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In order to bridge the gap of information between the in silico model and human subjects, we evaluated torsadogenic risk of cisapride, dl -sotalol, bepridil and verapamil selected from 12 training compounds in the comprehensive in vitro proarrhythmia assay using the chronic atrioventricular block monkeys. Cisapride (0, 1, and 5 mg/kg, n  = 5 for each dose), dl -sotalol (0, 1, 3, and 10 mg/kg, n  = 5 for each dose), bepridil (0, 10, and 100 mg/kg, n  = 4 for each dose), verapamil (0, 1.5, 15, and 75 mg/kg, n  = 4 for each dose) were orally administered to the monkeys in conscious state. Five mg/kg of cisapride, 1, 3, and 10 mg/kg of dl -sotalol and 100 mg/kg of bepridil prolonged ΔΔQTcF, which was not observed by verapamil. Torsade de pointes was induced by 5 mg/kg of cisapride in 2 out of 5 animals, by 10 mg/kg of dl -sotalol in 5 out of 5 and by 100 mg/kg of bepridil in 2 out of 4, which was not induced by verapamil. These torsadogenic doses were normalized by their maximum clinical daily ones to estimate torsadogenic risk. The order of risk was dl -sotalol >bepridil ≥cisapride >verapamil in our study. Since the order was bepridil ≥ dl -sotalol >cisapride >verapamil in comprehensive in vitro proarrhythmia assay (CiPA) in silico mechanistic model validation, sympathetic regulation on the heart may play a pivotal role in the onset of torsade de pointes in vivo. [ABSTRACT FROM AUTHOR]