Cardiac deficiency of P21-activated kinase 1 promotes atrial arrhythmogenesis in mice following adrenergic challenge.

P21-activated kinase 1 (Pak1) signalling plays a vital and overall protective role in the heart. However, the phenotypes of deficiency in the cardiac atria have not been well explored. In this study, cardiac-conditional knock-out (cKO) mice were studied under baseline and adrenergic challenge conditions.

The age-dependence of atrial arrhythmogenicity in Scn5a+/- murine hearts reflects alterations in action potential propagation and recovery.

1. In the present study, we investigated the effect of age on atrial electrophysiological properties in Scn5a(+/-) hearts used to model corresponding increases in atrial arrhythmic tendency in human Brugada syndrome. 2.

Atrial arrhythmogenicity in aged Scn5a+/DeltaKPQ mice modeling long QT type 3 syndrome and its relationship to Na+ channel expression and cardiac conduction.

Recent studies have reported that human mutations in Nav1.5 predispose to early age onset atrial arrhythmia. The present experiments accordingly assess atrial arrhythmogenicity in aging Scn5a+/KPQ mice modeling long QT3 syndrome in relationship to cardiac Na(+) channel, Nav1.