Experimental design and vehicle control parameters. A, Langendorff-perfused rat heart shown with pacing electrodes on the right atria and apex, and monopolar electrodes placed to record electrocardiograms. B, The schematic timeline depicts perfusion protocols used in the study, including (top) vehicle control exposure, (middle) bisphenol chemical dose response, and (bottom) bisphenol chemical dose response and subsequent recovery. C, Cardiac electrophysiology parameters are consistent over time, and similar between baseline and vehicle (0.01% DMSO) exposure. Values reported as mean ± SD. Statistical significance determined by RM-ANOVA with multiple comparisons testing (0.1 FDR). Number of replicates indicated in each bar graph (n = 4). Abbreviations: ECG, location of electrocardiogram electrode; EP, electrophysiology protocol; HR, heart rate; BPM, beats per minute; P dur, P wave duration; PR, PR interval; WBCL, Wenckebach cycle length; AVNERP, atrioventricular node effective refractory period; msec, milliseconds; DMSO, dimethyl sulfoxide.