OBJECTIVE: Left ventricular (LV) remodeling after closure of patent ductus arteriosus (PDA) in adults was reported that LV EF remains low late after PDA closure compared with pre-closure state and pre-closure LV EF is the best index to predict late post-closure LV EF. The aim of this study was to access the results of left ventricular remodeling after device closure of PDA in children. METHODS: In 42 patients with PDA who underwent closure of PDA successfully using Amplatzer occluder, echocardiography studies were performed before closure and 1 day after closure, and then were repeated about after 6 months. Echocardiographic parameters of LV were analized. RESULTS: Immediate after ductal closure, LV ejection fraction(EF) decreased(70.5짹5.8% -> 64.5짹7.0%, mean짹SD, p=.000), while LV diameter and volume index did not change significantly. However, during follow-up period, end-systolic volume index(ESVI), end-diastolic volume index(EDVI) decreased significantly and LV EF was recovered to the pre-closure state. In 25 patients with pulmonary to systemic flow ratio(Qp/Qs) above 1.5, LV EF was decreased immediately(71짹6.1% ->63.6짹7.6%, p=.000) after ductal closure. During the follow-up period, LV EF increased compared to the 1 day state after closure ( 63.6짹7.6%->70.5짹7.5%, p=.004) and was recovered to the pre-closure level. Both LV ESVI and EDVI were decreased immediately and follow-up period after ductal closure. However, in 17 patients with Qp/Qs below 1.5, LV diameter and volume index as well as LV EF were not changed after 1 day or during follow-up period. CONCLUIONS: Left ventricular (LV) remodeling after closure of PDA in children was somewhat different from that in adults. Only in the children with PDA with significant shunt, LV EF was decreased immediately after closure, but it was recovered during follow up period. Qp/Qs was the main determinant of LV change after PDA closure in children.