1. Mexiletine Shortened QT Interval and Reduced Ventricular Arrhythmias in a Pedigree of Type 2 Long QT Syndrome Combined with Left Ventricular Non-Compaction
- Author
-
Jing Yang, Boda Zhou, Bihe Xu, Fei She, Tingting Lv, Yuanwei Liu, Rong He, Kun Li, Ping Zhang, Fang Liu, and Lingyun Kong
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities ,medicine.medical_specialty ,Heart Ventricles ,Long QT syndrome ,hERG ,Mexiletine ,Propranolol ,030204 cardiovascular system & hematology ,Sudden death ,QT interval ,Ventricular Function, Left ,Electrocardiography ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Missense mutation ,cardiovascular diseases ,030212 general & internal medicine ,biology ,business.industry ,Syncope (genus) ,General Medicine ,medicine.disease ,biology.organism_classification ,Pedigree ,Long QT Syndrome ,Echocardiography ,Tachycardia, Ventricular ,cardiovascular system ,Cardiology ,biology.protein ,Female ,Cardiology and Cardiovascular Medicine ,business ,Anti-Arrhythmia Agents ,circulatory and respiratory physiology ,medicine.drug - Abstract
In this study, we present a case of a 22-year-old female with a family history of syncope, suffering from recurrent syncope since childhood. She had an obvious prolonged QTc interval of up to 651 ms, a bifid T wave pattern on electrocardiogram, and torsade de pointes, corresponding to a syncope episode. Additionally, her echocardiogram showed left ventricular non-compaction in the apex. After treatment with mexiletine, the QTc interval has been observed to shorten immediately, and the T wave morphology recovered. A similar effect was also observed in her mother and young sister. Administration of propranolol prolonged her QTc interval. Target sequencing of candidate genes revealed a missense mutation in the pore area of the hERG protein, coded by KCNH2. We diagnosed this as a case of type 2 long QT syndrome in which mexiletine could be effective in shortening the QTc interval.
- Published
- 2021