<unk>  <unk> S) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, palpitations, shortness of breath, lightheadedness, or syncope. Rarely, cardiac arrest may occur. The most common type of irregular heartbeat that occurs is known as paroxysmal supraventricular tachycardia. The cause of<unk>  is typically unknown and is likely due to a combination of chance and genetic factors. A small number of cases are due to a mutation of the PRKAG2 gene which may be inherited from a person's parents in an autosomal dominant fashion. The underlying mechanism involves an accessory electrical conduction pathway between the atria and the ventricles. It is associated with other conditions such as Ebstein anomaly and hypokalemic periodic paralysis. The diagnosis of<unk>  occurs with a combination of palpitations and when an electrocardiogram (ECG) show a short PR interval and a delta wave. It is a type of pre-excitation syndrome.<unk>  syndrome may be monitored or treated with either medications or an ablation (destroying the tissues) such as with radiofrequency catheter ablation. It affects between 0.1 and 0.3% in the population. The risk of death in those without symptoms is about 0.5% per year in children and 0.1% per year in adults. In some cases, non-invasive monitoring may help to more carefully risk stratify patients into a lower risk category. In those without symptoms ongoing observation may be reasonable. In those with<unk>  complicated by atrial fibrillation, cardioversion or the medication procainamide may be used. The condition is named after Louis<unk> , John Parkinson, and Paul Dudley<unk>  who described the ECG findings in 1930.
Wolff–Parkinson–White syndrome
Lown–Ganong–Levine syndrome
Catel–Manzke syndrome
Parkinson-plus syndrome
De Barsy syndrome
Dravet syndrome
Benedikt syndrome
Stratton Parker syndrome