Figure 6: GMCT Mitigates AF-Induced Shortening of APD

(A) Representative action potentials from optical mapping of saline-treated (dotted line) and GMCT-treated hearts (solid line) at 2.5 Hz pacing. (B) Atrial optical mapping data shows cycle length (CL) dependence of action potential duration at 90% repolarization (APD90) from saline-treated (N = 6) and GMCT-treated hearts (N = 6). ##p < 0.01, ###p < 0.001 versus saline-treated group. (C) Current-voltage relationships for inward rectifier potassium current (IK1). For right atrium: N/n = 3/8 (sham), N/n = 4/12 (saline), and N/n = 3/9 (GMCT), for LA: N/n = 3/9 (sham), N/n = 3/13 (saline), and N/n = 3/13 (GMCT). *p < 0.05 versus sham, #p < 0.05 versus GMCT. Repeated measures 2-way analysis of variance with Bonferroni multiple comparisons test. (D) Representative Kir2.3 Western blots (left: sham, middle: saline, right: GMCT) and quantification of protein expression (N = 4, all groups; *p < 0.05). RA = right atrium; other abbreviations as in Figure 4.