Comparative Analysis of Heart and Chamber Areas on Scans in Healthy Fetuses and Fetuses with Congenital Heart Defects

Background: The implementation and application of modern mathematical models for data analysis in the radiological diagnosis of congenital heart defects (CHD) represents a significant challenge. The use of modern neural networks for predicting CHD has the potential to reduce the incidence of undiagnosed cases.

Objective: To compare the areas of heart and its chambers, including the atrial to ventricular ratios, during the second trimester obstetric screening between fetuses with and without CHD.

Materials and Methods: An observational non-randomized study was conducted involving 85 pregnant women during the second trimester obstetric screening. The patients were divided into two groups: Group I (n=45) – pregnant women with healthy fetuses and Group II (n=40) – pregnant women carrying fetuses with CHD. During the examination, the areas of the heart and its chambers were determined, and the cardio-cardial index (CCI) was calculated in healthy fetuses and in the fetuses with СHD. The atrial to ventricular area ratios were evaluated in both healthy fetuses and fetuses with CHD. The study was conducted using a Samsung H60 ultrasound scanner (Samsung Medison, South Korea) in the Perinatal Center of Children’s Regional Clinical Hospital (Krasnodar). Statistical analysis of data from 132 cases was performed using the STATISTICA 13.3 software package (TIBCO Software Inc., USA).

Results: Reference values were determined for the area of the heart (2.57-3.97 mm2) and for the areas of its chambers: right atrium (RA) 0.26-0.46 mm2, left atrium (LA) 0.27-0.53 mm2, right ventricle (RV) 0.25-0.46 mm2, left ventricle (LV) 0.34-0.64 mm2. A significant difference from the reference values was observed in fetuses with CHD: RA ≤ 0.25 mm2 or ≥ 0.47 mm2; LA ≤ 0.26 mm2 or ≥ 0.54 mm2; RV ≤ 0.24 mm2 or ≥ 0.47 mm2; LV ≤ 0.33 mm2 or ≥ 0.65 mm2. The CCI was 0.11-0.14 in healthy fetuses, 0.05-0.25 in fetuses with CHD. In congenital heart defects, the ratios depend on the type of malformation and are determined by right heart overload resulting from the characteristics of fetal circulation.

Conclusion: Determination of the fetal heart area in the range of 2.57 mm2 to 3.97 mm2 during the second trimester obstetric screening allows for the exclusion of CHD with high probability. Evaluation of CCI is a valuable diagnostic method: the range of 0.11-0.14 is associated with healthy fetuses, while in fetuses with CHD, the values vary widely due to altered fetal blood flow, indicating the presence of cardiovascular pathology in CHD with increased pulmonary blood flow and in anomalies of the pulmonary venous connection. In cases of CHD with decreased pulmonary blood flow, conotruncal anomalies or CHD with obstruction of systemic blood flow, fetal cardiac MRI should be performed alongside fetal echocardiography to ensure an accurate diagnosis. Improving ultrasound methods and equipment, as well as the introduction of fetal cardiac MRI, are expected to enhance the early detection of CHD and should become an important tool in routine practice of radiologists, enabling the integration of mathematical analysis into clinical practice. 

1. Lloyd DF, van Amerom JF, Pushparajah K, et al. An exploration of the potential utility of fetal cardiovascular MRI as an adjunct to fetal echocardiography. Prenat Diagn. 2016;36(10):916-925. PMID: 27521762. PMCID: PMC5082528. https://doi.org/10.1002/pd.4912

2. Sun L, Lee FT, van Amerom JFP, Freud L, Jaeggi E, Macgowan CK, et al. Update on fetal cardiovascular magnetic resonance and utility in congenital heart disease. Journal of Congenital Cardiology. 2021;5(1). https://doi.org/10.1186/s40949-021-00059-x

3. Haris K, Hedström E, Kording F, et al. Free-breathing fetal cardiac MRI with doppler ultrasound gating, compressed sensing, and motion compensation. J Magn Reson Imaging. 2020;51(1):260-272. PMID: 31228302. PMCID: PMC6916642. https://doi.org/10.1002/jmri.26842

