This is called a noncompensatory pause, where the sinus P wave to the ectopic P wave to the next sinus P wave is less than the sinus P wave to sinus P wave to sinus P wave.

这被称为非代偿间歇，窦性P波到异位P波，再到下一个窦性P波，要比窦性P波到窦性P波再到窦性P波的时间短。