TABLE OF CONTENTS
1. Introduction	4
1.1. Purpose	4
1.2. Organization of the writing committee	4
1.3. Methodology and evidence review	4
1.4. Document review and approval	5
1.5. Scope of the document	5
2. Genetic influences on disease and modes of inheritance	5
3. Different methods of genetic testing	8
3.1. Methods to interrogate genetic variation	8
3.2. Genome‐wide association study and polygenic risk scores	11
4. Choice of genetic tests and interpretation of variants	12
4.1. Background	13
4.1.1. Use of the obtained genetic knowledge	13
5. State of genetic testing for inherited arrhythmia syndromes	14
5.1. Long QT syndrome	14
5.1.1. Impact of genetic testing for the index case	14
5.1.2. Background	15
5.1.3. Summary of the major long QT syndrome genes	15
5.1.4. Prognostic and therapeutic implications of long QT syndrome genetic testing	17
5.1.5. Acquired long QT syndrome	17
5.2. Catecholaminergic polymorphic ventricular tachycardia	18
5.2.1. Impact of genetic testing for the index case	18
5.2.2. Background	18
5.2.3. Diagnostic implications of catecholaminergic polymorphic ventricular tachycardia genetic testing	18
5.2.4. Prognostic and therapeutic implications of catecholaminergic polymorphic ventricular tachycardia genetic testing	20
5.3. Brugada syndrome	20
5.3.1. Impact of genetic testing for the index case	20
5.3.2. Background	20
5.3.3. Diagnostic implications of Brugada syndrome genetic testing	21
5.3.4. Prognostic and therapeutic implications of Brugada syndrome genetic testing	22
5.4. (Progressive) cardiac conduction disease	22
5.4.1. Impact of genetic testing for the index case	22
5.4.2. Background	22
5.4.3. Diagnostic implications of genetic testing in cardiac conduction disease/progressive cardiac conduction disease	23
5.4.4. Prognostic and therapeutic implications of genetic testing	23
5.5. Short QT syndrome	25
5.5.1. Impact of genetic testing for the index case	25
5.5.2. Background	25
5.5.3. Diagnostic implications of short QT syndrome genetic testing	25
5.5.4. Prognostic and therapeutic implications of short QT syndrome genetic testing	26
5.6. Atrial fibrillation	26
5.6.1. Impact of genetic testing for the index case	26
5.6.2. Background	26
5.6.3. Genetic forms of atrial fibrillation	27
5.7. Sinus node disease	28
5.7.1. Impact of genetic testing for the index case	28
5.7.2. Background	28
5.7.3. Diagnostic implications of genetic testing in sinus node dysfunction	28
5.7.4. Prognostic and therapeutic implications of genetic testing	30
5.8. Early repolarization syndrome	30
5.8.1. Impact of genetic testing for the index case	30
5.8.2. Background	30
5.9. Wolff–Parkinson–White syndrome	31
5.9.1. Background	31
5.9.2. Genetics of Wolff–Parkinson–White	31
6. State of genetic testing for cardiomyopathies	31
6.1 Hypertrophic cardiomyopathy	31
6.1.1. Impact of genetic testing for the index case	31
6.1.2. Background	31
6.1.3. Diagnostic implications of genetic testing	32
6.1.4. Prognostic and therapeutic implications of genetic testing	34
6.2. Dilated cardiomyopathy	34
6.2.1. Impact of genetic testing for the index case	34
6.2.2. Background	34
6.2.3. Diagnostic implications of dilated cardiomyopathy genetic testing	35
6.2.4. Prognostic and therapeutic implications of dilated cardiomyopathy genetic testing	36
6.3. Arrhythmogenic cardiomyopathy	37
6.3.1. Background	37
6.3.2. Diagnostic implications of arrhythmogenic cardiomyopathy genetic testing	37
6.3.3. Prognostic and therapeutic implications of arrhythmogenic cardiomyopathy genetic testing	39
6.4. Left ventricular non‐compaction cardiomyopathy	39
6.4.1. Background	39
6.4.2. Diagnostic implications of left ventricular non‐compaction genetic testing	40
6.4.3. Prognostic and therapeutic implications	40
6.5. Restrictive cardiomyopathy	41
6.5.1. Background	41
6.5.2. Diagnostic implications of restrictive cardiomyopathy genetic testing	41
6.5.3. Prognostic and therapeutic implications	42
7. State of genetic testing for sudden cardiac death or survivors of unexplained cardiac arrest	42
7.1 Background	43
8. State of genetic testing for congenital heart disease	44
8.1. Background	44
8.1.1. Antenatal testing	44
8.1.2. Antenatal screening	44
8.1.3. Neonates and infants requiring investigation or procedures for congenital heart disease	47
8.1.4. Patients with congenital heart disease and extracardiac anomalies	47
8.1.5. Familial forms of congenital heart disease	47
8.1.6. Sporadic non‐syndromic congenital heart disease	47
8.1.7. Heterotaxy	47
9. State of genetic testing for coronary artery disease and heart failure	48
10. Conclusion and future directions	48