anxiety vs heat of passion

anxiety

noun
  • A state of restlessness and agitation, often accompanied by a distressing sense of oppression or tightness in the stomach. 

  • An unpleasant state of mental uneasiness, nervousness, apprehension and obsession or concern about some uncertain event. 

  • An uneasy or distressing desire (for something). 

heat of passion

noun
  • An outburst of anger that leads one to commit a criminal act, and is itself influenced by preceding events that might cause a reasonable person to lose self control. 

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