The fetal cardiac isovolumetric contraction time in normal pregnancy and in pregnancy with placental vascular disease: the first clinical report using a new ultrasound technique.
OBJECTIVE
To study the fetal cardiac isovolumetric contraction time in normal and complicated pregnancies with placental vascular disease using a newly developed digital Doppler cardiography system.


METHODS
A preliminary case-control study.


METHODS
Tertiary referral hospital.


METHODS
One hundred and sixteen normal fetuses (20 to 40 weeks) and 55 complicated pregnancies with placental vascular disease as documented by a high systolic: diastolic ratio in the umbilical artery Doppler flow study.


METHODS
A digital Doppler cardiography system with a high sampling rate (4,000 Hz) was used to detect the fetal cardiac valvular movements. The isovolumetric contraction time was measured as the interval between the mitral valve closing and the aortic valve opening with a built-in scale device.


RESULTS
In normal pregnancy the isovolumetric contraction time remained remarkably constant with gestation and fetal heart rate. Comparison between clinical outcome and the isovolumetric contraction time of the complicated fetuses who were born within a week after the last determination of the isovolumetric contraction time revealed a strong correlation between prolonged isovolumetric contraction time duration and abnormalities in the perinatal course (non-reactive fetal heart rate pattern, low pulsatility index in the fetal middle cerebral artery Doppler flow and low birthweight infant).


CONCLUSIONS
The isovolumetric contraction time is constant with gestation and fetal heart rate in normal pregnancy. In the presence of placental vascular disease a prolonged fetal isovolumetric contraction time predicts adverse outcome.
Department of Obstetrics and Gynaecology, University of Sydney at Westmead Hospital, NSW, Australia.
T
T
Koga
N
N
Athayde
B
B
Trudinger
D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D009200:Myocardial Contraction / Q000502:physiology*; D010922:Placenta Diseases / Q000503:physiopathology; D011247:Pregnancy / Q000502:physiology*; D011249:Pregnancy Complications, Cardiovascular; D011256:Pregnancy Outcome; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014469:Umbilical Arteries