Short QT syndrome
Also calledSQTS · short QT · short QT interval syndrome · congenital short QT syndrome
Definition
An inherited channelopathy defined by an abnormally short rate-corrected QT interval. Under the 2022 ESC guideline it is diagnosed at a QTc of 360 ms or less together with a pathogenic mutation, a family history of short QT syndrome, or survival of a ventricular tachycardia or fibrillation episode without heart disease, and it is considered at a QTc of 320 ms or less on its own; the 2013 HRS/EHRA/APHRS consensus diagnosed it at a QTc of 330 ms or less, or under 360 ms with one of those features or a family history of sudden death at age 40 or younger. It has been linked to gain-of-function variants in potassium-channel genes such as KCNH2 and KCNQ1, and variants in L-type calcium-channel genes have also been found in patients with a short QT interval. Tall T waves can be present, and the syndrome predisposes to premature atrial fibrillation and ventricular fibrillation in a structurally normal heart.
Clinical noteThe stand-alone cutoff differs by source (2022 ESC 320 ms or less, as a class IIa criterion; 2013 HRS/EHRA/APHRS 330 ms or less), and Bazett-corrected QTc can be substantially in error at fast heart rates.
Sources
- Zeppenfeld K, Tfelt-Hansen J, de Riva M, et al. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J. 2022;43(40):3997-4126. doi.org/10.1093/eurheartj/ehac262
- Priori SG, Wilde AA, Horie M, et al. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes. Heart Rhythm. 2013;10(12):1932-1963. doi.org/10.1016/j.hrthm.2013.05.014
- Konemann H, Dagres N, Merino JL, et al. Spotlight on the 2022 ESC guideline management of ventricular arrhythmias and prevention of sudden cardiac death: 10 novel key aspects. Europace. 2023;25(5):euad091. doi.org/10.1093/europace/euad091
- Rautaharju PM, Surawicz B, Gettes LS. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part IV: the ST segment, T and U waves, and the QT interval. Circulation. 2009;119(10):e241-e250. doi.org/10.1161/CIRCULATIONAHA.108.191096
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.