Class III 7. ICD as a standalone therapy is not indicated in an asymptomatic patient with a diagnosis of CPVT. 8. Programmed electrical stimulation is not indicated in CPVT patients.

The entity of adrenergic-dependent, potentially lethal tachyarrhythmia with no structural heart disease deserves to be individualized. It may form a variant of the congenital long QT syndrome in which the ECG marker is lacking; this primary ventricular arrhythmia must be looked for in a pediatric patient with stress- or emotion-induced syncope because only beta-blocking therapy can prevent sudden death and therefore must be given for the patient's lifetime.

Background-The pathophysiological background of catecholaminergic polymorphic ventricular tachycardia is well understood, but the clinical features of this stress-induced arrhythmic disorder, especially the incidence and risk factors of arrhythmic events, have not been fully ascertained. Methods and Results-The outcome in 101 catecholaminergic polymorphic ventricular tachycardia patients, including 50 probands, was analyzed. During a mean follow-up of 7.9 years, cardiac events defined as syncope, aborted cardiac arrest, including appropriate discharges from implantable defibrillators, or sudden cardiac death occurred in 27 patients, including 2 mutation carriers with normal exercise tests. The estimated 8-year event rate was 32% in the total population and 27% and 58% in the patients with and without ␤-blockers, respectively.

Brugada syndrome is a rare cardiac arrhythmia disorder, causally related to SCN5A mutations in around 20% of cases1–3. Through a genome-wide association study of 312 individuals with Brugada syndrome and 1,115 controls, we detected 2 significant association signals at the SCN10A locus (rs10428132) and near the HEY2 gene (rs9388451). Independent replication confirmed both signals (meta-analyses: rs10428132, P = 1.0 × 10−68; rs9388451, P = 5.1 × 10−17) and identified one additional signal in SCN5A (at 3p21; rs11708996, P = 1.0 × 10−14). The cumulative effect of the three loci on disease susceptibility was unexpectedly large (Ptrend = 6.1 × 10−81). The association signals at SCN5A-SCN10A demonstrate that genetic polymorphisms modulating cardiac conduction4–7 can also influence susceptibility to cardiac arrhythmia. The implication of association with HEY2, supported by new evidence that Hey2 regulates cardiac electrical activity, shows that Brugada syndrome may originate from altered transcriptional programming during cardiac development8. Altogether, our findings indicate that common genetic variation can have a strong impact on the predisposition to rare diseases.

Triggers from the Purkinje arborization or the right ventricular outflow tract have a crucial role in initiating ventricular fibrillation associated with the long-QT and Brugada syndromes. These can be eliminated by focal radiofrequency ablation.

No abstract

This document does not address the indications of genetic testing in patients affected by inherited arrhythmias and their family members. Diagnostic, prognostic, and therapeutic implications of the results of genetic testing are also not included in this document because this topic has been covered by a recent publication 1 coauthored by some of the contributors of this consensus document, and it remains the reference text on this topic. Guidance for the evaluation of patients with idiopathic ventricular fibrillation, sudden arrhythmic death syndrome, and sudden unexplained death in infancy, which includes genetic Contents lists available at ScienceDirect

This document does not address the indications of genetic testing in patients affected by inherited arrhythmias and their family members. Diagnostic, prognostic, and therapeutic implications of the results of genetic testing are also not included in this document because this topic has been covered by a recent publication 1 coauthored by some of the contributors of this consensus document, and it remains the reference text on this topic. Guidance for the evaluation of patients with idiopathic ventricular fibrillation, sudden arrhythmic death syndrome, and sudden unexplained death in infancy, which includes genetic Contents lists available at ScienceDirect