Subjects for the study were drawn from the Rochester Family Heart Study which initiated recruitment for the family study in January 1985. In 31 months of recruitment, 443 households were contacted and 300 agreed to participate. In August 1987 all individuals identified by these households had completed their clinic visits providing 1,999 physical exams. The 300 households yielded 276 three and four generation pedigrees with 593 parents, 598 grandparents, 14 great-grandparents, and 854 children. Disease information was obtained from medical records for an additional 400 grandparents. In 1988 an additional 2,100 individual members of 300 families were surveyed.