Long QT syndrome (LQTS) is a genetic disease that affects the heart. When present, it increases the risk of arrhythmias, syncopes and cardiac arrests. The name derives from the prolongation of the QT interval, a specific electrocardiogram parameter. The disease occurs in the first years of life and, if not diagnosed, can lead to death.
The severity of the disease depends in part on the gene involved and the type of mutation. Depending on the variant, it can occur in children or puberty. Furthermore, it can be transmitted in an autosomal dominant or recessive manner. The first is the most frequent variant and is called Romano-Ward syndrome. The second is rarer and often associated with deafness; it is called Jervell and Lange-Nielsen syndrome. In the latter case, both parents are healthy carriers of the disease.
The most common diagnostic method for LQTS is the resting and stress electrocardiogram. Other basic elements are clinical and family history. At-risk children suffer from frequent syncopations and have had cases of arrhythmia. In addition, there have often been cases of sudden death in the family. After the electrocardiogram and anamnesis, genetic tests are carried out to identify the mutation and the most effective therapy in the specific case.
To date, there is no remedial therapy for long QT syndrome. People suffering from it must take beta-blocker drugs that protect them from arrhythmias. In most cases, enough is enough to prevent symptoms. However, the effectiveness may vary depending on the genetic defect and the severity of the disease. In severe cases, it is necessary to resort to the installation of an automatic defibrillator.