OBJECTIVE To explore the effects of different concentrations of aconitine on the ventricular electrophysiology of the rat heart when applied to the heart. METHODS By optical mapping technology, the effects of different concentrations of aconitine on ventricular action potential and calcium signal in rats before and 15 min after administration were observed by in vitro administration of aconitine 0.3, 1, 3 ng·mL−1. RESULTS Compared with the blank group, aconitine could be concentration-dependent to delay the conduction of action potentials under both spontaneous and 6 Hz stimulation rhythms, and there was a significant difference at a concentration of 3 ng·mL−1(P<0.05 or P<0.01). Compared with blank group, when the concentration of aconitine was 1 and 3 ng·mL−1, the action potential duration(APD) of the ventricle was significantly prolonged(P<0.01). Aconitine could also increase the dispersion of action potential conduction(P<0.05) and reduce the ratio of effective refractory period(ERP) to APD90(P<0.01). In addition, aconitine could also be concentration-dependent delay of calcium signal conduction, reduce the speed of calcium conduction(P<0.05 or P<0.01), increase the dispersion of calcium conduction and calcium transient duration(P<0.05 or P<0.01), and reduce the amplitude of calcium signal(P<0.01). CONCLUSION Using the optical labeling technique, it can be visualized that aconitine induces arrhythmia by concentration-dependent delay of ventricular action potential and calcium signaling in rats.To explore the effects of different concentrations of aconitine on the ventricular electrophysiology of the rat heart when applied to the heart. METHODS By optical mapping technology, the effects of different concentrations of aconitine on ventricular action potential and calcium signal in rats before and 15 min after administration were observed by in vitro administration of aconitine 0.3, 1, 3 ng·mL−1. RESULTS Compared with the blank group, aconitine could be concentration-dependent to delay the conduction of action potentials under both spontaneous and 6 Hz stimulation rhythms, and there was a significant difference at a concentration of 3 ng·mL−1(P<0.05 or P<0.01). Compared with blank group, when the concentration of aconitine was 1 and 3 ng·mL−1, the action potential duration(APD) of the ventricle was significantly prolonged(P<0.01). Aconitine could also increase the dispersion of action potential conduction(P<0.05) and reduce the ratio of effective refractory period(ERP) to APD90(P<0.01). In addition, aconitine could also be concentration-dependent delay of calcium signal conduction, reduce the speed of calcium conduction(P<0.05 or P<0.01), increase the dispersion of calcium conduction and calcium transient duration(P<0.05 or P<0.01), and reduce the amplitude of calcium signal(P<0.01). CONCLUSION Using the optical labeling technique, it can be visualized that aconitine induces arrhythmia by concentration-dependent delay of ventricular action potential and calcium signaling in rats.