Objective: To verify, based on the literature, what the main cardiac complications are in patients with COVID-19, during treatment in a hospital unit. Materials and methods: An integrative review, carried out by searching for studies in eight national and international databases. The final sample consisted of 16 studies published between January and May 2020, which were subjected to structural evaluation by the following instruments: Case Report Guidelines, for case reports; and Strengthening the Reporting of Observational Studies in Epidemiology, for observational studies. Results: The main cardiac complications were predominantly obstructive events, herein understood as acute myocardial infarction, followed by severe arrhythmic conditions and heart failure, all due to the hyperinflammation condition resulting from viral infection. Conclusions: The knowledge about cardiac complications during COVID-19 treatment has become important, since it can collaborate for the adoption of more effective treatment protocols and guide the assistance offered by health professionals, in order to identify such complications and intervene early.