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. In order to search for other adverse phenomena of di-4-ANEPPS use, its effect on heart rate variability (HRV) was investigated during staining and washout periods in jive New Zealand White rabbit isolated hearts. Time domain, frequency domain and non-linear HRV parameters (21 in total) revealed that there are no significant changes between control, staining and washout periods. Voltage-sensitive dye di-4-ANEPPS does not affect HRV when applied into the isolated heart coronary system. It can be concluded that di-4-ANEPPS may be safely used in studies combining optical mapping and HRV analysis.