TMEM43 and familial dilated cardiomyopathy: Indeed, intensive exercise and competitive sports may precipitate fatal arrhythmias in DCM, particularly in patients carrying mutations associated with intrinsically high arrhythmic risk—such as LMNA, FLNC, transmembrane protein 43 (TMEM43), and PLN [2] or in patients with severely impaired left ventricular function (EF < 40%), complex arrhythmias, or with significant structural alterations such as ventricular dilation and fibrosis [40].