KCNA3 and atrioventricular block: Myocardial hypertrophy in pathological settings in humans [16]–[18] and in animal models, especially in the chronic atrioventricular (AV) block dog model [19] and heart failure models [20]–[22], has been shown to cause electrophysiological remodeling where the expression of different ion channels, including potassium channels critical for repolarization, and exchangers is altered.