Why the study?
Intracellular calcium cycling plays a significant part in pacemaking, but its role in sinoatrial node phase-locking is unknown.
This computational study demonstrates that intracellular calcium cycling significantly impacts sinoatrial node phase-locking, providing insights into sub-cellular dynamics of heart rate modulation.
Incorporating ICC into SAN models refines phase-locking simulations; leaves open clinical translation for rate modulation or arrhythmias.
The phase-locking behavior of the sinoatrial node (SAN) may be related to heart rate modulation, which can be physically studied from the perspective of nonlinear dynamics. However, previous studies have treated the myocyte as a pure membrane oscillator without considering its intracellular dynamics. Intracellular calcium cycling (ICC) plays a significant part in pacemaking, but its role in phase-locking is unknown. In the present work, we employ an updated SAN myocyte model incorporating ICC to reinvestigate this problem. The influences of ICC-relevant parameters are determined and explained. Some features which did not appear in older models arise in the presence of ICC. Moreover, we employ our previously proposed theoretical formulas to calculate the phase-locking range. The present work sheds light on the impact of sub-cellular-scale dynamics on the classical SAN phase-locking problem and provides some suggestions for regulating the pacemaking activity.
No takes yet. Share an insight, caveat, or question.
Fang et al. (2020) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: