The link between abnormal calcium handling and electrical instability in acquired long QT syndrome - Does calcium precipitate arrhythmic storms?

Divergent Ca2+ dynamics among different myocardial regions leads to temporal instability of AP duration and - on the patient level - in T wave lability. Although T-wave alternans has been linked to cardiac arrhythmias, non-alternans lability is observed in pre-clinical models of the long QT syndrome (LQTS) and CPVT, and in LQTS patients. Analysis of T wave lability may provide a real-time window on the abnormal Ca2+ dynamics causing specific arrhythmias such as Torsade de Pointes (TdP).