Congenital heart disease
Dr. Mohanad K. Shukur Alghanimi
Pediatrics cardiology
Definition of congenital heart disease
Congenital heart disease(CHD) is defined as the
structural ,functional or positional abnormality of
the heart, in isolation or in combination, present
from birth, but may manifest any time after birth
or may not manifest at all
Classification of congenital heart disease
1-Acynotic CHD
A- LV or RV volume overload as: VSD, PDA and ASD
b- LV or RV pressure overload as: AS, COA and PS
2-Cynotic CHD
A- With decrease of pulmonary blood flow as: TOF,
DORV+PS and single ventricle +PS
B- With increase of pulmonary blood flow as: DTGA, TAPVD
and truncus arteriosus
Causes of congenital heart
disease
1-Maternal causes:
Disease:
-
A
DM: TGA, HCM and VSD
SLE: congenital complete heart block
infection:
-
B
Rubella: PDA, peripheral PS
Coxasckie B virus: Myocarditis (late
pregnancy)
Drug:
Insulin, Thyroid hormone and Oral
contraceptive: TGA, TOF and VSD
Lithium: Ebstein anomaly and TV atresia
Vitamin A: TGA
Vitamin D: Supravalvular aortic stenosis
Phyntoin: PS, AS and COA
High altitude: ASD and PDA
Sex:
Male: Bicuspid aortic valve, AS, COA, TOF and TGA
Female: ASD and PDA
The Recurrence Risk with:
- 1 sib with CHD: 2-4%
- 2 sibs with CHD: 6-12%
- Mother with CHD:6-12%
- Father with CHD: 2-4%
In 1/2 of these families the same defect recur
s.
Septal Defects:
Ventricular
Ventricular septal defects (VSDs) are the most
common form of congenital heart disease if
bicuspid aortic valve is excluded,
slightly
more common in females approximately 56%
female, 44% male
Type of VSD
1-perimembranous VSD =70%
2-Outlet (infundibular or conal) defects account for
5% to 7% of all VSDs in the Western world and
about 30% in Far Eastern countries
3-Inlet (or AV canal) defects account for 5% to 8%
4-Trabecular (or muscular) defects account for 5% to
20% of all VSDs
Clinical Manifestations
Small VSD:
In infants with small VSDs, a murmur usually is detected at 1 to
6 weeks of age when the infant returns for the initial checkup
after discharge from
the newborn nursery.
With small defects, the clinical course is benign throughout
infancy and childhood.
There are normal patterns of feeding, growth, and
development.
The only risk is that of endocarditis, which is rare before the
age of 2 years.
By palpation, the precordial activity is normal. A thrill may be
palpable along the lower left sternal border and is associated
with a grade IV to VI holosystolic murmur
size VSD:
Moderate and Large
may develop symptoms as early as 2 weeks of age. The initial
symptoms consist of tachypnea with increased respiratory
effort, excessive sweating owing to increased sympathetic
tone, and fatigue when feeding. The infant progressively tiers
with feeding; this symptom begins during the first month and
increases in severity as pulmonary vascular resistance
decreases. Symptoms occur earlier in the premature than in
the full-term infant, it is not unusual for symptoms to be
preceded by respiratory infection.
In the absence of infection,
the cardiovascular basis for the respiratory symptoms
probably is pulmonary edema of mild to moderate degree
with elevated pulmonary venous pressure and decreased
lung compliance
In children with large shunts for 4 to 6 months, the left anterior
thorax bulges outward the pulmonary component of the
second sound is usually ,
loud.
Cyanosis during the early weeks of life is often transient and
frequently presents only with superimposed stress or illness.
Persistent cyanosis from birth indicates a more complicated
lesion than isolated VSD. However, the occurrence of
cyanosis after infancy suggests reversal of the shunt to right
to left because of progressive pulmonary vascular disease or
the development of significant infundibular pulmonary
stenosis(pulmonary stenosis)
Palpation reveals a prominent right ventricular lift that is usually
maximal in the xiphoid region. There may be a very short or
no systolic murmur from the VSD
Investigation:
1) ECG
A. With a small VSD, the ECG is normal.
B- moderate and large size VSD with LVH and RVH and sign of
PHT
2) CXR
A-Small VSD may be Normal CXR
B- Cardiomegaly of varying degrees is present and involves the
LA, left ventricle (LV), and sometimes RV. Pulmonary vascular
markings increase. The degree of cardiomegaly and the
increase in pulmonary vascular markings directly relate to the
magnitude of the left-to-right shunt
3) Echocardiography
4) Magnatic resonance imaging
5) Cardiac catheterization
Treatment
Therapy
Medical
Children with small VSDs are asymptomatic and have
excellent long-term prognosis. Neither medical therapy
nor surgery is indicated. If children with moderate or
large VSDs develop symptomatic congestive heart, a
trial of medical therapy is indicated. Furosemide is used
in a dosage of 1 to 3 mg/kg/day divided into two or three
doses. Chronic furosemide can result in hypocalcaemia,
hypokalemia, metabolic alkalosis and renal damage.
Addition of spironolactone can be helpful to minimize
potassium loss. Potassium supplementation is difficult to
achieve in most infants because of the unpalatable taste
of the supplement
s.
Additional to initial therapy includes increasing the caloric
density of the feedings by using milk with24-30Kcl/once
Systemic afterload reduction with enalapril (initial dosage of
0.1 mg/kg/24 hours divided into twice daily, gradually
increasing to 0.5 mg/kg/24hours divided into twice daily
dose.
A traditional approach has been to administer digoxin
to infants with congestive heart failure associated with
moderate or large VSD and increased pulmonary blood flow.
Several studies have shown that the contractile function of
the left ventricle is normal or increased, casting doubt on the
usefulness of digoxin.
Digoxin may be indicated if diuresis
and afterload reduction do not provide adequate symptom
relief and surgery is not advisable. The usual dose of digoxin
is 10
µg/kg/day that can be given once daily or in divided
doses twice a day
Clinical Course and Prognosis
1-Patients with small defects have an excellent prognosis, albeit
with a small risk of endocarditis, aortic valve insufficiency, and
late cardiac arrhythmia
2-A large number of these defects close spontaneously; this
number approaches 75% to 80%, with most closing in the first
year of life
3- with moderate-sized defects may develop large left-to-right
shunts in infancy, and their main risk is heart failure between 1
and 6 months of age.
4-Moderate and large defects, occasionally develop significant
infundibular pulmonary stenosis
5-Patients with large defects are the most difficult to manage
because of the dangers of mortality in the first year of life
owing to heart failure and associated pulmonary infections as
well as the problem of development of elevated pulmonary
vascular resistance