Key result
Mechanical stimulation during atrial and ventricular filling in the working heart mode did not significantly alter any of the 27 heart rate variability parameters compared to the Langendorff mode.
Why the study?
Does mechanical stimulation during cardiac filling alter heart rate variability in isolated rabbit hearts?
Does mechanical stimulation during cardiac filling alter heart rate variability in isolated rabbit hearts?
p-value: p=>0.05
Mechanical stimulation during atrial and ventricular filling does not significantly alter heart rate variability in isolated rabbit hearts.
No effect on HRV in isolated rabbit hearts; leaves open relevance to intact physiology or humans.
Presence of heart rate variability (HRV) in isolated hearts is widely recognized; however, its mechanisms are still subject of debate. One of the possible explanations is that mechanoreceptors in cardiac tissue affect HRV. In order to evaluate possible dependence of HRV on heart mechanoreceptors activated during left ventricle filling, the HRV parameters in two perfusion modes of isolated heart were compared: Langendorff and working heart mode. Ten New Zealand rabbit isolated hearts were perfused (Krebs-Henseleit, 37C, 85 mmHg) in Langendorff mode and consecutively in working heart mode (8 cmH2O preload, 60 cmH2O afterload). A total of 27 HRV parameters in time, frequency, geometric, and non-linear domain were computed. No significant differences (Wilcoxon signed rank test, p < 0.05) were found among all studied HRV parameters between Langendorff and working heart mode. The study confirms the presence of heart rate fluctuation in isolated hearts in both Langendorff and working heart modes. Results of statistical analysis show that heart rate fluctuation is irrespective to mechanical stimulation of heart during atrium and ventricle filling.
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Janoušek et al. (2016) studied Isolated heart model (n=10). Working heart mode vs. Langendorff mode was evaluated on Heart rate variability parameters (27 parameters in time, frequency, geometric, and non-linear domains) (p=>0.05). Mechanical stimulation during atrial and ventricular filling in the working heart mode did not significantly alter any of the 27 heart rate variability parameters compared to the Langendorff mode.
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