Computer simulations suggest that intercellular coupling is more robust than membrane excitability with regard to changes in and safety of conduction. Clinical studies indicate that SCN5A (excitability) and/or Connexin43 (Cx43, intercellular coupling) expression in heart disease is reduced by approximately 50%. In this retrospective study we assessed the effect of reduced membrane excitability or intercellular coupling on conduction in mouse models of reduced excitability or intercellular coupling.
Methods and Results
Epicardial activation mapping of LV and RV was performed on Langendorff-perfused mouse hearts having the following: 1)
Reducing excitability but not intercellular coupling by 50% affects CV restitution and activation delay in RV, indicating a higher safety factor for intercellular coupling than excitability in RV.
Publisher: Public Library of Science
Date Published: 1-June-2011
Author(s): Stein M., van Veen T., Hauer R., de Bakker J., van Rijen H.