Intractable Atrial Flutter Successfully Treated with Flecainide and Propranolol in a Premature Infant

Although Atrial flutter (AFL) in newborn infant with normal cardiac anatomy has benign clinical course, an intractable AFL is associated with an increased risk of development of heart failure and sudden death, and is still difficult to manage. It requires multiple external electrical cardioversions, and it shows a poor response to antiarrhythmic drug therapy. We report a case of a premature infant with an intractable AFL, which we successfully treated with oral flecainide and propranolol in spite of recurred AFL. A 1-month-old, 34-week gestation, premature baby presented with an irregular heart beat and irritability. An AFL with 2:1 atrioventricular conduction was documented. Because of the intractable AFL, repeated electrical cardioversion and amiodarone were continued for 14 days. However, amiodarone was discontinued in favour of flecainide and propranolol because of the recurrent AFL and newly developed transient hypothyroidism. During 1-year follow-up period, in which oral flecainide and propranolol were continued, no AFL was observed.