Table 2.

Aggregated consensus guideline indications for genetic testing in inherited arrhythmia syndromes.

Condition	Diagnosis / Strong suspicion	Relative is index case with known mutation	Reference
Long QT syndrome	I1 / IIb2	I	1
Catecholaminergic polymorphic ventricular tachycardia	I	I	1
Brugada syndrome	IIa	I	1
Cardiac conduction system disease	IIb3	I	1
Short QT syndrome	IIb	I	1
Hypertrophic cardiomyopathy	I	I	1,2
Arrhythmogenic ventricular cardiomyopathy	IIa4 / IIb5	I	1
Dilated cardiomyopathy	I6 / IIa7	I	1
Left ventricular noncompaction cardiomyopathy	IIa	I	1
Restrictive cardiomyopathy	IIb	I	1
Out of hospital cardiac arrest	I8	–	1
Sudden unexplained death & sudden infant death syndrome	IIb9	I	1
Atrial fibrillation	–	–	1

¹Strong clinical suspicion, or asymptomatic with QTc > 500 (adult) or > 480 (prepuberty) on repeated occasions

²Asymptomatic with QTc > 480 (adult) or >460 (prepuberty)

³Isolated CCD or with concomitant congenital heart disease, especially with family history of cardiac conduction system disease

⁴Task force clinical diagnosis of arrhythmogenic ventricular cardiomyopathy

⁵Task force possible arrhythmogenic ventricular cardiomyopathy

⁶With conduction disease or family history of sudden death

⁷To confirm diagnosis with familial dilated cardiomyopathy

⁸If exam suggests channelopathy or cardiomyopathy

⁹If evaluation suggests long QT syndrome or catecholaminergic polymorphic ventricular tachcyardia

These indications represent a summary of class I and II indications based on consensus guideline statements. ¹,²