Influence of intrauterine hemodynamics on the C segment of the aortic arch in the fetus

Objective. To assess the correlation between the hemodynamic characteristics of the left ventricle and geometric features of the aortic arch in the fetus. Methods. The study involved 31 fetuses from 29 to 34 weeks of gestation by echocardiography. The scientists assessed the morphogeometric characteristics of the left ventricle andaortic arch. They studied the following parameters: end-diastolic volume ofthe left ventricle (LVEDV), stroke volume of the leftventricle (LVSV), velocity-time integral of the flow through aortic valve (VTI AV), diameter of the aortic valve ring (AV), diameterof the aortic arch segment between brachiocephalic trunk and left carotid artery (dС). Results. The average gestational age was 31,9±1,4weeks (95% CI: 31,4–32,4 weeks). Average body weight 1899±377 g (95% CI: 1762–2038 g). LVEDV = 1,57±0,64 ml (95% CI: 1,3–1,8). LVSV = 1,3±0,45 ml (95% CI: 1,1–1,4 ml). AV 0,4±0,07 cm (95% CI: 0,39–0,44 cm). C segment of the aorticarc is 0,37±0,07 cm (95% CI: 0,035–0,040 cm). There was direct correlation between the variables used to calculate dC (Pearson correlation coefficient: LVEDV = 0,51; p= 0,002; LVSV = 0,46; p= 0,005; AV = 0,52, p= 0,001). The diameter of the C segment of the aortic arch can be calculated using the following equations: dС= 0,76· LVSV +2,8 (95% CI LVSV 0,2–1,3 95% CI for constant2,1–3,6; Fisher’s criterion 7,6 р =0,01). dС= 0,59· LVEDV +2,8 (95% CI LVEDV 0,2–0,98; 95% CI for constant 2,2–3,5; Fisher’s criterion 10 р =0,004). dС= 0,59·AV+1,3 (95% CI AV 0,22–0,95; 95% CI for constant – 0,23–2,9; Fisher’s criterion 10,7; р =0,003). Conclusion. 1)hemodynamic characteristics of the left ventricle allow predicting the sizeof the aortic arch in fetuses from 29 to 34 weeks of gestation; 2)morphogeometric characteristics of the aortic arch are determined by the characteristics of the left ventricular stroke volume, end-diastolicvolume of the leftventricleand the sizeof the fibrous ring of the aortic valve.