TRPM4 and cardiac rhythm disease: Previous studies reported that the TRPM4 current contributes to the mammalian atrial action potential (Simard et al., 2013) as well as to the notch and early repolarisation phases of the action potential in Purkinje cells (Hof et al., 2016), providing a potential link to cardiac arrhythmias (Guinamard et al., 2015; Hedon et al., 2021; Wang et al., 2018).