Fig. 3. ( A ) Representative trace demonstrating the effect of droperidol (1 μm) on KCl (35 mm)–induced increase in intracellular free Ca2+concentration. ( B ) Summarized data for the concentration-dependent effects of droperidol on the KCl-induced increase in intracellular free Ca2+concentration. Results are expressed as percent of control. *P < 0.05 compared with control; n = 15 cells from five hearts.