Pulmonary Arterial Abnormalities in the Sudden-Infant-Death Syndrome

Abstract

The sudden-infant-death syndrome is the greatest single cause of death between one week and one year of age in the United States. In the current study, 40 such babies had 1.6 times as much muscle in their small pulmonary arteries as controls. Three quarters of this added muscle was due to hypertrophy, and the rest to hyperplasia of smooth-muscle fibers. Increased muscle at these sites is a characteristic consequence of chronic alveolar hypoxia. age-matched infants living at high altitude at the time of death had 2.3 times as much muscle in their small pulmonary arteries as the low-altitude controls. These findings are consistent with the recent observation that some victims of the syndrome have had periods of apnea before death. (N Engl J Med 289:1167–1170, 1973)