Oxygen uptake efficiency slope as a useful measure of cardiorespiratory functional reserve in adult cardiac patient. - Baba,R.; Tsuyuki,K.; Kimura,Y.; Ninomiya,K.; Aihara,M.; Ebine,K.; Tauchi,N.; Nishibata,K.; Nagashima,M. (Eur J Appl Physiol, 1999)