Congenital long QT syndrome is associated with neonatal -

Many people with long QT syndrome have no signs or symptoms. Symptoms that do occur are generally caused by abnormal hea rhythms or arrhythmias, most commonly a form of ventricular tachycardia called Torsades de pointes. If the arrhythmia reves to a normal rhythm by itself then the affected person may experience a faint known as syncope, which may be associated with seizures and sinus bradycardia. However, if the arrhythmia continues, the affected person may experience a cardiac arrest leading to sudden death. The arrhythmias that lead to faints and sudden death are more likely to occur in response to specific circumstances, in pa determined by which genetic variant is responsible for the condition. While arrhythmias can occur at any time, in some forms of LQTS arrhythmias are more commonly seen in response to exercise or mental stress (LQT1), in other forms following a sudden loud noise (LQT2) , and in some forms during sleep or immediately upon waking (LQT3). Some rare forms of long QT syndrome are associated with symptoms affecting other pas of the body. These include deafness in the Jervell and Lange-Nielsen form of the condition, and periodic paralysis in the Andersen-Tawil (LQT7) form Ref Harrison 20th edition pg 1443