short QT syndrome
Any of a family of (at least) 5 inherited calcium or potassium ion channelopathies which are characterised by the presence of a short—< 300 ms, range, 210 to 340 ms—QT interval on an EKG, that does not significantly change with heart rate, and is typically accompanied by tall and peaked T waves.
Clinical findings Patients are typically young and healthy and have no structural cardiac defects. They are first identified as having short QT syndrome at any point from infancy–in which it may cause SIDS, to the sixth decade of life—median age = 30 years. The most common presentation is cardiac arrest (one-third of cases); others present with palpitations or syncope due to atrial fibrillation or self-terminating ventricular arrhythmias.
EKG Short QT interval, short atrial and ventricular effective refractory periods and, as a result, increased risk of atrial and ventricular fibrillation
Pathogenesis Mutations cause either hyperfunction of the delayed rectifier potassium current or calcium current hypofunction, resulting in a shortened repolarisation period and increased transmural dispersion of repolarisation
Management ICD–implantable cardioverter defibrillator is the treatment of choice in SQTS.
E-Journal, ESC Council for Cardiology Practice 2010; 9:17 Sept 2010