In the last decade there have been considerable advances in the understanding of 
the pathophysiology of malignant ventricular tachyarrhythmias (VA) and Sudden 
Cardiac Death (SCD). Over 80% of SCD occurs in patients with organic heart 
disease. However, approximately 10-15% of SCD occurs in the presence of 
structurally normal heart and the majority of those patients are young. In this 
group of patients, changes in genes encoding cardiac ion channels produce 
modification of the function of the channel resulting in an electrophysiological 
substrate of VA and SCD. Collectively these disorders are referred to as Cardiac 
Ion Channelopathies. The 4 major syndromes in this group are: The Long QT 
Syndrome (LQTS), the Brugada Syndrome (BrS), the Short QT Syndrome (SQTS), and 
the Catecholaminergic Polymorphic VT (CPVT). Each of these syndromes includes 
multiple subtypes with different and sometimes complex genetic abnormalities of 
cardiac ion channels. Many are associated with other somatic and neurological 
abnormalities besides the risk of VA and SCD. The current management of cardiac 
ion channelopathy could be summarized as follows: 1) in symptomatic patients, 
the implantable cardioverter defibrillator (ICD) is the only viable option; 2) 
in asymptomatic patients, risk stratification is necessary followed by the ICD, 
pharmacotherapy, or a combination of both. A genotype-specific approach to 
pharmacotherapy requires a thorough understanding of the molecular-cellular 
basis of arrhythmogenesis in cardiac ion channelopathies as well as the specific 
drug profile.