title: Left ventricular systolic time intervals and plasma noradrenaline concentrations during acute hypovolaemia in newborn infants.
abstract: Left ventricular systolic time intervals and plasma noradrenaline concentrations were determined in twelve newborn infants during acute moderate hypovolaemia. Rapid withdrawal of 8.5 ml of blood per kg body weight shortened the left ventricular ejection time from 204 to 176 msec (P less than 0.001) and increased the plasma noradrenaline concentration from 3.4 to 4.0 nmol/l (P less than 0.05). Systemic blood pressure was unchanged. It is concluded that even a moderate reduction in blood volume is associated with marked changes in left ventricular dynamics. The shortening of left ventricular ejection time during hypovolaemia probably reflects left ventricular adaptation to decreased volumes and response to increased noradrenaline release.
mesh_terms: D001803:Blood Transfusion; D001810:Blood Volume; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles; D006801:Humans; D007231:Infant, Newborn; D009200:Myocardial Contraction; D009638:Norepinephrine / Q000097:blood*; D010951:Plasma Exchange; D013318:Stroke Volume; D013599:Systole; D013997:Time Factors
chemical_list: D009638:Norepinephrine