EPIDEMIOLOGY
Most common causes of cyanotic congenital
heart disease
Most common CHD that survive (10%)
Four typical features of TOF
1. VSD
2. Pulmonary stenosis
3. Right ventricular hypertrophy
4. Aorta overriding VSD
CLINICAL FEATURES
Symptoms
Dyspnoea and fatigue is main presentation
After exercise (hypoxic cell), child usually adopt a squatting
position because it can increases peripheral vascular resistance and decreases
the degree of Rt to Lt shunt.
Growth retarded
On CVS examination
Central
cyanosis (commonly present from birth)
Clubbing
of finger and toes + polycythaemia (obvious after 12 months)
Auscultation
: systolic ejection murmur at Lt upper sternal border
PATHOPHYSIOLOGY
With substantial obstruction of the
Rt ventricular outflow tract, blood is shunted thru the ventricular septal
defect from right to left. Thus the patient will presented with central
cyanosis.
INVESTIGATION
CXR shows RV hypertrophy & small pulmonary artery (classic
boot-shaped heart)
ECG shows RV hypertrophy with Rt bundle
branch block (RBBB)
Echocardiography shows discontinuity between aorta and
anterior wall of ventricular septum
CT & MRI give valuable information for
planning the surgery
 |
| Boot-shaped heart
TREATMENTS
Without intervention (mortality rate
95% by age 20)
Give
02 and place knee-chest position
Morphine
can sedate the child + relaxing the outflow of pulmonary
Long
term B-blocker may be needed
Give
endocarditis prophylaxis
With intervention ( survival rate is
90-95% by age 20)
In infants (palliative procedure usually done before age 1 yr)
– an anastomosis between subclavian
artery and pulmonary artery (Blalock shunt), in order to increase blood supply
to the lungs.
Older child – A complete surgical correction is required.
REFERENCES
1. Kumar P, Clark M, editors. Kumar and Clark Clinical Medicine, 7th ed. 2. Mohammad Inam Danish, editor. "Medical Diagnosis and Management"
3. Longmore,editor. “Oxford handbook of Clinical Medicine”
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