Global Cx43 deletion leads to right ventricular outflow tract obstruction and increased arrhythmia risk [271, 272], while cardiomyocyte-specific deletion of Cx43 leads to myocardial hypertrophy, prolongation of the QRS interval, ventricular tachyarrhythmias, and juvenile death [270, 273]. Here, GJA1 is linked to cardiac arrhythmia.