Body Surface Area–Adjusted Sotalol Dosing for Refractory Atrial Flutter in an Extremely Premature Infant: A Case Report

Neonatal atrial flutter is a rare arrhythmia that can rapidly lead to hemodynamic instability, particularly in infants with underlying cardiopulmonary disease. We present the case of a male infant born at 28 weeks’ gestation with severe pulmonary hypertension and right ventricular dysfunction who developed recurrent atrial flutter despite vagal maneuvers, adenosine, betablockade, and synchronized cardioversion. Tachycardia at 230 beats/min was identified as atrial flutter on electrocardiography (ECG) on day of life (DOL) 9, and cardioversion successfully restored sinus rhythm. On DOL 10, the infant experienced recurrent 2:1 atrial flutter and atrial reentrant tachycardia, requiring repeated cardioversions and intravenous amiodarone. By DOL 11, the infant responded to combined esmolol and amiodarone therapy. On DOL 12, treatment was transitioned to oral sotalol using a bodysurfacearea–based dosing calculation with neonatal age adjustment. Serial ECGs were obtained to monitor the QT interval. By DOL 13, the infant remained free of breakthrough arrhythmias, with only mild QTc prolongation observed. This case highlights the challenges of managing neonatal arrhythmias, demonstrates the use of sotalol in a very premature infant, and emphasizes the importance of precise dosing and vigilant QTc monitoring when initiating sotalol therapy in extremely premature neonates.