The escalating demand for functional myocardial tissue following ischemic injury has catalyzed the development of biomimetic and electroactive 3D cardiac patches. In this study, a hybrid bioink—comprising decellularized bovine pericardium (dECM), silk fibroin (SF), alginate, and gold nanoparticles (AuNPs)—was developed and systematically optimized for extrusion-based 3D bioprinting to fabricate structurally robust and electrophysiologically active constructs. The bioink was engineered to recapitulate the biochemical complexity of the native extracellular matrix (ECM) while providing essential mechanical reinforcement and conductive properties to facilitate synchronized cardiac tissue regeneration. In the subsequent phase, the biodegradability, biocompatibility, and regenerative efficacy of the 3D-bioprinted patches were evaluated within a dynamic 3D perfusion culture system. Under physiologically relevant flow conditions, the constructs were assessed for their capacity to support cellular adhesion, proliferation, and hierarchical tissue organization. The functional role of the patches in cardiac reconstruction was evaluated through a multi-parametric approach, including biochemical assays, histological assessments, and immunofluorescence analyses of cardiac-specific biomarkers and ECM remodelling. Furthermore, the safety profile of the construct was rigorously established through ISO-standardized cell viability assays, in vitro irritation/corrosion tests, and in vitro skin sensitization assessments. The degradation kinetics and structural integrity were systematically monitored to ensure controlled biodegradability. Our findings demonstrate that this hybrid 3D cardiac patch offers a biomimetic microenvironment with favorable mechanical–electroactive properties and high biosafety, supporting cardiac maturation within a perfusion environment. This study provides a comprehensive framework for the development of multifunctional cardiac constructs and underscores their translational potential in regenerative cardiovascular medicine.