infarction vs matter of life and death

infarction

noun
  • The process which causes an infarct. 

  • An infarct (an area of ischemic necrosis). 

matter of life and death

noun
  • Something whose outcome could result in either someone's survival or their death 

  • An extremely urgent matter. 

How often have the words infarction and matter of life and death occurred in a corpus of books? (source: Google Ngram Viewer )