Short QT syndrome [9 genes]

Short QT syndrome is a very rare genetic entity generally caused by an increase in function in some cardiac ion channels, which leads to an abnormal shortening of cardiac repolarization. It is associated with a high predisposition to ventricular arrhythmias, and patients may present syncope, cardiac arrest or sudden death. As in the case of long QT syndrome, these can be the first manifestations of the disease and can occur at any age.

The estimated prevalence in the adult population is 0.02%-0.1%, and has not been defined in the pediatric population.

The genetic study in short QT syndrome is part of the diagnostic criteria because it provides etiological confirmation, while allowing a more precise study of family members and a better family genetic counseling.

Genetic study is indicated in patients diagnosed with short QT syndrome, with level I evidence according to the main international clinical recommendation guidelines.
It is indicated in:

• Patients with a diagnosis of QTc <330 ms.
• Patients with QTc between 340-360 ms and who also present:
• Family history of short QT syndrome
• Having survived an episode of VT/VF (Ventricular Tachycardia/Ventricular Fibrillation) in the absence of structural heart disease.

The yield of the genetic study in short QT syndrome ranges between 20% and 25%.