Fig. 1. Comparison of the time course of the inotropic effects of metabolic acidosis (pH = 7.10, n = 8) and respiratory acidosis (pH = 7.10, n = 8) compared with a control group (pH = 7.40, n = 8) in isotonic (A ) and isometric (B ) conditions at a calcium concentration of 2.5 mM. Data are mean percent of baseline ± SD. Vmax= maximum unloaded shortening velocity; AF = isometric active force for cross-sectional area.