Overexpression of calcineurin in mouse causes sudden cardiac death associated with decreased density of K+ channels.

Background: Overexpression of calcineurin in transgenic (TG) mice results in cardiac hypertrophy and unexpected deaths.

Methods And Results: None of the TG survived beyond 24 weeks (n=38) whereas all of the wildtype (WT, n=47) survived. Prolongation of repolarization preceded the development of sustained pleomorphic ventricular tachycardia and high degree atrioventricular block, which occurred during spontaneous sudden deaths.