Coarctation of aorta

Two types

1. Infantile type (preductal, 2%) :
   • Proximal to the origin of left subclavian artery, so, left radial pulse is weak and rib notching on right side.
   • It presents with heart failure in infancy
   • Without other communication, patients do not survive.
   • It may be associated with PDA.
2. Adult type (postductal/juxtaductal)
   • Distal to origin of left subclavian artery, where ductus arteriosus joins the aorta.
   • It presents between 15 and 30 years of age.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 254; Short and Long Cases in Clinical Medicine, HN Sarker Page: 66

When pulse is absent in upper limb, but present in lower limb, it is called reverse coarctation.

It occurs in Takayasu’s disease.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 254

• Coarctation of aorta is twice more common in male than female.
• It is 7% of all congenital heart diseases.
• Even if there is hypertension, renal involvement is unusual and the fundal changes are also unusual.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 255

As follows:

• Congenital (the most common).
• Rarely, may be acquired in trauma, Takayasu’s disease.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 255

Murmur in coarctation of aorta is due to:

• Usually due to increased flow through collateral vessels.
• Also may be due to associated congenital bicuspid aortic valve.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 254

Conditions associated with coarctation of aorta include:

• Cardiac
  • Bicuspid aortic valve (50% of cases)
  • Patent ductus arteriosus
  • Ventricular septal defect
  • Mitral valve anomalies
  • Aortic arch hypoplasia.
• Non-cardiac
  • Turner’s syndrome (35% of cases)
  • Berry aneurysms
  • Hemangiomas
  • Renal abnormalities.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 66

Usually systolic hypertension, diastolic may be normal. Causes of hypertension are:

• Mechanical
• Renin angiotensin mechanism (due to coarctation, there is less blood flow to kidney)
• Resetting of baroreceptors.

Note

Collateral vessels are formed involving periscapular, internal mammary and intercostal arteries.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 254

Severe narrowing of the aorta encourages the formation of collateral arterial circulation to develop from the upper to lower parts of the body between

• Internal mammary arteries to external illiac arteries
• Spinal and intercostal arteries to the descending aorta.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67; Long Cases in Clinical Medicine, ABM Abdullah Page: 255

As follows:

• Coarctation of aorta (before the origin of left subclavian artery)
• Blalock-Taussig shunt (iatrogenic, done in Fallot’s tetralogy)
• Subclavian artery obstruction
• Neurofibromatosis
• Congenital

* Long Cases in Clinical Medicine, ABM Abdullah Page: 255

As follows:

• Coarctation of aorta (after the origin of left subclavian artery)
• Neurofibromatosis
• Congenital

* Long Cases in Clinical Medicine, ABM Abdullah Page: 255

As follows:

1. Arterial cause:
   • Coarctation of aorta
   • Subclavian artery obstruction.
2. Venous causes:
   • SVC obstruction (rare)
   • IVC obstruction (rare).
3. Neurological cause:
   • Neurofibromatosis
   • Enlarged nerve (as in amyloidosis, congenital hypertrophic polyneuropathy).
4. Others:
   • Congenital
   • Blalock-Taussig shunt (iatrogenic).

* Long Cases in Clinical Medicine, ABM Abdullah Page: 255, 256

• Collaterals from dilated tortuous arteries cause rib notching at the middle part posteriorly between the 3rd and 9th ribs.
• The anterior portions are spared, as the anterior intercostal arteries do not run in the costal grooves.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67

Presentations are as follows

• May be asymptomatic
• Hypertension
• Symptoms of hypertension, such as headache, nose bleeding
• Features of reduced blood supply to lower limbs – claudication of lower limbs and cold legs.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 66

The murmurs heard are as follows

• A systolic murmur at the site of coarctation – best heard posteriorly
• An ejection systolic murmur of aortic stenosis due to bicuspid aortic valve
• An early diastolic murmur of aortic regurgitation due to bicuspid aortic valve
• Systolic bruits over the collaterals.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67

The investigation must include

• X-ray chest PA view
• ECG
• Echocardiogram
• Cardiac catheterization
• MRI
• Aortogram (for confirmation).

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67

The ray findings include

• Rib notching
  • Mostly at the middle part posteriorly, due to enlargement of intercostal arteries from 3rd rib downwards. 1st and 2nd ribs are not affected, because intercostal arteries here arise from subclavian artery above the constriction.
• Prominent aortic knuckle
• Figure of 3 (constriction at coarctation, pre-and poststenotic dilatation)
• Cardiomegaly and pulmonary congestion (if left ventricular failure)

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67; Long Cases in Clinical Medicine, ABM Abdullah Page: 253

ECG shows

• Left ventricular hypertrophy +/- strain
• Left atrial dilatation.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67

• Because radial pulse is high volume, femoral pulse is feeble and there is radio-femoral delay.
• Also, the BP is very high in upper limbs and very low in lower limbs.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 253

The treatment must include

• Surgical repair of defect
  • Resection of segment of coarctation with end-to-end anastomosis of the aorta
  • Patch aortoplasty
  • Left subclavian flap angioplasty
• Cathceter-based intervention
  • Balloon angioplasty with stent insertion.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67

As follows :

• Hypertension and its complication (LVF, CVA)
• Hypoplastic limbs
• Infective endocarditis
• Left ventricular dysfunction and failure
• Rupture at the coarctation site
• Dissecting aneurysm
• Aneurysm of aorta
• Subarachnoid hemorrhage (rupture of Berry aneurysm of circle of Willis).

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 67; Long Cases in Clinical Medicine, ABM Abdullah Page: 254

As follows:

• Acute left ventricular failure
• Dissecting aneurysm or aorta
• Subarachnoid hemorrha

* Long Cases in Clinical Medicine, ABM Abdullah Page: 254