LQTS, depending on the genetic mutation, is associated with physical exercise, swimming, and sleep; in 85% of cases, the genetic analysis of all genes identifies the cause of the disease, with 80% carrying the pathogenic variant in three principal genes, KCNQ1, KCNH2, and SCN5A, which are recommended by current guidelines [52,61]. Here, KCNH2 is linked to familial long QT syndrome.