Noninvasive determination of the fetal cardiac interatrial pressure gradients by Doppler ultrasonography: preliminary results

Abstract

Objective

In 2000, Johnson et al. measured the atrial pressures puncturing the atria invasively in 19 fetuses that will be terminated. In this study, it is aimed to define the fetal cardiac interatrial pressure gradient noninvasively. The pressure gradients were calculated using the ductus venosus (DV) and pulmonary vein (PV) blood flow velocities and Bernoulli equation for flowing fluids.

Methods

“S,” “a,” and the time-averaged maximum velocities in both veins of 246 fetuses were used in the simplified Bernoulli equation; Δp=4 (${\mathrm{V}}_{\text{DV}}^2-{\mathrm{V}}_{\text{PV}}^2$). Additionally, the umbilical vein maximum velocity is measured in order to calculate ducto-umbilical pressure gradient.

Results

The average interatrial pressure gradient was biggest in the ventricular systole and the least gradient was in the atrial systole of a cardiac cycle. The pressure gradient changes throughout the second and the third trimester have four periods with two increases and two decreases.

Conclusions

The interatrial and ducto-umbilical pressure gradients can be measured noninvasively in order to follow the hemodynamic of the fetal circulatory system.

Keywords:

• Doppler ultrasound
• ductus venosus
• noninvasive prenatal diagnosis
• second trimester

Ethical approval

The research was conducted ethically in accordance with the World Medical Association Declaration of Helsinki. The authors state that subjects (or their parents or guardians) have given their written informed consent and that the study protocol was approved by the institute’s committee on human research.

Acknowledgments

To Dr Nermin Bayar from the Department of Cardiology, Antalya Training and Research Hospital for explaining their perspective for approaching the patients with aortic stenosis by ultrasonography.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Cemil Gürses: Study design, imaging and measurements, data collections.

Onur Erol: Study design, writing and final approval.

Burak Karadağ: Study design, data entry and statistical analysis.

Mete Çağlar: Data control, follow up the patients’ and statistical analysis.