Effects of stochastic channel gating and distribution on the cardiac action potential

► First study to assess effects of stochastic channel gating and distribution on cardiac conduction. ► APD variability is essentially caused by stochastic channel gating of IKs, persistent INa and ICa,L. ► Natural variability of gap junctions leads to heterogeneous propagations and blocks. ► High safety of conduction with low intercellular coupling must be considered with caution.