Soft implantable bioelectronics create engineered interfaces that mechanically match cardiac tissues, enabling stable, low-impedance coupling with the beating heart. We design device architectures and wireless system modules optimized for chronic cardiovascular use, ensuring reliable operation under continuous dynamic deformation. In detail, we developed high-efficiency wireless communication and power-transfer technologies suitable for deep-tissue implantation (^(M)Nature Reviews Bioengineering, 2024; ^(ⅰ)Science Advances, 2022), enabling continuous monitoring of electrophysiological and hemodynamic signals essential for detecting arrhythmia, ischemia, and early heart-failure progression. We also engineered minimally invasive sensors, soft stimulators, and compact RF-ablation tools to reduce surgical burden and increase procedural precision in interventional cardiology (^(ⅱ)Nature Communications, 2015; ^(ⅲ)Advanced Materials, 2024). In addition, our conformal multichannel epicardial electrode arrays provide high-resolution conduction mapping and targeted modulation of arrhythmogenic regions (^(ⅳ)Science Advances, 2023). Cell-sheet–based approaches further offer complementary potential for cardiac tissue regeneration (^(v)Nature Communications, 2019). Together, these technologies establish a foundation for next-generation, closed-loop cardiac bioelectronic systems for personalized cardiovascular diagnostics and therapy.