In clinical studies, mirabegron has been shown to cause a small increase in heart rate with a slight increase in QTc interval, as indicated on electrocardiograms. The mechanisms of these effects are unclear. The findings of a recent study might provide some new clues, although, the relevance of these new observations to the treatment of patients with overactive bladder syndrome have yet to be established.
Refers to Mo, W. et al. The β3-adrenoceptor agonist mirabegron increases human atrial force through β1-adrenoceptors: an indirect mechanism? Br. J. Pharmacol.http://dx.doi.org/10.1111/bph.13897 (2017)