Thu hẹp lòng động mạch chủ tạo ra một cản trở dòng chảy. Preductal: thu hẹp là gần ống động mạch. Postductal: thu hẹp là xa ống động mạch. A: Nếu không phát triển bình thường của vòm động mạch chủ trong tuần thứ 5 và thứ 6 của thai kỳ. A / R: hội chứng Turner, rubella bẩm sinh | 28 Coarctation of the aorta COA CONDITIONS D Narrowing of the lumen of the aorta that produces an obstruction to flow. Preductal the narrowing is proximal to the ductus arteriosus. Postductal the narrowing is distal to the ductus arteriosus. A Failure of normal development of the aortic arch in the 5th and 6th week of gestation. A R Turner syndrome congenital rubella VSD PDA hypoplastic left heart interruption of the aortic arch severe form of coarctation with no connection between the proximal and distal aorta . E 1 10000 live births. Antenatal often diagnosed on antenatal USS. Neonatal when the ductus arteriosus closes in the 2nd to 3rd week of life there is a sudden overflow of blood into the left ventricle which causes LVF dyspnoea lethargy feeding difficulties and failure to thrive . Infancy symptoms depend on the severity of stenosis and the development of collateral circulation Preductal COA usually has good collateral circulation. Postductal COA has a variable collateral circulation. Childhood adulthood patients with good collateral circulation may be asymptomatic until childhood adolescence or adulthood. E Nodding head movements accompanying each heart beat weak femoral pulse difference in BP between upper and lower limbs SBP 20 loud S1 and narrow split S2 usually no murmur. _P Collateral circulation connects the proximal and the distal aspects of the aorta over time. This develops mainly from the subclavian scapular internal thoracic and intercostal arteries. Low BP and flow exist in the arteries that branch off distal to the constriction. High BP occurs in the arteries that branch off closer to the heart. Therefore a high BP exists in the upper body and arms and a low BP in the lower body and legs. I CXR cardiomegaly with pulmonary vascular markings LVF a hypoplastic aortic knob with dilated post-stenotic segment of the aorta. ECG LVH in older children. Doppler echo diagnostic and demonstrates pressure gradient. M If COA is diagnosed antenatally child
