In silico assessment of genetic variation in KCNA5 reveals multiple mechanisms of human atrial arrhythmogenesis
Fig 3
KCNA5 loss-of-function mutations induced EADs following the beta-adrenergic stimulation.
A(i) In the presence of ISO, EADs were produced by Y155C and P488S, but not in WT or D469E in RA; (ii) EADs were induced by D469E in CT but not in PM. B Under uniform application of ISO in a 1D strand model with D469E, EADs in the CT but not PM induced conduction block at an S2 of 689 ms (i) and success at 690 ms (ii). C 1D conduction patterns under mutations and application of ISO in various configurations. On the left of each panel is a breakdown of the regions in the 1D model and an illustration of the anatomical conduction pathway to which they correspond; on the right is the regions of tissue to which ISO was applied. (i) Regular conduction pattern under WT and uniform ISO application; (ii) Under uniform application of ISO, D469E led to alternating bidirectional conduction block due to EADs in the CT; (iii) D469E and non-uniform ISO can lead to unidirectional conduction block, resulting from EADs in the CT regions with ISO; (iv) Unidirectional block can also be attained through a different pathway to the PM, in which the CT on one side of the SAN is of insufficient extent to develop significant EADs. In the simulations effects of beta-adrenergic stimulation was modelled by simulated application of ISO (1 μM).