Which pathway tends to repolarize more slowly?

Which pathway tends to repolarize more slowly?

• A. The fast pathway
• B. The slow pathway
• C. Both equally
• D. Neither

Answer: (A)

In dual AV nodal pathways, the speed of repolarization is tied to how long a pathway remains refractory after activation. The fast pathway has a longer refractory period, so it takes longer to recover excitability and repolarize. The slow pathway, with a shorter refractory period, recovers sooner and repolarizes more quickly. Therefore, the fast pathway tends to repolarize more slowly. This difference helps explain how reentrant circuits can form, since the timing of recovery on each pathway determines which one can conduct again.

In dual AV nodal pathways, the speed of repolarization is tied to how long a pathway remains refractory after activation. The fast pathway has a longer refractory period, so it takes longer to recover excitability and repolarize. The slow pathway, with a shorter refractory period, recovers sooner and repolarizes more quickly. Therefore, the fast pathway tends to repolarize more slowly. This difference helps explain how reentrant circuits can form, since the timing of recovery on each pathway determines which one can conduct again.