Endotoxin injection in rats prolonged memory in the time-series of atrial electrical activity of isolated hearts compared to saline controls, indicating reduced cardiac rhythm controllability.
Does endotoxin alter the memory length and controllability of cardiac rhythm in isolated rat hearts?
Endotoxaemia prolongs memory in the time-series of atrial electrical activity in isolated rat hearts, suggesting that reduced heart rate variability in sepsis may be partly due to intrinsic changes in cardiac pacemaker cells rather than solely altered autonomic input.
Decreased heart rate variability (HRV) has both diagnostic and prognostic value in patients with sepsis. However, it is not known whether reduced HRV in sepsis reflects an altered input from the autonomic nervous system or a remodeling of the cardiac pacemaker cells by inflammatory mediators. The present study aimed to investigate the effect of endotoxin on the heart rate dynamics of a denervated isolated heart in rats. Saline or endotoxin was injected into rats and their hearts were isolated and perfused. Atrial electrical activity was recorded and memory length in the time-series was assessed using inverse statistical analysis. Memory was defined as a statistical feature that lasts for a period of time and distinguishes the time-series from a random process. Endotoxaemic hearts exhibited a prolonged memory compared to the controls with respect to observing rare events. This indicates that a sudden decelerating event could potentially affect the cardiac rhythm of an endotoxaemic heart for a longer time than the controls. The prolongation of memory is indirectly linked to a reduced controllability in a complex system; therefore our data may provide evidence for a reduced controllability in cardiac rhythm following endotoxaemia.
Mazloom et al. (Thu,) conducted a other in Endotoxaemia. Endotoxin vs. Saline was evaluated on Memory length in the time-series of atrial electrical activity. Endotoxin injection in rats prolonged memory in the time-series of atrial electrical activity of isolated hearts compared to saline controls, indicating reduced cardiac rhythm controllability.