Part 1

article, previous criteria set by the World Health Organization (WHO) required two of three conditions for diagnosis: symptoms of ischemia (such as chest pain) indicating insufficient blood supply to the heart muscle, ECG changes consistent with ischemia, and elevated blood levels of certain enzymes (usually creatine kinase-MB). The new definition includes measuring troponins (another type of enzyme that is released from heart muscle). According to the new criteria, elevated levels of enzymes (including creatine kinase-MB or troponin I or T) with either symptoms or ECG changes suggestive of ischemia constitute an acute MI.