True about cardiac 02 demand is: (A) Directly propoional to mean aerial pressure, (B) Inversely propoional to hea rate, (C) Inversely propoional to cardiac work, (D) Has a constant relation to the external work done by the hea
Answer is A. 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