FIG. 2.

Changes of propagation velocity in engineered strands of cultured neonatal rat atrial myocytes and in human atrial tissue. Left: Genetic ablation of Cx43 in patterned cultures of neonatal mice atrial myocytes leads to a decrease in propagation velocity. Right: Genetic ablation of Cx40 in patterned cultures of neonatal mice atrial myocytes leads to an increase in propagation velocity. Reproduced with permission from P. Beauchamp et al., Circ. Res. 99, 11 (2006). Copyright 2006 Wolters Kluwer Health, Inc.¹⁶ Lower panel: Propagation velocity in excised human atrial tissue depends on the relative contribution of the Cx40 fluorescence signal to signals of total atrial connexins (sum of Cx43 and Cx40). Note that an increase in the relative contribution of Cx40 in human atria leads to a decrease in electrical propagation velocity, in line with the results from the mice cultures shown in the upper panel. Reproduced with permission from P. Kanagaratnam et al., J. Am. Coll. Cardiol. 39, 1 (2002). Copyright 2002 Elsevier.¹⁸