PATHOPHYSIOLOGY OF MYOCARDIAL ISCHEMIA

Causes other than coronary aa. stenosis:

  1. Increased myocardial O2 demand
  1. Tachycardia
  2. Hypertrophic cardiomyopathy
  3. Increased afterload, e.g.
    1. Severe HTN
    2. Thyrotoxicosis
    3. Fever
    4. Toxins/drugs
    5. Aortic stenosis
    6. Severe CHF
  1. Increased preload
    1. Endogenous catecholamines
    2. Hyper-inotropic state LV dilation
  1. Decreased myocardial O2 delivery
  1. Hypoxemia
  2. Hyperviscosity, e.g. polycythemia
  3. Anemia, inc. methemoglobinemia