Role of atrial endothelial cells in the development of atrial fibrosis and fibrillation in response to pressure overload.

•The left atrial (LA) endothelium was morphologically changed shortly after pressure overload.•Pressure overload increased macrophage infiltration into LA tissue through endothelial gaps.•Pressure overload enhanced the expression of adhesion molecules in the LA endothelium.•Pressure overload facilitated LA fibrosis and increased the inducibility of atrial fibrillation.