Congenital heart disease
Dr. Mohanad K. Shukur
Al-Ghanimi
Pediatric 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 recurs
Ventricular Septal Defects:
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
Moderate and Large size VSD:
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
gation:
Investi
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
Medical Therapy
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
supplements
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