Rare but lethal short QT syndrome: most recent understanding of the disease

Abstract

Short QT syndrome (SQTS) is a rare genetic channelopathy that affects the repolarization of cardiac cells and is associated with cardiac arrhythmia and sudden cardiac death (SCD). “Abbreviated repolarization” is the hallmark of the disease, which is secondary to genetic defects; mutations in several genes that encode different cardiac ion channels have been identified in individuals with the disease. Presentations of the disease include syncope, atrial or ventricular arrhythmia and SCD. SQTS is diagnosed with a corrected-QT (QTc) interval of <340 milliseconds (ms) or a QTc of 340-360 ms and either personal or family history of SCD, family history of SQTS or an identified genetic mutation. Implantable cardioverter-defibrillator (ICD) is the main treatment used in the secondary prevention of SCD in patients with the disease who have experienced previous major arrhythmic events. Pharmacological treatment with quinidine is used as an adjuvant therapy to ICD in the setting of recurrent shocks or as an alternative treatment when ICD is not feasible. The goal of this review article is to describe this rare and under-studied condition, highlight steps to diagnosis and describe treatment modalities, particularly in South America where there is a lack of studies and understanding of this disease.