beating vs palpitation

beating

noun
  • The pulsation of the heart. 

  • The action by which someone or something is beaten. 

  • A heavy defeat or setback. 

palpitation

noun
  • An abnormal beating of the heart that may be perceived by the patient, a result of excitement, exertion, or illness. 

How often have the words beating and palpitation occurred in a corpus of books? (source: Google Ngram Viewer )