Table 1.

Myocardial energy metabolism: source, process and site of ATP production.

Source of ATP production	Pathway of ATP production	Oxygen consumption (per unit ATP)	Accumulation of acid metabolites	Rate of ATP production	Net ATP yield (per unit substrate)	Site of ATP production
CrP	CrP ⇆ ATP shuttle	None	–	Very fast	1	Cytoplasm
Glucose	Anaerobic glycosis	None	+ + +	Fast	2	Cytoplasm
Glucose	Aerobic oxidation	Less	–	Moderate	38	Mitochondria (predominant) and cytoplasm
Free fatty acids	Aerobic oxidation	More	–	Slow	Usually > 100 (depending on the number of carbon atoms in the molecule of free fatty acid)	Mitochondria (predominant) and cytoplasm

ATP, adenosine triphosphate; CrP, creatine phosphate/.