When Educating a Patient About to Undergo a Pacemaker Insertion

Multiple Choice

When educating a patient about to undergo a pacemaker insertion, the nurse explains the normal phases of cardiac muscle tissue. During the repolarization phase, the nurse will stress that membranes must be repolarized before they can be reexcited. Within the cell, the nurse understands that

A) potassium channels open while sodium channels close, causing repolarization to the resting state.
B) the influx of calcium is the primary stimulus for the repolarization of cardiac tissue.
C) only the electrical activity within the heart will determine when repolarization occurs.
D) the cell membranes need to stay calm resulting in muscle tissue becoming refractive.