Early after-depolarizations occur after the cardiac cells have repolarized.

• A. True
• B. False
• C. They occur during depolarization
• D. They occur before depolarization

Answer: (B)

Early after-depolarizations happen during the repolarization phase of the cardiac action potential, often during the plateau or the early part of repolarization (phases 2–3). They arise when repolarization is delayed, such as with QT-prolonging conditions or drugs, and involve reactivation of inward currents (like L-type calcium channels) that create a new depolarizing surge before the cell fully returns to its resting potential. If a depolarization were to occur after the cell has completed repolarization, that would be a late afterdepolarization, which is a different phenomenon tied to diastolic calcium overload. So the statement is false because early after-depolarizations do not occur after repolarization; they occur during repolarization itself.