Korean Circulation Journal

The Korean Society of Cardiology (대한심장학회)
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The Outcome of Long QT Syndrome, a Korean Single Center Study

  • Kyung Jin Ahn (Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine) ;
  • Mi Kyoung Song (Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine) ;
  • Sang Yun Lee (Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine) ;
  • Ja Kyoung Yoon (Department of Pediatrics, Sejong General Hospital) ;
  • Gi Beom Kim (Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine) ;
  • Seil Oh (Department of Internal Medicine, Seoul National University Children's Hospital, Seoul National University College of Medicine) ;
  • Eun Jung Bae (Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine)
  • Received : 2022.03.14
  • Accepted : 2022.08.10
  • Published : 2022.10.01
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Abstract

Background and Objectives: Although long QT syndrome (LQTS) is a potentially life-threatening inherited cardiac channelopathy, studies documenting the long-term clinical data of Korean patients with LQTS are scarce. Methods: This retrospective cohort study included 105 patients with LQTS (48 women; 45.7%) from a single tertiary center. The clinical outcomes were analyzed for the rate of freedom from breakthrough cardiac events (BCEs), additional treatment needed, and death. Results: LQTS was diagnosed at a median age of 11 (range, 0.003-80) years. Genetic testing was performed on 90 patients (yield, 71.1%). The proportions of genetically confirmed patients with LQTS types 1, 2, 3, and others were 34.4%, 12.2%, 12.2%, and 12.2%, respectively. In the symptomatic group (n=70), aborted cardiac arrest was observed in 30% of the patients. Treatments included medications in 60 patients (85.7%), implantable cardioverter-defibrillators in 27 (38.6%; median age, 17 years; range, 2-79 years), and left cardiac sympathetic denervation surgery in 7 (10%; median age, 13 years; range, 2-34). The 10-year BCE-free survival rate was 73.2%. By genotype, significant differences were observed in BCEs despite medication (p<0.001). The 10-year BCE-free survival rate was the highest in patients with LQTS type 1 (81.8%) and the lowest in those with multiple LQTS-associated mutations (LQTM). All patients with LQTS survived, except for one patient who had LQTM. Conclusions: Good long-term outcomes can be achieved by using recently developed genetically tailored management strategies for patients with LQTS.

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References

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