. 2016 Dec 14;97(1):283–409. doi: 10.1152/physrev.00007.2016

Table 1.

Human and murine ventricular and atrial expression of cardiac ionic currents mediating excitable activity

			Human		Mouse
Current/Symbol	Protein	Gene	Ventricle	Atrium	Ventricle	Atrium	Action Potential Contribution
*Voltage-gated inward currents*
Fast Na⁺ current, I_Na	Nav1.5	SCN5A	+++	+++	+++	+++	[0]
L-type Ca²⁺ current, I_CaL (dihydropyridine receptor: DHPR)	Ca_v1.2	CACNA1C	+++	++	++	++	[2]
*Voltage-gated outward currents*
Fast transient outward K⁺ current, I_to,f	Kv4.2	KCND2	++	+++	++	+++	[1]
	Kv4.3	KCND3
Slow transient outward K⁺ current, I_to,s,	Kv1.4	KCNA4	++	+++	++	+++	[1]
Delayed rectifier K⁺ current, I_Kr	Kv11.1	KCNH2 (HERG)	+++	+	+	+	[3]
Delayed rectifier K⁺ current, I_Ks	Kv7.1	KCNQ1	+++	+	+	+	[3]
4-Aminopyridine-sensitive, rapidly activating, slowly inactivating K⁺ current, I_Kslow1	Kv1.5	KCNA5	−	−	++	+
4-Aminopyridine-insensitive, rapidly activating, slowly inactivating K⁺ current, I_Kslow2	Kv2.1	KCNB1	−	−	++	+
Sustained 4-aminopyridine-sensitive delayed rectifier K⁺ current, I_ss	Kv1.5	KCNA5	−	−	++	+
Atrial-specific 4-aminopyridine-sensitive ultrarapid delayed rectifier K⁺ current, I_Kur	Kv1.5	KCNA5	−	++	−	++
*Inward rectifiers*
Inwardly rectifying current, I_K1	Kir2.1	KCNJ2	+++	++	+++	++	[3], [4]
	Kir2.2	KCNJ12
	Kir2.3	KCNJ4
Acetylcholine-activated, K⁺ current, I_KACh	Kir3.1	KCNJ3	−	+++	−	+++
	Kir3.4,	KCNJ5
ATP-sensitive potassium channel, I_KATP	Kir6.2	KCNJ11	++	++	++	++
*Leak currents*
Two-pore domain K⁺ leak current, I_K2_p	K2p3.1	KCNK3	+++	++	++	+++
Ca²⁺-activated K⁺ currents, I_KCa	K_Ca2.x-	KCNNx	−	+++	−	+++
*Exchange currents*
Transient, inward, Na⁺-Ca²⁺ exchange current, I_ti	NCX	SLC8A1	++	++	++	++

Action potential contributions (human ventricle): [0], phase 0 rapid depolarization; [1], phase 1 initial rapid repolarization; [2], phase 2 plateau; [3], phase 3 repolarization; [4], phase 4 electrical diastole.