Sinus tachycardia (also colloquially known as sinus tach or sinus tachy) is an elevated sinus rhythm characterized by an increase in the rate of electrical impulses arising from the sinoatrial node. In adults, sinus tachycardia is defined as a heart rate greater than 100 beats/min (bpm).

Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate.

In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults.

Heart rates above the resting rate may be normal (such as with exercise) or abnormal (such as with electrical problems within the heart).

Earlier tachycardia for seizures originating from the right versus left hemisphere in a patient with bilateral mesial temporal lobe epilepsy ¹⁾.