Fig. 4

A baby with true coarctation of the aorta (CoA) before and after birth. (A1-E1) Fetal ultrasound image at the gestational age 24 weeks and 6 days after birth. (A1) In the aortic arch long axis section, a “stent sign” was shown in the aortic isthmus whose inner diameter was 0.17 cm (Z-Score: -3.65). (B1) The isthmic blood flow spectrum was normal with no obvious reflux. (C1) The left and right heart ratio was normal with the left atrial transverse diameter of 1.15 cm and right atrial transverse diameter of 1.18 cm. (D1) In the three vessel tracheal section, the isthmic inner diameter was 0.19 cm, and the aortic transverse arch inner diameter was 0.22 cm. (E1) The ratio of the pulmonary valve annulus diameter to the aortic valve annulus diameter was increased, and the aortic valve diameter was 0.28 cm (left) and the pulmonary artery was 0.45 cm (right). (A2-E2) Ultrasound images 35 h after birth before the closure of the ductus arteriosus (DA). (A2) The shape of the aortic arch is irregular, with a tortuous and thin inner diameter of 0.22 cm near the descending aorta at the distal end of the arch (→: thinner isthmus). (B2) The diastolic blood flow spectrum at this location increased with a peak systolic velocity (PSV) of 1.56 m/s at the isthmus and a pressure difference of 9.71 mmHg. (C2) The right heart is slightly larger. (D2) The left ventricular systolic function is normal with an ejection fraction (EF) of 63.02% and fraction of shortening (FS) 31.15%. (E2) The abdominal aortic spectrum showed a “small slow wave”. (A3-E3) Ultrasound images forty-two days after birth with closure of the DA. (A3) The distal end of the descending part of the aortic arch was thin, with an inner diameter of 0.23 cm (→: thinner isthmus). (B3) The flow velocity was significantly increased with a PSV 3.51 m/s and a pressure difference of 49.36mmHg. (C3) The left ventricle was slightly larger in the four chamber view. (D3) The left ventricular systolic function was reduced with an EF 56.79% and FS 24.38%. (E3) The abdominal aortic spectrum was a “small slow wave”. LA left atrium, LV left ventricle, RA right atrium, RV right ventricle, AO aorta, AA0 ascending aorta, and PA pulmonary artery.