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

It is well known that exercise, mental excitement, and stress induce torsade de pointes (TdP) in congenital long QT syndrome (LQTS). The excitability of the sympathetic neuron is believed to be deeply involved especially in LQT1 and LQT2. Therefore, beta blockers are the first-line drugs considered to prevent TdP, but in some cases, continuing medication is difficult because of internal medication compliance issues. The patient was a 14-year-old girl who had no apparent family history of LQTS, sudden death, or fainting, but had repeated syncopal attacks after starting elementary school. Long QT was identified in a school health examination, and the patient was referred to our hospital. She was diagnosed as having long QT syndrome (LQT2) on the basis of genetic screening results. Βeta blocker was administered to prevent attacks. Over time, no syncopal attacks occurred, but she suspended her own treatment at age 10 years because of reduced exercise tolerability. She returned to our hospital as an outpatient at age 13 years because of repeated syncopal attacks and received beta blocker and exercise restrictions. The syncopal attacks ceased, but the patient became mentally unstable and stopped attending school. Moreover, she had palmar hyperhidrosis in both hands. At age 14 years, she was performed endoscopic thoracic sympathectomy (ETS). The palmar hyperhidrosis improved, and no side effects such as compensatory hyperhidrosis or Horner’s syndrome were observed. Moreover, the corrected QT when resting improved from 570 to 511 ms.