Metformin treatment reduced mitochondrial content and respiration in mutant iPSC-CMs and significantly attenuated the arrhythmias.<h4>Discussion</h4>These findings increase our understanding of <i>PRKAG2</i>-associated cardiomyopathy, and propose metformin as a novel modality for managing the metabolic and electrophysiological aberrations of this genetic disorder. Here, PRKAG2 is linked to Arrhythmia.