Korean Circulation Journal is the official journal of the Korean Society of Cardiology, the Korean Pediatric Heart Society, the Korean Society of Interventional Cardiology, and the Korean Society of Heart Failure. Abbreviated title is 'Korean Circ J'. Korean Circulation Journal, established in 1971, is a professional, peer-reviewed journal covering all aspects of cardiovascular medicine, including original articles of basic research and clinical findings, review articles, editorials, images in cardiovascular medicine, and letters to the editor. Korean Circulation Journal is published monthly in English and publishes scientific and state-of-the-art clinical articles aimed at improving human health in general and contributing to the treatment and prevention of cardiovascular diseases in particular. The journal is published on the official website (https://e-kcj.org). It is indexed in PubMed, PubMed Central, Science Citation Index Expanded (SCIE, Web of Science), Scopus, EMBASE, Chemical Abstracts Service (CAS), Google Scholar, KoreaMed, KoreaMed Synapse and KoMCI, and easily available to wide international researchers