It is caused by mutations in genes encoding ion channels that shorten the cardiac action potential, and appears to be inherited in an autosomal dominant pattern.

[1] In addition, far more dangerous heart rhythm disturbances such as ventricular fibrillation can also occur in those with short QT syndrome, leading to blackouts or even sudden death.

[1] If someone with short QT syndrome is examined while their heart is beating in an abnormal rhythm such as atrial fibrillation, this can be detected by feeling their pulse.

[6] No abnormal signs will usually be found when examining someone with short QT syndrome while their heart is beating in its normal or sinus rhythm.

Short QT syndrome is a genetic disorder caused by mutations in genes responsible for producing certain ion channels within heart cells.

In contrast, during atrial or ventricular fibrillation, waves of electrical activation spiral through the cardiac muscle chaotically in a mass of disorganised, broken wavelets.

If a triggering impulse arrives at this critical point in the cardiac cycle, the wavefront of electrical activation will conduct in some regions but block in others, potentially leading to wavebreak and re-entrant arrhythmias.

[9] The second mechanism relates to the increased number of fibrillatory wavelets that can simultaneously exist if the action potential decreases, in a concept known as the arrhythmia wavelength.

[1] Other features that may be seen on the ECG in short QT syndrome include tall, peaked T-waves and PR segment depression.

[12][13] The treatment for short QT syndrome is aimed at preventing abnormal heart rhythms and reducing the risk of sudden cardiac death.

In those with short QT syndrome who have already experienced a life-threatening abnormal heart rhythm such as ventricular fibrillation, an implantable cardioverter-defibrillator (ICD) may be recommended to reduce the chance of sudden death.

[8] Those who develop atrial fibrillation may also require medication to decrease blood clotting in order to reduce the risk of stroke.

[1] The findings from invasive electrophysiological studies do not predict an individual with short QT syndrome's risk of cardiac arrest.

[10] Recently the first animal model of short QT syndrome was presented, enabling more in depth analysis of arrhythmia mechanisms.