Coarctation of The Aorta

(COA)

5 – 7 % of CHD .

Constriction of the Aorta of varying degree which may occur at any point from the transverse arch to the iliac bifurcation .

M : F 2 : 1 .May be a feature of Turner

syndrome .Associated with bicuspid Aortic valve

in >70 % of cases

Types & Pathophysiology :

Discrete juxtaductal obstruction ( adult type ).

• 98 % of cases .• Occurs just below the origin of L

subclavian artery , at the origin of Ductus Arteriosus .

• LV hypertrophy & LV HT .• L R Ductal shunting occurs following

birth .

Preductal (infantile type ) :

• Tubular hypoplasia of transverse aorta , starting at one of the head &neck vessels & extending to Ductal area .

• RV PDA descending Aorta (R L shunt ): palpable femoral pulse , differential cyanosis . Sever pul. HT & high pul. Vascular resistance &

HF . BP elevated in vessels proximal to

coarctation . BP & pulse pressure lower below coarctation . With time collateral circulation (early

adulthood)

Clinical Manifestations :

• After infancy , most patients are a symptomatic .

• Some children , adolescents weakness or pain (or both ) in lower extremities after exercise .

• HT on routine physical examination .Classic signs :Disparity in pulsation & BP in the arms & legs Weak or absent pulse(up to 40 % ) in LL ,

bounding in UL & neck , lower BP in LL relative to UL

Radial – femoral delay .

90 % of patients have systolic HT in UL > 95th percentile for age .

Precordial impulse &heart sounds are normal .

Systolic thrill in supra sternal notch bicuspid AS .

Short systolic murmur along L sternal border at 3rd, 4th ICS well transmitted to L infra scapular area, neck.

Murmur of AS 3rd R ICS . In older patients systolic or continuous

murmur heard L & R sides of chest laterally & Posteriorly associated with a palpable thrill .

In neonates or infants with sever COA :

• Sign of lower body hypo perfusion (differential cyanosis) .

• Acidosis & sever HF • O/E cardiomegaly systolic murmur , heard

along L sternal border . loud S2 .

Investigations :

CXR : finding depends on : Age , effect of HT , collateral circulation sInfants with sever COA cardiomegaly & pul.

Congestion .After 1st decade :• Mild – moderate cardiomegaly ( LV) .• Notching of inferior border of ribs (late childhood

).• Descending Aorta has an area of post steno tic

dilatation .

ECG :

• Neonates & young infants R or biventricular hypertrophy .

• Young children normal .• Older patients LV hypertrophy .

• Echo :• Visualize the segment of coarctation ,

& look for associated lesion . Cardiac Catheterization &

selective L ventriculography &Aortography :

• Visualization of collateral blood vessels .

Treatment :

• PGE2 infusion for neonates with sever COA & management of associating HF .

• Surgical repair soon after the diagnosis & stabilization of the general condition .

• Timing of surgery should not be delayed after 2nd decade because of associating LV dysfunction .

Prognosis & complications :

• CVA severe neurologic damage or death.• Premature coronary artery disease , HF ,

hypertensive encephalopathy , intracranial Hg complication of HT .

• Infective endocarditis or endarteritis adult

• Aneurysms of the descending Aorta & of collaterals .

• HF & hypo perfusion (life threatening ) .• Complication of associating lesions .• Abnormalities involving L subclavian artery .

Tetra logy of Fallot(TOF)

5 – 7 % of CHD .

• Consist of :1)Obstruction of RV outflow ( RV

infundibulum, PS ) .2)VSD .3)Dextro position of the Aorta with

Septal over –ride .4)RV hypertrophy .

Pathophysiology

Clinical Manifestations :

In infancy :• Mild RV outflow obstruction HF ( L

R shunt across VSD ) with no cyanosis at birth .

( cyanosis occurs later in 1st year of life ).

• Sever degree of RV outflow obstruction neonatal cyanosis , sever collapse following closure of Ductus Arteriosus .

Older Children :

• Cyanosis with dusky blue skin , gray sclerae & engorged blood vessels .

• Clubbing of fingers & toes . • Dyspnea on exertion & tendency to

squat .• Paroxysmal hyper cyanotic attack

( hypoxic , blue or tet spells) :Common in 1st 2 years .Hyperpneic , restless , cyanosis increase ,

gasping respiration & syncope may result .

Occurs in the morning after initial awakening or after a vigorous crying .

Lasts from few min. to few hrs., rarely fatal .

Disappearance or decrease in the intensity of murmur

Mild attacks weakness & sleep .Severe attacks unconsciousness ,

convulsion ,hemi paresis .Prolonged attacks sever systemic

hypoxia & metabolic acidosis . • Growth & developmental delay .

Physical signs :

• precordial bulge with sub sternal impulse RVH .

• Systolic thrill along L sternal border in 3rd &4th para sternal space .

• Systolic murmur : ejection in type at the upper sternal border , holo systolic at the lower sternal border .

• S2 either single or pulmonic component is soft.

• Continuous murmur in presence of collaterals .

Investigations

• CXR :Normal in size , boot shaped .Clear hilar & pulmonary vascularity

(oligaemic lung ).R sided Aortic arch in 20-25 % of

cases .

• ECG:RVH , P- pulmonale , RAD .

• Echo :

• Cardiac Catheterizations :

Treatment :

• Aim provides an immediate increase in pul. Blood flow to prevent the sequel of sever hypoxia .

• Lines of therapy :Maitainence of normal body temperature

& blood glucose . IV administration of PGE potent

relaxant of Ductal smooth muscle .Prevention & prompt treatment of

dehydration . Iron therapy : improves exercise tolerance

& decrease the frequency of spells .

Oral propranolol decrease severity & frequency of hyper cyanotic spells .

Surgical treatment as soon as spells begins .• Palliative systemic –to-pulmonary artery

shunt . ( Blalock – Taussig shunt ).• Corrective open heart surgery .Treatment of hyper cyanotic spells :Placement of the infant on the abdomen in

the knee – chest position .O2, rehydration, morphine (not > 0.2 mg/kg

S.C ).Correction of metabolic acidosis NaHCO3 .Drugs increasing systemic vascular

resistance (phenylephrine, methoxamines) B-blockers .

Complications :

• Polycythemia & dehydration cerebral thrombosis & CVA .

• Brain abscess .• Bacterial endocarditis ,• HF unusual unless in pink TOF & following

surgery .• Growth retardation & pubertal delay .• Complications of hyper cyanotic spells .• Post – operative complications

chylothorax , diaphragmatic paralysis , Horner syndrome .