Correction to: Nature Chemical Biology https://doi.org/10.1038/s41589-018-0090-8, published online 16 July 2018

In the version of this Brief Communication originally published, the commercial human cardiomyocytes used in the study (Cor4U, NCardia AG) were believed to be derived from human induced pluripotent stem cells during the studies. After studies had been completed, short tandem repeat testing by NCardia determined that Cor4U cardiomyocytes were derived from the human embryonic stem cell line RUES2, which have been shown to produce functional cardiomyocytes (Chong, J. J. H. et al. Human embryonic-stem-cell-derived cardiomyocytes regenerate non-human primate hearts, Nature 510, 273–277 (2014)). The correction has been reflected in a change in the first sentence of the Methods section ‘Recording of field potentials (FPs) with a multi-electrode array (MEA) from cardiomyocytes with localized FHU-779 switching’. The different provenience of these well characterized cardiomyocytes likely does not change the findings nor the interpretation of the data.