NIH Definition:
An episode that is frightening to the observer and that is characterized by some combination of apnea (central or occasionally obstructive), color change (usually cyanotic or pallid but occasionally erythematous or plethoric), a marked change in muscle tone (usually marked limpness), choking, or gagging.
Apnea = cessation of breathing >20 seconds.
Etiology of ALTE:
Gastrointestinal (33%)
Gastroesophageal reflux
Gastroenteritis
Esophageal dysfunction
Colic
Surgical abdomen
Dysphagia
Neurologic (15%)
Seizure
Central apnea/hypoventilation syndromes (apnea of prematurity, Ondine’s curse)
Head injury (intraventricular hemorrhage, subarachnoid hemorrhage)
Meningitis/encephalitis
Hydrocephalus
Brain Tumor
Neuromuscular disorders
Vasovagal reaction
Congenital malformation of the brainstem
Respiratory (11%)
Respiratory syncytial virus
Pertussis
Aspiration pneumonia
Other lower or upper respiratory tract infection
Reactive airway disease
Foreign body
Otolaryngologic (4%)
Laryngomalacia
Subglottal and/or laryngeal stenosis
Obstructive sleep apnea
Cardiovascular (1%)
Congenital heart disease
Cardiomyopathy
Cardiac arrhythmia/prolonged QTc
Myocarditis
Metabolic/endocrine
Electrolyte disturbance
Hypoglycemia
Inborn error of metabolism
Other infections
Sepsis
Urinary tract infections
Child maltreatment syndrome
Shaken baby syndrome
Intentional suffocation
Munchausen-by-proxy syndrome
Other
Physiologic event (periodic breathing, acrocyanosis)
Breath-holding spell
Choking
Drug or toxin reaction
Unintentional smothering
Anemia
Hypothermia
Idiopathic/apnea of infancy (23%)