Subcutaneous and transvenous implantable cardioverter defibrillator in high-risk long-QT syndrome type 3 associated with Val411Met mutation in SCN5A

Yasuhiro Yokoyama, Takeshi Aiba, Nobuhiko Ueda, Kenzaburo Nakajima, Tsukasa Kamakura, Mitsuru Wada, Kenichiro Yamagata, Kohei Ishibashi, Yuko Inoue, Koji Miyamoto, Satoshi Nagase, Takashi Noda, Satoshi Yasuda, Wataru Shimizu, Kengo Kusano

Research output: Contribution to journalArticlepeer-review

Abstract

Congenital long-QT syndrome type 3 (LQT3) with SCN5A-V411M mutation has been reported as a malignant case of LQT3 with highest risk for sudden cardiac death (SCD). Here, we present two cases of LQT3 with SCN5A-V411M who had been implanted with subcutaneous (S-) or transvenous (TV-) implantable cardioverter defibrillators (ICD). Case 1, a 2-year-old boy, although he had no symptoms, was diagnosed as having LQT3 (V411M-SCN5A) due to family history. The QTc interval was still longer than 500 ms during follow-up even under oral mexiletine. Case 2 (his aunt) diagnosed as LQT3 suffered from syncope caused by ventricular fibrillation at 35-years-old despite taking mexiletine. Furthermore, case 1’s father and half-brother, both had the V411M mutation with LQT3, had suddenly died. Thus, case 1 was recommended S-ICD when he was 15-years-old for primary prevention of SCD but not necessary for pacing therapy, while, case 2 had been implanted TV-ICD for secondary prevention of SCD. They had no event after ICD implantation, however, case 2 had to have added an extra ICD-lead due to lead failure when she was 44-years-old. The S-ICD may be a potent therapeutic option for high-risk LQTS when patients are younger and do not need pacing therapy. <Learning objective: In congenital long-QT syndrome (LQTS) type 3, some of the first events are lethal, particularly, LQT3 with V411M-SCN5A mutation is the highest risk for sudden cardiac death (SCD). Which implantable cardioverter defibrillator (ICD), transvenous (TV-ICD) or subcutaneous (S-ICD) is better for primary prevention of SCD in LQTS is still controversial. The S-ICD rather than TV-ICD may have a potent benefit for high-risk LQTS when patients are younger and do not need pacing therapy.>

Original languageEnglish
Pages (from-to)238-241
Number of pages4
JournalJournal of Cardiology Cases
Volume22
Issue number5
DOIs
Publication statusPublished - 2020 Nov
Externally publishedYes

Keywords

  • Implantable cardioverter defibrillator
  • Long-QT syndrome
  • SCN5A
  • Sudden cardiac death

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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