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  1. #1
    dr_ashima is offline Newbie 510 points
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    question

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    if QRS complex is positive in lead 2 and avf and negative in lead 3 what is the mean electrical axis between
    a . -30 and 0
    b. 0 and 30
    c. 30 and 60
    d. 60 and 90
    e. 90 and 120
    can someone please tell the answer and explain it

  2. #2
    petarm Guest
    I know the method of fast determining mean electrical axis by using lead 1, V2 and aVF. If you want me to explain it, tell me.

  3. #3
    petarm Guest
    And, about your question,
    I would say between 0 and 60.
    I draw a diagram i.e. a circle showing all three standard leads (1,2,3) and aVF (something between EKG three-axis and six-axis system, I don't know if you understand what I am trying to say). Then I mark area of the circle where mean electrical axis (MEA) can be if lead 2 is positive, then the same thing for lead 3 being negative, and the same procedure for aVF being positive. Intersected area is between 0 and 60.
    The problem is that there is not such a result offered in the question, but this is what I get by way of drawing it as I have described above. What do you think?

  4. #4
    ducman is offline Moderator 511 points
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    Answer

    I would say that the answer is d) between 60 and 90

    Please see the attached document on the mean axises of depolarization.


    Attached Files Attached Files
    Ducman
    Saba University School of Medicine

  5. #5
    snickers is offline Newbie 510 points
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    actually none of the answers are correct. If lead II is positive and lead III is negative..that gives a range between -30 and +30 degrees and that gives you a MEAN ELECTRICAL AXIS of 0 degrees.

    Hope this helps

  6. #6
    petarm is offline Newbie 510 points
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    Re

    I have to correct myself. The answer is 0 to 30

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