II. Definition

  1. Myocardial Perfusion Imaging using Adenosine (or Regadenoson/Lexiscan)

III. Approach

  1. Hold nitrates (Nitroglycerin) on day of the test
  2. Hold methylzanthines 24 hours before test
    1. Theodur
    2. Aminophylline
    3. Dipyridamole

IV. Preparations

  1. Adenosine or
  2. Regadenoson (Lexiscan)
    1. Longer half life than Adenosine
    2. Can be adminstered as bolus instead of continuous infusion

V. Advantages

  1. Short duration of Adenosine action (<3 seconds)
  2. Vasodilator increases coronary flow 5x
  3. More sensitive than Dobutamine (but less specific)
  4. ST Depression specific for serious disease
    1. Left main Coronary Artery Disease
    2. Three-vessel Coronary Artery Disease

VI. Indications

VII. Contraindications

  1. Asthma
  2. Severe Chronic Obstructive Pulmonary Disease (COPD)
  3. Concurrent medication use
    1. Dipyridamole
    2. Aggrenox
    3. Theophylline
    4. Caffeine prior to test (e.g. Coffee, Chocolate)

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