Figure 1. Timeline of the key developments in the history of cardioplegia. 
Figure 2. Electrophysiology Principles in Cardioplegia.  Schematic diagram showing cardiomyocyte function including cation transport (Na+/HCO3- symporter, Na+-H+ exchanger, LTCC, G-protein coupled receptor, VGCC, Na+/Ca2+ exchanger, voltage-gated Na+ channels, Na+/K+ pump, voltage-gated K+ channel), excitation-contraction coupling, acid-base balance regulation, and adrenergic and muscarinic receptors.
SR  sarcoplasmic reticulum, M2  muscarinic receptor 2, A1  adenosine receptor 1, R  -adrenergic receptor, GLUT  glucose transporter 1, Gi  inhibitory G protein, Gs  stimulatory G protein, AC  adenylate cyclase, ATP  adenosine triphosphate, cAMP  cyclic adenosine monophosphate, ADP  adenosine diphosphate, KATP  ATP-sensitive potassium channel, PLC  phospholipase C, PKC  phosphokinase C, NF-kB  nuclear factor kappa B, CICR  calcium-induced calcium release, PDH  pyruvate dehydrogenase.‘