<unk>  increases the risk of abnormal heart rhythms or arrhythmias. These are typically a form of ventricular tachycardia known as Torsades de Pointes which can cause faints, seizures, or even sudden death. Less dangerous arrhythmias such as atrial fibrillation also occur, causing symptoms of heart racing or palpitations. However, many of those with<unk>  will remain free from arrhythmias and therefore free from symptoms. Certain situations are more likely to precipitate arrhythmias such as exercise or mental stress in the LQT1 subtype, sudden loud noise in the LQT2 subtype, and during sleep or immediately upon waking in the LQT3 subtype.<unk>  can be differentiated from other forms of long QT syndrome by<unk> -Ward's sole involvement of the heart. While other forms of long QT syndrome are associated with deafness (Jervell and Lange-Nielsen syndrome), intermittent weakness and bone abormailities (LQT7, Andersen-Tawil syndrome), and autism spectrum disorder (LQT8, Timothy syndrome), these extra-cardiac manifestations are not seen in<unk> -Ward.
Romano–Ward syndrome
Brugada syndrome
Witteveen–Kolk syndrome
Andersen–Tawil syndrome
Townes–Brocks syndrome
Laugier–Hunziker syndrome
Baggio–Yoshinari syndrome
Morgagni Stewart Morel syndrome