Idiopathic Atrial Flutter Associated with Dilated Cardiomyopathy in a Preterm Newborn: A Case Report

Background: Arrhythmias in neonates are uncommon and usually affect newborns with a normal heart or associated with structural heart disease. Meanwhile, one uncommon type of supraventricular arrhythmias is atrial flutter (AF), which is reentry mechanisms in the atrium. The AF may result in heart failure or even death, but the majority of its cases have revealed favorable prognosis in the event of early prenatal diagnosis and immediate treatment [J Am Coll Cardiol. 2006;48:1040–6, Semin Fetal Neonatal Med. 2006;11:182–90, and Arch Argent Pediatr. 2007;105:427–35]. A persistent tachyarrhythmia can progress to a state of cardiac dysfunction known as tachycardia-induced cardiomyopathy. While this may be a rare cause of dilated cardiomyopathy and heart failure in children, the condition is usually reversible and should be considered in newborn and infants [Europace. 2011;14(4):466–473]. Case Report: A preterm 33+1-week male newborn with birth weight 2,790 g was delivered through cesarean section. The baby presented with tachycardia after birth associated with respiratory distress. The physical examination showed heart rate >220/min, and ECG showed “saw tooth pattern” after intravenous adenosine boluses confirming diagnosis of AF (2-3:1). The heart rate reverted to sinus rhythm after synchronized cardioversion. Due to poor LV myocardial performance with dilated chambers, the baby received intravenous milrinone, followed by oral captopril. The baby was discharged on oral medications in perfect clinical condition, and follow-up showed no recurrence AF with improved cardiac function. Conclusion: Despite the rare occurrence, AF should be considered in differential diagnosis of newborn arrhythmia and diagnosed after intravenous adenosine injection. In few cases, AF can be associated with dilated cardiomyopathy which is a reversible condition.