The diagnosis is based upon the patient’s symptoms (e.g. syncope, palpitations), family history (of syncope, sudden death or atrial fibrillation at an early age) and characteristic findings on the 12-lead ECG. [litfl.com]

The most common symptoms are: Heart pounding (palpitations) Fainting (syncope) Sudden cardiac death (may be the first symptom for some patients) Atrial fibrillation If SQTS causes atrial fibrillation, other symptoms may include shortness of breath, dizziness [my.clevelandclinic.org]

Other symptoms often documented are syncope and palpitations. [escardio.org]

Cardiac arrest seems to be the most frequent presenting symptom (up to 40 %). 5 Palpitations are very common (30 %), followed by syncope (25 %) and AF, which is the first presenting symptom in up to 20 % of patients. [ncbi.nlm.nih.gov]

Population-based and genetic studies show that QTc interval 6 – 8 Data from over 10,000 adults suggest that, in the healthy population, the prevalence of QT c 6 Therefore, males with QTc 330 ms and females with QT c 340 ms have abnormally short QT and [ncbi.nlm.nih.gov]

Known patients with SQTS genotypes 1-3 all had QTc intervals 300-320 ms Known patients with SQTS genotypes 4 & 5 all had QTc intervals 360 ms A recent review by Viskin suggested the following approach: QTc intervals 330 ms in males or 340 ms in females [litfl.com]

Isolated reported cases (16) suggest that it may facilitate appropriate decision-making in symptomatic patients with an abnormal but nondiagnostic ECG given the prognostic and therapeutic implications. [escardio.org]

The Q-T interval is the section on the electrocardiogram (ECG) that represents the time it takes for the electrical system to fire an impulse through the ventricles (lower chambers of the heart) and then recharge. [my.clevelandclinic.org]

Atrial fibrillation in the setting of familial short QT interval. Heart Rhythm 2004; 1: S165 (abstract). [escardio.org]

QT interval, tall, peaked T waves and nearly absent ST segments. [ncbi.nlm.nih.gov]

Short QT interval There is currently no universally accepted lower limit of normal for the QT interval that can be used to diagnose SQTS. [litfl.com]

[…] particularly in the precordial leads Short or absent ST segments Episodes of atrial or ventricular fibrillation QT, ST and T-wave changes in SQTS Short QT interval, peaked T waves and short ST segments in two patients with SQTS 1. [litfl.com]

T waves and nearly absent ST segments. [ncbi.nlm.nih.gov]

SQTS 16 often have tall, peaked and symmetrical T waves, SQTS 38 show asymmetrical peaked T wave due to the acceleration of the final phase of the action potential repolarization, and SQTS 4 and 59 coexist with Brugada type ST elevation in precordial [escardio.org]

U wave can be observed, separated by an isoelectric T–U segment. 14 Longer T peak – T end interval may be observed, suggestive of augmented transmural dispersion of refractoriness. 15 Depression of the PQ segment, due to a heterogeneous abbreviation [ncbi.nlm.nih.gov]

U wave can be observed, separated by an isoelectric T–U segment. 14 Longer T peak – T end interval may be observed, suggestive of augmented transmural dispersion of refractoriness. 15 Depression of the PQ segment, due to a heterogeneous abbreviation [ncbi.nlm.nih.gov]