Cardiac and respiratory responses to esophageal dilatation during REM sleep in human infants.
Forty-one preterm and fullterm infants (26.5-40.5 weeks gestational age and 31.5-50 weeks postconceptional age) free from neurologic and cardiopulmonary disease at the time of testing underwent a standardized esophageal dilatation test (EDT) during polygraphically controlled REM sleep. RR interval and total duration of the respiratory cycle (TTOT) were measured (1) during the 60 s preceding the EDT, i.e. mean control RR and mean control TTOT; (2) during EDT. Percent RR (%RR) was defined as the longest RR interval in milliseconds during EDT divided by mean control RR in milliseconds multiplied by 100, and percent TTOT (%TTOT) as the longest TTOT in seconds during EDT divided by mean control TTOT in seconds multiplied by 100. EDT provoked prolongation of both RR interval and TTOT. %RR decreased significantly with advancing gestational age (p less than 0.003), and %TTOT with advancing postconceptional age (p less than 0.003), indicating that both cardiac and respiratory responses to an EDT challenge are blunted with maturation.
Ramet
J
J
Laboratory of Physiology, Hospital Antoine-Béclère, Clamart, France.
Praud
J P
JP
d'Allest
A M
AM
Dehan
M
M
Guilleminault
C
C
Gaultier
C
C
D004562:Electrocardiography; D004569:Electroencephalography; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010528:Peristalsis; D012119:Respiration; D012895:Sleep, REM / Q000502:physiology*