highest blood flow per gram of left ventricular myocardium

Discussion in 'MRCP Forum' started by susan, Sep 19, 2004.

  1. susan

    susan Guest

    The highest blood flow per gram of left ventricular myocardium would occur :

    (1) When aortic pressure is highest

    (2) At the beginning of diastole

    (3) When aortic blood flow is highest

    (4) At the beginning of isovolemic contraction
  2. jasmine2

    jasmine2 Guest

    reply.

    could be no 3, pl.correct me ,thanx.
  3. Gyan

    Gyan Guest

    reply

    can be no2,pl.correct me, thanx.
  4. qquin.

    qquin. Guest

    Flow is highest just at the beginning of diastole because, during this phase of the cardiac cycle, aortic pressure is still relatively high and vascular resistance is low due to the fact that the coronary vessels are no longer being squeezed by the contracting myocardium.
  5. Guest

    Guest Guest

    The Answer is: At the beginning of diastole

    Explanation:
    Blood flow through the coronary vessels of the left ventricle is determined by the ratio of perfusion pressure to vascular resistance. The perfusion pressure is directly related to the aortic pressure at the ostia of the coronaries. Myocardial vascular resistance is significantly influenced by the contractile activity of the ventricle. During systole, when the ventricle is contracting, vascular resistance increases substantially. Flow is highest just at the beginning of diastole because, during this phase of the cardiac cycle, aortic pressure is still relatively high and vascular resistance is low due to the fact that the coronary vessels are no longer being squeezed by the contracting myocardium.

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