Short QT syndrome (SQTS) is a very rare and poorly understood condition with less than 200 cases of the condition worldwide to date.
As the name suggests the QT interval in carriers is shorter than normal, which means that the heart takes a short time to repolarise or reset itself.
People with this condition can sometimes develop ventricular arrhythmias, as well as less dangerous heart rhythms from the top chamber of the heart (atrial fibrillation).
Often none. Unfortunately patients can present with cardiac arrest before development of any symptoms.
Often there are no physical signs, except if there is atrial fibrillation, where the pulse is irregular when felt by the doctor.
The ECG abnormalities are usually detected either on a standard ECG or a 24-hour Holter where the QT interval is shorter than normal. An electrophysiological (EP) study may also help the doctor make a diagnosis. Genetic testing may find a potassium channel mutation in affected members of a family that may then also be found in other relatives.
An ICD is recommended for patients with SQTS who have suffered a cardiac arrest, in order to treat future dangerous arrhythmias.
For patients with SQTS who have no symptoms or have never had a cardiac arrest, treatment with ICD is not usually recommended. Treatment is usually with medication (tablets).