When a premature atrial contraction consistently comes after each normal cardiac cycle, it’s called atrial bigeminy and when one consistently comes after every two normal cardiac cycles, it’s called atrial trigeminy.

当房性期前收缩总是紧正常心动周期而来时，它被称为二联律；当房性期前收缩总是紧两正常心动周期而来时，它被称为三联律。