Which statement is true about stimulation during the excitable gap in a reentrant circuit?

Which statement is true about stimulation during the excitable gap in a reentrant circuit?

• A. It prolongs the rhythm
• B. It terminates the tachycardia
• C. It has no effect
• D. When the stimulus hits the excitable gap it breaks the rhythm

Answer: (D)

The excitable gap is the window in a reentrant circuit where tissue has recovered and can be captured by a stimulus. A premature stimulus arriving during this gap can propagate into the circuit and collide with the circulating wavefront in a way that interrupts the loop, terminating the tachycardia. So stimulation hitting the excitable gap breaks the rhythm. If the stimulus lands outside this window, the reentry often persists or has little effect.

The excitable gap is the window in a reentrant circuit where tissue has recovered and can be captured by a stimulus. A premature stimulus arriving during this gap can propagate into the circuit and collide with the circulating wavefront in a way that interrupts the loop, terminating the tachycardia. So stimulation hitting the excitable gap breaks the rhythm. If the stimulus lands outside this window, the reentry often persists or has little effect.