Pharmacological and Biological Risk Factors for Cardiac Arrhythmias

Sudden death is among the most common causes of death in developed countries. Sudden death from cardiac causes accounts for approximately 50% of all deaths from cardiovascular diseases and 20% of all deaths. The majority (80-85%) of sudden cardiac deaths are caused by acute ventricular arrhythmia. An important potential cause of ventricular arrhythmia is prolongation of ventricular repolarization, for instance, as is observed in the rare and genetically-determined ´congenital long QT syndrome´. Prolongation of ventricular repolarization may result in early after depolarizations (EAD), which in turn may induce re-entry and thereby provoke Torsade de Pointes and fatal ventricular arrhythmia.