%0 Case Reports
%T Case report: Mexiletine suppresses ventricular arrhythmias in Andersen-Tawil syndrome.
%A Yang J
%A Li K
%A Lv T
%A Xie Y
%A Liu F
%A Zhang P
%A Yang J
%A Li K
%A Lv T
%A Xie Y
%A Liu F
%A Zhang P
%J Front Cardiovasc Med
%V 9
%N 0
%D 2022
%M 36093155
%F 5.846
%R 10.3389/fcvm.2022.992185
%X It is arduous to determine clinical solutions for Andersen-Tawil syndrome (ATS) in patients intolerant of β-blocker. Here, we present the case of a 7-year-old boy with periodic paralysis and dysmorphic features who experienced syncope four times during exercise. His ECG revealed enlarged U waves and QU-prolongation associated with ATS-specific U wave patterns, frequent PVCs, and non-sustained bidirectional or polymorphic ventricular tachycardia. The genetic test showed a de novo missense R218W mutation of KCNJ2. With the diagnosis of ATS and intolerance of β-blocker, the patient was prescribed oral medications of mexiletine 450 mg/day without severe adverse effects. The repeat ECG showed decreased PVC burden from 38 to 3% and absence of ventricular tachycardia. He remained symptom-free during over 2 years of outpatient follow-up. This case demonstrates a new anti-arrhythmic therapy with mexiletine for prevention of life-threatening cardiac events in patients with ATS who are intolerant of β-blocker treatment.