4-AP	4-aminopyridine
AP	action potential
APA	action potential amplitude
APD	action potential duration
APD90	action potential duration at 90% of repolarization
APVC	action potential voltage-clamp
CBA	4-chloro-2-(2-chlorophenoxy)acetamido) benzoic acid
[Ca2+]i	intracellular Ca2+ concentration
DAD	delayed afterdepolarization
EAD	early afterdepolarization
EC50	half effective activator concentration
ICa,L	L-type Ca2+ current
ICBA	CBA-sensitive current
ICl(Ca)	Ca2+-activated Cl− current
IK1	inward rectifier K+ current
IKr	rapid component of delayed rectifier K+ current
IKs	slow component of delayed rectifier K+ current
INa,L	late Na+ current
INCX	Na+/Ca2+ exchange current
Iti	transient inward current
Ito	transient outward K+ current
OSP	overshoot potential
Phase-1 slope	maximal rate of early repolarization
PIP2	phosphatidylinositol 4,5-bisphosphate
Plateau50	membrane potential at the half duration of APD90
RMP	resting membrane potential
RSV	relative short-term variability of repolarization
SV	short-term variability of repolarization
TRP	transient receptor potential
TRPM4	transient receptor potential melastatin 4
V+max	maximal rate of depolarization
V−max	maximal rate of terminal repolarization