Infants dying of Sudden Infant Death Syndrome (SIDS) while on home cardiorespiratory monitors have demonstrated terminal bradycardia preceding apnea. Cigarette smoking during pregnancy is a known risk factor for SIDS and a dose response relationship has been demonstrated. Therefore the home cardiorespiratory monitor printouts of all infants who were evaluated in our apnea program were collected and analyzed for bradycardias (B) and cigarette exposure (CE) over a 6 month period. There were 242 patients with a total of 1536 true Bs; of these 66 patients were exposed (E) and 176 patients were not exposed (NE) to cigarette smoke. Table

Table 1
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Multivariate analysis of covariance was performed to examine the relationship between CE and the number of Bs. BW was the sole covariate. No significant relationships were found. Analyses were also computed to examine the relationships between the maternal dose of CE versus the number of Bs. No significant relationships were found. We speculate that infants with CE may have higher resting heart rates and thus not have an increased number of Bs under normal conditions.