Mark Boyett

Age-dependent Remodelling of the Sinoatrial Node and Right Atrium: Remodelling of Ion Channels and Extracellular Matrix Are Responsible for Sinoatrial Node Dysfunction Mark Boyett

Ageing is associated with a decline in the function of the sinoatrial node (SAN; there is decrease in intrinsic heart rate) and an increase in the incidence of sick sinus syndrome. We investigated the effect of ageing on ion channels in the SAN using young and old (3 and 24 months) rats. Although it is well known that there is an age-dependent remodelling of the extracellular matrix (ECM) in the heart, it is unclear whether there is a remodelling of ECM in the SAN. The aim of the present study was to investigate the effect of age on the expression of ion channels and components of the ECM and factors that control the ECM in the SAN and right atrium. In conclusion, although there is a remodelling of the ECM, the decline in SAN function during ageing is likely to be the result of a remodelling of ion channel expression and not due to fibrosis.