The exciting activity transition rule of single cardiac myocytes and the generation of delayed after-depolarization and early after-depolarization during transition process
心肌单细胞兴奋模式转迁规律和转迁过程中延迟后去极化、早后去极化的生成

Several exciting activity patterns, together with delayed after-depolarization (DAD) and early after-depolarization (EAD), were observed in cultured Neonatal rat's single cardiac myocytes in normal Tyrode solutions by using whole cell current clamp. These different patterns could transit among each other during an inward or outward current injection. With the outward current decreased and the inward current increased gradually, the cell showed a clearly transition process, from the resting state of polarization to the DAD rhythm, the uninterrupted exciting rhythm, the EAD rhythm, finally to the resting state of over-depolarization, which formed a “spectrum of rhythms”. The DAD rhythm was located between the resting state of polarization and the uninterrupted exciting rhythm, and the EAD rhythm located between the uninterrupted exciting rhythm and the resting state of over-depolarization in this “spectrum of rhythms”. The "spectrum of rhythms" established a deep relationship between normal and abnormal cardiac rhythms.