Brundel et al. also demonstrated that phosphorylated HSPB1 (HSP27) could prevent the atrial tachycardia–induced Ca2+ handling, L-type Ca2+ channel current reduction and associated action potential duration (APD) shortening in tachypaced HL-1 cardiomyocytes and isolated canine atrial cardiomyocytes [41]. Here, HSPB1 is linked to atrial tachycardia.