Fig. 12.

Identification of early (EAD) and delayed afterdepolarizations (DAD) after isoprenaline (ISO) challenges. A: typical traces of EAD formation in action potentials with short (1), normal (2), and long duration (3) and the corresponding first derivative (dV/dt) traces from ovariectomized (OVx) myocytes. Action potentials were recorded during 2-Hz stimulation in 50 nM ISO. B: typical DADs that form in one OVx myocyte during 0.5-Hz stimulation in 50 nM ISO. The recording illustrates a DAD-induced (triggered) extrasystole.