Those affected by<unk>  (SQT) have an increased risk of developing abnormal heart rhythms. These abnormal heart rhythms often occur at a young age. They may take relatively benign forms such as atrial fibrillation, leading to symptoms of palpitations, breathlessness, or fatigue. Accordingly, atrial fibrillation presenting in a newborn should raise the suspicion of<unk> . In addition, far more dangerous heart rhythm disturbances such as ventricular fibrillation can also occur in those with<unk> , leading to blackouts or even sudden death. More than a third of those with<unk> <unk>  present with ventricular arrhythmias or sudden cardiac death, while one in five cases are detected during family screening, and one in five cases are found incidentally after an electrocardiogram (ECG) has been recorded for another reason. If someone with<unk>  is examined while their heart is beating in an abnormal rhythm such as atrial fibrillation, this can be detected by feeling their pulse. No abnormal signs will usually be found when examining someone with<unk>  while their heart is beating in its normal or sinus rhythm.
Short QT syndrome
Long QT syndrome
Opitz G/BBB syndrome
Brugada syndrome
Familial atrial fibrillation
Aicardi–Goutières syndrome
Phidippides cardiomyopathy
Pacak–Zhuang syndrome