Neonatal hypertrophic cardiomyopathy: a case report and family study.

An infant of a diabetic mother is described with severe neonatal hypertrophic obstructive cardiomyopathy. Commencement of regular intravenous propranolol was associated with marked clinical improvement. Long-term oral propranolol was continued and at 12 months of age there was complete resolution of the cardiomyopathy. Familial hypertrophic cardiomyopathy hypertrophy was present in two other generations of this family. The results of family screening and tissue typing are presented, with the suggestion that tissue typing may be a useful tool in the assessment of doubtful cases in certain affected families.