Occurs in 1% of live births.
Overall male predominance.
Aetiology of congenital cardiac disease is often unknown, but recognised associations include:
- Maternal prenatal rubella infection – persistant ductus arteriosis and pulmonary valvular and arterial stenosis
- Maternal alcohol abuse – foetal alcohol syndrome (FAS) = septal defects
- Maternal drug treatment and radiation
- Genetic abnormalities – familial form of arterial septal defect and congenital heart block
Down syndrome: ASVD (endocardial cusion defect) in ~40%, VSD in 30%
Turner syndrome: Obstructive lesions of the left side of the heart = bicuspid aortic valve and coarctation of the aorta (these two paths account for around 50% of HD is Turners)
Noonan syndrome: Pulmonary valve stenosis (50%), ASD (10%), VSD – less common, Heart murmur, CMP.
|Percentage of congenital lesions|
|Ventricular septal||39 (in trisomy 13, 18, 21)|
|Persistant ductus arteriosis||10|
|Coarctation of the aorta||7|
Ventricular septal defect (VSDs)
Definition: a defect in the ventricular septum causing an acyanotic shunt.
Classification of disease: Either the defect is near the atrioventricular divide and will be larger and need repair, or it will be more apical in the ventricle and probably be innocent or self-close.
Four different septal defects exist, with peri-membranous most common, outlet, atrioventricular, and muscular less commonly
Epidemiology: most common congenital cardiac defect (2-6 / 1000 births), thought to exist in 2-5 / 100 births, but close spontaneously in 80-90% of these without any presentation.
Clinical presentation: Pansystolic (Holosystolic) murmur (depending upon the size of the defect) +/- palpable thrill, parasternal heave, a displaced apex beat, FTT, sweaty and tachypnoiec with feeding
Risk factors: downs syndrome, FH, faults with NKX2.5 gene.
Pathophysiology: LR shunt = blood from systemic to lungs = overload RV (=RVH and therefore PAH) and loss of oxygenation ( = SOB, FTT, difficulty feeding)
Investigations: pan-systolic murmur on auscultation, echo (=cardiomegaly), USS, cardiac catheterisation, CXR (prominent pulmonary arteries due to increased pulmonary flow)
- Medical = cardiac glycosides (e.g., digoxin 10-20mcg/kg per day), loop diuretics (e.g., furosemide 1–3 mg/kg per day) and ACE inhibitors (e.g., captopril 0.5–2 mg/kg per day).
- Surgical = patch, suture.
Atrial septal defect:
Definition: a defect in the atrial septum causing an acyanotic shunt.
Classification of disease: There are many types of ASDs. They are differentiated from each other by whether they involve other structures of the heart and how they are formed during the developmental process during early foetal development:
- The ostium secundum ASD is the most common type of ASD (6-10%) of all congenital heart diseases. OS-ASD = enlarged PFO, may also have a MVP
- PFO – linked to decompression sickness, paradoxical embolism and migraine.
Ostium primum ASD = more commonly classified as an AVSD
Sinus venosus ASD = involves the venous inflow of either the SVC
Common or single atrium – and frequently associated with heterotaxy syndrome
- 1 / 1500 live births.
- PFO are quite common (appearing in 10 – 20% of adults) but asymptomatic and therefore undiagnosed
- Ostium secundum ASD accounts for 7% of all congenital heart lesions (M>F, 1:2)
Pathophysiology: L R shunt = blood from systemic to lungs = overload RV (=RVH and therefore PAH) and loss of oxygenation ( = SOB, FTT, difficulty feeding)
Investigations: often diagnosed in utero, USS, echo (shows defect), auscultation, physical examination, bubble study, ECG (shows degree of RBBB and right axis deviation), CXR (prominent pulmonary arteries)
Treatment: surgical / percutaneous closure via patch / suture
Atrioventricular septal defect (AVSD):
Definition: is characterized by a deficiency of the atrioventricular septum of the heart
Classification of disease: A variety of different classifications have been used, but the defects are usefully divided into “partial” and “complete” forms.
- Partial AVSD = defect in the primum or inferior part of the atrial septum but no direct intraventricular communication (ostium primum defect).
- Complete AVSD = there is a large ventricular component beneath either or both the superior or inferior bridging leaflets of the AV valve. The defect involves the whole area of the junction of the upper and lower chambers of the heart, i.e. where the atria join the ventricles
Epidemiology: this defect is associated to patients with Down’s syndrome (35-40% DS pts have an AVSD)
Clinical presentation: tachypnoeia, hard breathing, sweat/tire during feed, FTT, wt loss.
Pathophysiology: It is caused by an abnormal or inadequate fusion of the superior and inferior endocardial cushions with the mid portion of the atrial septum and the muscular portion of the ventricular septum.
Investigations: cardiac auscultation (= systolic and diastolic murmurs), echo, cardiac catherisation. Can be diagnosed in utero via careful antenatal USS.
Treatment: repair defects (open surgery / percutaneous endovascular methods). In neonate, if stable, hold off from doing repair until signs of resp distress or HF show, as this gives more time for the heart to grow and this increases efficacy of repair.
Can also use furosemide, ACEi and digoxin to ease symptoms prior to repair.
Prognosis: mortality of repair ~5-10%
Coarctation of the aorta
Definition: is a congenital condition whereby the aorta narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts.
Classifications of disease: There are three types:
- 1. Preductal coarctation: The narrowing is proximal to the ductus arteriosus. This is the type seen in 5% of Turner Syndrome.
- 2. Ductal coarctation: The narrowing occurs at the insertion of the ductus arteriosus.
