Respiratory behavior in near-miss sudden infant death syndrome.

Seventeen infants with unexplained prolonged apnea that has been designated near-miss sudden infant death syndrome were monitored for sleep and cardiorespiratory variables during a 12-hour, all-night recording session. Infants were matched for gestational age, sex, and age at recording with control infants. Respiratory variables studied included respiratory rate, respiratory variability, apnea duration, apnea density, and periodic breathing. No statistically significant differences were found in sleep state or respiratory variables between near-miss and control infants. Eight infants (47%) had no recurrence of prolonged apnea, whereas three (17.6%) had recurrent apneic episodes for six weeks to eight months following the original episode. No clinical or polygraphic finding predicted which infant would exhibit recurrent apnea. None of the infants was monitored at home. All infants were developing normally when examined at 1 to 2 years of age.