Table 1.

Major structural, electrophysiological and metabolic differences between human PSC-derived CMs and maturated/adulte CMs.

PSC-Derived CM	Mature/Adult CM
Smaller in size, roundish in shape	Larger in size, elongated in shape
Disorganized sarcomeres	Organized sarcomeres
Slow/skeletal troponin I (TnIs)	Adult cardiac troponin I (TnIc)
Titin N2BA isoform	Titin N2B isoform
Higher αMHC:βMHC	Lower αMHC:βMHC
Poor expression of ion-transport components genes (e.g., KCNJ2, RYR2)	High expression of ion-transport components genes
Less efficient Calcium handling	Improved Calcium handling
Less negative resting membrane potential	More negative resting membrane potential
No or few T-tubules	Abundant T-tubules
Few, underdeveloped mitochondria Glucose as major energy source	Dense, well-distributed and developed mitochondria Fatty acids as major energy source