VCL and polymorphic ventricular tachycardia: In mice with cardiac-myocyte-specific excision of VCL gene (cVCL-KO), there were two stages of phenotype: one stage with ectopy, complete atrioventricular block, and nonsustained polymorphic ventricular tachycardia, and sudden death within the first 3 months of life, despite preserved systolic cardiac function; the second stage in mice who survived the first stage developed DCM and died of heart failure by around 6 months of age20.