Assessment of contractility and myocardial function in small and appropriate for gestational age premature neonates using the stress-velocity relationship and tissue Doppler imaging immediately after birth.

Our aim was to determine whether small for gestational age (SGA) neonates exhibit reduced left ventricular contractility and diastolic dysfunction, through the assessment of tissue by Doppler imaging and investigation of the stress-velocity relationship (SVR). The study subjects were limited to 37 neonates just after birth. These patients were grouped into 14 SGA neonates with birth weights below the 10th percentile (aged 29-36 weeks, birth weight 860-2066 g) and 23 appropriate for age (AGA) neonates with birth weights between the 10th-90th percentile (aged 20-36 weeks, birth weight 954-2945 g). Although there were no significant differences in the SVR or diastolic function between the SGA and AGA neonates, wall stress correlated significantly and inversely with birth weight in all subjects with a higher E/Ew ratio by tissue Doppler imaging. In conclusion, there were no significant differences in cardiac function between SGA and AGA neonates. By contrast, the relationship between wall stress, diastolic dysfunction, and birth weight may be due to physiological alterations in neonates, including those with low birth weights, just after birth.