Short QT syndrome natural history, complications and prognosis

Short QT syndrome(SQTS) is associated with an increased risk of atrial fibrillation, syncope and sudden death due to ventricular fibrillation. The disease symptoms develop in between the second and fourth decade of life . The most common presentation is syncope and palpitations. Most of the pediatric patients remain asymptomatic and get diagnosed only when they have an index case in the family prompting a genetic testing. Without treatment most of the pediatric patients who present within first decade of life succumb to Sudden cardiac death and younger patients with QTc of 285 msec and adults with QT less than 300 msec have increased risk of sudden cardiac death.

The symptoms of SQTS usually develop between the second and fourth decade of life and start with symptoms such as syncope and palpitations. The primary manifestations of SQTS are palpitations, syncope, atrial fibrillation, and cardiac arrest. Without treatment, the patient will develop a worsening of arrhythmia, which may eventually lead to cardiac arrest. It is believed that most of the pediatric patients remain asymptomatic and get diagnosed only when they have an index case in the family prompting a genetic testing. The circumstances in which symptoms arise in SQTS patients are highly variable. According to a few studies, SQTS patients can be asymptomatic in a significant proportion of the study population and get diagnosed only with a strong familial predisposition^[1].

Complications can result due to SQTS.

• atrial fibrillation
• ventricular fibrillation
• Sudden cardiac death

Long term prognosis has not been assessed due to the unavailability of data. Severe shortening of QT values in adults ≤300 msec and in young patients with median QTc of 285 msec have increased risk of SCD either at rest or in sleep^[2].