Heart failure in congenital thyrotoxicosis.

Abstract

Congenital thyrotoxicosis, or Graves9 disease of the newborn, may be complicated by cardiac decompensation. Both the disease and its complication are self-limited, but they may become severe and endanger the life in the neonatal period. Failure of the heart may be related to interference with formation of high-energy phosphate bonds in the myocardial mitochondria by high levels of thyroid hormone. This phenomenon depletes the source of energy for myocardial contraction. The treatment should be primarily directed toward the hyperthyroidism. The enhanced rate of growth of the hyperthyroid fetus may lead to a developmental state where a small, apparently premature infant has well-formed and well-functioning organs, some aged far in advance of the relatively short intrauterine life. The term accelerated maturity is suggested to describe this state.