HCN and SCN5A channel mutations: Implications for impaired atrioventricular nodal conduction in a heterogeneous computer model of the whole mouse heart

The atrioventricular (AV) node is a specialised region of the cardiac conduction system, allowing electrical excitation to propagate from the atria to the ventricles. AV block occurs when the AV node prevents electrical excitation waves reaching the ventricles, ultimately leading to a decrease in cardiac output. HCN4 and SCN5A defects have been associated with AV block, but the mechanisms underlying impaired AV node conduction remain incompletely understood.