Fig. 2.

A: active force development increases in isolated rabbit cardiac trabeculae when length of the muscle is increased. The amplitude of the intracellular calcium transient also increases but is less pronounced. B: RT₅₀ of the force transient is slowed when muscle length is increased, whereas the 50% decline in the intracellular calcium transient is slightly accelerated. C: assessment of calcium sensitivity shows that at higher length, the muscle becomes more sensitive to calcium, whereas maximal force production is increased. Data were recorded at a stimulation frequency of 2 Hz at 37°C and modified from Monasky et al. (39) and Monasky et al. (37).