Healthcare providers in developing countries manage their medical data in Electronic Health Records (EHRs) system in silos with different structures and data formats that causes the problem of data sharing, interoperability, and data security. This paper aims to propose a concept of blockchain-based EHRs that is relevant to the case of developing countries, especially in Indonesia. The research method used is a narrative review of several literature related to the design of blockchain-based EHRs using Smart Contract from 2016-2020. The design proposed permissioned blockchain with several health care stakeholders as nodes in the network. Different with most previous research that using proof-based, we propose to use vote-based consensus protocol to execute transaction faster. Based on number of national health insurance policy holders, outpatient, and inpatient visits per year, the storage capacity required to keep the transaction is estimated around 2,7 TB per year with 77 transactions per seconds. This design is intended to be a contribution for EHRs platform architecture in the future.