Developing electroactive elastic scaffolds with micropatterned surface would be beneficial for cardiac therapy due to their capability of mimicking the anisotropy, electrical propagation, and mechanical property of native myocardium. In this study, we presented a series of micropatterned, electroactive, and degradable polymeric films with suitable mechanical property for cardiac tissue engineering. Specifically, we developed a kind of degradable bioelastomers based on poly(glycerol sebacate) (PGS) copolymerized with aniline trimer (AT) with micropatterned surface structure, electroactive property and modulus within the same order of magnitude of native heart tissue. All of these films with different AT contents (5 wt%, 10 wt%, and 15 wt%) showed a good cell viability and promoted the proliferation of rat cardiomyoblast-derived H9c2 cells. Especially, the electroactive film with the 10 wt% AT content was able to significantly enhance the cell-cell interaction, maturation and synchronous calcium transients of neonatal rat primary cardiomyocytes (CMs). Moreover, this electroactive elastomer was fabricated into micropatterned films, which showed the ability to guide CMs' alignment and elongation along with the aligned groove/ridge micropatterned surface and promote the amount of available intercellular Ca2+. These data suggest that this highly tunable micropatterned, electroactive, and biodegradable elastomer demonstrated the promising potential as an excellent scaffolding biomaterial for cardiac tissue repair and regeneration.