MDCAT Physics MCQ #722

A patient with a pacemaker implanted receives a defibrillator shock. What is the primary effect of the electrical discharge?

MDCAT Physics MCQ #722

  1. Question 1

    Q1. A patient with a pacemaker implanted receives a defibrillator shock. What is the primary effect of the electrical discharge?

    • A) Increased ionized calcium in cardiac tissue
    • B) Inactivation of cardiac sodium channels
    • C) Depolarization of cardiac muscle fibers
    • D) Blockage of potassium channels in the heart

    Answer: Depolarization of cardiac muscle fibers

    Explanation: The electrical discharge causes depolarization of cardiac muscle fibers to interrupt abnormal heart rhythms.