Abstract

Objective
Long QT syndrome is a rarely seen disease during newborn period with high mortality. We report a newborn admitted outpatient clinics with complaints of cyanosis and breastfeeding difficulties diagnosed as ventricular tachycardia due to long QT syndrome that is resistant to the treatment and diagnostic and management approaches to in the light of current literature.
Case
A newborn delivered at 41 th week of pregnancy by cesarean delivery with a birth weight of 3460 grams was admitted to the outpatient clinic at postnatal seventh day with complaints of decreased breastfeeding frequency and cyanosis. Newborn was in a poor condition with depressed peripherical circulation also respiratory frequency was 80 breaths per minute and heart rate was 280 beats per minute also oxygen saturation was 60 percent. Newborn was admitted to the neonatal intensive care unit after intubation. Electrical cardioversion at 1 joule/kg was performed due to ventricular tachycardia detected at electrocardiography. After restoration of sinus rhythm corrected QT interval were measured 0.53 second. Echocardiography were performed and no structural cardiac anomaly were detected but severe mitral and tricuspid valve regurgitation were present and ejection fraction were 30 percent. Because of recurrence of ventricular tachycardia synchronized cardioversion at 1 joule/kg and 2 joule/kg were performed but because of cardioversion failure lidocaine were given to the patient. Due to the resistance of ventricular tachycardia to the treatment amiodarone, flecainide and esmolol were given subsequently. Patient failed to respond to any antiarrhythmic treatment and died at the third day of treatment with emerging ventricular fibrillation.
Conclusion
Long QT syndrome is a rarely seen disease during newborn period with high mortality. Early diagnosis of disease may assist to the treatment but the main prognostic factors are the QT interval length and the associated congenital anomalies.
Screening of newborns with risk factors by electrocardiography is debatable but it may be considered to the cases with defined risk factors. Also interventional procedures may be considered to the cases resistant to medical treatments.

Key words: Newborn, Mortality, Long QT