Risk stratifications in inherited arrhythmia syndromes: who should be treated?

Recently, it has been reported that genotype-phenotype correlations determine genotype-specific characteristics, prognosis and therapies in various inherited arrhythmias syndromes, including long QT syndrome (LQTS) and short QT syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), Brugada syndrome, early repolarization syndrome (ERS), progressive cardiac conduction disease, laminopathy and arrhythmogenic right ventricular cardiomyopathy. Genotypes in LQTS determine the T wave morphologies, trigger for torsades de pointes and specific therapies. Regardless of the genotypes, clinical observations, such as significant QT prolongation in LQTS, spontaneous type 1 ECG in Brugada syndrome and definite diagnosis of CPVT are also important to stratify risk of lethal arrhythmic events. The indications of medication, implantable electrical devices and radiofrequency catheter ablation are evident in patients who already have arrhythmic symptoms or lethal arrhythmic events.
However, risk stratification methods have been debated in patients who only have mild symptoms or do not have any symptoms in various inherited arrhythmic syndromes. For example, a patient with early repolarization pattern but not having any symptoms or familial sudden cardiac death could not be diagnosed as ERS until his/her sudden cardiac death. Not all asymptomatic patients with spontaneous Brugada type 1 ECG should receive an implantable cardioverter defibrillator.
We would like to discuss the recent development of risk stratification methods using gene analysis, clinical characteristics, and examinations to determine the indications of medical therapy, implantable electrical devices, and radiofrequency catheter ablation in inherited arrhythmic syndromes.