Treatment and follow-up study of long QT syndrome with syncope in 11 children

Abstract

Objective To assess the clinical features and treatment of children with long QT syndrome(LQTS) and syncope. Methods Eleven cases of children with LQTS and syncope between January 2009 and July 2014 in Hunan Children's Hospital were retrospectively analyzed for clinical features, treatment and long term follow-up. Results There were 11 cases of children with LQTS aged 4.0-14.5(9.16±2.71) years, 8 male and 3 female, with syncope more than once.The range of QTc was 460-521(483.72±22.90) ms.For 3 cases of acquired LQTS, 1 case was parathyroid hypothyroidism causing hypocalcemia, 1 case was myocarditis complicated with third degree atrioventricular block, and 1 case showed atrial flutter receiving amiodarone post congenital cardiac surgery.All patients recovered after the inducement removed and primary illness cured.For 8 cases of congenital LQTS, 3 cases of LQTS underwent genetic test (1 case of KCNQ1 gene mutation, 2 cases of KCNH2 gene mutation). One case died after frequent torsade de pointes (Tdp) and ventricular fibrillation during hospitalization, the remaining 7 patients were given oral propranolol, potassium chloride sustained-release tablets after discharge.Follow-up time was 8 to 75 months, an average of (45.73±24.42) months.One case died suddenly at home after 25 months of follow-up.The remaining 6 cases of children with congenital LQTS could withstand general activities without syncope, in which 4 cases had normal QTc by electrocardiography(ECG), and the findings in 2 cases did not change compared with those previously.The QTc returned to normal in children with acquired LQTS in the follow-up review. Conclusions Children with congenital LQTS should receive early genetic screening and genotyping for rational use of drugs.For children with higher risk of sudden death, drug therapy combined with implantable cardioverter defibrillator should be considered.For acquired LQTS, it should be better to remove the inducement and treat primary disease actively. Key words: Child; Long QT syndrome; Syncope; Torsade de points