QTc in milliseconds

<370

1

<350

2

<330

3

J point-T peak interval

<120

1

Clinical History

Sudden cardiac arrest

2

Polymorphic VT or VF

2

Unexplained syncope

1

Atrial fibrillation

1

Family History

1s or 2nd degree relative to SQTS

2

1st or 2nd degree relative to sudden death

1

Sudden infant death syndrome

1

Genotype

Genotype positive

2

Mutation of undetermined significance in a culprit gene

1