pulsation

noun

1. 1

   the rhythmic contraction and expansion of the arteries with each beat of the heart

   he could feel the beat of her heart

2. 2

   (electronics) a sharp transient wave in the normal electrical state (or a series of such transients)

   the pulsations seemed to be coming from a star

3. 3

   a periodically recurring phenomenon that alternately increases and decreases some quantity