Normal sinus rhythm (NSR)

Heart rate originating from the Sinus (natural pacemaker) activity, i.e. resulting from an electrical stimulus generated in the Sinus and propagated normally by the electrical conduction system of the heart.

Sinus rhythm is defined as normal if the rate is between 60 and 100 per minute.

This rhythm can be above or below the limits of range in certain physiological situations, for instance during exercise or during sleep, respectively, but also as a reaction to pathological situation.