4. Vollbrecht TM, Hart C, Zhang S, et al. Fetal Cardiac Cine MRI with Doppler US Gating in Complex Congenital Heart Disease. Radiol Cardiothorac Imaging. 2023;5(1):e220129. PMID: 36860838. PMCID: PMC9969216. https://doi.org/10.1148/ryct.220129

5. Tavares de Sousa M, Hecher K, Yamamura J, et al. Dynamic fetal cardiac magnetic resonance imaging in four-chamber view using Doppler ultrasound gating in normal fetal heart and in congenital heart disease: comparison with fetal echocardiography. Ultrasound Obstet Gynecol. 2019;53(5):669-675. PMID: 30381848. https://doi.org/10.1002/uog.20167

6. Roy CW, van Amerom JFP, Marini D, Seed M, Macgowan CK. Fetal Cardiac MRI: A Review of Technical Advancements. Top Magn Reson Imaging. 2019;28(5):235-244. PMID: 31592990. PMCID: PMC6791520. https://doi.org/10.1097/rmr.0000000000000218

7. Lloyd DFA, Pushparajah K, Simpson JM, et al. Three-dimensional visualisation of the fetal heart using prenatal MRI with motion-corrected slice-volume registration: a prospective, singlecentre cohort study. Lancet. 2019;393(10181):1619-1627. PMID: 30910324. PMCID: PMC6484696. https://doi.org/10.1016/s0140-6736(18)32490-5

8. Qi H, Cruz G, Botnar R, Prieto C. Synergistic multi-contrast cardiac magnetic resonance image reconstruction. Philos Trans A Math Phys Eng Sci. 2021;379(2200):20200197. PMID: 33966456. https://doi.org/10.1098/rsta.2020.0197

9. Tsibizova VI, Pervunina TM, Artemenko VA, et al. Placenta crucially affects formation of fetal congenital heart disease. Obstetrics, Gynecology and Reproduction. 2022;16(1):66–72. https://doi.org/10.17749/2313-7347/ob.gyn.rep.2022.262

10. Pomortsev A.V., Karakhalis M.N., Matulevich S.A., Daschyan G.A., Khalafyan A.A., Sencha A.N. Congenital Heart Diseases: Risk Factors and Ultrasound Diagnostic Potential at the First Screening. Innovative Medicine of Kuban. 2023;(4):51-59. (In Russ.) https://doi.org/10.35401/2541-9897-2023-8-4-51-59

11. Khalafyan A.A. STATISTICA 6. Matematicheskaya statistika s elementami teorii veroyatnostey. Moscow: Binom; 2010. (In Russ.).

12. Vonck S, Staelens AS, Lanssens D, et al. Low Volume Circulation in Normotensive Women Pregnant with Neonates Small for Gestational Age. Fetal Diagn Ther. 2019;46(4):238-245. PMID: 30726847. https://doi.org/10.1159/000495507

13. Fu Q. Hemodynamic and Electrocardiographic Aspects of Uncomplicated Singleton Pregnancy. Adv Exp Med Biol. 2018;1065:413-431. PMID: 30051399. https://doi.org/10.1007/978-3-319-77932-4_26

14. Barkhordarian M, Ghorbanzadeh A, Frishman WH, Aronow WS. Endocardial Fibroelastosis: A Comprehensive Review. Cardiol Rev. 2024. PMID: 38230923. https://doi.org/10.1097/crd.0000000000000653

15. Aldawsari KA, Alhuzaimi AN, Alotaibi MT, Albert-Brotons DC. Endocardial fibroelastosis in infants and young children: a state-of-the-art review. Heart Fail Rev. 2023;28(5):1023-1031. PMID: 37222928 https://doi.org/10.1007/s10741-023-10319-0

16. Zhou Q, Liu D, Zhou J, et al. Factor Analysis of the Missed Diagnosis of Total Anomalous Pulmonary Venous Connection in Prenatal Echocardiography. Birth Defects Res. 2024;116(12):e2426. PMID: 39691945. https://doi.org/10.1002/bdr2.2426

17. PomortsevA.V., KarakhalisM.N., KrivonosovaN.V., GoloseevK.F. Multimodal Approach (MRI and Ultrasonography) to the Diagnosis of Fetal Congenital Heart Diseases. Innovative Medicine of Kuban. 2024;(4):21-29. https://doi.org/10.35401/2541-9897-2024-9-4-21-29