Figure 2: Assessment of Electrical Conduction in the SAN in Wild-Type and NPR-C

(A) Atrial preparation used in optical mapping. Dashed line indicates the location of the crista terminalis. The SAN is located in the intercaval region of the right atrial posterior wall adjacent to the crista terminals. The yellow box illustrates the area that was typically mapped. (B) Representative activation maps in atrial preparations from wild-type and NPR-C−/− mice treated with saline or Ang II. Bars = 1 mm. (C) Summary data for cycle length in wild-type and NPR-C−/− mice treated with saline or Ang II. *p < 0.001 versus saline; +p = 0.048 versus wild type by 2-way analysis of variance (ANOVA) with Tukey post hoc test. (D) Summary data for SAN CV in wild-type and NPR-C−/− mice treated with saline or Ang II. *p < 0.001 versus saline; +p < 0.001 versus wild type by 2-way ANOVA with Tukey post hoc test; n = 16 hearts for wild type/saline, 24 hearts for wild type/Ang II, 13 hearts for NPR-C−/−/saline, and 12 hearts for NPR-C−/−/Ang II. (E) Representative spontaneous SAN optical APs in wild-type and NPR-C−/− mice treated with saline or Ang II. Dashed lines run through the maximum diastolic potential. AP = action potential; CV = conduction velocity; IAS = interatrial septum; IVC = opening of inferior vena cava; SVC = opening of superior vena cava; other abbreviations as in Figure 1.