HRV in isolated rabbit hearts and in vivo rabbit hearts

Heart rate variability of seven isolated and five in-vivo rabbit hearts was compared. Heart rate of isolated hearts is lower and RR-intervals longer than those of in-vivo hearts. Characteristic peaks in characteristic frequency bands are different and powers of these bands are almost twice higher in in-vivo hearts than in isolated ones. LF/HF ratio is more than five-times higher in isolated heart than in in-vivo hearts.