Compared with baseline,terfenadine prolonged QT interval and MAPD_(90) at different concentration with different pacing cycle length,which was from 400ms to 2 400ms. EADs were recorded in 10/18 rabbit hearts.

• 各浓度特非那丁低钾镁台氏液灌流都可延长QT间期和单向动作电位复极达90%25时限(MAPD90),10/18例记录到EADs,起搏周长1 400~2 400 ms。