A Case of Long QT Syndrome Type 3 Aggravated by Beta-Blockers and Alleviated by Mexiletine: The Role of Epinephrine Provocation Test

• Published in: Yonsei medical journal Vol. 54; no. 2; pp. 529 - 533
• Main Authors: Park, Junbeom, Kim, Sook Kyoung, Pak, Hui-Nam
• Format: Journal Article
• Language: English
• Published: Korea (South) Yonsei University College of Medicine 01.03.2013; 연세대학교의과대학
• Subjects: Adolescent; Adrenergic beta-Antagonists - adverse effects; Adrenergic beta-Antagonists - therapeutic use; Case Report; Defibrillators, Implantable; Diagnosis, Differential; Diagnostic Techniques, Cardiovascular; Epinephrine; Female; Humans; Long QT Syndrome - classification; Long QT Syndrome - diagnosis; Long QT Syndrome - genetics; Long QT Syndrome - therapy; Mexiletine - therapeutic use; Pedigree; Syncope; 의학일반
• ISSN: 0513-5796; 1976-2437; 1976-2437
• DOI: 10.3349/ymj.2013.54.2.529

Long QT syndrome (LQTs) is an uncommon genetic disease causing sudden cardiac death with Torsade de Pointes (TdP). The first line drug treatment has been known to be β-blocker. We encountered a 15-year-old female student with LQTs who had prolonged QTc and multiple episodes of syncope or agonal respiration during sleep. Although her T wave morphology in surface electrocardiography resembled LQTs type 1, her clinical presentation was unusual. During the epinephrine test, TdP was aggravated during β-blocker medication, but alleviated by sodium channel blocker (mexiletine). Therefore, she underwent implantable cardioverter defibrillator implantation.