Short QT syndrome (SQTS) is an inheritable primary electrical disease of the 
heart, discovered in 1999. It is characterized by an abnormally short QT 
interval (<300 ms) and a propensity to atrial fibrillation and sudden cardiac 
death (SCD). Like in the case of long QT syndrome there is more than one genetic 
mutation that can lead to a short QT interval in the ECG and so far two have 
been identified. Shortening of the effective refractory period combined with 
increased dispersion of repolarization is the likely substrate for reentry and 
life threatening tachyarrhythmias. Only 22 people have been classified as having 
SQTS: 15 from the actual measurement of a short QT interval in their ECG and 7 
by history, all having died from SCD. It is very likely that several cases, 
especially among children, have been overlooked, since the shortness of the QT 
interval only becomes apparent at heart rates <80 beats/min. The best form of 
treatment is still not known, but prevention of atrial fibrillation has been 
accomplished by propafenone, and an implantable cardioverter defibrillator is 
recommended for prevention of SCD.