A genetic heart abnormality in which the duration of the ECG QT-interval is between 210 and 340 milliseconds while in normal people it is between 350 and 440 milliseconds. In contrast to its mirror-image disorder long QT syndrome, there is not much known about SQTS. However, impressive progress has been made in the genetics of SQTS.
Having a short QT-interval in the ECG does not in itself cause any symptoms, but it can lead to two different types of rhythm disturbance, which in turn can cause symptoms.
The first type is atrial fibrillation, which is an irregular heart rhythm originating in the upper chambers (atria) of the heart. It causes palpitations, shortness of breath, dizziness, chest tightness and fatigue. It can occur in short episodes, starting and stopping by themselves, or it can become a more permanent condition.
The second type is ventricular tachycardia or fibrillation. It is a very fast rhythm disturbance originating in the lower chambers (ventricles) of the heart. It is a much more serious problem, which can lead to sudden cardiac death.
Rhythm disturbances from both upper and lower chambers of the heart can in addition lead to passing out spells (syncope), where a person may wake up by him/herself.
An ICD is recommended as first-line treatment to prevent sudden cardiac death. Quinidine has thus far proved to be the most effective drug but should be used with an ICD.