Sinus tachycardia is when the heart beats faster than it normally does at rest, and the heart rhythm is regular without any abnormalities.
It is usually a response to exercise, anxiety or in a situation of fight, flight or stress when the body releases stress hormones of epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine.
Note: There are currently no drugs listed for "Sinus Tachycardia".