Attenuating loss of cardiac conduction during no-flow ischemia through changes in perfusate sodium and calcium
Gregory S. Hoeker, Carissa C. James, Allison N. Tegge, Robert G. Gourdie, James W. Smyth, Steven Poelzing
Abstract
Conduction slowing during acute ischemia creates an arrhythmogenic substrate. We have shown that extracellular ionic concentrations can alter conduction by modulating ephaptic coupling. Here, we demonstrate increased extracellular sodium and calcium significantly attenuate conduction slowing during no-flow ischemia. This effect was associated with selective widening of the perinexus, an intercalated disc nanodomain and putative cardiac ephapse. These findings suggest that acute changes in ephaptic coupling may serve as an adaptive response to ischemic stress.
Topics & Concepts
IschemiaPerfusionThermal conductionInternal medicineCalciumNerve conduction velocityCardiologyChemistryOptical mappingBiophysicsMedicineAnesthesiaMaterials scienceBiologyComposite materialCardiac electrophysiology and arrhythmiasIon channel regulation and functionAdvanced MRI Techniques and Applications