title: [Development of the heart rate in the first year of life and infant ill health].
abstract: Heart rate during the 1st year of life decreases from 149 to 117/min (mean) and 227 to 186 (upper range), as determined by Holter monitoring. There is little change in those at the lower frequencies. A decrease in nocturnal rhythm becomes evident by 3 months of age. In comparison to these controls, near-miss infants or their sibs and infants with "spells" demonstrate a lower basal rate with longer pauses and wider range of instantaneous variability from the 1st days of life. Near-miss infants and sibs of sudden infant death syndrome infants are harder to differentiate. However, the "sibs" + "spells" groups show prolonged pauses over 1 second in the first weeks of life and become even more prominent at 3 months. This vagal hyperreactivity may be due to immature or poorly regulated cholinergic bulbar centers.
mesh_terms: D001049:Apnea / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000503:physiopathology; D002302:Cardiac Output; D002940:Circadian Rhythm; D004562:Electrocardiography / Q000379:methods; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000502:physiology*; D012024:Reflex, Oculocardiac; D013398:Sudden Infant Death / Q000503:physiopathology
vernacular_title: Evolution des fréquences cardiaques au cours de la première année et malaises du nourrisson.