Beat
Palpitate, Pulse, Throb
noun, する verb
The beat that moves inside your body is the beating of your heart. Put your hand up to your neck and you should be able to feel it pulse.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
少女の顔が赤くなり、鼓動が高鳴りました。
The young girl’s face turned red and her heart throbbed.