Table 1

Main ion currents involved in common iatrogenic disorders

CurrentCloneGeneAP phaseFunctions
Inward
 INa-fastNav1.5SCN5APhase 0Conduction (atrial, ventricular myocardium)
 ICaLCav1.2CACNA1CPhase 2AP plateau and contractility (atrial, ventricular myocytes)
 ICaLCav1.2CACNA1CPhase 0Pacemaker activity, AV nodal cells
 ICaTCav1.3
Cav3.2
CACNA1GPhase 4/0Pacemaker activity, AV nodal cells
 IfHCN2/4HCN2/4Phase 4Excitability in SA-AV nodes
Outward
 Ito-fastKv4.2
Kv4.3
KCND2/3Phase 1APD (refractory period)
 Ito-slowKv1.4/1.7
Kv3.4
KCNA4/7, KCNC4Phase 1APD (refractory period)
 IK,urKv1.5/3.1KCNA5, KCNC1Phase 1Atrial myocytes specific (APD)
 IKrhERGKCNH2Phase 3APD (refractory period, atrial, ventricular myocardium, SA, AV nodal cells
 IKsKVLQT1KCNQ1Phase 3APD (refractory period) in atrial, ventricular myocardium
 IK1Kir2.1/2.2KCNJ2/12Phase 3/4Cellular excitability (atrial, ventricular myocardium)
 IK,achKir3.1/3.4KCNJ3/5Phase 4Excitability in SA-AV nodes
 IK,ATPKir6.2KCNJ11Phase 1–2APD (refractory period, atrial, ventricular myocardium) excitability in SA, AV nodes
  • AP, action potential; APD, action potential duration; AV, atrioventricular; ICaL, L-type calcium current; ICaT, T-type calcium current; IK,ach, acetylcholine-dependent G protein-gated potassium current; IK,ATP, ATP-sensitive potassium current; IKr, rapid delayed rectifier potassium current; IKs, slow delayed rectifier potassium current; IK,ur, ultra-rapid outward potassium current; IK1, inward rectifier potassium current; INa, sodium current; Ito, transient outward potassium current; SA, sino-atrial.