Conductive biomaterials have shown promising results for correcting pathological cardiac electrical signaling. However, their mechanisms of operation are still largely unclear. One reason behind disrupted cardiac intercellular communication, though, is lowered expression of the gap junction protein connexin43 (Cx43), which may be alleviated by conductive biomaterials. In this study, we aimed to test this hypothesis, using the self-doping conductive biomaterial poly-3-amino-4-methoxybenzoic acid-gelatin (PAMB-G). An in vitro model was established, in which cardiomyocytes (CMs) were treated with anisomycin, while the in vivo model involved anisomycin-treated mice subjected to electrical pacing to induce atrial fibrillation (AF). Cx43 expression, Ca