Fig. 1.

Inhibiting class I HDACs reduces atrial remodeling and arrhythmias in Hopx transgenic mice. Trichrome-stained images of the left atrium from HopX^Tg (A), wild-type (B), HopX^Tg mouse treated with CI-994 (C), and wild-type mouse treated with CI-994 (D). (E) Plot showing percentage of atrial fibrosis from at least 26 fields/atrium and four different atria/group. (F) An episode of induced atrial arrhythmia in a Hopx^Tg mouse. (G) Number of atrial tachyarrhymia (AT) episodes induced in each group of eight mice. (H) Average duration of induced AT episodes in each group. (I) Percentage of mice with inducible AT in each group of eight mice. *P < 0.05 versus Hopx^Tg; ^†P < 0.05 versus WT (wild type); ^‡P < 0.05 versus Hopx–CI-994; ^§P < 0.05 versus WT–CI-994.