A, simulated human APs at control, following IK1 block (70% reduction), IKr block (50% reduction), and combined IK1+IKr block. B, corresponding data for dog IK1+IKr block. C, simulated human APs at control, following IKs block (50% reduction), IKr block (50% reduction), and combined IKs+IKr block. D, corresponding data for dog IKs+IKr block.