Evaluation of drug induced frequency dependent QT-prolongation using a flexible computer-based programmable stimulator

The proarrhythmic potential of therapeutic drugs can be evaluated by in-vivo electrophysiological testing using stimulated bradycardias. Since conventional stimulators are limited in the number of bradycardic beats, they cannot be used to evaluate the dynamic change of QT-intervals from the onset of bradycardia until a steady state has been achieved. Therefore, we designed and implemented a computer-based programmable stimulator, that enables complex stimulation protocols. This application was then rested in an experimental guinea-pig model to evaluate the characteristics of droperidol-induced QT-interval prolongation.