infarction vs obstacle

infarction

noun
  • The process which causes an infarct. 

  • An infarct (an area of ischemic necrosis). 

obstacle

noun
  • Something that impedes, stands in the way of, or holds up progress, either physically or figuratively 

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