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Test Findings

Pathological Q Waves



  • While T wave and ST changes revert post myocardial infarction, Q waves are permanent and thus their presence may indicate previous infarction.
    • Look For

      A negative deflection that is either broad or deep:
    • Broad: >40ms (1mm) in duration
    • Deep: >0.2mV (2mm) or ≥1/3 of R wave size
    • Pathological Q Waves
  • Non-pathological Q waves may occur in I, III, aVL, V5 and V5.
    • Causes of Pathological Q Waves

    • Myocardial infarction
    • Hypertrophic cardiomyopathy (inferior / anterior leads)
    • Dilated cardiomyopathy (leads V1 to V4)
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