A family of 28 individuals spanning four generations was investigated because of a finding of complete heart block in five members and the existence of a low degree of atrioventricular (A-V) heart block in a sixth member. The disorder was characterized by 1) adult onset in all, 2) complete A-V heart block in five and first degree A-V heart block in one, 3) sinus bradycardia in three, 4) atrial ...

As part of routine prenatal care, the obstetrician of a 25-year-old gravida 1, para 0 woman performed fetal heart-rate monitoring at 22 weeks gestational age. The fetal heart rate was 90 bpm, below the expected range of 120 –160 bpm. This finding prompted a subsequent fetal ultrasound and echocardiogram. The ultrasound exam showed no evidence of hydrops. Cardiac anatomy was normal, with 4 appro...