Atrial pacing for the management of ventricular arrhythmias in Andersen-Tawil syndrome

Introduction Andersen-Tawil syndrome (ATS) is a rare autosomal dominant or sporadic disorder defined by a triad of periodic muscle paralysis, ventricular arrhythmias (long QT-7), and dysmorphic features. The estimated prevalence is 1 in 1,000,000. The underlying mutation is in the KCNJ2 gene encoding the inward rectifier potassium channels (Kir2.1) present in both skeletal and cardiac muscles. About 80% 90% of ATS cases have an identified KCNJ2 mutation, and these cases are classified as ATS1, with the rest designated ATS2. The clinical phenotype of the cardiac presentation is varied, ranging from prolonged QT interval, prominent Uwave, and premature ventricular complexes (PVCs) to bidirectional ventricular tachycardia and, rarely, ventricular fibrillation or sudden cardiac death (SCD). Ventricular arrhythmias are precipitated by adrenergic stimuli like exercise or intense emotion, which accounts for the use of beta-blockers as standard therapy. We present a case of ATS with ventricular arrhythmias not responsive to different antiarrhythmics including betablockers and managed successfully with atrial pacing.