Impaired Distensibility of the Proximal Aorta in Fetuses With Tetralogy of Fallot.

Background Increased aortic wall stiffness, which even persists after repair, has been reported in patients with tetralogy of Fallot (TOF). We aimed to observe the distensibility of the ascending aorta and descending aorta in fetuses with TOF and explore its relation with aortic blood flow volume and aortic and pulmonary annular size. Methods and Results Twenty-three fetuses with TOF and 23 gestational age-matched normal fetuses were included in this prospective cross-sectional study. The distensibilities of the ascending aorta and descending aorta were assessed by aortic strain (AS), which was defined as follows: 100×(maximum internal diameter in the systolic phase-minimum internal diameter in the diastolic phase)/minimum internal diameter in the diastolic phase. The maximum internal diameter in the systolic phase and minimum internal diameter in the diastolic phase of the ascending aorta and descending aorta were measured by M-mode echocardiography. Associations between AS and aortic blood flow volume and aortic and pulmonary valve diameters were assessed in both groups. AS of the ascending aorta in TOF group was lower than that in controls (20.48%±4.19% versus 28.17%±4.54%;