A variant of long QT syndrome manifested as fetal tachycardia and associated with ventricular septal defect

Two patients with a nobel variant of long QT syndrome are described. The cl inical course was characterised by an in utero onset of ventricular tachyca rdia and atrioventricular block (at 26 and 30 weeks' gestational age, respe ctively), and an association with a ventricular septal defect. Studies of b oth patients' families identified relatives with prolonged QT interval, syn cope, or sudden death. One patient died of intractable ventricular tachycar dia at 4 days old. The other received beta blocker treatment and a pacemake r. She died suddenly at the age of 10 months. The unique association with v entricular septal defect and the malignant clinical course warrants further molecular diagnosis of this novel variant of long QT syndrome.