日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Congenital long QT syndrome (LQTS), a genetic disorder, is characterized by delayed repolarization and a long QT interval on 12-lead electrocardiography (ECG). The hallmark of LQTS is syncope, convulsion, sudden cardiac death, and aborted cardiac arrest caused by torsade de pointes. Variations in genes encoding for cardiac ion channels, accessory ion channel subunits, or proteins modulating the function of the ion channel have been identified in 17 genes as disease-causing mutations. However, an international, evidence-based reappraisal of genes reported that LQT1, LQT2, and LQT3 are the major three types. The genetically determined prevalence of LQTS is approximately 1 : 2000. In the general population, the probability of diagnosing LQTS through ECG is 1 : 1000 in seventh graders (aged 12 years). Treatment was implemented based on the genotype–phenotype relationship. The prognosis of patients with LQTS, particularly those who are diagnosed by a school-based ECG screening program, has been improving through the control of lifestyles and well adherence to pharmacotherapy.