Regional Blood Flow Distribution and Left Ventricular Output during Early Neonatal Life: A Quantitative Ultrasonographic Assessment

Abstract

To examine the serial changes of left ventricular output and regional blood flow distribution during the early neonatal period, we measured blood flow volume in the ascending aorta, middle cerebral artery, celiac artery, superior mesenteric artery, and renal artery in 23 normal term infants at 1, 4-8, 24, and 96 h after birth. The blood flow volume in each vessel was measured by the pulsed Doppler technique. In the middle cerebral artery, celiac artery, and superior mesenteric artery, the blood flow volume at 1 and 4-8 h of age was significantly lower than after 24 h of age. In contrast, renal artery blood flow volume did not change significantly throughout the study period. The reduced organ blood flow volume soon after birth was related to a low diastolic blood flow in the major vessels, and the percent diastolic integral of blood flow velocity in each vessel showed an inverse linear correlation with the diameter of the ductus arteriosus. The left ventricular output 1 h after birth was 365 +/- 69 mL/kg/min, which was significantly higher than after 4-8 h of age. Left ventricular output gradually declined to 301 +/- 63 mL/kg/min at 4-8 h of age (p < 0.05 versus 96 h), 272 +/- 48 mL/kg/min at 24 h, and 258 +/- 54 mL/kg/min at 96 h. There was a significant positive correlation between left ventricular output and the ductus arteriosus diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac function and morphology studied by two‐dimensional doppler echocardiography in unsedated newborn pigs

“…The younger the animal the greater is the relative size of the heart (Schultz & Giordano, 1962). The aortic diameter and the heart weight related to body weight were very similar to those found in preterm infants, while the calculated physiological measurements -cardiac output and velocities across the four valves corresponded closely to those reported in term humans (Walther et al 1985;Hirsimaki et al 1988;Hudson et al 1990;Gossler & Goldberg, 1991;Agata et al 1994;Guajardo et al 1994). An exception is the anatomical arrangement of the liver veins (Silver et al 1988).…”

Sonographic Changes in Hypoxic-Ischaemic Encephalopathy

“…A severe increase in the BFV and the decrease in cerebrovascular resistance take place during the first week of life with largest changes occurring within the first 24 hour as a part of neonatal adaptation after birth (Agata et al, 1994;Hayashi et al, 1992;Ilves et al, 2008;Kempley et al, 1996;Martinussen et al, 1994;Yildirim et al, 2005). Ductal close and progressive increase in the blood pressure may explain the observed increase in BFV and decrease in the RI in healthy infants (Agata et al, 1994;Hayashi et al, 1992;Ilves et al, 2008;Martinussen et al, 1994;Yildirim et al, 2005).…”

“…A severe increase in the BFV and the decrease in cerebrovascular resistance take place during the first week of life with largest changes occurring within the first 24 hour as a part of neonatal adaptation after birth (Agata et al, 1994;Hayashi et al, 1992;Ilves et al, 2008;Kempley et al, 1996;Martinussen et al, 1994;Yildirim et al, 2005). Ductal close and progressive increase in the blood pressure may explain the observed increase in BFV and decrease in the RI in healthy infants (Agata et al, 1994;Hayashi et al, 1992;Ilves et al, 2008;Martinussen et al, 1994;Yildirim et al, 2005). Autoregulation of the cerebral blood flow is operative in a normal full term infant (Ilves et al, 2008), however a pressure-passive state of the cerebral circulation is observed in seriously asphyxiated full term infants Pryds et al, 1990, Ilves et al, 2008 The resistance index is also influenced by the flow velocity, the blood volume, the presence of congenital cardiac anomalies and the peripheral vascular resistance.…”

“…Kidneys can be scanned from the dorsolateral view, and the size, structure and echogenicity of the kidneys are evaluated to establish normality. The BFV in the renal artery (RA) can be visualized by placing the transducer in the right dorsolateral area of the flank below the costal arch and the sampling volume placed in the proximal portion of the vessel with a simultaneous viewing of the abdominal aorta (Adriani et al, 2001;Agata et al, 1994;Ilves et al, 2008). .…”

“…. The origin of the coeliac artery (CA) and the superior mesenteric artery (SMA) is localized from the aorta in a longitudinal plane and the sampling volume is placed in the proximal SMA and CA (Agata et al, 1994;Ilves et al, 2008;Weir et al, 1995).…”