['To investigate how affects electrical-conduction function following myocardial infarction (MI) in rats.', 'Thirty SD rats of either sex (220-250 g) were anesthetized using chlorine hydrate and were randomly divided into three groups: control group, MI group and transplantation group. The field potential (FP) morphology and activation-conduction duration were recorded with microeletrode array techniques.', 'The MEA recorded clear FP morphology. Activation-conduction duration was (6.5 ± 2.12) ms in the control group, (17.5 ± 3.54) ms in the MI group, and (9.13 ± 1.31) ms in the transplantation group.'] Does engineered heart tissue transplantation alter electrical-conduction function in rats with myocardial infarction?