The concentrations of free Ca²⁺ required for half-maximal force (EC₅₀) and the maximal Ca²⁺-activated force per cross-sectional area (Fmax) for three surgery groups under varying experimental conditions.

Data are presented as average ± S.E.M. *: denotes P<0.016 compared to perfused fibers under identical experimental conditions. †: denotes P<0.016 compared to perfused and reperfused fibers under identical experimental conditions. ‡: denotes P<0.016 compared to perfused and ischemic fibers under identical experimental conditions.