- 3. Postductal coarctation: The narrowing is distal to the insertion of the ductus arteriosus. Rib notching on CXR due to inc collateral supply
Epidemiology: M>F (2:1), seen in girls with Turners syndrome.
- In mild disease = no/few symptoms
- Working hard to breathe, poor appetite, troubled feeding, FTT, cold peripheries/arms and legs, symptoms of large heart, dizziness, SOB, angina, headaches, nosebleeds, intermittent claudication
- Severe disease: Arterial hypertension in the right arm with normal to low blood pressure in the lower extremities is classic. Poor peripheral pulses and a weak femoral artery pulse.
If the coarctation is situated before the left subclavian artery, asynchronous radial pulses will be detected in the right and left arms. Abnormal radial-femoral delay pattern.
Investigations: ‘figure 3 sign’ on CXR, magnetic resonance angiography, echo, CT, MRI, angiography.
Treatment: balloon angioplasty, or surgical resection of area of disease.
Prognosis: good if identified early and managed effectively
Tetralogy of Fallot (ToF)
Definition: is a congenital heart defect involving 4 anatomical abnormalities (A = PS, B = over-riding aorta**, C = VSD, D = RVH). It is the most common cyanotic heart defect, and the most common cause of blue baby syndrome
- ** Over-riding aorta = it is situated above the VSD and connected to both the R&L ventricle
- It is also possible to have a PFO, or ASD = ‘pentalogy of Fallot’
Epidemiology : 400 / million live births
Clinical presentation: cyanosis, heart murmur, difficulty in feeding, FTT, retarded growth and physical development, SOBOE, clubbing of the fingers and toes, and polycythemia.
Aetiology: associated with chromosome 22 deletions and DiGeorge syndrome.
Pathophysiology: results in low pO2 of blood due to the mixing of oxygenated and deoxygenated blood in the left ventricle via the VSD and preferential flow of the mixed blood from both ventricles through the aorta because of the obstruction to flow through the pulmonary valve
Investigations: echo, CXR = ‘boot-shaped heart’.
Treatment: total surgical repair
- Survival for untreated ToF: ~75% after the first year of life, 60% by four years, 30% by ten years, and 5% by forty years.
- Survival for treated patients: depends on pts heart and success of surgical repair, but much better
Transposition of great arteries (TGA)
with ‘egg on side’ sign on CXR
Definition: an abnormal spatial arrangement of the pulmonary artery and the aorta
Classification of disease: TGV is often accompanied by other heart defects, the most common type being ASDs (PFO), VSDs, PDAs. Stenosis, or other defects, of valves and/or vessels may also be present.
When no other heart defects are present = ‘simple’ TGV. Other defects are present = ‘complex’ TGV.
- Transposition is the most common cyanotic congenital heart lesion presenting in the neonate.
- Annual incidence is 20-30 / 100,000 live births
- M>F (3:1)
- Transposition is rarely associated with syndromes or extracardiac malformations
Clinical presentation: cyanosis, SOB, tachycardia, tachypnoea, HF, VSD (systolic murmur), may present in similar way to ToF.
Risk factors: Gestational DM, and pre-existing DM, maternal rubella/viral illnesses, alcoholism, inc maternal age (>40yo).
Aetiology: unknown, genetic inheritance.
Investigations: antenatal USS, post-natal CXR, echo, catheterisation, ECG, pulse oximetry.
Treatment: keep PDA open with prostaglandins and low flow oxygen support, antibiotic prophylaxis, cardiac catheterisation and balloon atrial septostomy are used to increase the atrial level shunt and to improve mixing. The definitive corrective procedure = arterial switch operation
- Untreated = mortality approximately 30% in the first week, 50% in the first month, and 90% by the end of the first year. Treated = survival approximately 90% at 15 years of age
Patent ductus arteriosus (PDA)
Definition: is a congenital disorder wherein a neonate’s ductus arteriosus fails to close after birth.
Clinical presentation: ‘machine murmur’, wide pulse pressure, low birth weight,
Risk factors: maternal rubella, preterm infant, Downs, foetal alcohol syndrome, birth asphyxia, low O2 sats/perfusion.
Aetiology: due to RF, or can be idiopathic.
Pathophysiology: PDA allows blood flow between the aorta and the pulmonary artery. PDA is common in neonates with persistent respiratory problems such as hypoxia. Has a high occurrence in premature children. In hypoxic newborns, too little oxygen reaches the lungs to produce sufficient levels of bradykinin and subsequent closing of the DA. Premature children are more likely to be hypoxic and thus have PDA because of their underdeveloped heart and lungs.
In TGA, a PDA may need to remain open. The PDA is the only way that oxygenated blood can mix with deoxygenated blood. In these cases, prostaglandins and low flow O2 are used to keep the PDA open until surgery can be performed to correct
Investigations: echo, ECG (tall R in V6), CXR (enlargement of the pulmonary arteries, veins, left atrium and left ventricle).
Treatment: without treatment PDA may go from L R shunt to a R L shunt (Eisenmengers complex: LR shunt = increased pulmonary pressure = PAH) = cyanosis = eventually fatal.
Options: watch and wait (monitor), ligate PDA closed, use NSAIDS/indomethacin/ibruprofen to close (as remember prostaglandins keep PDA open)
Prognosis: if successful closure occurs, lifetime prognosis is near on normal
Large right atria due to tricuspid valve displacement. RF = lithium in pregnancy (bipolar women), also seen in WPW syndrome.
Sudden cardiac death (=due to sudden VF), genetic cause, abnormality of calcium or sodium channel.