Systolic myocardial velocity alterations in the growth-restricted fetus with cerebroplacental redistribution.
OBJECTIVE
Intrauterine growth restriction (IUGR) is associated with cerebroplacental redistribution (CPR), fetal stress and poor outcome, all of which may be related to dysfunction of the fetal myocardium. The aim of this study was to specifically assess myocardial function in IUGR fetuses with CPR in comparison with normal fetuses using color Doppler myocardial imaging (CDMI).


METHODS
CDMI was used to evaluate and compare myocardial velocities in the left and right ventricles in normal fetuses and in IUGR fetuses with CPR. Peak systolic tissue velocities (S') were acquired from both ventricular free walls in 20 IUGR fetuses (gestational age at scan ranged from 26 + 1 to 34 + 6 weeks, with serial measurements obtained in nine) and 42 normal fetuses (35 at week 28, with the remaining seven undergoing serial scans every 4 weeks, ranging from 18 + 6 to 39 + 1 weeks). Umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV) flows were also recorded.


RESULTS
Left and right S' increased with gestational age in normal pregnancy. Fetuses with IUGR and CPR had lower left ventricular S' than normal fetuses (mean, 2.41 (95% CI, 1.96-2.86) cm/s vs. 3.30 (95% CI, 3.05-3.55) cm/s; P = 0.0006). This reduction in S' correlated with the grade of UA flow abnormality (P = 0.0002). Fetuses with reversed diastolic UA flow had significantly lower left S' (mean, 2.0 (95% CI, 1.4-2.6) cm/s; P = 0.001) than normal fetuses. There was no correlation between left S' and MCA pulsatility index (P = 0.37) in the IUGR-CPR group, but there was a reduction in S' approaching statistical significance in fetuses with reversed DV flow in comparison to those without it (P = 0.09). Right S' was similar in the two study groups and did not correlate with worsening UA flow class. All fetuses with a left S' below 1.6 cm/s and reversed UA flow died in the perinatal period.


CONCLUSIONS
CDMI facilitates acquisition of fetal myocardial ventricular S'. The combination of IUGR and CPR is associated with a reduced left ventricular S', especially in those with reversed UA flow. In this subgroup a left S' below 1.6 cm/s seemed to predict mortality in the perinatal period.
Larsen
L U
LU
Department of Obstetrics and Gynecology, Aarhus University Hospital Skejby, Aarhus, Denmark. unmack@stofanet.dk
Sloth
E
E
Petersen
O B
OB
Pedersen
T F
TF
Sorensen
K
K
Uldbjerg
N
N
D001783:Blood Flow Velocity / Q000502:physiology; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D009206:Myocardium; D011247:Pregnancy; D012016:Reference Values; D012307:Risk Factors; D014427:Twins; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*