OP-15. Andersen-Tawil Syndrome Diagnosed with Bidirectional Ventricular Tachycardia during Pregnancy

Aim: Andersen-Tawil syndrome (ATS) is a rare autosomal dominant potassium channelopathy and caused by loss-of-function mutations in the KCNJ2 and KCNJ5 genes. It is characterized by the clinical triad of periodic paralysis, cardiac arrhythmias and dysmorphic feature. This report describes a pregnant patient with ATS presenting bidirectional ventricular tachycardia. Case: A 23 year-old female with 28 week of pregnancy refered our outpatient clinic with palpitations and dizziness. She has no remarkable medical past and no history of syncope. The physical examination revealed short stature, micrognathia, broad nose, short neck, broad forehead and fifth digit clinodactyly (Fig. 1). An initial ECG showed a prolonged QTc (518 ms) and runs of non-sustained bidirectional ventricular tachycardia (Fig. 2). Her mother and younger sister also have history of ventricular arhythmias and fifth digit clinodactyly. Her examination was unremarkable except of irregular pulse rate. 24 hours holter revealed 40.314 (%38) premature ventricular contractions and 7 beats bidirectional non sustained ventricular tachicardia. Exercise stress testing showed non sustained bidirectional VT without an increase with egzercise. Laboratory testing and transthoracic echocardiogram were normal. Genetic testing revealed KCJN2 gene mutation also in mother and sister. She was given metoprolol 2x50 mg and her holter revealed no reduction on PVCs burden and 37 beats bidirectional VT. She gave birth to her second healthy baby during approximately 4 years of follow-up. The patient, who did not accept the previously recommended ICD device, accepted the device to be inserted after her second birth. The patient with a dual ICD is being followed without any problems. Also, mother and other daughter are being followed without symptoms. Conclusion: ATS is a rare autosomal dominant potassium channelopathy. Treatment of ventricular arrhytmias in patients with ATS is contraversial and the efficency of medicament is vague. Eventhough the prognosis of ATS is believed to be benign, close monitoring is essential due to assign the patients with high risk for sudden cardiac arrest. Discussion: ATS, also known as Long QT syndrome Type 7 (LTQ7), is a rare autosomal dominant potassium channelopathy, with a prevalence of 1/500,000. It's characterized by the clinical triad of periodic paralysis, cardiac arrhythmias (frequently ventricular arrhythmias), and dysmorphic features which includes short stature, hypertelorisms