Chapter 26: Coarctation of the Aorta (Children) Flashcards
Coarctation of the Aorta (CoA)
a narrowing or stricture of the descending aorta distal to the carotid arteries
- a congenital narrowing of the aorta, which is the largest artery present at the top of the heart
- acyanotic
- obstructive lesion
- coarctation is classified by its location: preductal, ductal, or post-ductal
When do physicians suspect a CoA?
> Normally blood pressure (BP) in the legs should be higher or equal to that in the arms
-when a BP in the lower extremities is lower than that of the upper arms by 10 mm Hg or more =suspects CoA
occasionally, the BP is the right arm is higher than the left; this usually occurs with a preductal coarctation in which the flow to the left arm is supplied by the flow of the blood through the ductus, which is a lower pressure system; for this reason, if only one upper extremity is used as a comparison with the lower extremities, it should be the right arm. If a child is hypertensive CoA is suspected
Signs and Symptoms
> murmur
-not always present
-systolic ejection murmur heard at upper right sternal border and left sternal border
-cycle radiates to left axilla and left intrascapular area of the back
may show signs of CHF
child may have pain in the legs or cyanotic lower extremities
Diagnosis
high gradient, which is the difference in the pressure measurements between the arms and legs (use right arm if comparing with one arm)
Nursing Care
focuses on postoperative management of child
- child is followed by health-care provider for evidence of restenosis (recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow)
- monitoring of upper and lower blood pressures
- post-surgically the child may have rebound hypertension; the ventricles have become accustomed to pushing hard against the narrowed area in the aorta; when this area is opened up, the heart muscle still wants to contract strongly against the gradient; if there is nothing to push against, there is still an abnormally high blood pressure; this is controlled by antihypertensive agents for 6 months to a year after surgery and may be required through life
Medical Care
pharmacological agents include after-load (wall stress) reducing agents, which control the blood pressure
-captopril (Capoten) and enalapril (Vasotec)
Surgical Care
surgery is always indicated
-invasive treatment for older infants and adolescents involves a balloon angioplasty and stent placement