FIGURE 3.
Energy utilization in a pair of asynchronously activated elements in series. (Parameters identical to those used for Fig. 2.) Lower panel: Rate of ATP hydrolysis by the first-stimulated (continuous curve) and second-stimulated (dashed) elements of the two-element heart. Although the contraction of the second element prolongs the ATP turnover of the earlier-contracting element, the area under the energy consumption curve is greater for the second element. Upper panel: The cumulative ATP use is higher in the late-activated element (dashed curve) compared to that of the early-activated element (continuous curve), even though both have exactly the same parameters.