Fig. 3.
Increased susceptibility to sustained reentry in ankyrin-B+/− atrial tissue. Simulated duration of reentry as a function of tissue area in heterogeneous grids comprised of WT and ankyrin-B+/− cells [based on CRN model (7)] interspersed with poorly coupled electrically inexcitable cells (fibroblasts) at levels corresponding to experimental measurements (3 and 9% for WT and ankyrin-B+/−, respectively) (A); homogeneous (0% fibrosis) 2-dimensional grids comprised of WT (black), ankyrin-B+/− (red), Cav1.3-deficient (gray), or NCX/NKA-deficient (green) cells (B); heterogeneous grids comprised of ankyrin-B+/− cells interspersed with varying degrees of fibroblasts: 0 (black), 3 (gray), and 9% (red) (C); heterogeneous grids comprised of ankyrin-B+/− cells with 9% fibrosis distributed in a diffuse (red) or clustered (gray) pattern (D). E–H: simulated activation maps during 1 cycle of reentry in heterogeneous WT and ankyrin-B+/− grids (E and F) and homogeneous grids with no fibrosis (G and H). Isochrone lines are labeled with corresponding activation time (in ms). I and J: simulated APs at a point remote from the reentry core during 1 s of reentrant activation in heterogeneous (I) and homogeneous (J) WT and ankyrin-B+/− grids. K: average CL during 2 s of sustained reentry in WT and ankyrin-B+/− grids with varying levels of fibrosis (0, 3, and 9%). Longitudinal (L) and transverse conduction velocity (CV; M) of a plane wave propagating in WT and ankyrin-B+/− grids with varying levels of fibrosis.