What happens when the aorta narrows?
The aorta carries blood from the left ventricle to the rest of the body. With coarctation, there is an area of narrowing in the thoracic region, usually near the junction of the ductus arteriosus. The blood in front of the obstacle creates increased pressure, so the vessels of the brain and eyes suffer, and the left ventricle constantly overcomes resistance and thickens. Below the constriction, blood flow is reduced. The body partially compensates for this by developing bypass pathways through the intercostal arteries - over time, the dilated vessels leave characteristic imprints on the ribs.
- Narrowing most often in the area of the aortic isthmus
- High pressure above the constriction
- Reduced blood flow in the lower half of the body
- Left ventricular hypertrophy
- Development of bypass vessels through intercostal arteries
- Often associated with bicuspid aortic valve
Causes and risk factors
The defect is formed in utero when the tissue of the ductus arteriosus spreads to the wall of the aorta and, when the duct closes, tightens it. It is usually impossible to name a specific reason. Coarctation is more common in boys and is noticeably more often combined with a bicuspid aortic valve, so the patient must also have the valve evaluated. The defect is typical of Turner syndrome in girls. Family predisposition to congenital heart defects also matters.
- Impaired formation of the aorta in the fetus
- Male gender
- Bicuspid aortic valve
- Turner syndrome
- Congenital heart defects in relatives
- Combination with septal defects and cerebral vascular anomalies
Symptoms at different ages
In newborns with critical narrowing after closure of the ductus arteriosus, a serious condition quickly develops: pallor, lethargy, refusal to breastfeed, rapid breathing, weak or absent pulse in the legs. Older children may have no complaints, and the defect is detected by high blood pressure or noise. Teenagers and adults complain of headaches, nosebleeds, tinnitus, chilliness and tired legs when walking. A characteristic feature is strong, developed arms with weaker legs.
- In newborns: lethargy, shortness of breath, weak pulse in the legs
- High pressure in the arms with normal or low pressure in the legs
- Headache, nosebleeds, tinnitus
- Fatigue and pain in the legs when walking
- Cold feet
- Murmur in the heart and on the back between the shoulder blades
Diagnostics
The first and most accessible step is to measure blood pressure in both arms and legs and feel the pulse in the femoral arteries. The pressure difference and weakened pulse in the legs directly indicate a defect. Echocardiography shows the location and degree of narrowing, the condition of the aortic valve and left ventricle. To accurately assess the anatomy and plan intervention, a CT or MRI of the aorta is performed. Chest X-rays in adults can reveal characteristic changes in the contour of the aorta and rib structure. ABPM is needed to control blood pressure.
- Measuring pressure on the arms and legs
- Palpation of the pulse in the femoral arteries
- Echocardiography with gradient and valve assessment
- CT or MRI of the aorta
- Chest X-ray
- ABPM before and after intervention
- ECG
Treatment and observation after surgery
The narrowing is eliminated surgically: the narrowed area is excised, connecting the ends of the aorta, or plastic surgery is performed. In older children and adults, as well as in case of repeated narrowing, the endovascular method is often used - balloon expansion with stenting through the vessel. In critically ill newborns, the ductus arteriosus is kept open before surgery. After successful correction, the pressure usually decreases, but in some patients hypertension persists and requires treatment. Lifelong observation: repeated narrowing and aortic aneurysm are possible.
- Surgical resection of the narrowing with anastomosis
- Aortic repair with patch or flap
- Balloon angioplasty with stenting
- Maintaining a patent duct in newborns
- Treatment of persistent arterial hypertension
- Lifelong follow-up with echocardiography and aortic imaging
- Aortic valve assessment
