Polysomnograms and cardiopneumograms in SIDS research.

Polysomnographic (PSG) and cardiopneumographic (CPG) recordings are commonly used in research on sudden infant death syndrome (SIDS). PSG and simultaneous CPG recordings were compared in order to clarify two practical problems: reliability of sleep state evaluation with CPG and comparability of the number of respiratory pauses evaluated by these two recording techniques. This comparison shows that: (1) evaluation of sleep states by CPG technique is only reliable for quiet sleep and (2) there was a significant difference in the number of pauses, the evaluation with PSG being systematically higher than with CPG. The abnormalities found or suspected in CPG home recordings must be confirmed by PSG in the laboratory.