ABSTRACT
Andersen-Tawil syndrome (ATS) is a rare hereditary long QT syndrome type 7 caused by a missense mutation in the KCNJ2 gene. ATS is characterized by ventricular arrhythmia, periodic limb paralysis and minor external malformations. Although only three reports of pregnant women with Andersen-Tawil syndrome have been reported to date, no exacerbation of ventricular arrhythmia was observed from pre-partum to delivery in all cases compared to that before pregnancy, and it was suggested that the risk of arrhythmic events from pre-partum to delivery is not high. Unlike these previous reports, we herein present a case of Andersen-Tawil syndrome in which ventricular arrhythmias increased and sustained ventricular tachycardia was developed during labor progression. We also advise caution that pregnant patients with Andersen-Tawil syndrome may have varying times of exacerbation of the arrhythmia, and ventricular arrhythmias may be associated with painful uterine contractions.