Instructions for use Title Fetal Presentation of Long QT Syndrome: Evaluation of Prenatal Risk Factors : A Systematic Review

16 OBJECTIVE: This systematic review was conducted to determine prenatal sings 17 suggestive of fetal manifestation of long QT syndrome (LQTS). 18 METHODS: Prenatal cardiac findings suggestive of fetal LQTS were studied in the 30 19 English literature reports that were abstracted from the database of PubMed (1979 – 20 December 2011) using the search terms including “long QT syndrome”, “fetal 21 arrhythmia”, and “congenital heart disease. 22 RESULTS: LQTS accounted for 15% to 17% of fetal bradycardias < 110 bpm among 23 fetuses with a normally structured heart. Seventeen to 35% of the patients with 24 significant prenatal findings of LQTS exhibited a slightly reduced baseline fetal heart 25 rate (FHR) of 110 – 120 bpm on electronic cardiotocography. Other prenatal sings were 26 sinus or intermittent bradycardia < 110 bpm arising from atrioventricular block, 27 tachyarrhythmias, pleural effusion and hydrops. More than 30% of Japanese infants 28 with LQTS born at or after the mid-1980s exhibited the above-mentioned in-utero signs. 29 CONCLUSIONS: Fetal factors including a slightly reduced baseline FHR of 110 – 120 30 bpm, bradycardia < 110 bpm, tachyarrhythmias, or clinical signs of heart failure, such 31 as pleural effusion and hydrops were associated with a higher frequency of LQTS. The 32 use of these signs might help to increase a fraction of patients with perinatally 33