The effect of voltage-sensitive dye di-4-ANEPPS on heart rate variability in Langendorff-perfused isolated rabbit heart

Optical mapping of heart electrical activity in Langendorff-perfused isolated hearts is based on voltage-sensitive dyes, of which the most commonly used one is di-4-ANEPPS. Prolongation of action potential duration by di-4-ANEPPS was reported in isolated cells; however, this phenomenon was not observed in the whole heart model.