True regarding myocardial 02 demand
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
Inversely related to hea rate
Has constant relation to external cardiac work
Directly propoional to duration of systole
Is negligible at rest
Cardiovascular system