title: Where most heart attacks begin. Often, they start in arteries that aren't blocked. Here's how.
mesh_terms: D003324:Coronary Artery Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D009203:Myocardial Infarction / Q000209:etiology*; D014463:Ultrasonography