cardiopulmonary resuscitation vs heart massage

cardiopulmonary resuscitation

noun
  • A first aid procedure for cardiac arrest involving compression of the chest wall alternating with artificial respiration. 

heart massage

noun
  • Cardiopulmonary resuscitation. 

How often have the words cardiopulmonary resuscitation and heart massage occurred in a corpus of books? (source: Google Ngram Viewer )