A-B, Delayed afterdepolarizations (DADs) and spontaneous action potentials (sAPs) were increased by high-glucose treatment in control (n=21 cells from 13 animals), but it was prevented in CaMKIIδ-S280A (n=23 cells from 12 animals). Nested t-test. C-D, Glucose-induced spontaneous diastolic activities were prevented by EGTA, OSMI-1 and in CaMKIIδ cKO and S280A. Additional Ang-II treatment further enhanced the arrhythmogenic activities, which were prevented in NOX2−/− and CaMKIIδ-cKO and MMVV (n=total number of cells/animals is reported in the figure). Nested one-way ANOVA, followed by Dunnett’s multiple comparisons test was used to compare 3 groups. Nested t-test was used to compare two groups (EGTA, OSMI, Thm-G).