Ultrasound diagnosis of hydrops fetalis due to fetal tachycardia

Fetal congestive heart failure due to intra-uterine tachycardia with or without arrhythmia is an unusual cause of hydrops fetalis in the newborn (Silber and Durnin, 1969; Van der Horst, 1970; Etches and Lemons, 1979.) With the increasing use of ultra sound, cases are now being diagnosed during pregnancy (Kerenyi et al., 1980; Rees et al., 1980). We report two further such cases diagnosed in utero.