Figure 6.

Structural remodelling (fibrosis) near the crista terminalis altered reentry dynamics and resulted in the rotor being displaced. (A) The rotor displaced from the fibre discontinuity and attached to the scar, with decreasing rotational frequency as in Figure 5. (B) The increased spatially excitable gap permits a wave (driven by more rapid activity originating in the left atrium) to impinge on the rotor core. Eventually the rotor is displaced by the invading wavefront suggesting that regions of fibrosis may enable the localized source to convert to macro-reentry with an excitable gap. Orientation: posterior right atrial view; top, superior vena cava; right, lateral right atrium.