Obstruction to blood flow, Decreased pulmonary blood flow
Coarctation of Aorta
Narrow of aortic arc (large blood vessel) usually in juxtaductal position (region of ductus arteriosus and left subclavian artery).
Types of coarctation of Aorta
1. Infantile or preductual type
Above entrance of ductus arteriosus
Constriction of aorta between left subclavian artery and ductus arteriosus.
2. Post ductal type
Below entrance of ductus arteriosus.
Constriction at or distal to ductus arteriosus.
Pathophysiology
Narrowing involve small or long segment of aortic arc (mild constriction to total occlusion).
Impede (difficult) blood flow to lower portion of body.
Creating increased pressure proximal to obstruction
Increase pressure in upper part of body and lower pressure in lower part of body.
Clinical features
Two groups of patients with coarctation
1. Symptomatic in infancy
2. Remain asymptomatic, diagnosed later
Symptomatic children
Increase blood pressure in upper part of body, resulting in -
Headache
Dizziness
Fainting
Epistaxis (nose bleed)
Later cerebrovascular accident
3. Decrease in blood pressure in lower extremities (resulting in absent or diminished femoral and pedal pulse).
4. Weakness or pain in legs on excercise, leg cooler than arm
5. Present with congestive heart failure and failure to thrive.
Symptoms include-
Respiratory distress
Poor weight gain
Feeding problem
Irritability
Tachycardia
6. Mottling (mark with spots) , seen in lower extremities
7. Infants with coarctation and PDA may have adequate blood flow to lower extremities, good pedal pulse and no difference in blood pressure bin upper and lower extremities.
Once PDA closes- Symptoms develop
Diagnostic evaluation
1. Cardiac Examination
May no murmur present
Systolic murmur may present
2. Electrocardiogram
Left and right ventricular hypertrophy seen on ECG in infants with coarctation.
Older child may have left Ventricular hypertrophy or normal ECG.
3. Echocardiogram
Presence of coarctation and degree of narrowing.
4. MRI and cardiac catheterization
Useful in clearly defining area and extent of narrowing.
Therapeutic Management
1. End-to-end anastomosis
Narrowed portion of aorta removed band two normal parts are joined.
2. Subclavian flap aortoplasty
Longitudinal incision made in aorta across coarctated site and continued to the end of distally divided left subclavian artery
Left subclavian artery uses as patch or flap to increases diameter of aorta.
3. Patch aortoplasty
Patch graft is placed on aorta to widen it.
4. Balloon aortoplasty
Balloon catheter is introduced to aorta during cardiac catheterization and inflated at site of coarctation to relieve obstruction.
5. Tube graft
6. Medical management
Medical management for CHF and hypertension.
Continued antibiotic prophylaxis
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