HDAC9 and cardiac hypertrophy: Myocardial angiotensin II levels were similar between groups, suggesting that HDAC-inhibition reverses atrial fibrosis, Cx40 remodeling and atrial arrhythmia vulnerability, rendering the atrium almost refractory to arrhythmia inducibility, independent of angiotensin II in cardiac hypertrophy (Liu et al., 2008).