Fig. 1. Ca²⁺ transients in electrically-paced ventricular myocytes. (A) Recordings depict the typical response of a single ventricular myocyte immediately after isolation, loaded with indo-1 to repetitive field stimulation. Arrows indicate field stimulation. (B) Normalised response (mean ± s.e.m.; n=28 cells) of ventricular myocytes to electrical pacing over a 25-minute period. (C) Traces show typical Ca²⁺ responses from a single cell at the start of an experiment (black trace) and after 25 minutes of stimulation (grey trace). There were no significant changes in the time of increase, peak amplitude or recovery of the Ca²⁺ transient.