FAMILIAL ATRIAL-FIBRILLATION WITH FETAL ONSET

A woman presented during two pregnancies (at 25 and 23 weeks' gestatio n, respectively) because the fetuses had rapid, irregular tachycardia and hydrops. After maternal drug treatment and achievement of slower f etal heart rates, the hydrops gradually resolved. Both babies were bor n full term with continuing atrial fibrillation. In the first, an ecto pic atrial rhythm was temporarily achieved during high dose flecainide treatment but, in the younger sibling, all medications and repeated c ardioversions failed even temporarily to convert the atrial fibrillati on with an almost isoelectric baseline in ECG to sinus rhythm. Good ra te control has been achieved with digoxin in both patients. No infecti ve, immunological, or structural cause was found in either case, and t hus an inherited aetiology is probable.