ABSTRACT
Apnea during infancy remains a difficult problem in pediatrics: what is physi-
ologic and what is pathologic? To address this quandary, this chapter will first
attempt to describe what is considered the spectrum of normal breathing for a
‘‘healthy’’ term infant from the gold standard of polysomnography as well as
multichannel recordings in the hospital and at home. This review will then
examine the challenging chief complaint of an apparent life-threatening event
(ALTE). ALTE was defined by a National Institutes of Health expert panel in
1986 as ‘‘an episode that is frightening to the observer and that is characterized
by some combination of apnea (central and occasionally obstructive), color
change (usually cyanotic or pallid but occasionally erythematous or plethoric),
marked change in muscle tone (usually marked limpness), choking, or gagging’’
(1). In the subsequent 20 years there has been improved understanding in the
epidemiology, diagnosis, and management of this heterogeneous group of
patients with diverse underlying pathophysiology. This chapter focuses on
examining the cardiorespiratory abnormalities of those infants who have been
identified as idiopathic ALTE, specifically those infants in whom no underlying
diagnosis was found.
