True about cardiac 02 demand is
Experimental studies have shown that oxygen consumption of the hea and the chemical energy expended during contraction are directly related to the external work Ref: Guyton and Hall Textbook of Medical Physiology (12th Edn) page No:209
Directly propoional to mean aerial pressure
Inversely propoional to hea rate
Inversely propoional to cardiac work
Has a constant relation to the external work done by the hea
Cardiovascular system