreased heart rate, nor does it often lead to an irregular heart rhythm in the context of a standard panic attack unless other underlying conditions are present.