The evaluation of systolic time intervals and impedance cardiogram of neonates.
The left ventricular systolic time intervals (STI) and impedance cardiogram were studied in 295 newborn infants. The wave pattern of the carotid was mainly anacrotic, similar to the wave pattern of hypertensive adult patients. In the neonatal period Q-I and Q-II intervals were gradually shortened and the prolongation of the preejection period (PEP), isometric contraction time (ICT) and an increase in PEP/ET were most prominent in the group at 24-72 hours after birth. The impedance cardiogram was able to be recorded clearly in newborn infants by the 4 electrode method. Stroke volume and cardiac output calculated from Kubicek's formula were most decreased in the group at 5-6 hours after birth. The estimated values were 3.79 +/- 0.78 ml and 456.2 +/- 92.2 ml/min. respectively at that stage, and gradually increased thereafter. In the babies in which the umbilical cord was clamped and tied later than 3 minutes after delivery, prolongation of the Q-I, Q-II intervals, pulse propagation time, PEP, ICT and a decrease in ET/PEP were remarkable, and cardiac output and blood pressure were relatively increased until about 120 hours after birth. These STI measurement and impedance cardiograms were useful to use in observing various cardiovascular changes in newborn infants. It was clear that the timing of clamping of the umbilical cord after delivery affected the cardiovascular hemodynamics of neonates.
Department of Obstetrics and Gynecology, Hirosaki University School of Medicine.
A
A
Kagiya
N
N
Echizenya
A
A
Hamada
T
T
Tachizaki
S
S
Satoh
Y
Y
Saitoh
D002302:Cardiac Output; D002307:Cardiography, Impedance; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D009200:Myocardial Contraction; D010992:Plethysmography, Impedance; D013318:Stroke Volume; D013599:Systole