Fig 6. The human SAN model without the insulation boundary between the SAN and the lateral RA (right) had difficulty in replicating dramatic shift in the leading pacemaker and earliest atrial activation sites.

A, Activation patterns and earliest atrial activation sites in the computer model of the human SAN complex, and in the computer models of the SAN without the crista terminalis (CT) side insulation boundary at different conduction diffusivities. B and C, Activation maps in the computer models of the SAN without the insulation boundary at 100% conduction diffusivity and at 50% conduction diffusivity at the baseline and with increasing the concentrations of Ado up to 10% (B) and 50% (C) which led to SAN arrests, respectively. See other abbreviations in Fig 2.