Normally the heart pumps blood through the aorta to reach the rest of the body. In the presence of a tightness or (stenosis) the normal flow of blood is hindered leading to the build up of pressure behind the stenosis. If the stenosis occurs after the left subclavian this leads to decreased blood pressure in the lower limbs and high blood pressure in the upper limbs & upper 1/2 of the body. If the stenotic band is situated before the left subclavian these changes may affect the right limb and upper 1/2 of the body.
Coarctation of the aorta eventually leads to the appearance of collaterals, which are vessels that open up as a result of the pressure build up and attempt to create alternate pathways for the blood flow around the ring-like tightness.
Symptoms and signs
High blood pressure in a young patient or painful legs on walking due to lack of blood supply to the legs (a condition known as intermittent claudication) usually warrants further investigation. The presence of a large difference between blood pressure in different limbs and the presence of collaterals (e.g. in intercostal areas) can help make the diagnosis clearer.
A harsh, late systolic murmur may be heard in the back.
- EKG shows left ventricular hypertrophy.
- Chest x-ray may show rib notching due to collaterals.
- Doppler ultrasound readily diagnosis the condition once suspected.
- Transeophageal echo may help in some cases
- Angiography can measure the gradient across the coarctation.
Most patients have already been treated by childhood, rarely does it appear in adults while investigating hypertension or intermittent claudication.
Surgical correction is the 1st choice of treatment as the natural history of the disease is progressive. If the child is asymptomatic it is preferable to wait till 4-6 years of age.
In cases of recurrence a balloon is inserted in the ring to widen it.
Endocarditis prophylaxis should be given to all patients after surgical correction.
Twenty percent of patients remain hypertensive after surgical correction and require blood pressure control medications.