A family with evidence of severe malfunction of the sinus node in two senior members and
with electrocardiographic evidence of sinus node malfunction in four junior members and an
additional adult is presented. Acquired heart disease has been clinically excluded in the
patients described. None of the patients demonstrates QT interval prolongation, and there is
no family history of congenital deafness. Family histories relative to syncopal episodes,
serious cardiac arrhythmia, breath holding spells, or palpitations should be obtained from all …