Successful ablation of refractory neonatal atrial flutter

Case report The patient was a male infant born at 38 weeks’ gestation. Atrial flutter was diagnosed in utero at 35 weeks of gestation, at which time no hydrops fetalis was present and no treatment was commenced. At 6 hours of life, the infant developed tachycardia. The electrocardiogram (ECG) showed atrial flutter with 2:1 atrioventricular conduction (Figure 1). Initially the rhythm could be reverted to sinus by biphasic direct current (DC) cardioversion. However, atrial flutter recurred despite intravenous amiodarone infusion. The infant developed heart failure on day 3 of life. An echocardiogram demonstrated a structurally normal heart with significant biatrial dilation and moderately impaired biventricular function. No intracardiac thrombus was evident. Transesophageal overdrive pacing was attempted but failed. DC cardioversion (at 1 J/kg) could revert the rhythm to sinus, but atrial flutter recurred within 12 hours. In total, DC cardioversion was attempted 6 times with varying combinations of intravenous amiodarone (15 μg/kg/min), intravenous esmolol (up to 175 μg/kg/min), oral digoxin (8 μg/kg/day), sotalol (4.5 mg/kg/day), and flecainide (4 mg/ kg/day), but none of them could maintain the rhythm in sinus, and atrial flutter recurred within 12 hours. In view of the persistent ventricular dysfunction with biatrial dilation, electrophysiologic study with potential radiofrequency ablation of the atrial flutter was performed on day 14 of life.