Refers to a rhythmic pulsation, often used in a poetic context.
El lateo de su corazón se aceleró al verla entrar.
The throbbing of his heart quickened as he saw her enter.
El lateo de su corazón se aceleró al ver a su amor acercarse con una sonrisa.
The throbbing of his heart quickened when he saw his love approaching with a smile.