CLINICAL CHARACTERISTICS OF AN APPARENT LIFE-THREATENING EVENT (ALTE)AND THE SUBSEQUENT OCCURRENCE OF PROLONGED APNEA OR PROLONGED BRADYCARDIA

The objective of this study was to test the hypothesis that the charac teristics of an apparent life-threatening event (ALTE) influence the r isk for a subsequent episode of prolonged apnea or bradycardia. Data w ere obtained from 182 infants referred because of an apparent life-thr eatening event who were followed up at home for 2 lunar months on an a pnea/bradycardia monitor with recording capability. A prolonged episod e was defined as apnea greater than or equal to 20 sec long or an epis ode of bradycardia greater than or equal to 10 sec in duration as vali dated and measured from the event recordings. Seventeen percent of inf ants had at least one episode of prolonged apnea or prolonged bradycar dia. Change in skin color, degree of resuscitative intervention, and b ehavioral state were not statistically significant factors influencing the risk of a subsequent prolonged episode. Contrary to clinical expe ctation, a significantly greater percentage of infants subsequently ha d a prolonged episode whose muscle tone was described as normal during the ALTE (24.0%), when compared with those infants whose ALTE was ass ociated with limpness or increased muscle tone (9.3%). The coexistence of gastroesophageal reflux did not influence the overall results. The observations in this study place in question the clinical approach of relying on the detailed characteristics of an ALTE in determining the need for follow-up studies and/or home monitoring.