Autosomal dominant inheritance of sinus node disease.

A family with sinus node disease is presented. The mother was severely affected by sinus bradycardia and required a permanent atrial pacing system. The father is asymptomatic and has no evidence of conduction disturbances. All their offspring (one son and two daughters) are affected with variable degrees of severity. The occurrence of the disease in this family is suggestive of autosomal dominant inheritance with variable penetrance.