palpitation vs pulsation

palpitation

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

pulsation

noun
  • The regular throbbing of the heart, an artery etc. in a living body; the pulse. 

  • Any rhythmic beating, throbbing etc. 

  • A single beat, throb or vibration. 

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