Reference values for fetal tissue velocity imaging and a new approach to evaluate fetal myocardial function.
OBJECTIVE
Myocardial function can be evaluated using color-coded tissue velocity imaging (TVI) to analyze the longitudinal myocardial velocity profile, and by expressing the motion of the atrioventricular plane during a cardiac cycle as coordinated events in the cardiac state diagram (CSD). The objective of this study was to establish gestational age specific reference values for fetal TVI measurements and to introduce the CSD as a potential aid in fetal myocardial evaluation.


METHODS
TVI recordings from 125 healthy fetuses, at 18 to 42 weeks of gestation, were performed with the transducer perpendicular to the apex to provide a four-chamber view. The myocardial velocity data was extracted from the basal segment of septum as well as the left and right ventricular free wall for subsequent offline analysis.


RESULTS
During a cardiac cycle the longitudinal peak velocities of septum increased with gestational age, as did the peak velocities of the left and right ventricular free wall, except for the peak velocity of post ejection. The duration of rapid filling and atrial contraction increased during pregnancy while the duration of post ejection decreased. The duration of pre ejection and ventricular ejection did not change significantly with gestational age.


CONCLUSIONS
Evaluating fetal systolic and diastolic performance using TVI together with CSD could contribute to increase the knowledge and understanding of fetal myocardial function and dysfunction. The pre and post ejection phases are the variables most likely to indicate fetuses with abnormal myocardial function.
Nina Ne
NN
Elmstedt
Jonas Jj
JJ
Johnson
Britta Bl
BB
Lind
Kjerstin Kfw
KK
Ferm-Widlund
Lotta Lh
LL
Herling
Magnus Mw
MM
Westgren
Lars-Åke Lab
LÅ
Brodin
D001783:Blood Flow Velocity / Q000502:physiology; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D016014:Linear Models; D009200:Myocardial Contraction / Q000502:physiology; D011247:Pregnancy; D012016:Reference Values; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D016216:Ultrasonography, Prenatal / Q000379:methods*