Congenital heart disease (CHD)

Q24.9

DESCRIPTION

Structural abnormalities of the heart or great vessels present at birth. They fall into 4 pathophysiological groups:

  1. Acyanotic Left to right shunts - ventricular septal defect (VSD), patent duct arteriosus (PDA), atrial septal defect (ASD), atrioventricular septal defect (AVSD), Truncus arteriosus.
  2. Acyanotic Obstructive lesions - pulmonary stenosis, aortic stenosis, coarctation of the aorta.
  3. Cyanotic CHD - mostly right to left shunts tetralogy of fallot (TOF), pulmonary atresia (PA), tricuspid atresia (TA), but including parallel circulation - transposition of great arteries (TGA) See Cyanotic Heart Disease in the Newborn and Eisenmenger syndrome.
  4. Regurgitant lesions - aortic incompetence (AI), mitral incompetence (MI) are not common in CHD.

Some patients with CHD present with life threatening symptoms in the newborn period See Heart Failure in Neonates . Left to right shunts if large may be symptomatic due to pulmonary over circulation and pulmonary hypertension or if small may present with an incidental murmur. Many will require surgery but this may follow a period of medical therapy.

Obstructive lesions are often asymptomatic until they precipitate ventricular failure or symptoms related to decreased cardiac output. The management is usually surgical or interventional. Angiotensin-converting enzyme inhibitor (ACE-Inhibitor) should be avoided in the treatment of heart failure in patients with obstructive lesions.
Right to left shunts present with cyanosis and variable degrees of effort intolerance. Patients with tetralogy of Fallot may present with hypercyanotic spells.

CYANOTIC CONGENITAL HEART DISEASE WITH HYPOXAEMIA ATTACKS/SPELLS (HYPERCYANOTIC SPELLS)

Q24.9

DESCRIPTION

Acute worsening of central cyanosis in patients with a Tetralogy of Fallot and certain other cyanotic heart diseases with pulmonary stenosis and ventricular septal defect.

DIAGNOSTIC CRITERIA

Clinical

  • Rapid worsening of central cyanosis, tachypnoea/dyspnoea, anxiety and alteration in consciousness in the presence of congenital cyanotic heart disease.
  • Restless and crying in the presence of congenital cyanotic heart disease.
  • Decrease in intensity or disappearance of the systolic murmur in Tetralogy of Fallot during crying.

GENERAL AND SUPPORTIVE MEASURES

  • Exclude and treat precipitants such as fever or dehydration.
  • Calm patient and keep on mother’s lap, if possible.
  • Place patient in knee-chest position to raise systemic blood pressure and increase systemic venous return.
  • Monitor SaO2, heart rate, respiratory rate and acid-base status.
  • Ensure adequate hydration.

MEDICINE TREATMENT

  • Oxygen, 100%, by facemask or by nasal cannula
  • Volume expander e.g. sodium chloride 0.9%, IV bolus, 20mL/kg administered over 5 minutes.
  • Morphine, IV, 0.1–0.2 mg/kg as a single dose.
    • May cause impairment of airway reflexes and respiratory depression.

If clinically acidotic or pH < 7.2:

  • Sodium bicarbonate 4.2%, IV, 2 mL/kg.

If failure to improve the cyanotic spell, consider in consultation with specialist:

  • Ketamine, IV, 0.5–1 mg/kg.

Note: IV ketamine is a general anaesthetic.
Take standard precautions for respiratory arrest.

After resolution of spell:
If Hb < 10 g/dL, child is anaemic:

  • Packed red cells, 10 mL/kg administered over 3 hours.
  • Propranolol, oral, 0.5–1 mg/kg/dose 6 hourly.
    • Do not exceed 5 mg/kg/day.

REFERRAL

  • If above measures do not work refer urgently.
  • Refer all cases for assessment.

TETRALOGY OF FALLOT

Q21.3

DESCRIPTION

Ventricular septal defect with aortic override and right ventricular outflow tract obstruction. Suspect tetralogy of Fallot in a child with cyanosis after the neonatal period.

DIAGNOSTIC CRITERIA

Clinical

  • Child with central cyanosis.
  • May be plethoric due to polycythemia – normal haemoglobin represents relative anaemia.
  • May have clubbing.
  • Possible history of cyanotic spells.
  • Heart not clinically enlarged.
  • Right ventricular hypertrophy usually not palpable.
  • Single second heart sound.
  • Coarse, ejection systolic murmur over right ventricular outflow tract.
  • Chest X-ray:
    • normal/small heart,
    • boot shaped/pulmonary bay – concavity where pulmonary artery should be,
    • oligaemic lung fields.
  • ECG:
    • right axis deviation and right ventricular hypertrophy.

GENERAL AND SUPPORTIVE MEASURES

  • Good dental hygiene.

MEDICINE TREATMENT

  • Iron (elemental), oral, 1 mg/kg/dose 8 hourly.
  • Folic acid, oral, 2.5– 5 mg/day.
  • Propranolol, oral, 0.5–1 mg/kg/dose 6 hourly.
    • Do not exceed 5 mg/kg/day.

Endocarditis prophylaxis:
See Endocarditis, infective .

REFERRAL

  • Refer all children with cyanotic heart defects.

CONGENITAL HEART DISEASE WITH LEFT TO RIGHT SHUNT

DESCRIPTION

Structural abnormalities of the heart and great vessels that are usually associated with left to right shunting - most commonly: ventricular septal defect, atrial septal defect, patent ductus arteriosus and atrioventricular septal defect.

DIAGNOSTIC CRITERIA

Each condition has specific clinical, radiological and ECG findings.
Large left to right shunts present clinically with:

  • Tachypnoea and indrawing.
  • Sweating during feeds.
  • Failure to thrive.
  • Chest deformity: respiratory sulcus, praecordial bulge.
  • Chest X-ray: usually cardiomegaly with plethoric lung fields.

GENERAL AND SUPPORTIVE MEASURES

  • Special attention to nutrition.

MEDICINE TREATMENT

  • Furosemide, oral, 1mg/kg/dose 8-12 hourly.
  • Supplement with potassium chloride, oral, 25-50 mg/kg/dose 8-12 hourly.

If needed:

  • Spironolactone oral, 1 mg/kg/dose 12 hourly in which case potassium supplementation should be stopped.

And if needed, in consultation with a paediatric cardiologists:

  • ACE inhibitor, e.g.
    • Captopril, oral
      • Infants: 0.15-0.3 mg/kg/dose, 8-12 hourly (maximum 2 mg/kg/day).
      • Children: 0.3-0.5 mg/kg/dose 8-12 hourly (maximum 6 mg/kg/day).

LoEIII [4]
LoEIII [5]

REFERRAL

  • All children with suspected left to right shunts due to CHD should be referred to a paediatric cardiology centre for diagnostic evaluation and planning of further management.